CONTROL TECHNIQUES
                FOR
PARTICULATE AIR POLLUTANTS
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
            Public Health Service
 Consumer Protection and Environmental Health Service

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     CONTROL TECHNIQUES
                  FOR
PARTICULATE AIR POLLUTANTS
   U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
              Public Health Service
    Consumer Protection and Environmental Health Service
       National Air Pollution Control Administration
               Washington, D.C.
                 January 1969

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Notional  Air  Pollution  Control  Administration  Publication  No.  AP-51

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                                  PREFACE

      Throughout the development of Federal air pollution legislation, the
Congress has consistently found that the States and local governments have the
primary responsibility for preventing and controlling air pollution at its source.
Further,  the Congress has consistently declared that it is the responsibility
of the Federal government to provide technical and financial assistance to State
and local governments  so that they can undertake these responsibilities.
      These principles were reiterated in the Air Quality Act of 1967.  A key
element of that Act directs the  Secretary of Health,  Education,  and Welfare to
collect  and make available information on all aspects of air pollution and its
control.  Under the Act the issuance of control techniques information is a
vital step in a program designed to assist the States in taking responsible
technological, social, and political action to protect the public from the
adverse effects of air pollution.
      Briefly, the Act calls for the Secretary of Health, Education,  and Welfare
to define the broad atmospheric areas of the Nation in which climate,
meteorology,  and topography, all of which influence the capacity of air to
dilute and disperse pollution, are generally homogeneous.
      Further, the Act requires the Secretary to define those geographical
regions in the country where  air pollution is a problem—whether interstate or
intrastate.  These air quality control regions are designated on the basis of
meteorological, social, and political factors which suggest that a group of
communities should be treated as a unit for setting limitations on concentrations
of atmospheric pollutants.  Concurrently, the Secretary is required to issue
air quality criteria for those  pollutants he believes may be harmful to health
or welfare,  and to publish related information on the techniques which can be
employed to control the sources of those pollutants.
                                     in

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      Once these steps have been taken for any region, and for any pollutant
or combination of pollutants, then the State or States responsible for the
designated region are on notice to develop ambient air quality standards ap-
plicable to the region for the pollutants involved, and to develop plans of action
for meeting the standards.
      The Department of Health,  Education,  and Welfare will review, evaluate,
and approve these standards  and plans and, once they are approved, the States
will be expected to take action  to control pollution sources in the manner
outlined in their plans.
      At the direction of the Secretary, the National Air Pollution Control
Administration has established appropriate programs  to carry out the several
Federal responsibilities specified in the legislation.
      Control Techniques for Particulate Air Pollutants is the first of a series
of documents to be produced  under the program established to carry out the
responsibility for developing and distributing control technology information.
The document is  the culmination of intensive and dedicated effort on the part
of many persons.
      In accordance with the  Air Quality Act, a National Air Pollution Control
Techniques Advisory Committee was established, having a membership
broadly representative of industry, universities, and all levels of government.
The committee, whose members are listed following this  discussion, provided
invaluable advice in identifying the best possible methods  for controlling the
sources of particulate air pollution, assisted in determining the costs involved,
and gave major assistance in drafting this document.
      As further  required by the Air Quality Act, appropriate Federal
departments and  agencies, also listed on the following pages, were consulted
prior to issuance of this document.  A Federal consultation committee,
comprising members designated by the heads of  17 departments and agencies,
reviewed the document, and met with staff personnel of the National Air
Pollution Control Administration to discuss its contents.
                                     IV

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      During 1967, at the initiation of the Secretary of Health, Education, and
Welfare, several government-industry task groups were formed to explore
mutual problems relating to air pollution control.  One of these, a task group
on control technology research and development, looked into ways that industry
representatives could participate in the review of the control techniques reports.
Accordingly, several industrial representatives, listed on the following pages,
reviewed this document and provided helpful comments and suggestions.  In
addition, certain consultants to the National Air Pollution Control Administration
also reviewed and assisted in preparing  portions of this document.  (These
also are listed on the following pages.)
      The Administration is pleased to acknowledge the efforts of each of the
persons  specifically named,  as well as those of the many not so listed who
contributed  to the publication of this volume.  In the last analysis, however,
the National Air Pollution Control Administration is responsible for its content.
      The control of air pollutant emissions is a complex problem because of
the variety of sources and source characteristics.   Technical  factors
frequently make necessary the use of different control procedures for different
types of  sources.  Many techniques are still in the  developmental stage, and
prudent control strategy may call for the use of interim methods until these
techniques are  perfected.  Thus, we can expect that we will continue to
improve, refine, and periodically revise the control technique information so
that it will continue to reflect the most up-to-date knowledge available.
                                      John T.  Middleton
                                      Commissioner
                                      National Air Pollution Control
                                        Administration

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NATIONAL AIR POLLUTION CONTROL TECHNIQUES ADVISORY COMMITTEE
Mr.  Louis D. Alpert
General Manager
Midwestern Department of the
  Federated Metals Division
American Smelting & Refining Company
Whiting,  Indiana

Professor James H. Black*
Department of Chemical Engineering
University of Alabama
University, Alabama

Mr.  Robert L.  Chass
Chief Deputy Air Pollution
  Control Officer
Los Angeles County Air Pollution
  Control District
Los Angeles, California

Mr.  W. Donham Crawford
Administrative  Vice President
Consolidated Edison Company
  of New York,  Inc.
New York, New York

Mr.  Herbert J. Dunsmore
Assistant to Administrative
  Vice President of Engineering
U. S. Steel Corporation
Pittsburgh, Pennsylvania

Mr.  John L. Gilliland
Technical Director
Ideal Cement Company
Denver, Colorado
Mr.  James L. Parsons
Consultant Manager
Environmental Engineering
Engineering Department
E. I. duPont de Nemours & Co. ,  Inc.
Wilmington, Delaware

Professor August T. Rossano
Department of Civil Engineering
Air Resource Program
University of Washington
Seattle, Washington

Mr.  Jack A. Simon
Principal Geologist
Illinois State Geological Survey
Natural Resources Building
Urbana, Illinois

Mr.  Victor H. Sussman
Director
Division of Air Pollution Control
Pennsylvania Department of
 Health
Harrisburg,  Pennsylvania

Mr.  Earl L. Wilson, Jr.
Manager
Industrial Gas Cleaning Department
Koppers Company, Inc.
Metal Products Division
Baltimore, Maryland

Dr. Harry J. White
Head
Department of Applied Science
Portland State College
Portland, Oregon
  Resigned September 16, 1968.
                                    VI

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              FEDERAL AGENCY LIAISON REPRESENTATIVES


Department of Agriculture
Kenneth E. Grant
Associate Administrator
Soil Conservation Service

Department of Commerce
Paul T. O'Day
Staff Assistant to the Secretary

Department of Defense
Colonel Alvin F. Meyer, Jr.
Chairman
Environmental Pollution Control Committee

Department of Housing and Urban Development
Charles M. Haar
Assistant Secretary for Metropolitan Development

Department of the Interior
Harry Perry
Mineral Resources Research Advisor

Department of Justice
Walter Kiechel,  Jr.
Assistant Chief
General Litigation Section
Land  and Natural Resources Division

Department of Labor
Dr. Leonard  R.  Linsenmayer
Deputy Director
Bureau of Labor Standards

Department of Transportation
William H. Close
Assistant Director for  Environmental Research
Office of Noise Abatement
                                   vn

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Department of the Treasury
Gerard M. Brannon
Director
Office of Tax Analysis

Federal Power Commission
F. Stewart Brown
Chief
Bureau of Power

General Services Administration
Thomas E.  Crocker
Director
Repair and Improvement Division
Public Buildings Service

National Aeronautics and Space Administration
Major General R. H.  Curtin, USAF (Ret.)
Director of Facilities

National Science Foundation
Dr. Eugene W. Bierly
Program Director for Meteorology
Division of Environmental Sciences

Post Office Department
Louis  B. Feldman
Chief
Transportation Equipment Branch
Bureau of Research and Engineering

Tennessee Valley Authority
Dr. F. E.  Gartrell
Assistant  Director of Health

U. S. Atomic Energy Commission
Dr. Martin B. Biles
Director
Division of Operational Safety
                                   viu

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Veterans Administration
Gerald M.  Hollander
Director of Architecture and Engineering
Office of Construction

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                             CONTRIBUTORS
Mr.  L.  P.  Augenbright
Assistant Sales Manager
Western Knapp Engineering Division
Arthur G.  McKee and Company
San Francisco, California

Dr. Allen D.  Brandt
Manager
Industrial Health Engineering
Bethlehem  Steel Company
Bethlehem, Pennsylvania

Mr.  William  Bodle
Senior Advisor
Institute of Gas Technology
Chicago, Illinois

Dr. Donald A. Borum
Consulting  Chemical Engineer
New York,  New York

Mr.  John D.  Cap Ian
Technical Director
Basic and Applied Sciences
Research Laboratories
General Motors Corporation
Warren, Michigan

Mr.  R.  R.  Chambers
Vice President
Sinclair Oil Corporation
New York,  New York

Mr.  John M.  Depp
Director
Central Engineering Department
Monsanto Company
St. Louis,  Missouri

Mr.  Harold F.  Elkin
Sun Oil Company
Philadelphia,  Pennsylvania
Mr.  B.  R.  Gebhart
Vice President
Freeman Coal Mining Corporation
Chicago, Illinois

Mr.  James R. Jones
Chief Combustion Engineer
Peabody Coal Company
Chicago, Illinois

Mr.  Olaf Kayser
Vice President-Manufacturing
Lone Star Cement Corporation
New York,  New York

Mr.  David Lurie
Consultant
Wyckoff, New Jersey

Mr.  Glenn A. Nesty
Vice President
Senior Technical Officer
Allied Chemical Corporation
New York,  New York

Dr. Arthur L. Plumley
Senior Project Engineer
Kresinger Development
  Laboratory
Combustion Engineering, Inc.
Windsor, Connecticut

Mr.  James H. Rook
Director of Environmental
  Control Systems
American Cyanamid  Company
Wayne,  New Jersey

Mr.  T.  W. Schroeder
Manager of Power Supply
Illinois  Power Company
Decatur, Illinois
                                    x

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Dr. Seymour C.  Schuman
Private Consultant
Princeton,  New Jersey

Mr. R.  W.  Scott
Coordinator for Conservation
  Technology
Esso Research and Engineering
  Company
Linden, New Jersey

Mr. David  Swan
Vice President-Technology
Kennecott Copper Corporation
New York,  New York

Mr. R.  A.  Walters
Project Director of Smelter Studies
Western Knapp Engineering Division
Arthur G. McKee and Company
San Francisco, California
                                   XI

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                              CONTENTS

                                                            Page
PREFACE                                                    iu

LIST OF FIGURES

LIST OF TABLES                                             xxxi

SUMMARY                                                    1

1.   INTRODUCTION                                           1-1

2.   BACKGROUND INFORMATION                              2-1

  2.1  DEFINITIONS                                          2-1

  2.2  MAJOR SOURCES OF PARTICULATE MATTER            2-3

    2.2.1  Combustion Sources                                 2-3

    2.2.2  Industrial Sources                                  2-4

    2.2.3  Mobile Sources                                     2-4

3.   PARTICULATE SOURCES AND CONTROLS                   3-1

  3.1  INTRODUCTION                                        3-1

  3.2  INTERNAL COMBUSTION ENGINES                      3-3

    3.2.1  Gasoline- Fueled Vehicles                            3-3

    3.2.2  Diesel-Powered Vehicles                            3-7

  3.3  CONTROL OF PARTICULATE  EMISSIONS FROM
       STATIONARY COMBUSTION SOURCES                    3-10

    3.3.1  Introduction                                        3-10

      3.3.1.1  General                                       3_10

      3.3.1.2  Sources                                       3-10
                                  xn

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                                                            Page
    3.3.1.3  Emissions                                      3-10

  3.3.2   Control Techniques                                 3-15

    3.3.2.1  Gas Cleaning                                   3-16

    3.3.2.2  Source Relocation                               3-20

    3.3.2.3  Energy Substitution                             3-20

    3.3.2.4  Energy Conservation                            3-25

    3.3.2.5  Good Practice                                  3-27

    3.3.2.6  Source Shutdown                                3-30

    3.3.2.7  Dispersion                                     3-30

3.4  INDUSTRIAL PROCESSES                                3-31

  3.4.1  Introduction                                        3-31

  3.4.2  Iron and Steel Mills                                 3-34

    3.4.2.1  Sintering Plants                                 3-34

    3.4.2.2  Blast  Furnaces                                 3-34

    3.4.2.3  Steel Furnaces                                  3-35

  3.4.3   Gray Iron Foundries                                3-37

  3.4.4   Petroleum Refineries                               3-39

  3.4.5   Portland Cement                                   3-41

  3.4.6   Kraft Pulp Mills                                   3-42

  3.4.7   Asphalt Batching Plants                             3-43

  3.4.8   Acid Manufacture                                  3-44
                                xin

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                                                             Page
    3.4.8.1  Sulfuric Acid                                    3-44

    3.4.8.2  Phosphoric Acid                                 3-45

  3.4.9   Coke Manufacture                                   3-45

  3.4.10  Primary and  Secondary Recovery of Copper, Lead,
          Zinc, and Aluminum                                3-49

  3.4.11  Soap and Synthetic  Detergent Manufacture             3-50

  3.4.12  Glass Furnaces and Glass Fiber Manufacture         3-51

  3.4.13  Carbon Black                                      3-53

  3.4.14  Gypsum Processing                                 3-53

  3.4.15  Coffee Processing                                   3-54

  3.4.16  Cotton Ginning                                      3-56

3.5  CONSTRUCTION AND DEMOLITION                       3-57

  3.5.1  Introduction                                         3-57

  3.5.2  Demolition of Masonry                               3-58

  3.5.3  Open Burning                                        3-58

  3.5.4  Road Dust                                           3-59

  3.5.5  Grading Roads and Other Surfaces                     3-59

  3.5.6  Handling Dusty Materials                             3-59

  3.5.7  Sandblasting                                         3-59

3.6  SOLID WASTE DISPOSAL                                 3_61

  3.6.1  Introduction                                         3-61

  3.6.2  Definition of Solid Waste                             3_62
                                 xiv

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                                                               Page
    3.6.3  Amounts of Solid Waste Generated                    3-63

      3.6.3.1  Disposal Methods to Minimize Air Pollution      3-65

      3.6.3.2  Disposal Methods Without Incineration            3-67

      3.6.3.3  Disposal Methods With Incineration               3-73

    3.6.4   Air Pollution Potential From Solid Waste Disposal
            Methods                                          3-86

    3.6.5   Public Health Service Programs and Assistance
            in Solid Waste Disposal                             3-86

4.   GAS CLEANING DEVICES                                  4-1

  4.1  INTRODUCTION                                        4-1

    4.1.1  Preliminary Selection of Equipment                  4-3

  4.2  SETTLING CHAMBERS                                  4-10

    4.2.1  Introduction                                        4-10

    4.2.2  Definition of Terms                                 4-10

    4.2.3  Design Considerations                               4-12

    4.2.4  Typical Applications                                4-13

  4.3  DRY CENTRIFUGAL COLLECTORS                      4-15

    4.3.1  Introduction                                        4-15

    4.3.2  Types of Centrifugal Collectors                      4-16

    4.3.3  Design                                             4-19

      4.3.3.1  Operating Pressure Drop                       4-26

      4.3.3.2  Dust Loading                                   4-27

      4.3.3.3  Other Design Considerations                    4-28
                                    xv

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                                                            Page
  4.3.4  Typical Applications                                 4-29

4.4  WET COLLECTORS AND MIST ELIMINATORS            4~32

  4.4.1  Introduction                                        4-32

    4.4.1.1  Collection Theory                               4-32

    4.4.1.2  Efficiency                                      4-34

  4.4.2   Equipment Description and Design                   4-35

    4.4.2.1   Spray Chamber                                4-35

    4.4.2.2   Gravity Spray Towers                          4-39

    4.4.2.3   Centrifugal Spray Scrubbers                    4-40

    4.4.2.4   Impingement Plate Scrubbers                   4-43

    4.4.2.5   Venturi Scrubbers                             4-44

    4.4.2.6   Packed  Bed  Scrubbers                          4-51

    4.4.2.7   Self-Induced Spray Scrubbers                   4-59

    4.4.2.8   Mechanically Induced Spray Scrubbers           4-59

    4.4.2.9   Disintegrator Scrubbers                        4-61

    4.4.2.10  Centrifugal Fan Wet Scrubbers                  4-63

    4.4.2.11  Inline Wet Scrubber                            4-63
             r
    4.4.2.12  Irrigated Wet Filters                           4-66

    4.4.2.13  Wet Fiber Mist Eliminators                    4-66

    4.4.2.14  Impingement Baffle Mist Eliminators            4-73

    4.4.2.15  Vane-Type Mist Eliminators                    4.74

    4.4.2.16  Packed  Bed  Mist Eliminators                   4-76
                                xvi

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                                                              Page
     4.4.2.17  Mist and Vapor Suppression                     4-76

     4.4.2.18  Liquid Distribution                             4-77

     4.4.2.19  Spray Nozzles                                  4-78
                                    i

   4.4.3   Typical Applications of Wet Scrubbers                4-83

   4.4.4   Water Disposal                                     4-83

     4.4.4.1  Settling Tanks and Ponds                         4-83

     4.4.4.2  Continuous Filtration                            4-85

     4.4.4.3  Liquid Cyclones                                 4-85

     4.4.4.4  Continuous Centrifuge                            4-85

     4.4.4.5  Chemical Treatment                             4-86

 4.5  HIGH-VOLTAGE ELECTROSTATIC PRECIPITATORS      4-87

   4.5.1  Introduction                                         4-87

   4.5.2  Operating Principles                                 4-87

   4.5.3  Equipment Description                               4-91

     4.5.3.1  Voltage Control and Electrical Equipment         4-91

     4.5.3.2  Discharge Electrodes                            4-95

     4.5.3.3  Collecting Surfaces                              4-95

     4.5.3.4  Removal of Collected Particulate Matter           4-95

   4.5.4   High-Voltage Electrostatic Precipitator
           Equipment Design                                   4-99

     4.5.4.1  Conditioning Systems                            4-101

     4.5.4.2  Voltage,  Electrical Energy, and Sectionalization
              Requirements                                    4-101
                                  xvn
331-716 O - 69 - 2

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                                                              Page
    4.5.4.3   Gas Velocity, Treatment Time, and Flow
              Distribution                                    4-102

    4.5.4.4   Collecting Surfaces and Discharge Electrodes     4-103

    4. 5. 4. 5   Materials of Construction                        4-104

    4.5.4.6   Collected Particulate Matter Handling Systems    4-104

    4.5.4.7   Controls and Instruments                        4-104

    4.5.4.8   Layout                                         4-105

  4.5.5    Specifications and Guarantees                        4-105

  4.5.6    Maintaining Collection Efficiency                    4-107

  4.5.7    Improvement of Collection Efficiency                4-108

  4.5.8    Typical Applications                                4-109

    4.5.8.1   Pulverized Coal-Fired Power Plants              4-109

    4.5.8.2   Integrated Steel Making Operations               4-111

    4.5.8.3   Cement Industry                                4-111

    4.5.8.4   Kraft Pulp Mills                                4-112

    4.5.8.5   Sulfuric Acid                                   4-112

4.6  LOW-VOLTAGE ELECTROSTATIC  PRECIPITATORS      4-113

  4.6.1  Introduction                                         4-113

  4.6.2  Major Components of Low-Voltage Electrostatic
         Precipitators                                        4-114

  4.6.3  Auxiliary Equipment                                 4-116

  4.6.4  Design Parameters                                  4-116
                                 xvi 11

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                                                             .Page
  4.6.5  Materials of Construction                            4-123

  4.6.6  Typical Applications of Low-Voltage Electrostatic
         Precipitators                                        4-123

    4.6.6.1  Machining Operations                            4-123

    4.6.6.2  Asphalt Saturators                              4-124

    4.6.6.3  Meat Smokehouses                              4-124

    4.6.6.4  Other Applications                              4-125

  4.6.7   Air Distribution                                    4-125

  4.6.8   Maintenance                                        4-126

4.7  FABRIC FILTRATION                                   4_127

  4.7.1  Introduction                                         4-127

    4.7.1.1  Range of Application                             4-127

  4.7.2   Mechanisms  of Fabric Filtration                    4-129

    4.7.2.1  Direct Interception                              4-130

    4.7.2.2  Inertial Impaction                               4-130

    4.7.2.3  Diffusion                                        4-131

    4.7.2.4  Electrostatic Attraction                          4-132

    4.7.2.5  Gravitational Settling                            4-132

  4.7.3   Filter Resistance                                   4-132

    4.7.3.1  Clean Cloth Resistance                          4-132

    4.7.3.2  Dust Mat Resistance                             4-134

    4.7.3.3  Effect of Resistance on Design                   4-137
                                  xix

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                                                            Page
  4.7.4  Equipment Description and Design                    4-138

    4.7.4.1  Baghouse Design                                4-149

    4.7.4.2  Fabric Filter Shape                             4-155

    4.7.4.3  Cloth Type                                     4-158

    4.7.4.4  Fabric Cleaning                                4-164

    4.7.4.5  Fabric Selection                                4-171

    4.7.4.6  Auxiliary Equipment                            4-173

    4.7.4.7  Individual Collectors Versus Large Collecting
             Systems                                        4-174

  4.7.5   Typical Applications                                4-175

    4.7.5.1  Cement Kilns                                   4-175

    4.7.5.2  Foundry  Cupolas                                4-176

    4.7.5.3  Electric  Arc Steel Furnaces                     4-176

    4.7.5.4  Open Hearth Furnaces                           4-177

    4.7.5.5  Nonferrous  Metal Furnaces                      4-178

    4.7.5.6  Carbon Black Plants                            4-179

    4.7.5.7  Grain Handling Operations                       4-179

  4.7.6   Operational  Practices                              4-180

  4.7.7   Maintenance Procedures                            4-181

  4.7.8   Safety                                            4-183

4.8   AFTERBURNERS                                      4-184

  4.8.1  Introduction                                        4-184
                                 xx

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                                                             Page
      4.8.1.1  Definition of Terms                             4-184

      4.8.1.2  Advantages  and Disadvantages of Afterburners     4-185

      4.8.1.3  Combustion Theory                             4-186

    4.8.2   Afterburner Design Criteria                        4-189

      4.8.2.1   General                                       4-189

      4.8.2.2   Heat Transfer                                 4-189

      4.8.2.3   Reaction Temperature                         4-189

      4.8.2.4   Retention Time                                4-191

      4.8.2.5   Heat Recovery                                4-196

      4.8.2.6   Fuel Requirements                             4-200

      4.8.2.7   Modified Furnace Afterburners                 4-202

      4.8.2.8   Hood and Duct Considerations                   4-203

      4.8.2.9   Gas Burners                                  4-204

      4.8.2.10  Construction Materials                         4-211

      4.8.2.11  Typical Applications                           4-213

5.   EMISSION FACTORS FOR PARTICULATE AIR POLLUTANTS  5-1

6.   ECONOMIC CONSIDERATIONS IN AIR POLLUTION
    CONTROL                                                6-1

  6.1  SELECTION OF CONTROL SYSTEM                      6-1

  6.2  COST-EFFECTIVENESS RELATIONSHIPS                6-5

  6.3  COST DATA                                           6-8

  6.4  UNCERTAINTIES IN DEVELOPING COST
       RELATIONSHIPS
                                  xxi

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                                                                   Page
6. 5  DESCRIPTION OF CONTROL COST ELEMENTS                  6-10

  6.5.1  General                                                   6"~10

  6.5.2  Capital Investment                                         6~14

  6.5.3  Maintenance and Operation

    6.5.3.1  General                                               6~15

    6.5.3.2  Gravitational and Centrifugal Mechanical Collectors      6-22

    6.5.3.3  Wet  Collectors                                        6~23

    6.5.3.4  Electrostatic Precipitators                             6-25

    6.5.3.5  Fabric Filter                                          6~26

    6.5.3.6  Afterburners                                          6-27

  6.5.4  Capital Charge                                            6-27

  6. 5. 5  Annualization of Costs                                      6-28

  6. 5. 6  Assumptions in Annualized Control Cost Elements            6-28

    6. 5. 6.1  Annualized Capital Cost Assumptions                    6-29

    6. 5. 6.2  Operating Cost Assumptions                            6-30

    6. 5. 6. 3  Maintenance Cost Assumption                           6-30

6. 6  METHOD FOR ESTIMATING ANNUAL COST OF
     CONTROL  FOR A SPECIFIC SOURCE                           6-30

  6.6.1  General                                                   6-30

  6.6.2  Procedure                                                 6-30

  6.6.3  Sample Calculations                                       6-33

  6.6.4  Annualized Cost Variation                                  6-36
                                   xxn

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                                                                Page
  6.7  COST CURVES BY EQUIPMENT TYPE                      6-36

    6.7.1   General                                              6-36

    6.7.2   Gravitational  Collectors                               6-38

    6.7.3   Dry Centrifugal Collectors                             6-39

    6.7.4   Wet Collectors                                        6-39

    6.7.5   High-Voltage  Electrostatic Precipitators                6-44

    6.7.6   Low-Voltage Electrostatic Precipitators                6-47

    6.7.7   Fabric Filters                                        6_47

    6.7.8   Afterburners                                          6-50

  6.8  DISPOSAL OF COLLECTED PARTICULATE EMISSIONS      6-54

    6.8.1   General                                              6-54

    6.8.2   Elements of Disposal Systems                          6-55

    6.8.3   Disposal Cost for Discarded Material                   6-59

    6.8.4   Return of Collected Material to Process                 6-61

    6.8.5   Recovery of Material for Sale                           6-63

7.  CURRENT  RESEARCH IN CONTROL OF PARTICULATE
    MATTER                                                     7-1

8.  BIBLIOGRAPHY                                              8-1

AUTHOR INDEX                                                  A-l

SUBJECT INDEX                                                 A-27
                                   XXlll

-------
                             LIST OF FIGURES



Figure



 2-1       Sources of particulate matter and quantities


           produced in tons per year.



                                                                      3-6
 3-1       Motor vehicle crankcase control system.




 3-2       Costs of incinerator at three levels of control of

                                                                      3—81
           particulate emissions.




 4-1       Composite grade  (fractional) efficiency curves


           based on test silica dust:,




 4-2       Terminal velocities of spherical particles in air.             4-11





 4-3       Balloon dust.                                               4~12




 4-4       Baffled expansion chamber with dust hopper.                 4-13




 4-5       Dust settling chamber.                                      4-14




 4-6       Multiple-tray dust collector.                                 4-14




 4-7       Conventional reverse-flow cyclone.                          4-18




 4-8       Axial inlet cyclone.                                         4-18




 4-9       Straight-through-flow cyclone.                               4-20





 4-10      Dynamic cyclone showing method by which dust is dynami-


           cally precipitated and delivered to the storage hopper.        4-21




 4-11      Various types of cyclone dust discharge.                     4-25




 4-12      Cyclones arranged in parallel.                               4-28





 4-13      Cyclones arranged in parallel.                               4-29





 4-14      Arrangement of nozzles in smoke stack spray system.        4-38




 4-15      Typical layout for spray tower.                              4-41




 4-16      Centrifugal spray scrubbers.                                4-42




 4-17      Impingement plate scrubber.                                 4-45





                                    xxiv

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Figure                                                              Page

 4-18       Venturi scrubber may feed liquid through jets (a), over
            a weir (b), or swirl them on a shelf (c).                   4-47

 4-19       Flooded disk (variable throat orifice)  scrubber.            4-48

 4-20       Multiple-venturi jet scrubber.                            4-50

 4-21       Vertical venturi scrubber,                               4-51

 4-22       Wet scrubber packings.                                  4-52

 4-23       Packed-bed scrubbers.                                   4-53

 4-24       Flooded-bed scrubber.                                   4-57

 4-25       Floating-ball (fluid-bed) packed scrubber.                 4-58

 4-26       Self-induced-spray scrubbers.                            4-60

 4-27       Mechanically induced spray scrubbers.                    4-62

 4-28       Centrifugal fan wet scrubber.                             4-64

 4-29       Inline wet scrubber.                                      4-65

 4-30       Wetted and impingement plate filters.                     4-67

 4-31       Low-velocity filtering elements.                          4-70

 4-32       High-velocity filtering elements.                         4-71

 4-33       Wire mesh mist eliminators.                             4-72

 4-34       Coke quench mist elimination baffle system.               4-74

 4-35       Details of baffle design.                                  4-74

 4-36       Streamline mist eliminator baffles.                       4-75

 4-37       Screen and mist eliminator details.                       4-75

 4-38       Bed of Berl saddles added to discharge stack.             4-77

 4-39       Spray nozzles commonly used in wet scrubbers.           4-79
                                     xxv

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Figure

4-40      Weir and sieve plate liquid distributors commonly
              , .      ,  , ,                                          4-82
          used m packed towers.

4-41      Multiple precipitator installation in basic oxygen
          furnace plant.

4-42      Detarrer precipitators installed in steel mill.             4-89

4-43      Schematic  view of a flat  surface-type electrostatic
                                                                   4_oo
          precipitator.

4-44      Schematic  view of tubular surface-type electrostatic
          precipitator.                                             4-92

4-45      Cutaway view of a flat surface-type electrostatic
          precipitator.                                             4-93

4-46      Cross-sectional view  of irrigated tubular blast
          furnace precipitator.                                     4-94

4-47      Typical double half wave silicon rectifier with
          twin output bushings.                                      4-96

4-48      Internal view of one type of rectifier control
          console showing component parts.                         4-97

4-49      Electrostatic precipitator collecting plates and
          discharge electrodes.                                     4-98

4-50      Hopper discharge valves, (a) Rotary valve  and
          (b) swing valve .                                          4-99

4-51      Electrostatic precipitator rapper mechanisms.
          (a) Pneumatic impulse rapper, (b) Magnetic impulse
          rapper, and (c) Pneumatic reciprocating rapper.          4-100

4-52      Variation of precipitator efficiency with sparking
          rate for a given fly ash precipitator.                      4-103

4-53      Electrostatic precipitator installed after air heater
          in power plant steam generator system.                   4-110
                                   xxvi

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Figure                                                            Page

4-54      Operating principle of two-stage electrostatic
          precipitator.                                            4-115

4-55      Two-stage precipitator used to control oil mist from
          machining operations.                                   4-117

4-56      Two-stage electrostatic precipitator with auxiliary
          scrubbers, mist eliminator, tempering coil, and
          gas distribution plate (top view).                          4-118

4-57      Efficiency of two-stage precipitator as function
          of velocity for several industrial operations .              4-121

4-58      Typical simple fabric filter baghouse design.              4-128

4-59      Streamlines and particle trajectories approaching
          filter elements .                                         4-131

4-60      System analysis for fabric filter collector design.         4-139

4-61      Pressure drop versus filter ratio for fabrics on
          60-minute cleaning cycle for electric furnace dust.        4-149

4-62      Typical performance of reverse-jet baghouses  using
          felted fabrics on a variety of dusts  (dust load versus
          filtering ratio at 3.5 in.w.c. pressure drop).              4-150

4-63      Open pressure baghouse .                                4-151

4-64      Open pressure baghouse unit showing installation
          without a separate clean gas housing .                     4-152

4-65      Closed pressure baghouse.                               4-153

4-66      Closed pressure baghouse unit .                          4-154

4-67      Closed suction baghouse.                                 4-155

4-68      Closed suction concrete baghouse unit.                    4-155

4-69      Typical flat or envelope dust collector bag .               4-156
                                 xxvn

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Figure                                                            P§ge_

4-70      Typical round or tubular dust collector bag.               4-157

4-71      Typical multi-bag dust collection system.                 4-157

4-72      Bottom entry design uni-bag.                             4-158

4-73      Top entry design uni-bag.                                4-158

4-74      Basic fabric weaves used for woven filter bags .           4-162

4-75      Mechanical shaking of bottom entry design uni-bag
          dust collector.                                           4-166

4-76      Air shaking wind-whip cleans dust collector bags.          4-166

4-77      Bubble cleaning of dust collector bags.                    4-168

4-78      Jet pulse dust collector bag cleaning.                     4-168

4-79      Reverse air flexing to clean dust collector bags by
          repressuring .                                           4-168

4-80      Sonic cleaning of dust collector bags .                     4-169

4-81      Repressuring cleaning of dust collector bags.              4-169

4-82      Cloth cleaning by reverse flow of ambient air.             4-170

4-83      Reverse jet cleaning of dust collector bags .               4-171

4-84      Effect of cleaning frequency on  filter resistance in
          reverse-jet baghouse.                                    4-182

4-85      Effect of air velocity and particle diameter on the
          combustion rate of carbon.                               4-190

4-86      Combustion efficiency of catalytic afterburner.            4-191

4-87      Effect of temperature and velocity on abatement
          effectiveness: spiral-wound metal foils catalyst support.   4-192
                                  xxviu

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Figure                                                           Page

4-88      Typical direct-fired afterburner with tangential entries
          for both fuel and contaminated gases .                     4-196

4-89      Portable canopy hood with stack afterburner.             4-197

4-90      Afterburner energy requirements with fume energy
          content and temperature parameters .                     4-198

4-91      Counter-flow type.                                      4-199

4-92      Parallel-flow type.                                      4-199

4-93      Cross-flow type.                                        4-199

4-94      Fixed-bed, pebble-stone,  regenerative destencher.        4-199

4-95      Direct recirculation of combustion gases to recover heat.  4-201

4-96      Heat exchanger to recover heat from combustion gases.    4-201

4-97      Integration of fume disposal from a kettle cooking
          operation with factory make-up air heating.               4-205

4-98      Packed bed flame arrester.                             4-206

4-99      Corrugated metal flame arrester with cone removed
          and tube bank pulled partly out of body .                   4-206

4-100     Dip leg flame arrester .                                 4-206

4-101     Cross-sectional view of open-type  inspirational
          premix burner.                                         4-208

4-102     Cross-sectional view of forced  air, premix, multiple-
          port burner.                                            4-208

4-103     Multiple-port high-intensity premix burner.               4-210

4-104     Service temperature ranges for refractories.             4-214
                                 xxix

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Figure

4-105       Degree of refraction for alumina-silica system
            products.
                                                                      6—2
            Criteria for selection of gas cleaning equipment.
                                                                      f* £J
            Cost of control.
                                                                      fi—V
6-3         Expected new cost of control.

6-4         Diagram of cost  evaluation for a gas cleaning system.       6-12

6-5         Purchase cost of gravitational collectors.                   6-40

6-6         Installed cost of  gravitational collectors.                   6-40

6-7         Purchase cost of dry centrifugal collectors.                6-41

6-8         Installed cost of  dry centrifugal collectors.                 6-41

6-9         Annualized cost  of operation of dry centrifugal
            collectors.                                                6-42

6-10        Purchase cost of wet collectors.                            6-42

6-11        Installed cost of  wet collectors.                            6-43

6-12        Annualized cost  of operation of wet collectors.              6-43

6-13        Purchase cost of high-voltage electrostatic
            precipitators.                                              6-45

6-14        Installed cost of  high-voltage electrostatic
            precipitators.                                              6-45

6-15        Annualized cost  of operation of high-voltage
            electrostatic precipitators.                                 6-46

6-16        Purchase cost of low-voltage electrostatic
            precipitators.                                              6-46
                                    xxx

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Figure                                                                Page

6-17       Installed cost of low-voltage electrostatic
           precipitators.                                              6-48

6-18       Annualized cost of operation of low-voltage
           electrostatic precipitators.                                 6-48

6-19       Purchase cost of fabric filters.                             6-49

6-20       Installed cost of fabric filters.                              6-49

6-21       Annualized cost of operation of fabric filters.               6-51

6-22       Purchase cost of afterburners.                             6-51

6-23       Installed cost of afterburners.                              6-52

6-24       Annualized cost of operation of afterburners.                6-52

6-25       Flow diagram for disposal of collected particulate
           material from air pollution control equipment.              6-58

6-26       Economic  cost of dust control with valuable material
           recovered: industrial viewpoint.                           6-62
                                      xxxi

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Table
                             LIST OF TABLES

                                                                       Page
 1          Typical pressure drops and efficiency ranges for gas
           cleaning devices used for stationary combustion
           sources

 2          Industrial process control summary

 3          Advantages and disadvantages of collection devices            8

 4          Examples of particulate emission factors                     11

 5          Installed costs of control equipment                          13

 6          Generalized annual operating and maintenance
           cost equations for control equipment                          14

 3-1        Comparison of motor vehicle particulate emissions with
           total particulate emissions for selected areas                 3-4

 3-2        Estimated 1966 United States energy consumption by
           selected consumer (10   Btu)                                3-11

 3-3        Common uses of various fuel-burning equipment              3-12

 3-4        Estimated amount and control status for particulate
           emissions from stationary combustion sources in 1966        3-14

 3-5        Optimum  expected performance of various types of gas
           cleaning systems for stationary combustion sources           3-17

 3-6        Comparison of energy substitution alternatives for
           electric power generation                                    3-22

 3-7        Comparison of energy substitution alternatives for
           stationary combustion sources of less than 10 million
           Btu/hr input                                                 3-23

           Comparison of energy substitution alternatives for
           stationary combustion sources of 10 million to 100
           million Btu/hr input                                         3-24
                                   xxxii

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Table                                                                  Page

 3-9       Trends in efficiency of coal, oil,  and gas use in
           United States                                                3-26

 3-10      Industrial process summary                                  3-32

 3-11      Steel production,  percentage by process                       3-36

 3-12      Average solid waste collected                                 3-64

 3-13      Maximum demonstrated collection efficiency of incinera-
           tor control  equipment                                        3-75

 4-1       Manufacturers' shipments of industrial gas cleaning
           equipment by end use in 1967                                 4-2

 4-2       Use of particulate collectors by industry                      4-7

 4-3       Relationship between particle size range and cyclone
           efficiency range                                             4-24

 4-4       Representative performance of centrifugal collectors          4-30

 4-5       Applications of centrifugal collectors                         4-31

 4-6       Typical industrial application of wet scrubbers                4-84

 4-7       Industrial operation of two-stage precipitators                 4-122

 4-8       Control mechanism for particle size collection                4-133

 4-9       Filter resistance coefficients (K)  for industrial dusts
           on woven fabric filters                                       4-136

 4-10      Physical  characteristics of bag fabrics tested in
           pilot plant                                                   4-141

 4-11      Recommended maximum filtering ratios and dust
           conveying velocities for various dusts and fumes  in
           conventional baghouses with woven fabrics                     4-142
                                   xxxi 11

  331-716 O - 69 - 3

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Table

 4-12      Recommended maximum filtering ratios and fabric for


                                                                       4-172
           dust and fume collection in reverse-jet baghouses               l 6
4-13       Filter fabric characteristics

                                                                      4-209
4-14       Gas burner classifications

4-15       ASTM classification of fire clay refractories                 4-212

4-16       Commonly used castable fire clay refractories               4-212

4-17       General physical and chemical characteristics of
           classes of refractory brick                                  4-216

4-18       Summary of afterburner applications and literature
           references                                                 4-217

5-1        Particulate emission factors                                5-3

6-1        Air pollution control equipment collection efficiencies        6-4

6-2        Approximate cost of wet collectors in 1965                   6-11

6-3        Total installation cost for various types  of control
           devices expressed as a percentage of purchase costs         6-16

6-4        Conditions affecting installed cost of control devices         6-17

6-5        Annual maintenance costs for  all generic types of
           control devices                                             6-18

6-6        Miscellaneous cost and engineering factors                   6-19

6-7        Hourly fuel costs                                            6-28

6-8        Illustrative presentation of annual costs  of control for
           60,000 acfm wet scrubber (dollars)                          6-37

6-9        Costs of specific disposal systems                          6-60

6-10       Cost of ash disposal by electric utilities                      6_gl
                                  xxxiv

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                                 SUMMARY






PARTICULATE SOURCES





      Particulate material found in ambient air originates from both stationary





and mobile sources.  Of the  11. 5 million tons of particulate pollution produced




in 1966,  6 million tons were emitted from industrial sources, including in-





dustrial fuel burning; 5 million tons from power generation,  incineration, and





space heating;  and 0. 5 million ton from mobile sources.




      The following techniques are in use for controlling the source or reducing




the effects of particulate pollution:




            1.    Gas cleaning



            2.    Source relocation



            3.    Fuel substitution



            4.    Process changes



            5.    Good operating practice



            6.    Source shutdown



            7.    Dispersion




Internal  Combustion Engines




      Although particulate emissions from internal combustion engines are





estimated to contribute  only  4 percent of the total particulate emissions on a





nationwide basis, they do contribute as much as 38 percent in certain urban





areas.  The relative percentages of particulate emissions for this and other





source categories differ from one area to another depending on automobile





density,  degree of stationary source control, and types of sources present in





the area.
                                     1

-------
      For each 1000 gallons of fuel consumed, diesel-fueled engines produce




about 110 pounds of particulate matter.  Gasoline-fueled engines produce about





12 pounds per 1000 gallons of fuel consumed.




      Gasoline engine-produced particulate matter emanates from the crank-




case and exhaust gases.  It consists of carbon,  metallic ash, aerosol hydro-





carbons, and metallic particles.




      The particulate matter emitted from a diesel engine  comprises




carbon and hydrocarbon aerosols.  Control of diesel engine emissions effects





reduction in smoke.




Stationary Combustion Sources




      In the United States more  than 29 million  stationary combustion sources





are currently  in operation.  About 2 percent are fired with coal, 61 percent





are fired with gas, and 37 percent are fired with fuel oil.   The relative usage




of fuels on a Btu basis shows  coal to be 31 percent, natural gas 48  percent, and




fuel oil 21 percent.





      Types of gas cleaning devices currently being used for stationary com-




bustion sources are listed in Table 1.   Newer control systems  are  now being




installed which will be used to control both particulate matter and sulfur oxides.




Industrial Sources





      Industrial processes,  including industrial fuel burning, discharged an




estimated 6. 0 million tons of  particulate materials in 1966. This  amounts  to




more than 50 percent of the total particulate pollution on a nationwide basis.




Major pollutants are dusts,  fumes, oils,  smoke,  and mists.

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                    Table 1.  TYPICAL PRESSURE DROPS AND EFFICIENCY RANGES FOR GAS CLEANING

                                 DEVICES USED FOR STATIONARY COMBUSTION SOURCES
                              Unit
Pressure drop, in. HO
                    £t
Efficiency, percent
                     Settling chambers


                     Large-diameter cyclones


                     Small-diameter cyclones


                     Electrostatic precipitator
        0.5


       0.5-4.0


         2-8


       0.1-0.5
   20 - 60


   30 - 65


   70 - 90


   75 - 99.5
CO

-------
      Table 2 presents a summary of important industries, their pollutant
sources,  particulate pollutants,  and air cleaning techniques (equipment)
presently in use.
Construction and Demolition
      The principal demolition, construction, and related operations that gen-
erate particulate air pollution are:
            1.    Demolition  of masonry
            2.    Open burning
            3.    Movement of vehicles on unpaved roads
           4.    Grading of earth
            5.    Paving of roads and parking lots
            6.    Handling and batching of paving materials
           7.    Sandblasting of buildings
           8.    Spray painting
      Control of the above operations is accomplished by various means  which
include hooding and venting to air pollution control equipment, wetting down
working surfaces with water or oil, and using sanitary landfill.
Solid Waste Disposal
      Although solid waste disposal by incineration accounts for less than 10
percent of the total particulate pollution (1 million tons in 1966),  it does, how-
ever, inspire many complaints about air pollution.  Of the  190 million tons of
solid wastes collected in 1967, 86 percent went into land disposal sites,  8 per-
cent was burned in municipal incinerators, and 6 percent was disposed of in
sanitary landfills.   Since open burning is practiced at three-fourths of the land

-------
                                           Table 2.   INDUSTRIAL PROCESS AND CONTROL SUMMARY
                    Industry or process
01
                   Iron and steel mills
                   Gray iron foundries
                   Metallurgical
                      (non-ferrous)

                   Petroleum refineries
                   Portland cement
                   Kraft paper mills
                   Acid manufacture-
                   phosphoric, sulfuric
                   Coke manufacturing
                   Glass and glass fiber
                   Coffee processing
      Source of emissions
                                              Blast furnaces, steel making
                                              furnaces,  sintering machines
Cupolas, shake out systems,
core making
Smelters and furnaces
Catalyst regenerators,  sludge
incinerators
Kilns,  dryers, material
handling systems

Chemical recovery furnaces,
smelt tanks,  lime kilns

Thermal processes, phosphate
rock acidulating, grinding
and handling  systems

Charging and discharging
oven cells, quenching,
materials handling

Raw materials handling, glass
furnaces, fiberglass forming
and curing
Roasters, spray dryers, waste
heat boilers, coolers,
conveying equipment
                                       Particulate matter
                                     Iron oxide,  dust,
                                     smoke
Iron oxide,  dust,
smoke, oil, grease,
metal fumes

Smoke, metal fumes,
oil,  grease

Catalyst dust, ash
from sludge
Alkali and process
dusts

Chemical dusts
Acid mist, dust
Coal and coke dusts,
coal tars
Sulfuric acid mist,
raw materials dusts,
alkaline oxides,
resin aerosols

Chaff, oil aerosols,
ash from chaff burning,
dehydrated coffee dusts
                                                                                                                          Method of control
Cyclones, baghouses,  electro-
static precipitators, wet
collectors

Scrubbers, dry centrifugal
collectors
Electrostatic precipitators,
fabric filters

High-efficiency cyclones, electro-
static precipitators, scrubbing
towers, baghouses

Fabric filters, electrostatic
precipitator, mechanical collectors

Electrostatic precipitators, ven-
turi scrubbers

Electrostatic precipitators, mesh
mist eliminators
Meticulous design,  operation,
and maintenance
Glass fabric filters, afterburners
Cyclones, afterburners, fabric filters

-------
disposal sites, particulate emissions from these sites contribute significantly
to air pollution arising from the disposal of solid waste.
      Over 70 percent of existing municipal incinerators were installed before
1960, and lack adequate provisions for eliminating particulate emissions.
      An obvious means of reducing the air pollution resulting from solid waste
disposal is to use such non-incineration methods for disposal as follows:
            1.    Sanitary landfill
            2.    Composting
            3.    Shredding and grinding
            4.    Dispersion (hauling to another locale)
      These methods contribute little to air pollution problems.
      It is estimated that measures to upgrade existing land disposal sites, and thus
do away with openburning, will cost as  much as $230 million peryearfor 5 years.
      Where incineration is used for solid  waste disposal, the principal partic-
ulate pollutant emitted  is fly ash. Its removal from effluent gas streams is
accomplished by low pressure drop (0. 5 inch H2O) scrubbers, or settling
chambers.
      The estimated cost of upgrading or replacing existing inadequate in-
cinerators is $225 million, of  which  $75 million would be for air pollution
control equipment.
GAS CLEANING  DEVICES
      It has been estimated that total expenditures in 1966 on industrial air
pollution control equipment in  the United States were about $235 million.

-------
Value of shipments of the industrial gas cleaning equipment industry in 1967




was double the 1963 figure, and the backlog of orders recently nearly equalled




a year's productive output.  Undoubtedly legislative pressure and local pollu-




tion control regulations have supplied the impetus  for such rapid growth in this




industry.




      The selection of gas cleaning equipment is far from an exact science and




must be based on characteristics of particle and carrier gas, and process,




operation,  construction, and economic factors.  Information on particle size




gradation in the inlet gas stream is important in the proper selection of gas




cleaning equipment.  Particles larger than 50 microns may be removed satis-




factorily in inertial and cyclone separators and simple, low-energy wet




scrubbers.  Particles smaller than 1 micron can be arrested effectively by




electrostatic precipitators, high-energy scrubbers,  and fabric filters.




      Table 3 lists advantages and disadvantages in applicability of each of




the general types of air cleaners to given situations.




EMISSION  FACTORS




      Emission factors may be used to estimate emissions from sources for




which accurate stack test results are unavailable.   Process emission factors




for some selected source types are presented in Table 4.




ECONOMICS




     Air pollution control is viewed not only from the standpoint of available




technology but also with respect to the economic feasibility of control methods




and/or equipment.

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Table 3.  ADVANTAGES AND DISADVANTAGES OF COLLECTION  DEVICES
   Collector
         Advantages
                                                           Disadvantages
 Gravitational
 Cyclone
Wet collectors
Low Pressure loss, simplicity
of design and maintainance

Simplicity of design and
maintainance

Little floor space required
Dry continuous disposal
of collected dusts

Low to moderate pressure
loss

Handles large particles

Handles high dust
loadings

Temperature independent

Simultaneous gas
absorption and particle
removal
                 Ability to cool and clean
                 high-temperature, moisture-
                 laden gases

                 Corrosive gases and mists
                 can be recovered and
                 neutralized

                 Reduced dust explosion
                 risk

                 Efficiency can be varied
Much space required
Low collection efficiency

Much head room required
                                                    Low collection efficiency
                                                    of small particles

                                                    Sensitive to variable dust
                                                    loadings and flow rates
Corrosion, erosion problems

Added cost of wastewater
treatment and reclamation
                                   Low efficiency on submicron
                                   particles

                                   Contamination of effluent
                                   stream by liquid
                                   entrainment

                                   Freezing problems in cold
                                   weather

                                   Reduction in buoyancy and
                                   plume rise

                                   Water vapor contributes to
                                   visible plume under some
                                   atmospheric conditions.

-------
       Table 3  (continued).   ADVANTAGES AND DISADVANTAGES
                         OF COLLECTION DEVICES
   Collector
            Advantages
        Disadvantages
Electrostatic
  precipitator
Fabric
  filtration
Afterburner,
  direct flame
99+ percent efficiency
obtainable

Very small particles
can be collected
                 Particles may be collected
                 wet or dry
Pressure drops and power
requirements are small
compared to other high-
efficiency collectors

Maintenance is
nominal unless corrosive
or adhesive materials
are handled

Few moving parts

Can be operated at high
temperatures (550° to 850° F)

Dry collection possible
                 Decrease of performance
                 is noticeable

                 Collection of small
                 particles possible

                 High efficiencies
                 possible
High removal efficiency
of submicron odor-causing
particulate matter
Relatively high initial
cost

Precipitators are sensi-
tive to variable dust
loadings or flow rates

Resistivity causes some
material to be economi-
cally uncollectable

Precautions are required
to safeguard personnel
from high voltage

Collection efficiencies
can deteriorate gradually
and imperceptibly
Sensitivity to filtering
velocity
                                   High-temperature gases must
                                   be cooled to 200° to 550° F
Affected by relative
humidity (condensation)

Susceptibility of fabric
to chemical attack

High operational cost

Fire hazard

-------
          Table 3 (continued).  ADVANTAGES AND DISADVANTAGES
                         OF COLLECTION DEVICES
  Collector
          Advantages
        Disadvantages
Afterburner,
  direct flame
  (continued)
Afterburner,
  catalytic
 Simultaneous disposal of
 combustible gaseous and
 particulate matter

 Direct disposal of non-
 toxic gases and wastes
 to the atmosphere after
 combustion

 Possible heat recovery

 Relatively small
 space requirement

 Simple construction

 Low maintenance

 Same as direct flame
 afterburner

 Compared to direct flame:
 reduced fuel require-
ments, reduced temperature,
 insulation requirements,
and fire hazard
 Removes only combustibles
 High initial cost


Catalysts subject to
poisoning

Catalysts require
reactivation
                                    10

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      Table 4.  EXAMPLES OF PARTICULATE EMISSION FACTORS
    Source
     Specific process
         Particulate
       emission rate,
        uncontrolled
Aircraft

Solid waste
  disposal

Phosphoric acid
  manufacturing

Sulfuric acid
  manufacturing

Food and
  agricultural
Feed and
  grain mills

Primary metal
  industry
Secondary metal
  industry
Four engine fan jet

Open burning
dump

Thermal process
Contact process
Coffee roasting,
direct fired

Cotton ginning and incin-
eration of trash

General operation
Iron and steel manufacturing
furnace, open hearth (oxygen
lance)

Aluminum smelting,
chlorination-lancing

Brass and bronze
smelting rever-
beratory furnace

Gray iron foundry
cupola
    7.4   lb/flight

     16   Ib/ton of refuse
0.2-10.8  Ib/ton of phos-
          phorus burned

0.3-7.5   Ib/ton of acid
          produced

    7. 6   Ib/ton of green
          beans

   11.7   Ib/bale of cotton
      6   Ib/ton of product
     22   Ib/ton of steel
   1000   Ib/ton of chlorine
                                                  26.3   Ib/ton of metal
                                                         charged
                                                  17.4   Ib/ton of metal
                                                         charged
                                   11

-------
      Among the cost elements relevant to an air pollution control problem
 are:
            1.   Capital costs of control equipment.




            2.   Depreciation of all control equipment.




            3.   Overhead costs including taxes,  insurance, and interest





            for control equipment.




            4.   Operation and maintenance costs.




            5.   Collected waste material disposal costs.




            6.   Other capital expenditures for research and development,




            land,  and engineering studies to determine and design optimum




            control system.





      Many of  these elements differ from one installation to another.  Table




5 lists major collector types and their approximate installed costs for opera-




tional air flow  rates.  The  installed costs (purchase cost, transportation, and




preparation for on line operation) are average costs for  typical control equip-





ment.




      Table 6 presents generalized  operating and maintenance  cost equations





for various types  of control equipment.





BIBLIOGRAPHY




      A list of  references follows each section of this document.  Other ref-





erences relating to control technology for generic sources of particulate air




pollutants are cited in the bibliography,  which comprises the final section.
                                     12

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Table  5.  INSTALLED COSTS OF CONTROL EQUIPMENT
Collector
type
Gravity
Mechanical
Wet
High-voltage
electrostatic
precipitator
Low-voltage
electrostatic
precipitator
Fabric filter,
high temperature (550° F)
medium temperature (250° F)
Afterburner,
direct flame
catalytic
Approximate installed cost, in thousands
of dollars
Gas flow rates
(1000 actual cubic feet per minute)
2
0.5
-
-
-

-

-
8.2
16
5
.1.2
-
7.5
-

13

:
12
20
10
2.6
4
10
-

24

30
15
18
29
15
15
13
30
85

105

88
45

-
100
28
23
55
120

200

155
82

-
300
-
80
150
265

-

430
225

-
500
-
-
-
415

-

720
375

-
                         13

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  Table 6.  GENERALIZED ANNUAL OPERATING AND MAINTENANCE COST
                   EQUATIONS FOR CONTROL EQUIPMENT
Collector
Mechanical centrifugal
collector
Wet collector
Electrostatic
precipitator
Fabric
filter
Afterburner
Generalized
G=S TO. 7457 PHK +
L 6356 E
G=S 1 0.7457 HK (z -.
G=S [(JHK + M)]
G=S |"0. 7 457 PHK +
L 6356 E
G=S To. 7457 PHK +
L 6356 E
equation
M]
- Qh \ + WHL
19807
MJ
FH + MJ

+ M]
Where:
         G  = annual costs,  dollars, for operating and maintenance
         S  = design capacity of the unit, actual cubic feet per minute (acfm)
         P  = pressure drop, inches of water
         H  = hours of operation annually
         K  = cost of electricity; dollars per kilowatt-hour
         E  = fan efficiency expressed as decimal
         M  = maintenance cost per acfm, dollars per cfm
         F  = fuel costs, dollars per acfm per hour
         W  = make-up liquid rate in gallons per hour per acfm
         L  = cost of liquid in dollars per gallon
         Z  = total power input required for a specified scrubbing efficiency,
              horsepower per acfm
         J  = kilowatts of electricity per acfm
         h  = elevation for pumping of liquor in circulation system for
              collector,  feet
         Q  = water circulation, gallons per acfm
                                    14

-------
Although all of the articles cited in the bibliography do not necessarily reflect




the most modern control practices, they do provide useful background material




on the control technology for particulate air pollutants.
                                      15



   331-716 O - 69 - 4

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                             I.  INTRODUCTION
      Pursuant to authority delegated to the Commissioner of the National Air
Pollution Control Administration, Control Techniques for Particulate Air
Pollutants is issued in accordance with Section 107c of the Clean Air Act
(42 U. S.C.  1857c-2bl).
      Particulate matter in the atmosphere is known to have many adverse
effects upon health and welfare,  and reduction of emissions of this pollutant
is of prime importance to any effective air pollution abatement program.
Particulate pollutants originate from a variety of sources, and the emissions
vary widely in physical and chemical characteristics.  Similarly, the available
control techniques vary in type,  application,  effectiveness, and cost.
      The control techniques described herein represent a broad spectrum of
information from many engineering and other technical fields.  The devices,
methods, and principles  have been developed and used over many years, and
much experience has been gained in their application.  They are recommended
as the techniques generally applicable to the broad range of particulate emission
control problems.
      The proper choice  of a method, or combination of methods, to be applied
to any specific source depends on many factors other than the characteristics
of the source itself.  While a certain percentage of control, for example, may
be acceptable for a single source, a much higher degree may be required for the
same source when its emissions blend with those of others.  This document
provides a comprehensive review of the approaches commonly recommended
for controlling the sources of particulate air pollution.  It does not review all
                                     1-1

-------
possible combinations of control techniques that might bring about more stringent
control of each individual source.
      The many agricultural, commercial, domestic, industrial, and municipal
processes and activities that generate particulate air pollutants are described
individually in this document.  The various techniques that can be applied to
control emissions of particulate matter from these sources are reviewed and
compared.  A technical consideration of the most important types of gas clean-
ing devices  forms a major segment,  while sections on source evaluation,
equipment costs and cost-effectiveness analysis, and current research and
development also are included.   The bibliography contains important reference
articles, arranged according to applicable processes.
      While some data are presented on quantities of particulate matter emitted
to the atmosphere, the effects  of particulate matter on health and welfare are
considered  in a companion document, Air Quality Criteria for Particulate
Matter.
      The National Air Pollution Control Administration also is publishing a
document which discusses the philosophy underlying the issuance of air quality
criteria, and which suggests some general guidelines for utilizing the criteria
to develop air quality standards.  This latter publication also describes the
factors that the  Department  of Health,  Education,  and Welfare will consider
in evaluating the air quality  standards and the implementation plans proposed
by the States.
                                      1-2

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                     2.  BACKGROUND INFORMATION




2. 1  DEFINITIONS




     This section contains general definitions of the terms used throughout




this document.




     Pollutant or Contaminant—any solid,  liquid,  or gaseous matter in the




outdoor atmosphere which is not normally persent in natural air.




     Particulate Matter—as related to control technology, any material,  ex-




cept uncombined water, that exists as  a solid or liquid in the atmosphere or in




a gas stream at standard conditions.




     It is important that standard conditions for the measurement of particu-




late matter be included with its definition.  Some compounds are not solids or




liquids at stack conditions but condense in the ambient atmosphere. Unless




standard conditions for measurement of particulate matter are defined, these




materials would not be considered particulate and subject to control.




     Aerosol—a dispersion in gaseous media of solid or liquid particles of




microscopic size, such as smoke, fog, or mist.




     Dust—solid particles predominantly larger than colloidal  size and capa-




ble of temporary suspension in air and other gases.  Derivation from larger




masses through the application of physical force is usually implied.
                                   2-1

-------
       Fly Ash— finely divided particles of ash entrained in flue gases arising




 from the combustion of fuel.   The particles of ash may contain unburned fuel




 and minerals.




       Fog— visible aerosols in which the dispersed phase is liquid.  In meteor-




 ology, fog is a dispersion of water or ice.




       Fume—particles formed by condensation, sublimation, or chemical re-




 action,  of which the predominant part, by weight, consists of particles smaller




 than 1 micron.  Tobacco smoke and condensed metal oxides are examples of




 fume.




      Mist—low-concentration dispersion of relatively small liquid droplets.




 In meteorology, the term mist applies to a light dispersion of water droplets




 of sufficient size to fall from the air.




      Particle— small, discrete mass of solid or liquid matter.




      Smoke— small gasborne particles resulting from incomplete combustion.




 Such particles consist predominantly of carbon and other combustible material,




and are present in  sufficient quantity to be observable independently of other




solids.




      Soot— an agglomeration of carbon particles impregnated with "tar, "




formed in the incomplete combustion of carbonaceous material.




     Sprays— liquid droplets formed by mechanical  action.
                                    2-2

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 2.2   MAJOR SOURCES OF PARTICULATE MATTER

      An estimated 11. 5 million tons of particulate matter, about 10 percent of

 all pollutants emitted annually, was emitted in the United States during 1966.

 Figure 2-1,  which is based on Reference 1 and gasoline and fuel  consumption

 figures, shows that industrial sources  of particulate matter, including indus-

 trial fuel burning,  emit 6 million tons of particulate matter annually.  About

 5 million tons result annually from power generation, incineration,* and

 space heating.  Mobile (transportation) sources emit the remaining  0. 5 million
 tons.
         POWER
         GENERATION
         3 MILLION
                             INCINERATION
                             1 MILLION
                                         2.2.1  Combustion Sources
Combustion of coal and oil re-
                                         sults in an annual emission of 4. 5
                               HEATING
                               i MILLION   miiiion tons of particulate matter that
                               MOBILE
                               0.5 MILLION                iy asn from coai Com-
  Figure 2-1.  Sources of particulate matter
           and quantities produced in
           tons per year.
                                        bustion.  Emission sources are dis-

                                        cussed in Section 3.3 of this report.

                                              Refuse burning, both in inciner-

                                        ators and in dumps,  produces  approxi-

mately 1 million tons of particulate matter annually.  Much of this particulate

matter is dust,  fume,  smoke,  fly ash, and large pieces of partially burned

refuse.   Although refuse burning creates less than 15 percent  of the  total par-

ticulate matter emitted in the United States,  such emissions are usually
*Does not include agricultural burning and forest fires.

                                      2-3

-------
 concentrated in heavily populated areas and have a more significant impact on




 the population than these statistics may suggest.




 2.2.2  Industrial Sources




       Particulate emissions from industrial processes consist of dust, fume,




 smoke,  and mist arising largely from combustion and loss of process materi-




 als or products to the atmosphere.  Such emissions totaled 6  million tons in




 1966.  Major industrial sources are listed and discussed in Section 3.4 of




 this report.




      In some industrial processes, efficient collection of particulate matter




 increases overall plant operating efficiency by recovering a portion of the




 product that would otherwise be lost to the atmosphere.  Dust collectors used




 in cement plants, grain handling operations, and carbon black plants can re-




 cover valuable products.




 2.2.3 Mobile Sources




      Emissions from mobile sources, which total approximately 0. 5 million




tons of particulate matter per year, are largely caused by the  burning of




fuels  in motor vehicles.  Automobile exhaust is the largest  source of particu-




late matter in this category. It is characterized by an extremely large num-




ber of fine particles consisting of organic and inorganic materials,  including




lead.   Particulate emissions from diesel engines are more  concentrated




and may cause a visible plume.  Aircraft,  especially jet-powered planes,  also




produce visible particulate emissions.  The emission  rate is greatest during
                                     2-4

-------
takeoff and landing operations when the engines operate under conditions of a




high ratio of fuel to air.
                                      2-5

-------
                      REFERENCE FOR SECTION 2

1.    "The Sources of Air Pollution and Their Control. " U.S.  Dept.  of
     Health, Education, and Welfare, Div. of Air Pollution, Washington,
     D.C. ,  PHS-Pub-1548, 1966.
                                  2-6

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         3.   PARTICULATE SOURCES AND CONTROLS




3.1  INTRODUCTION




     The earliest approaches to air pollution control,  used in England




over 200 years ago,  were the restriction of smoke releases and re-




location of sources to "offensive trades zones. "  The latter was used




particularly when the odor of the source was offensive.  Relocation




is still used, or at least considered, by operators of some pollution




sources as an alternate to emissions control.  In most instances, however,




relocating a pollution source to  a remote area may only postpone the




adoption of emissions control.




      Many sources  such as transportation, space heating, and solid




wastes disposal are  inherent to  population  centers.  All generate partic-




ulate air pollution in urban areas.  Although remote power generation and




long distance hauling of solid wastes are possible, automobiles, busses,




incinerators, and home furnaces and manufacturing and commercial




operations that require workers will, in all likelihood, continue to operate




in our cities.




     To appreciate  the air pollution problem facing the United States,




it is necessary to have some understanding of the sources of air pollution
                               3-1

-------
 and the means of controlling them.  The multitude of small sources closest




 to the average citizen - automobiles,  home furnaces, on-site incinerators  -




 are often the least effectively controlled.  High-efficiency control equip-




 ment use is limited almost entirely to certain steam-electric generating




 stations and industrial operations, particularly the large installations.  Most




 of the high-efficiency  emissions controls are being developed for such




 sources as steel mills,  steam-electric generating stations, petroleum




 refineries, and chemical plants.  The most promising areas of improve-




 ment  for small sources involve basic  changes in source operation - cleaner




fuels,  automobile  engine modifications,  and improved means of solid




wastes disposal.
                               3-2

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3.2  INTERNAL COMBUSTION ENGINES




      Although stationary sources are the major contributors of particulate




matter, the motor vehicle contributes a significant amount of particulate




matter to the atmosphere.  The ranking of the motor vehicle emissions in




an urban community is a function of the relative magnitude of the vehicular




and industrial activities; the extent to which coal,  residual fuels, and refuse




are burned; and the extent and effectiveness of the air pollution control




measures used.  Each 1, 000 gallons of fuel consumed by diesel engines




produces about 110 pounds of particulate matter and gasoline engines produce




about 12 pounds of particulate for every 1, 000 gallons consumed.   Of the total




annual emission of 11. 5 million tons of particulate matter, motor vehicles




contribute approximately 4 percent or about 500, 000 tons.




      Table 3-1 presents examples of contribution by motor vehicles to




particulate emissions  in different communities.




3.2.1 Gasoline-Fueled Vehicles




      Particulate matter is emitted in the exhaust and crankcase blowby




gases of gasoline-fueled engines. Carbon, metallic ash, hydrocarbons in




aerosol form, and metallic materials present in engine  systems are emitted.




      Metal-based particles result almost entirely from the use of lead




antiknock  compounds in the fuel;  however, metallic lubricating oil additives




and engine wear particles are also present.   Carbon and some of the  hydro-




carbon aerosols result from incomplete combustion of fuel.  The rest of
                                  3-3

-------
Table 3-1. COMPARISON OF MOTOR VEHICLE PARTICULATE EMISSIONS
            WITH TOTAL PARTICULATE EMISSIONS FOR
                       SELECTED AREAS2"7
Metropolitan
area
Washington, D. C.
New York- Northern
New Jersey
Kansas City
Jacksonville, Florida
St. Louis
Los Angeles County
Particulate matter, tons/yr
Total
35,000
231,000
60,000
14,000
147,000
43,000
Motor
vehicle
5,700
33,800
5,000
600
4,700
16,400
Percent of
total from
motor vehicles
16
15
8
4
3
38
                               3-4

-------
the aerosols are emitted to the atmosphere from engines with vented crank-


cases or are produced by crankcase oil that leaks past the piston rings


into the combustion chamber and is emitted unburned with the exhaust gases.


      Particulate matter in automobile exhaust amounts  to approximately


5 percent by weight of the amount of gaseous hydrocarbon emitted.  It


consists of lead compounds, carbon particles,  motor oil, and nonvolatile


reaction products formed from motor oil in the combustion zone.  It is


suspected that these reactions involve the formation of high-molecular-


weight olefins, and carbonyl compounds.


      Particles in blowby gases consist almost entirely of unchanged


lubricating oil.  As a very rough approximation,  the amount of material


emitted in blowby gases is one-third to  one-half the amount emitted in


the exhaust.  The same approximate ratio applies to either particulate


emission or gaseous hydrocarbon emission.  Blowby emissions are


influenced to a greater extent than exhaust emissions by mechanical con-

                   g
dition of the engine.


      Partial control of vehicle particulate emissions  has been in effect


nationally since  1963.  Beginning with the 1968 automobile models,  the particu-


lates in crankcase gases were completely controlled (Fig. 3-1).  It is possible


the exhaust emission control measures  employed in the  1968 model passenger


cars reduce the emissions of some particulates.
                                 3-5

-------
         FILTERED AIR
                                         AIR INTAKE
                                              CONTROL VALVE
                                      CRANKCASE
                                      BLOWBY GASES
   C>  FILTERED AIR
   t  BLOWBY GASES
      FILTERED AIR + BLOWBY GASES
Hll>  COMBUSTIBLE MIXTURE
     Figure 3-1.  Motor vehicle emission control system.

-------
     Technology for the control of lead in exhaust emissions is in the devel-


opmental stage.   The National Air Pollution Control Administration is present-


ly evaluating two prototype electrogasdynamic precipitators for gasoline and

                             9
diesel motor vehicle exhausts.


     Lead emissions may also be controlled by restricting the concentration


of lead antiknock compounds that are permitted in the fuel.  The American


Petroleum Institute indicates that the additional cost of unleaded fuel would


be 1. 8 to 4. 7 cents per gallon.  Petroleum processing equipment is  available


for producing unleaded gasoline, but an estimated 5 to 10 years is necessary


for its installation at a capital investment of over $4 billion.    '


3.2.2 Dies el-Powered Vehicles


     Particulate matter emitted by diesel engines consists primarily of


carbon and hydrocarbon aerosols resulting from incomplete combustion of the


fuel.  Aerosols in the vent gases of the two-stroke-cycle diesel engine (from


air box drains) and in the exhaust, as a result of crankcase oil going through


the combustion process unburned,  produce a small amount of additional


particulate emissions.


     Federal  regulations scheduled for implementation in 1970 will limit


smoke from new diesel engines.  The regulations  establish a maximum in-


tensity of smoke emission (measured by reduction in light transmission) under


conditions of severe engine loading at (1) full-throttle acceleration from a


prolonged  idle and (2) "lugdown" from maximum governed speed, also at full
                                   3-7

 331-716 O - 69 - 5

-------
 throttle.  No new information or control devices are believed to be needed to



 reduce the smoke emissions from diesel engines to meet the established stand-



 ards.   As vehicle mileage increases, proper fuel system adjustment,  mainte-



 nance at appropriate intervals,  the use of the specified type of fuel, and good



 operating techniques can maintain low levels of visible emissions, particularly



 with respect to particulate carbon.



      New engines,  which will comply with the 1970 smoke standards,  will be



 adjusted by the engine manufacturer to a conservative fuel rate and power output.



 Increases in fuel rate above the manufacturer's setting will increase engine



 power, but also will raise the level of black smoke.  Even in a properly ad-



 justed engine,  injector deterioration (such as nozzle erosion) can effect a sub-



 stantial increase in the emission of black smoke.



      Investigations have been conducted to evaluate methods  of reducing



 diesel smoke.  Methods consist primarily of exhaust gas dilution and the use



 of smoke-suppressing fuel additives.  Neither of these methods can be recom-



 mended for general  application at this time.  The dilution technique at best,



 merely reduces the  opacity of the smoke plume without reducing the quantity of



particles  emitted.  Smoke suppressants have been reported to be effective in



overfueled engines in good mechanical condition.  One type of suppressant re-


                                       12
ported to  show promise contains barium.    Use of the  organic barium  additive



could,  however, result in the emission of toxic, water-soluble, barium
                                      3-8

-------
compounds.  Further study of additives is needed before this technology can




be broadly adopted.
                                   3-9

-------
 3. 3  CONTROL OF PARTICULATE EMISSIONS FROM STATIONARY

      COMBUSTION SOURCES



 3.3.1 Introduction



 3.3.1.1  General - Of the many techniques used to control participate air



 pollution from stationary combustion sources,  none has emerged as an all-



 inclusive answer to the control problem.



 3.3.1.2  Sources - More than 29 million stationary combustion sources are


                                          13
 currently in operation in the  United States.    About 2 percent are fired



 with coal,  61 percent are fired with gas, and 37 percent are fired with



 liquid fuels. Table 3-2  shows the consumption of energy by type of consumer.



 Coal, gas,  and oil are burned in a wide variety of equipment. The more



 common types  of equipment are shown in Table 3-3.



 3.3.L3  Emissions - Participate emissions from stationary combustion



 sources  in the  United States are estimated at 4.5  million tons (see Table



 3-4) of the total particulate emissions of almost 12 million tons per year


                 1 £!
 from all sources.   Local patterns of emissions  will usually differ from



 the national pattern because of differences in fuel and equipment use patterns.



      The rate of uncontrolled particulate emissions varies widely from



 unit to unit because processes,  practices, and fuels  all affect emission



 levels.   For each fuel, several different processes are used for  stationary



 combustion.  Steam, hot water, and warm air furnaces are in common use



for domestic heating and many specialized heaters are used by industry.
                                   3-10

-------
 Table 3-2.  ESTIMATED 1966 UNITED STATES ENERGY CONSUMPTION
                                                  19     14
                     BY SELECTED CONSUMER (10   Btu)


Energy
source
Anthracite coal
Bituminous and
lignite coal
Natural gas
Petroleum
Hydroelectric
Nuclear
Total
Consumer
Household
and
commercial
143
575

5,945
2,247a
0
0
8,910


Industrial
41a
2,206a

5,674a
2,512a
0
0
10,433

Power
generation
56
6,341

2, 692
905
2,060
58
12,112


Total
240
9,122

14,311
5,664
2,060
58
31,455
aExchides non-combustion consumption.

"Excludes naphtha, kerosene, and liquified petroleum gases.
                                 3-11

-------
    Table 3-3.   COMMON USES OF VARIOUS FUEL-BURNING EQUIPMENT
           Equipment
                                                  Common use
Coal-fired
   Hand-stoked equipment
   Single-retort underfeed
     stokers
   Multiple-retort underfeed
     stokers
   Spreader stokers
   Traveling grate stokers
   Chain grate stokers
   Vibrating grate stokers

   Pulverized-fuel-fired
     equipment (dry bottom
     or wet bottom)

Oil-fired
   High-pressure gun-type
     burners
   Low-pressure air-atomizing
     burners
   Rotary cup burners
   Steam atomizing burners
   High-pressure air-
     atomizing burners
Residential, institutional, and commercial
warm-air and boiler applications at
capacities up to 5 million Btu per hour input.
(Used primarily in coal-producing areas.)

Residential, institutional, and commercial
warm-air and boiler applications at
capacities up to 40 million Btu per hour
input.

Water tube and fire tube boiler applications
for institutional, commercial, and industrial
heating at capacities in range of 5 million
to 200 million Btu per hour input.
Water tube boiler applications for power
generation at capacities greater than 100
million Btu per hour input.
Residential warm air furnace or boiler
applications at capacities up to 3 gallons
per hour distillate oil.

Water tube and fire tube boiler applications
for institutional, commercial, and industrial
process heating with distillate or residual
oil.

Water tube and fire tube boiler applications
for institutional, commercial, and industrial
heating and power generation with residual
oil.
                                     3-12

-------
             Table 3-3 (continued).  COMMON USES OF VARIOUS
                       FUEL-BURNING EQUIPMENT
          Equipment
               Common use
Gas-fired
   Premixing burners
   Nozzle mixing burners
Residential warm-air furnace or boiler
applications and low-temperature industrial
applications.

Water tube and fire tube boiler applications
for institutional,  commercial,  industrial,
and power-generation applications.   (May
be combination type to permit fuel oil
firing when gas supply is interrupted.)
                                   3-13

-------
Table 3-4.  ESTIMATED AMOUNT AND CONTROL STATUS FOR PARTICULATE
         EMISSIONS FROM STATIONARY  COMBUSTION SOURCES IN 1966

Fuel and source
Anthracite coal
Household and
commercial
Industrial
Power
Sub total
Bituminous and
lignite coal
Household and
commercial
Industrial
Power
Sub total
Petroleum0
Household and
commercial
Industrial
Power
Sub total
Natural gas
Household and
commercial
Industrial
Power
Sub total
Grand total

Uncontrolled
emissions
10 tonsa


0.05
0.04
0.17
0.26



0.24
2.29
21.14
23.67


0.08
0.17
0.03
0.28


0.06
0.05
0.02
0.13
24.34
Estimated
control status
in 1966, b
percent


Negligible
62.0
86.5
-



Negligible
62.0
86.5
-


Negligible
Negligible
Negligible
-


Negligible
Negligible
Negligible
-

Estimated emissions
in 1966
106 tons


0.05
0.02
0.02
0.09



0.24
0.87
2.85
3.96


0.08
0.17
0.03
0.28


0.06
0.05
0.02
0.13
4.46
Percent
of total


1.1
0.4
0.4
1.9



5.4
19.5
64.1
89.0


1.8
3.8
0.7
6.3


1.3
1.1
0.4
2.8
100.0
  Basis for estimates:
  1. Emission factors Table 5-1.
  2. Energy consumption Table 3-2.
  3. Fuel properties
       Anthracite coal - 13,000 Btu/lb., 10 percent ash.
       Bituminous coal  12,000 Btu/lb., 10 percent ash.
       Distillate oil  140, 000 Btu/gal.
       Residual oil - 150,000 Btu/gal.
       Natural gas - 1000 Btu/ft3.

  Reference 15.
 "Excludes naphtha, kerosene, range oil, and LP gas.
                                          3-14

-------
Burners, combustion chambers,  heat transfer characteristics, draft systems,





and combustion controls of industrial heating units may vary widely.  The





practices of those responsible for selecting, installing, operating,  and





maintaining stationary combustion sources can also have significant effects




on particulate emissions.





      Because the rate of particulate emissions varies widely from unit




to unit,  the amount  of particulate emissions  that may be expected from a





given source has not been established with accuracy.  Data that are useful




for estimating emissions from groups of units have been compiled and are





reported as emission factors in Section  5.




3.3.2  Control Techniques




      Techniques that will control particulate air pollution from stationary





combustion sources may be broadly categorized  as follows:




        1.   Gas cleaning




        2.  Energy substitution





        3.  Energy conservation





        4.  Good practice





        5.  Source shutdown




      Although source relocation and dispersion  techniques will not reduce





particulate emissions from  stationary combustion sources,  they may effect




some measure of improvement in ambient air quality in selected areas.
                                  3-15

-------
 3.3.2.1  Gas Cleaning—Gas cleaning is the most common technique used




 for control of particulate  emissions from stationary combustion sources.




 As shown in Table 3-4, 20 million tons of an estimated total of 24.5 million




 tons of particulate matter from stationary combustion was recovered by




 gas cleaning devices in 1966.




      A wide  variety of gas cleaning equipment is available for control of




 particulate emissions from stationary combustion sources.   The cost of




 gas cleaning equipment is usually greater for devices of high efficiency;




 however, the performance of competitively priced gas cleaning equipment




 may differ considerably.  Table 3-5 shows  the optimum performance that




 may be expected from the various types of gas cleaning equipment that




 might be  used for removing particulate matter from flue gases of stationary




 combustion sources.  The efficiencies shown in Table 3-5 are estimates




 based on  an analysis of information on particle size  distribution, equipment




 efficiency, reports of experience from the field,  and actual source tests.




      More detailed information on the special application of these  devices




 to stationary combustion sources is given in Section  4,  Gas Cleaning Devices.




      Settling chambers - The settling chamber is a  low efficiency,  low




 cost, low pressure drop gas cleaning device.  Settling chambers are applied




 primarily to natural-draft, stoker-fired,  coal-burning units. Collection




efficiencies for  this application are estimated to be 50 to 60 percent. Only




a few oil-fired,  gas-fired,  and other coal-fired combustion sources are




equipped with  settling  chambers.






                                  3-16

-------
                           Table 3-5.  OPTIMUM EXPECTED PERFORMANCE OF VARIOUS TYPES OF

                              GAS CLEANING SYSTEMS FOR STATIONARY COMBUSTION SOURCES

Sources
Coal-fired
Spreader, chain grate, and
vibrating stokers
Other stokers
Cyclone furnaces
Other pulverized coal units
Oil-fired
Removal of uncontrolled particulate emissions, %
Systems in operation

Settling
chambers

50a
60"
ioa
20"
5b

Large
diameter
cyclones

60a
65"
15a
30a
iob

Small
diameter
cyclones

85a
90a
70a
a
80
30b

Electrostatic
precipitators

99.5°
99.5°
99.5°
99. 5C
75.0

Stack
sprays

GO6
806
f
f
f
Systems under development
8-in.
pressure
drop
scrubbers

99+g
99+g
f
99+g
f

Fabric
filters

99. 5h
99.5
f
h
99.5
f
CO
I
           Estimate based on references 17 and 18.
'Reference 19.
           Efficiency estimated - not commonly used.
                                                                             f.
 Insufficient data for estimate.
           'Estimate based on reference 15.
or
 Estimate based on reference 20.
           Estimate based on private reports of field experience.
 Estimate based on reference 21.

-------
       Large-diameter cyclones—Large-diameter cyclones are more




 efficient than settling chambers, but have higher pressure drops.  Effi-




 ciencies of large-diameter cyclones range from a high of 65 percent for some




 types of stoker-fired coal-burning units to a low  of 15 percent for coal-fired




 cyclone furnaces.




       Multiple small-diameter cyclones - Multiple small-diameter cyclones




 are used on mechanical draft combustion units either as precleaners for




 electrostatic precipitators or as final cleaners.  Efficiencies of well




 designed units range from 90 percent for some stoker-fired units to




 70 percent for coal-fired cyclone furnaces.




       Wet scrubbers - Sprays are used to a limited extent  in the stacks of




 coal-fired units to control particulate emissions during soot blowing.  The




 problems that limit  the use of wet scrubbers include high corrosion rates,




 high or fluctuating pressure drops,  adverse effects on stack gas dispersion,




 and waste disposal.   Technically, these problems can be overcome, but




 the feasibility of wet scrubber systems for stationary combustion source




 particle control has not yet been demonstrated.




      Wet scrubbers have  been used experimentally for the removal of




 sulfur oxides from the flue gases of coal-fired sources.  These scrubbers




 also removed combustion particulate matter with efficiencies of up to



             20
99.5 percent.     A recently completed full-scale system connected to a




pulverized coal-fired power plant boiler in  Missouri is similar to the
                                 3-18

-------
experimental installation.  Evaluation of the economic feasibility and



effectiveness of this system must be deferred until after shakedown runs



are complete.



      Electrostatic precipitators  - Electrostatic precipitators are the most



common gas cleaning devices used to remove  particulates from the flue



gases of large stationary combustion sources.  Such devices are capable



of collection efficiencies of at least 99.5 percent, and it is quite possible



that even more efficient systems can be provided if necessary.    Electro-



static precipitator systems are usually applied to large pulverized coal-



fired power boilers.  The cost of these systems has limited their use on



smaller combustion sources.



      Electrostatic precipitators are highly sensitive, and if not properly



designed,  small changes in the properties of the particles and the gas


                                                         22
stream can significantly affect their collection efficiencies.    Allowance



should be made for possible changes in fuels,  in fuel composition,  and in



gas temperature when consideration is given to the use of electrostatic



precipitators.  It has been established that low-sulfur fuels adversely



affect the particulate collection efficiency of electrostatic  precipitators


                             23
designed for high-sulfur fuels.



      Fabric  Filters  - Fabric filters are not commonly applied to  stationary



combustion sources.   Factors which limit the use of these devices are



uncertainty of performance and reliability, and availability of other



effective gas cleaning devices.
                                  3-19

-------
 3.3.2.2 Source Relocation  - Source relocation will not eliminate participate




 emissions from stationary combustion sources, but it will eliminate emissions




 from the original location of the source.  Due consideration should be given,




 however,  to possible air  pollution effects on other areas.




       Source relocation is ordinarily considered when new stationary com-




 bustion sources are to be built, particularly when a new plant is to be built




 to replace one that has  created  air pollution problems.




 3.3.2.3 Energy Substitution  -  The emission characteristics of fuels used




 in stationary combustion processes may differ widely.  Therefore, some




 measure of control may be effected by substituting among the various fuels.




 Control of emissions may also be effected through the  substitution of non-




 combustion energy for combustion energy.   The substitutions considered




 in this  section are limited to the more  commonly used  types of energy —




 hydraulic, electric, and nuclear—and fossil fuels.  Fuels that might




 be considered as substitutes are LPGgas, coke oven gas, blast furnace




 gas,  pipeline gas from coal, kerosene, range oil,  coke oven tar,  liquified




 coal, and low-ash coal. Although chemical,  solar,  and geothermal energies




 have  long-range potential  as substitutes that would reduce particulate




 emissions, these  sources  are not sufficiently developed to warrant current




 consideration.




      Information on cost  and availability  of energy substitution is given in




Control Techniques for Sulfur Oxide Air Pollutants,  U.  S. Department of




Health,  Education, and Welfare, 1969.






                                 3-20

-------
     Power generation by stationary combustion is a principal source of

participate emissions in the United States  (see Table 3-4).  Energy sources

used to generate power are water,  nuclear fuel, gas,  oil, and coal as shown

in Table 3-6.  Particulate  emissions from gas- and oil-fired power plants

total less than 0. 1 pound per million Btu input.  Coal-fired power plants

equipped with gas cleaning devices  that are 99.5 percent efficient compare

favorably with oil- and gas-fired plants.  Hydroelectric and nuclear power

plants are particulate pollution free.

     Substitutions commonly available for commercial,  industrial,  and

domestic stationary combustion sources are electric power,  coal, gas,

and oil. Fossil fuels may  be burned directly at the site where energy is

used, or the fuels may be used to produce electrical energy for transmission

to the site of use.  Tables  3-7 and 3-8 compare the effectiveness of various

substitution alternatives on the basis of particulate emissions per unit of

useful heat.

     When comparing substitution  alternatives, allowance should be  made

for differences in heat requirements between seemingly identical applications.

The differences that might be found between  fossil fuel and electrical heat
                                                                  f
requirements for space heating may be used as an example.  Because

electrically heated buildings are  often insulated better than fossil fuel

heated buildings,  heat requirements may not be the  same.  It is recom-

mended that individual studies be made to  determine these differences by
                                 3-21

-------
      Table 3-6.  COMPARISON OF ENERGY SUBSTITUTION
     ALTERNATIVES FOR ELECTRIC POWER GENERATION
   Energy substitution
       alternative
Particulate emissions,
  lb/106 Btu inputa
Hydroelectric

Nuclear

Gas (no control)

Oil (no control)

Coal - 90 percent fly ash
   removal

Coal - 99. 5 percent fly
   ash removal
         0

         0

         0.02

         0.07

         0.67


         0.03
aBased on emission factors from Table 5-1 and the following gross
 heating values:
       Coal - 12, 000 Btu/lb at 10 percent ash.
       Oil - 150,000 Btu/gal.
       Gas - 1,000 Btu/ft3.
                            3-22

-------
 Table 3-7.  COMPARISON OF ENERGY SUBSTITUTION ALTERNATIVES FOR
           STATIONARY COMBUSTION SOURCES OF LESS THAN
                         10 MILLION Btu/hr INPUT
         Energy substitution alternative
Particulate emission
              o
     equivalent
lb/106 Btu useful heat
Electric heat (hydroelectric or nuclear power
   plant originated)
Electric heat (gas-fired power plant originated)
Electric heat (oil-fired power plant originated)
Electric heat (coal-fired power plant originated
   90% fly ash removal)
Electric heat (coal-fired power plant originated
   99. 5% fly ash removal)
Gas-fired furnace on site (no control)
Oil-fired furnace on site (no control)
Coal-fired furnace on site (no control)
         0

         0.05
         0.22
         2.00

         0.10

         0.03
         0.08
         1.11
 Based on:
 1. Emission factors - Table 5-1.
 2. Fuel properties.
       Heating value, coal - 12,000 Btu/lb at 10% ash
       Heating value, oil - 140,000 Btu/gal
       Heating value, gas - 1,000 Btu/ft3
 3. Estimated thermal efficiency of on-site heating systems.
       Electric - 100%
       Coal, gas,  oil - 75%
 4. National average efficiency of power generation   -(Btu equivalent of
    generated power per unit of heat input).
       Coal - 33.42%
       Gas - 31.42%
       Oil - 30.77%
                                    3-23
   331-716 O - 69 - b

-------
   Table 3-8.  COMPARISON OF ENERGY SUBSTITUTION ALTERNATIVES
               FOR STATIONARY COMBUSTION SOURCES OF
                 10  MILLION TO 100 MILLION Btu/hr INPUT
         Energy substitution alternative
 Particulate emission
     equivalent,a
lbs/106 Btu useful heat
Electric heat (hydroelectric or nuclear power
   plant originated)
Electric heat (gas-fired power plant originated)
Electric heat (oil-fired power plant originated)
Electric heat (coal-fired power plant originated -
   90% fly ash removal)
Electric heat (coal-fired power plant originated -
   99. 5% fly ash removal)
Gas-fired furnace on site (no control)
Distillate oil-fired furnace on site (no  control)
Residual oil-fired furnace on site (no control)
Stoker-fired furnace on site (no control)
Stoker-fired furnace on site (90% fly ash removal)
Stoker-fired furnace on site (99. 5% fly ash removal)
        0

        0.05
        0.22
        2.00

        0.10

        0.03
        0.14
        0.20
        2.78
        0.28
        0.01
 Based on:
 1.  Emission factors - Table 5-1.
 2.  Fuel properties.
       Heating value, coal - 12,000 Btu/lb at 10% ash
       Heating value, distillate oil - 140,000 Btu/gal
       Heating value, residual oil - 150,000 Btu/gal
       Heating value, gas - 1,000 Btu/ft3
 3.  Estimated thermal efficiency of on-site heating systems.
       Electric - 100%
       Coal,  gas,  oil - 75%
 4.  National average efficiency of power generation24-(Btu equivalent
       generated power per unit of heat input).
       Coal - 33.42%
       Gas - 31.42%
       Oil - 30.77%
                                    3-24

-------
consulting with representatives of the fossil fuel, electrical, and building indus-



tries and by using information such as that published by the American Society


                                                        25
of Heating, Refrigerating, and Air Conditioning Engineers.



     To make comparisons for a given area, it is recommended that Tables



3-6, 3-7, and 3-8 be revised to reflect local conditions before substitution



alternatives are compared.



     Energy substitution can be an effective and useful technique for control



of particulate emissions from stationary combustion sources.  This technique



has special value for control of many small sources when the cost of effective



gas cleaning equipment would be excessive.  When use of this technique is con-



sidered, attention should also be  given to the effect of substitution on national



security, foreign relations, industry,  labor, commerce,  conservation, and the



public.



3.3.2.4  Energy Conservation



     Energy conservation limits particulate emissions from stationary combus-



tion sources by reducing fuel consumption.  Energy conservation that is econom-



ical should be encouraged per se. Energy conservation that is not economical



from the standpoint of  individual process costs may actually be economical



when compared with other techniques available for air pollution control.



     Improvement  of power generation efficiency through use of high-tempera-



ture, high-pressure steam electric power generating processes reduces fuel



consumption.  Table 3-9 shows average national trends in efficiency improvement
                                    3-25

-------
Table 3-9. TRENDS IN EFFICIENCY OF COAL, OIL,
       AND GAS USE IN UNITED STATES24
Year


1956
1963
1964
1965
Average Btu required to generate
1 (net) kw-hr
Coal
11,257
10,258
10,241
10,218
Oil
12,828
11,278
11,138
11,097
Gas
12,245
11,066
10,962
10,868
                   3-26

-------
for steam electric power generating plants.  Large,  modern power plants



with efficiencies near 8, 000 Btu per kw-hr reduce energy consumption sub-



stantially to below the national average of 10, 000 to 11,000  Btu per kw-hr, and



processes now under development, such as the magnetohydrodynamic, electro-


                                                                        26—28
gasdynamic, and fuel cell, have promise of improving efficiency even more.



3.3.2.5  Good Practice -  Equipment must be properly applied, installed,  oper-



ated,  and maintained to minimize emissions of participate matter.  Guidelines



for good practice are published by the fuel industry,  equipment manufacturers,



good practice are published by the fuel industry, equipment  manufacturers,



engineering associations,  and government agencies.   Although improper prac-



tices  are frequently the cause of visible particulate emissions, insufficient



information exists to permit numerical evaluation of the effect of good practice



on emission levels.  Some sources of information on good practice are:



         L  Air Pollution Control Association



         2.  American Boiler Manufacturers Association



         3.  American Gas Association



         4.  American Petroleum Institute



         5.  American Society of Heating, Refrigerating,  and Air



                Conditioning Engineers



         6.  American Society of Mechanical Engineers



         7.  Edison  Electrical Institute



         8.  Industrial Gas Cleaning Institute
                                     3-27

-------
         9.  The Institute of Boiler and Radiator Manufacturers




        10.  Mechanical Contractors Association of America




        11.  National Academy of Sciences - National Research  Council




        V2.  National Air Pollution Control Administration




        l;>.  National Coal Association




        11.  National Fire Protection Association




        15.  National Oil Fuel Institute




        16.  National Warm Air Heating and Air Conditioning Association




        17.  U. S.  Bureau of Mines




        18.  Various State and local air pollution control agencies




      Proper design and application— Combustion systems must be properly




selected to meet load requirements.   Components of the system should be com-




patible to avoid excessive emission of particulate matter.




      Stationary combustion units are designed to operate within a specific




range of load conditions.  If such a unit is operated outside design limits,




excessive discharge of particulate matter is possible.  It is therefore  neces-




sary that the load be accurately estimated before stationary combustion systems




are selected and applied. The total design capacity of the system should be




sufficient to carry the maximum load, and consideration should  be given to




future increases in load  requirements.  The minimum design capacity of one




unit of the combustion system should be  sufficient to carry the minimum load
                                     3-28

-------
requirements of the facility, and the total combustion system should be selected




to carry, within design limits, any load between maximum and minimum.




     Consideration must also be given to load characteristics when selecting




a combustion system.  The  combustion system should be able to supply energy




at a change in rate consistent with the demands of the facility without deviation




from design limits.




     Each component of the combustion system, such as the fuel handling sys-




tem, the draft system, the fuel burning system,  the flues and stacks, the ash




handling system, and the controls related to these systems, must be properly




selected and integrated to handle the load and the fuel to be burned.




     Proper installation  — Properly installed equipment will promote clean,




efficient operation of stationary combustion sources.  Comprehensive instal-




lation instructions and plans are  a prerequisite for proper installation.  The




designer of the  entire combustion system and the manufacturers of the system's




components are responsible for providing such plans and instructions.  Equip-




ment should be  installed only by qualified personnel,  and all work should be




inspected for quality.




     Proper operation and  maintenance — Proper operation and maintenance




of stationary combustion equipment will promote the reduction of particulate air




pollution.  Stationary combustion units  should be operated within their design




limits at all times and according to the recommendations of either the manu-




facturer or another authority on proper operational practices.  Combustion
                                    3-29

-------
units and system components should be kept in good repair to conform with




design specifications.  Sensitive monitoring systems  are helpful in indicating




needed combustion system repair.




      Proper operation also involves the reduction of emissions from fuel- and




ash-handling systems.  Storage pile fires  and fuel- and ash-handling operations




can become significant sources of particulate air pollution if good practice is




disregarded.




3.3.2.6  Source Shutdown -  Source  shutdown is a drastic control technique,




but it should not be completely disregarded.  Source shutdown is useful for




control of particulate emissions when air pollution levels threaten the public




health in emergency episode situations and for control of emissions when law-




ful orders to abate are ignored.




3.3.2.7  Dispersion - Dispersion is discussed in detail in Section 6 of the




report Control Techniques for  Sulfur Oxide Air Pollutants.
                                     3-30

-------
3.4 INDUSTRIAL PROCESSES




3.4.1 Introduction




     Approximately 6 million tons of dust, fume,  and mist,  roughly 50 per-




cent of the total particulate matter emitted in the United States, were dis-




charged from industrial processes and industrial fuels fired in 1966. This




quantity would be considerably greater if high-efficiency collectors were not




used by many industries.   However, the total would be drastically lower if




existing control technology were employed to the fullest.




     Some industries inherently create more particulate air pollution than




others,  and for such industries  one or two specific operations dominate the




emission picture.  In a given industry, particulate releases to  the atmosphere




are generally proportional to production rates.   Often these discharges can be




reduced dramatically through process changes or by the use of collection devices.




     .Table 3-10 lists many of the  industries that release large quantities of




particulate matter. As discharged, these particles include dry dusts,  com-




bustible oil and tar mists,  inorganic acid mists, and combinations of these




and other pollutants.  The  same processes frequently release gaseous pollu-




tants, some of which  may be more objectionable than the particulate matter.




Although this  discussion is limited to particulate matter, some remedial




measures also affect  sulfur oxides, odors,  or other gaseous  contaminants.




     The industries which are cited in the following pages  commonly use




several types of fired heaters and boilers.  Particulate emissions associated
                                   3-31

-------
                                   Table 3-10.  INDUSTRIAL PROCESS SUMMARY
Industry or process
Iron and steel mills

Gray iron foundries



Non-ferrous smelters


Petroleum refineries
and asphalt blowing


Portland cement


Kraft pulp mills

Asphalt batch plants

Acid manufacture
Phosphoric
Sulfuric
Annual
capacity,
1000 tons
(except
as noted)
149.000

17, 350



2,721


6
3,650 x 10
bbls.a


500 x 106
bbls.b

300,000

-


2,300
20,513
Number
of
plants
184

1,400



2, 500


318



ISO


40

-


66
223
Particulatc emissions
Nature
Iron oxide dust,
smoke
Iron oxide dust,
smoke, oil and
grease, metal
fumes
Smoke, metal
fumes, oil and
grease
Catalyst dust,
ash, sulfuric
acid mist,
liquid aerosols
Alkali and
product dusts

Chemical dusts,
mists
Aggregate dusts


Acid mist, dust
Acid mist
Principal sources
Blast furnaces, steel making
furnaces, sintering machines
Cupolas, shakeout systems,
core making


Smelting and melting furnaces


Catalyst regenerator, sludge
incineration, air blowing
of asphalt

Kilns, coolers, dryers,
material handling
systems
Chemical reclaiming furnaces,
smelt tanks lime kilns
Dryers, material handling
systems
Thermal processes - phosphate
rock acidulating, grinding and
handling system
Other
emissions
CO, combustion
products
Odors, combustion
products, hydro-
carbons from con-
taminated scrap
SOX combustion
products

Hydrocarbons, SOX,
Ho.S, odors


Combustion
products

Odors, SOX

Odors, combustion
products

HF, SOX, odors

Reference
29, 30

31, 32



31, 33


31, 34




31, 35

36




37

CO
I
to

-------
                                    Table 3-10  (continued).   INDUSTRIAL PROCESS SUMMARY
Industry or process
Coke manufacturing
Glass furnaces and
glass fiber manufacture
Coffee processing
Cotton ginning
Carbon black
Soap and detergent
manufacturing
Gypsum processing
Coal cleaning
Annual
capacity,
1000 tons
(except
as noted)
54,278


-
1,496
"
-
-
Number
of
plants
60


-
37
"
-
-
Particulate emissions
Nature
Coal and coke
dusts, coal tars
Sulfuric acid mist,
raw material dusts,
alkaline oxides,
resin aerosols
Chaff, oil aerosols,
ash dehydrated
coffee dusts
Cotton fiber,
dust and smoke
Carbon black
Detergent dusts
Product dusts
Coal dusts
Principal sources
Charging and discharging oven
cells, quenching, material
handling
Raw material handling, glass
furnaces, glass fiber forming
and curing
Roasters, spray dryers,
waste heat boilers, coolers,
stoners, conveying equipment,
chaff burning
Gins, trash incineration
Carbon black generators
Spray dryers, product and
raw material handling
systems
Calciners, dryers, grinding
and material handling systems
Washed coal dryers
Other
emissions
Phenols, H2S
Combustion
products

Defoliants and
insecticides

Combustion
products,
odors
Combustion
products
Combustion
products
Reference
29


38
39



CO
I
CO
CO
          aBarrel = 42 gallons.

          bBarrel = 376 pounds.

-------
with this equipment, for the most part,  are functions of the fuel burned.  Com-



bustion principles developed in Section 3.3 generally apply, and the combustion



processes are not cited unless specific problems are associated with them.



3.4.2  Iron and Steel Mills



      The major  sources of participate matter in iron and steel mills are blast



furnaces, steel-making furnaces, and sintering plants.  Coke ovens, which are



operated as adjuncts to steel mills,  are discussed in Section 3.4.9.



3.4.2.1  Sintering plants — Major sources of dust in sintering plants are the



combustion gases drawn through the bed and the  exhaust  gases from sinter


                                           40
grinding, screening,  and cooling operations.     Exhaust temperatures of the



combustion gases range from 160° to 390° F.  One 6000-ton-per-day plant oper-



ates at 350° F.  About 50 percent by weight of the particles discharged from a


                                              29
sintering machine are larger than 100 microns.    Because dust generated in



the sintering operation can be returned to the process, most plants are equipped



with cyclones, which, because of the large particle size,  usually operate at



over 90 percent efficiency by weight.  However,  cyclone exit loadings range from



0.2 to 0.6 grains per cubic foot.  High-efficiency baghouses and electrostatic



precipitators, therefore, offer promise of much better collection.  However,



few have been applied to sintering machines.



3.4.2.2  Blastfurnaces  — Iron ore, coke, and limestone are charged into a



blast furnace to make iron.   Under normal conditions the untreated gases from



a blast furnace contain from 7 to 30 grains of dust per standard cubic foot(scf)
                                     3-34

-------
      41
of gas.    Most of the particles are larger than 50 microns in diameter.  The



dust contains about 30 percent iron, 15 percent carbon, 10 percent silicon



dioxide, and small amounts of aluminum oxide,  manganese oxide, calcium



oxide, and other materials.  Blast furnace gas cleaning systems normally re-



duce particulate loading to less than 0.01 grain per standard cubic feet to pre-



vent fouling of the stoves where the gas is burned.  These systems  are com-



posed of settling chambers, low efficiency wet scrubbers, and high efficiency



wet scrubbers or electrostatic precipitators connected in series.



3.4.2.3  Steel Furnaces — The three most important types  of steel-making



furnaces are open  hearth furnaces, basic oxygen furnaces, and electric fur-



naces.  Relative usage as a percent of total production of each of these furnaces



in 1958, 1966, and 1967 is shown in Table 3-11.



      Average emission rate from a hot-metal open-hearth furnace is about



0.4 grain per scf for a conventional furnace and 1. 0 for an oxygen-lanced fur-


     43 44
nace.   '    Up to  90 percent of the particles are iron oxide, predominantly



FE 0    A composite of particles collected throughout a heat show that about
   ^ o


50 percent were less than 5 microns in size.  Control of iron oxide requires



high-efficiency collection equipment such as venturi scrubbers and electro-



static precipitators.  Because of the cost involved and the growing obsolescence



of open hearth furnaces, industry has been reluctant to invest money in the


                           44
required control equipment.    Often these furnaces have been replaced by



controlled basic oxygen furnaces and electric  furnaces.
                                    3-35

-------
Table 3-11. STEEL PRODUCTION, PERCENTAGE BY PROCESS42

Furnace type
Open hearth
Basic oxygen
Electric
Percent of total
1958
90.7
1.5
7.8
1966
72.1
17.4
10.5
1967
55.6
32.6
11.8
                           3-36

-------
      More emissions are created by the basic oxygen furnace than by the open-



hearth furnace.  The principal portion of the increase in emissions is  caused



from furnace oxygen blowing.  Emissions of about 5 grains per scf are reported


          45
as typical.     Particle size is small; 85 percent are  smaller than one  micron


            46
in diameter.    All basic oxygen furnaces in the United  States are equipped



with high-efficiency electrostatic precipitators or venturi scrubbers.



      Electric furnaces are usually used for alloy production, and because of



their flexibility, are becoming popular for most  metal melting operations.



Emissions from electric furnaces often reach particulate matter  concentrations



of 3 grains per scf.  Only 40 to 50 percent of the dust is iron oxide,  an amount



considerably smaller than that emitted by other furnaces.  The particles are



difficult to collect because of a strong tendency to adhere to fabric surfaces, a



high angle of repose,  and a high electrical resistivity,  and because they are



difficult to wet.  Approximately 70 percent by weight of  the particles are



smaller than five microns and 95 percent by number  are smaller than  0. 5


                   47
micron in diameter.    Nevertheless, except for difficulties inherent in the



charging operation, over 95 percent effective collection can be achieved with ap-



propriate hooding and high-efficiency collection equipment.  Baghouses are



especially suited for such collection.


3.4.3 Gray Iron Foundries



      Melting cupolas are the principal  sources of particulate matter at iron



foundries.  Casting shake-out systems,  sand handling systems, grinding and



deburring operations, and coke-baking ovens are other  sources.
                                  3-37

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      Cupola exhaust gases are hot and voluminous,  and contain significant




portions of combustible matter and inorganic ash.  The most effective control




system incorporates an afterburner to eliminate combustibles and a fabric




filter to collect the inorganic dust and fume.  Coolers must be used ahead of




the baghouse to protect fabric filters from the heat of the exhaust gas.  Most




such systems use glass fabrics,  but some synthetic cloths have been found to




be satisfactory.  Even though baghouse control systems provide excellent par-




ticle collection, they have not met with wide acceptance,  principally because of



     48
cost.    Dry centrifugal collectors and scrubbers with various efficiencies are




used in many instances.  High-efficiency scrubbers are reported to provide




about the same performance as fabric filters, but visible emissions are more




pronounced.




      Casting shake-out and sand cleaning are dusty operations that are nor-




mally well controlled.   The gas stream baghouses are commonly used; medium-




efficiency scrubbers and dry centrifugal collectors are also used.




      Core ovens create relatively smaller quantities of participate matter,




much of which is in the form of finely divided liquid aerosols.  Emissions from




core ovens are similar to those discharged from paint baking and resin curing




operations with odors being more objectionable than the particulates.  A pro-




perly designed afterburner will eliminate most of the particulates and malodors.
                                   3-38

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3.4.4  Petroleum Refineries

      Major sources of particulate matter at refineries are catalyst regen-

erators,  airblown asphalt stills, and sludge burners.   Lesser sources include

fired heaters, boilers,  and emergency flares.

      In modern fluidized catalytic crackers,  fine catalysts are circulated

through the reactor and regenerator vessels.   From 100, 000 to 150, 000 cfm

of hot, dusty gases  are vented from a large regenerator.  Dust collectors as

well as carbon monoxide waste heat boilers are often used to control air pol-

lution. It is  common practice to install  a carbon monoxide boiler to use the

fuel value of the clean gas stream exiting from the particulate collector.

      In typical installations 2-stage or  3-stage cyclones are located in the

regenerator vessels of FCC units for catalyst recovery and reutilization.  In

some cases external cyclones are installed to reduce the particulate content of

the flue gases leaving the regenerators of these units.   Catalyst dust losses

from the regenerator equipped with internal cyclones and  in some cases sup-

plemented by external cyclone equipment can range in the order of 100 to 350

pounds per hour depending on the size, age, and basis  of design of the unit.

      Electrostatic  precipitators may also be used to collect the fine particles

from the regenerator exit gases and  some refiners have reported catalyst dust

losses as low as 40-60 pounds per hour  although typical current installations

have higher emission rates.   The percent efficiency of the precipitators is a

function of the inlet dust loading from the regenerator and the desired

emission rate to the atmosphere.

                                    3-39
 331-716 O - 69 - 7

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      Airblowing of asphalts generates oil and tar mists and malodorous gaseous




pollutants.  It is common practice to scrub the oils and tars from the hot (300




to 400° F) gas stream.  Sea water is sometimes used for this purpose.  In any




case,  separators are necessary to reclaim the oil and prevent contamination




of effluent water.  Afterburners are used to incinerate  the uncondensed gases




and vapors, which can constitute an odor nuisance.




      At petroleum refineries,  the open burning or incineration of sludges can




be a major source of participate matter and sulfur dioxide emissions.  These




sludges are a mixture of heavy petroleum residues and such inorganic materials




as clay,  sand,  and acids.  Because the materials cannot be separated readily,




sludge is usually atomized in much the same way as heavy fuel oil. The or-




ganic fraction can be burned effectively in such an incinerator,  but any inorganic >




matter is entrained  in exhaust gases.   High-efficiency precipitators, baghouses,




and high-energy scrubbers are among the stack cleaning devices that are avail-




able to collect the fine dusts; the final choice of control unit would be based




upon the nature of the sludge.  Sulfur dioxide collection would not be effected.




However, if there is an accessible sulfuric acid plant,  sludge may be condi-




ioned and used as part of the acid plant's feed material. Very low grade




sludges may be dumped at sea.  It must be emphasized that incineration alone




is not the solution for the disposal of all forms of refinery waste sludges.




Solvent extraction is another method for recovering the organic fraction and




the  separated "clean" solids are acceptable to normal landfill sites.
                                    3-40

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3.4.5  Portland Cement


      Both mining of raw materials and manufacture of cement create dust.


Dust is generated at the blasthole drilling operation at the quarry,  during


blasting at the rock face,  and during loading of trucks.  At primary and sec-


ondary crushing plants, in the grinding mills,  at blending and transfer points,


and in the final bagfilling and bulk truck or  railroad car loading operations,


where the particulate-laden air is at ambient temperatures, bag filters are

                                 49
usually the best means of control.


      Rotary dryers used in  dry process  cement plants may be a major source


of dust generation and require collecting  systems designed for higher temp-


eratures. Dust concentrations of 5 to 10 grains per scf entering the collector


are normal.  Baghouses or combinations of multiple cyclones and baghouses


are frequently used.  Newer  dry process cement plants  incorporate the drying


operation into the raw grinding circuit.  In  such a "dry-in-the-mill" combination


drying and grinding circuit dusts are normally vented to a baghouse.


      The largest sources  of emissions at cement plants are direct-fired kilns


for burning Portland cement clinker.  Exit  gas participate loadings are usually


5 to 10 grains per scf for wet kilns and 10 to 20 grains per scf for dry-process


kilns.  Exhaust gases from wet-process kilns  contain considerably more  mois-


ture than gases from dry process kilns.  The volume of the hot (500 to 600° F)


kiln gases may exceed 250, 000 cubic feet per minute.  Over 85 percent by


weight of gasborne particles  are  smaller than  20 microns in diameter.  The
                                   3-41

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most prevalent chemical constituents are calcium oxide (CaO), about 41 per-



cent; silicon dioxide (SiO ),  19 percent; and aluminum and iron oxides (Al 0 +
                        £                                               Z 0

                                                             50
Fe O ), 9 percent.  The balance would be predominately CO .
   Li O

      Electrostatic precipitators are widely used to control  particulate emissions



from kilns.  Fabric filters of siliconized  glass bags have been installed on both



wet and dry process kilns.  Each control  device has been successful when ade-



quately designed and properly  maintained.



3.4.6 Kraft Pulp Mills



      The major source of particulate emissions in kraft pulping is the recovery



furnace in which spent cooking liquors are burned to remove the organic mate-



rials dissolved from the wood  to recover the inorganic cooking chemicals. So-



dium sulfate is the major chemical released as particulate matter. Small amounts



of sodium carbonate, salt, and silica,  and traces of lime, iron oxide,  alumina,



and potash also  are emitted.  Because 95  to 98 percent of the total alkali charged



to the digester finds its way to the  spent liquor, it is economically imperative



that it be  recovered.



      Electrostatic precipitators of about  90 percent efficiency are used to



recover particles emitted from recovery furnaces.  New installations call for



design efficiencies of about 97. 5 percent,  and at least one such unit has a de-



sign efficiency of over 99. 9 percent.



      Other sources of particulate  matter are smelt tanks and lime kilns.



Stack dust from  lime kilns can be collected in 85 to 90 percent efficient venturi
                                   3-42

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scrubbers.  Water sprays of 20 to 30 percent efficiency and mesh demisters of



80 to 90 percent efficiency are usually used on smelt tanks.



3.4.7 Asphalt Batching Plants


      Hot  asphalt batching plants  are potential sources of heavy dust emissions.



      Asphalt batching involves the mixing of hot, dry sand, aggregate, and


mineral dust with hot asphalt.  Although conveyors and elevators generate some


dust,  the major  source is the direct-fired dryer used to dry and heat aggregates.


Exit gases range from 250°  to  350- at volume rates of 15, 000 to 60, 000 standard



cubic feet per minute (scfm).   Most dryers employ simple cyclone separators



which collect 70 to 90 percent of the dust entrained in the exit gases.  Never-


theless, the remaining dust in the gas stream usually totals more than 1000


pounds per hour and further dust  controls are needed in most areas.



      Centrifugal and baffled scrubbers have been used with success in many


areas to control the fine dust which escapes the primary cyclone.  High effi-



ciencies are reported—some exceed 99.0 percent—with losses from most


tested plants ranging from 20 to 40 pounds per hour.  It is common to vent

                                                           51
elevators  and major conveyor transfer points to the scrubber.



      As high temperature fabrics were  developed, fabric filters found greater


acceptance at asphalt batch plants.   Such filters have been used successfully



at asphalt batch  plants since 1950.  Recently, several were installed in Chicago,



Illinois, in an effort to obtain better dust control than had been afforded with



scrubbers.  They are reported to provide excellent collection of fine particles

-------
with little or no visible emissions from the baghouse.  Although fabric filters



frequently are more expensive than scrubbers, they collect dry "fines" which



may be useable in high-grade asphaltic concrete mixes.  In addition, they



obviate the need for holding ponds and preclude water problems.



3.4.8  Acid Manufacture



      Most of the particulate matter attributed to acid manufacture is created



in the production of sulfuric and phosphoric acids.  Manufacture of the other



two major industrial acids—nitric and hydrochloric—does not generate large



amounts  of acid mist.



3.4.8.1  Sulfuric Acid — Over 90 percent of the sulfuric acid in the United


                                             37
States is manufactured by the contact process.    In the process sulfur or



other sulfur bearing materials are burned to sulfur dioxide (SO ) and catalyt-
                                                            Zj


ically converted to sulfur trioxide (SO ).  Uncontrolled emissions  range from
                                    O


0. 05 to 0. 23 grain per scf of exit gas.  Concentrations depend to a large degree



on plant design and proper operation of the acid absorber.  Most modern plants



are  equipped with high-efficiency electrostatic precipitators or mesh eliminators



in which  99 percent of the acid mist is recovered.  Acid mists are usually



controlled to a far greater extent than gaseous SO  releases.
                                               Li


      The primary source of emissions in the chamber process is the final Gay



Lussac tower.  Combined sulfuric acid mist and spray in the exit gas ranges



from 0. 08 to 0. 46 grains per scf.
                                    3-44

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3.4.8.2  Phosphoric Acid — Two processes are used to manufacture phosphoric



acid.  High-purity acid for the food and detergent industries is produced by



burning elemental phosphorous.  The process is similar to the contact sulfuric



acid process.  The  oxidation product,  phosphorous pentoxide (P O  ), is hydrated
                                                             2 5


and absorbed in phosphoric  acid.  Mist is collected from exhaust gases with



electrostatic precipitators or high pressure drop mesh entrainment separators.



Acid mists escaping collection are extremely hygroscopic so that visible emis-



sions are pronounced unless high collection efficiencies are achieved.  High-



purity phosphorous  for this  process  is manufactured in electric furnaces, which



create gaseous fluorine compounds and solid particulates.



      The wet process is used to produce less pure phosphoric acid for the



fertilizer industry.   During the manufacturing process,  sulfuric acid is reacted



with phosphate rock.  Except for material handling and grinding operations  few



particulates are generated.   However, the  acidulation reaction liberates large



quantities of gaseous silicon tetrafluoride (SiF  ), and scrubbers are required.



3.4.9  Coke Manufacture



      Metallurgical coke is  the solid material remaining after distillation of



certain coals.  About 90 percent of the United States  coke output is  used for



production of blast furnace iron.



      Conventional coking is done  in long rows of slot-type coke ovens into



which coal is charged through holes  in the top of the ovens.  Coke oven gas  or



other suitable  fuel is burned in the flues surrounding the ovens, to furnish
                                  3-45

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heat for coking.  Flue temperature is about 2600° F and the coking period aver-




ages 17 to 18 hours. At the end of the coking period, incandescent coke is




pushed out of the furnace into quenching cars  and carried to a quenching station,




where it is cooled with water sprays.




     The beehive oven  is a simpler type of coking oven.  Distillation products




from this  oven are not recovered.  Its use has diminished with the development




of the by-product oven.  The process persists because of an economic advan-




tage during peak production periods.  Capital investment is lower and inoper-




ative periods can be tolerated.   About 1.5  percent of the total coal coked in




1967 was produced  in these ovens.  A very large part, i. e. , 25 to 30 percent




of the coal charged to these ovens is emitted to the atmosphere  as gases and




participate matter.  Ducting these emissions to an afterburner appears to be




a feasible method of control.




      Coal and coke dust emissions result  from coal car unloading,  coal stor-




age, crushing and screening, the coking process (where the largest releases




of particulate dust occur during larry car coal charging of the by-product oven




and pushing of the  product  coke to quench cars), quenching, and final dumping




from the quench car.





      Slot type coke ovens  currently being  designed include the following fea-




tures that speed operations and minimize leaks:




        1.  Better  designed and thinner-walled heating flues to  improve heat




        transfer and minimize cool spots  and undercoking.  This results in




        a cleaner pushing operation.





                                   3-46

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 2.  Improved refractories, with less spalling and cracking.  These




 refractory defects cause warping of metal furnace parts,  gas leaks




 into flue systems and chimneys, and voids which fill with undercoked




 coal and cause smoke during pushing.




 3.  Gas-tight, self-sealing oven doors,  that minimize manual sealing




 with clay.




 4.  Mechanical cleaners or self-sealers for doors and for top-charging




 hole covers.  A few grains of sand on a metal seat can cause appre-




 ciable leakage of hot gases.




 5.  Sealing sleeves for levelling bars.   Levelling bars are used to




 even out the oven charge to allow free passage of gas over the charge




 into the gas collector main.




 6.  Mechanical removal of top coal-charging lids and means to charge




 all three  holes of an  individual -oven rapidly and  simultaneously, with




 gas recovery mains in operation.




 7.  Steam jet aspirators in byproduct header ducts.




 8.  An intercell header to  normalize the cell pressure throughout the




 battery.




 9.  Charging  car volumetric sleeves and dust entrainment chutes.




10.  Wooden baffling to  separate particulate matter from quench tower




effluent gases.
                           3-47

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      A breakthrough in coke manufacturing technology is needed to improve



 operations.52  Improvements have been slow.     Installations exist that have



 employed supposedly superior charging and discharging equipment,  but satis-



 factory operations have not been achieved.  A joint research effort by several



 steel companies has been under way for 5 years to develop new coke manu-



 facturing technology, but potential commercial  applications  appear to be five


            53
 years away.



      Another form of coke, used in blast furnace refractories and in the manu-



 facturing of electrodes for large steel and aluminum reduction furnaces, is



 calcined petroleum coke.  Petroleum coke is a  refinery product,  but is seldom



 calcined by the refinery.  Calcining occurs in a rotary kiln at 1700° F removing



 absorbed water  and heavy oil and forming a marble-size  product.  Volatilized



 hydrocarbons are usually passed to a 2200° F combustion chamber before being



released to the atmosphere.  Subsequent conveyance  of the dusty product to



the storage requires hooding and enclosed ducting. The dust is abrasive and



 causes heavy wear on bucket elevators  and  other transfer equipment.  Control



of particulate matter can be accomplished during loading of the coke.  One



 system uses concentric tubing; the inner filling  tube carries the coke and the



outer tube exhausts entrained dust from the enclosed railroad car, truck or



 ship hold.  Baghouses are used to capture dust from  loading as well as dust



generated at other handling and transfer points.
                                   3-48

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3.4.10 Primary and Secondary Recovery of Copper,  Lead, Zinc, and Aluminum




      Primary smelting of lead and zinc involves converting the sulfide of the




ore to an oxide through roasting,  and subsequent reduction of the metal oxide to




its metallic state in a separate vessel.  Copper,  however, requires a preliminary




smelting step, during which the naturally occurring complex sulfide is reduced




to the cuprous sulfide, CuS  , by mixing the charge with limestone.  The cuprous
                         ^



sulfide is then converted to blister copper in a converter where the sulfur is




removed by oxidation.  Sulfur dioxide gas is released from these operations,




along with particulate matter which is largely sublimed oxides, dust,  and acid




mists.  When sulfur dioxide emissions exceed 3 percent of these furnace ex-




haust volumes,  a sulfuric acid manufacturing plant is feasible.  Pretreatment




of the smelter gases going to the  acid is required to remove particulate  matter.




If sulfur dioxide recovery is not practiced, fiberglass demisters or precipitators




are usually used to remove particulate material from smelter exhaust gases.




For a more detailed discussion of smelting, refer to the report Control  Tech-




niques for Sulfur Oxide Air Pollutants.



      Most materials fed to  secondary recovery furnaces are alloys of copper,




zinc, tin, or lead in the form of solid scrap and drosses.  Gases from the fur-




naces may contain as fumes oxides of the low boiling metals.  Particularly




bothersome are submicron lead and zinc fume.  Zinc oxide fume particle size




ranges from a high of 0. 5 micron to a low of 0. 03 micron.  Baghouses are




usually used to control these oxide fumes; where the  fumes are corrosive ,
                                   3-49

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electrostatic precipitators are used.  Soiled scrap metal melting may evolve



grease or oil fumes as smoke during the heatup phase.   Incineration of the




smoke with a control afterburner is necessary if the metal cannot be cleaned




before melting.



      Metallic  aluminum is produced by the electrolytic  reduction of alumina




(Al O0,  in a bath of fused cryolite by the Hall-Heroult process.  Cell operating
   L±  O


temperatures range from 1700°  to 1800° F.  The gases  generated in the cells are




corrosive and toxic, and consist of hydrogen fluoride and volatilized fluorides.




Some fine particulate matter is entrained in the exit gases.   Water scrubbers




have long been used for collection of both the particulates and corrosive gases.


                                                                          54
Some installations have used baghouses with alumina coated cloth filter bags.




      Secondary aluminum recovery operations produce  particulate matter from




the fluxes used, from  impurities in the scrap,  and from chlorination of the




molten aluminum.  Oily or greasy scrap gives off smoke.  When chlorine gas




is used to degas the melt or remove magnesium,  hydrogen chloride gas and




aluminum chloride fume are evolved.   The fume is difficult to collect because




of its small particle size and hygroscopic nature.  Water scrubbers are used



to collect the gaseous  contaminants.




3.4.11  Soap and Synthetic Detergent Manufacture




      Principal sources of particulate matter in the making of soap and syn-




thetic detergents are the spray drying of products and the handling of dry raw




materials.  The wet chemical processes used  to make soaps and detergents
                                   3-50

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are relatively innocuous from the particulate standpoint, although malodorous




gases and vapors are generated in some instances.




      Gases from the spray dryers, discharged at approximately 200° F, con-




tain large amounts of moisture. In addition, the product is sticky at these




temperatures so that dry collection in fabric filters or electrostatic precip-




itators is difficult.   Multiple cyclones may be employed as precleaners, but




scrubbers are used almost exclusively to collect fine dust.  Moderate pressure




venturi units or baffled scrubbers provide adequate  control in many instances.




These scrubbers usually use slurries rather than merely water and product is




recovered from the slurries.  Residual fine particles,  together with high mois-




ture levels, frequently impart marked opaqueness to the stack gases.  It is




sometimes possible  to avoid this problem by adding some  of the less stable




ingredients to the product after the spray drying operation.




      Fabric filters  are widely used in soap and detergent plants to control




dusts generated from the handling of products and raw  materials and from




packaging operations.




3.4.12  Glass Furnaces and Glass Fiber  Manufacture




      Reverberatory furnaces are used to produce nearly all glass products.




The furnaces and raw materials generate significant quantities of particulate




matter.




      Glass furnaces are usually heated with oil or natural gas, which is fired




directly over the melt.  Heat is reclaimed in checkerwork regenerators used
                                    3-51

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to preheat combustion air.  Raw materials are charged at one end of the fur-




nace and molten glass is pulled from the other end.  Cullet (scrap glass), lime-




stone, soda ash,  and sand are the main ingredients fed to the furnace melter




section.   Glass temperatures are as high as 2700° F in the furnace, but are




usually near 2200° F at the point of discharge.  Participate matter in exhaust




gases is traceable to two principal sources: (I) Fine raw materials that are




entrained in combustion gases before they are  melted; and (2) Materials from




the melt, such as sulfur trioxide created by sulfate decomposition and other




solids picked up by escaping carbon dioxide gases.  Sulfur trioxide and the




oxides of potassium, sodium,  and calcium are the main constituents of partic-




ulate emissions.  Losses from large furnaces  range from less than 10 pounds




per hour to as  high as 100 pounds per hour.  Most units  release  less than 40




pounds per  hour.  Particulate releases tend to be affected by feeder designs




and the makeup of raw materials.




      Operators control emissions through furnace design, electric heating,




and raw material control rather than with stack cleaning devices.   Control of




emissions with fiberglass filters is feasible, but the particulate  matter is




extremely difficult to handle.





      In the manufacture of glass fiber, the emissions from the forming pro-




cesses are  considered unacceptable both from  the standpoint of odor and visible




particles.  Although suitable control methods  are not at hand, it appears that




a combination of process changes and stack controls will be required to render
                                    3-52

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exit gases acceptable in many communities.  These methods are being developed



and prospects are good that satisfactory techniques will be found.  Afterburners



have been employed with success at curing ovens where volumes are low in



comparison to forming lines.



3.4.13  Carbon Black



      Because of the extremely fine size (0. 01 to 0. 4 micron) and fluffy nature



of carbon black particles, they are readily emitted from improper handling and



transferring operations and during separation of them from the process gases.



Emissions have been particularly heavy from channel black process plants.



The furnace black process (oil and gas) accounts for  94 percent of the total



production and technology is available to control emissions from these plants.



      Furnace temperature  is kept at about 2500° F and the black-laden gases



are cooled to 450° and 550° F before entering the dust collecting equipment.   The


                                                                   39
preferred system consists of an agglomerator followed by a baghouse.     Coated



fiberglass bags last about 12 months.  The over-all particulate collection ef-



ficiency of such a system is about 99 percent.  The combination of cyclone



and electrostatic precipitator is no longer satisfactory because it collects



only about 60 percent of the particulate matter.



3.4.14  Gypsum Processing



      Gypsum, the basic ingredient of plaster and wallboard,  is manufactured



by grinding, drying,  and calcining gypsum rock. At most plants much of the



gypsum is processed into wallboard in highly mechanized systems. Grinding,
                                   3-53

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 drying,  and calcining processes are principal sources of dust.  Handling,




 packaging,  and wallboard manufacture are of secondary potential.




       Most grinding operations are controlled with fabric filters.  Fine grinders




 often are equipped with built-in pneumatic conveyors that allow the product to





 be collected in the filter.




       Gypsum is dried in direct-fired dryers to remove free moisture before




 calcining.  Exit gases of about 220° F contain a large amount of fine dust.




 Electrostatic precipitators, baghouses, or scrubbers are almost always used




 to remove this dust from exit gases.




      The calcining operation is conducted at 400° to 450°  F in externally heated




 kettles or conveyors.  In general, exit gases from the calcining operation are




 less voluminous than those from dryers.  Historically, electrostatic precipita-




 tors have been used to control calciners.  Dust collection has not always been




 adequate, and baghouses now find better acceptance.  Most new gypsum plants




 have been equipped with fabric filters.  High-temperature fabrics are required




 and heaters have to be installed to prevent moisture from condensing in duct




work.




      Baghouses are used extensively in modern gypsum plants to collect dust




from various  conveying and processing points.  In most instances a salable




product is reclaimed.




3.4.15  Coffee Processing




      The processing of green coffee beans and the production of dehydrated




instant coffee  generate dust and liquid aerosols as well  as odorous gases.  The





                                   3-54

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most prominent sources are roasters, spray dryers,  waste heat boilers,




and green coffee cleaners.




     Roasters are the predominant sources of oil aerosols  and  odors but also




create significant amounts of solid particulate matter. Chaff, a flaky membrane




from the bean, and other solids are collected in simple cyclones at tempera-




tures of 400° to 500° F.  Remaining aerosols and odorous  gases may be inciner-




ated in afterburners at temperatures ranging from 1200°  to 1400° F.




     Coolers  and stoners  create additional solid  particulate matter, but few




aerosols or malodors.  Cyclones normally provide adequate dust control.  With




some continuous systems,  the exit of roaster gases through close coupled coolers




requires the use of afterburners on the cooler exhaust stream.




     Spray dryers not unlike those used in other  industries are used to produce




instant coffee.  If the dryer is operated properly,  very little fine particulate




matter is generated and satisfactory dust control  can  be achieved with dry




multiple-cyclone collectors.  Periodic excursions can be expected with resultant




discharges of fine  dust.  Many  plants operate scrubbers or baghouses down-




stream  of mechanical collectors.  Collected fines are blended with  the main




product stream.   Dust recovered in dry collectors is  of sufficient value to make




it attractive to maintain collector efficiencies.




     At instant coffee plants,  large quantities of  leached coffee grounds are




produced.  Many operators burn the spent grounds in  waste heat boilers similar




to coal-fired boilers.  Particulate emissions are  dependent on the type  of firing
                                    3-55

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and the ash content (usually about 4 percent by weight of dry grounds).  A




common design incorporates  an underfeed stoker and auxiliary gas burners.




      Green coffee cleaning and handling creates dust and chaff which nor-




mally can be handled well in simple cyclones.




3.4.16  Cotton Ginning




      The major  sources of particulate matter in cotton ginning are the gin




itself and the subsequent incineration of the trash.  Relatively coarse materials




are emitted from the ginning operation and relatively fine materials escape the




associated lint cleaner.   High-efficiency multiple-cyclones successfully collect




the coarse particles, and the  recently developed stainless steel in-line filter




is effective on  the fine particles.




      Disposal of the cotton trash by composting,  rather than incineration,




is being practiced in some parts of the country.  Incineration of trash generates




a large portion of the particulate matter released from uncontrolled ginning




plants.
                                     3-56

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3. 5 CO NSTRUC TIO N AND DE MO LITIO N




3.5.1 Introduction




    The demolition and construction of buildings and roads creates particulate




air pollution with periodic emissions characteristically dependent on the specific




operations.  The  handling of dusty materials, movement of  trucks on temporary




roads, and breaking of masonry walls are a few of the more prominent dust




generating operations.  None is continuous and the dust from almost all can be




reduced if suitable procedures  are used.




    Principal demolition, construction,  and related operations that generate




particulate air pollution are:




    1.  Demolition of masonry.




    2.  Open burning of wooden structures, trees,  shrubbery, and construc-




        tion lumber.




    3.  Movement of vehicles  on unpaved .roads.




    4.  Grading of earth.




    5.  Paving of roads and parking lots..




    6.  Handling and batching  of Portland cement, plaster, and similar




        materials at the site.




    7.  Sandblasting of buildings.




    8.  Spray painting of exposed surfaces.




    Essentially all of  these processes generate particulates that create local




nuisances.  Techniques have been developed to minimize dust releases from
                                    3-57

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most offending operations; however,  none of  these are entirely satisfactory.



Furthermore, all of the control measures require some expense and attention



and offer little,  if any,  monetary return.



3. 5. 2  Demolition of Masonry



    When a brick, plaster or concrete wall is demolished,  most of the parti-



culate  matter is released when the broken wall hits the ground or floor.  In



urban  areas, water  sprays are used  to keep exposed surfaces as wet as pos-



sible.   Before walls are torn down they are sprayed with water,  and as the



debris crashes to the ground more water is sprayed onto the pile.   The pro-



cedure at best is inefficient and as it is ordinarily practiced may reduce



particulate  matter by only 10 to 20 percent.  In cold or freezing weather,



water  spraying systems become  almost completely inoperable.



    One concept of dust collection at demolition sites  calls for enclosing the



four sides of the building by means of plastic sheets attached to the scaffolding


                    55
by removable clips.    The top of the building is left open and air is sucked



in by a large exhaust fan into bag filters for collection.  As yet this concept



has not been applied.  Nevertheless, it offers one of the few possibilities for



adequate collection of demolition dust in congested metropolitan  areas.



3. 5. 3   Open Burning



    Because open burning cannot be  controlled adequately, the only solution is



to stop the practice  and remove wood and other combustibles to an  incinerator



or sanitary landfill or to handle it  in some other acceptable manner.
                                     3-58

-------
3_. 5.4 Road Dust




    Trucks moving across dry,  unpaved roads are a prime dust source at




construction projects.  Dust can be held to a tolerable level  by blacktopping or




at least oiling such surfaces.  For very temporary roads, frequent spraying




with water  may be satisfactory.




3. 5. 5  Grading Roads and Other Surfaces




    There  are few satisfactory remedies for dust created by earth-moving




equipment.  It is best to conduct such operations when winds are light and




materials are sufficiently moist to minimize entrainment of dust in ambient




air  currents.  Sand, rock, gravel,  and the roadbed can be sprayed with water.




3. 5. 6  Handling Dusty Materials




    Portland cement, plaster,  and similar items are easily rendered airborne




during handling and batching.  If the materials are mixed at  the site, greater




possibilities are presented for the evolution of dust.  The  best approach is to




mix such materials in a central  location,  hooding all major points and venting




the  dust to  a fabric filter.




3.5.7  Sandblasting




    The cleaning of stone and concrete surfaces by sandblasting creates




particles that are difficult to control by common techniques.  When access is




possible, hooding and ductwork  can be provided from the point of sandblasting




to a baghouse or similar  high-efficiency dust collection device.  A more




common practice has been to shroud the operator and the area being cleaned.
                                    3-59

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Most of the resultant dust is contained within the canvas shroud and drops to




the ground below.  A clean air supply has to be piped by hose to the operator.




The arrangement is  successful when winds are light.  Under strong wind




velocities much of the particulate matter remains airborne.  Sandblasting of




buildings has been replaced in many areas  by  steam cleaning and acid washing.
                                    3-60

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3.6 SOLID WASTE DISPOSAL



3.6.1 Introduction



      Disposal of solid wastes contributes to air and water pollution and threatens



to pollute the land (through improper disposal methods).  In 1967,  190 million



tons of solid wastes were collected excluding some industrial and agricultural

         £- f-t

sources.    Of this quantity, 86 percent was disposed of at land disposal sites,



8 percent was burned in municipal incinerators,  and only 6 percent was dis-


                                                       56
posed of in what could truly be called a sanitary  landfill.    Much of the



waste in disposal sites is ultimately burned in the open.  Although emissions



from the burning of solid wastes represent less than 10 percent of the 1 million



tons of particulate matter emitted in this country, these  emissions  represent


                                                                  57
the most frequent cause of local air pollution complaints by citizens.



Particulate emissions from incineration cause soiling, visibility reduction,



and a generally unsanitary appearance of the air.



      Better engineering and planning are required to cope with the problem of



disposing of solid wastes in a manner that will least affect our environment.



One survey indicates that if present trends continue and long-range plans are



not made and implemented,  this country will not have the capability to handle


                                                              58
the increased amount of solid wastes generated in the year 1975.     Planning,



perhaps on a regional basis, and proper use of existing technology, specifically
                                     3-61

-------
in the fields of incineration and sanitary landfill operation,  are the key to



mastering the problem of air pollution from solid waste disposal.



3. 6. 2  Definition of Solid Waste



    As defined in the Solid Waste Disposal Act of 1965, "The term 'solid waste'



means garbage, refuse,  and other discarded solid materials, including solid-



waste materials resulting from industrial,  commerical, and agricultural



operations,  and from community activities, but does not include solids or



dissolved material in domestic  sewage or other significant pollutants in water



resources.  .  ."  It includes both combustibles and non-combustibles, such as



garbage, rubbish, ashes, street refuse, dead animals, and abandoned auto-


                                                                59
mobiles.  Solid waste is grouped into the following five categories:



     1.   Residential and commercial solid waste.  Food waste, paper,



         plastics, metals, cloth,  wood, and numerous other materials are



         included in residential and commercial solid waste.  Heating value



         is approximately 4500  Btu per pound.  Uncompacted density is



         approximately 250 pounds per cubic yard  -  compacted density is



         approximately 500 pounds per cubic yard.



     2.   Construction and demolition waste.  This category includes building



         materials such as wood, steel, plaster,  brick, and concrete.



     3.   Institutional solid waste.  Wastes from hospitals, nursing homes, and



         other institutions are included in institutional solid waste.  Such



         wastes are similar to residential and commercial  solid  wastes,  but



         may contain pathogenic materials.




                                    3-62

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    4.   Industrial solid waste.  Waste products as produced by industry include




        a variety of combustible and non-combustible materials.




    5.   Agricultural waste.  Agricultural waste includes animal droppings and




        crop residue,  but does not include stands of timber or brush burned




        as a result of accidential forest fires.  Reference articles on agri-




        cultural waste disposal  may be found in Section 8, Bibliography,




        under the heading of Food and Agricultural Sources.




3. 6. 3 Amounts of Solid Waste Generated




    The amount of solid waste generated in this country is truly astronomical.




Altogether, 190 million tons per year or 5. 3  pounds per person per day are




collected.    A breakdown of this latter figure is  shown in Table  3-12.  These




figures however,  are only for that amount of  waste actually collected.  Other




amounts are also  generated beyond that collected  and these amounts are best




described in the following quotation from Reference 56.




           'It must be recalled that  10 to 15  percent of household and com-




     mercial wastes are collected or transported by the individual generating




     the waste.  Approximately 30 to 40 percent  of the industrial wastes are




     self-collected and transported.  Additionally, local regulations— or lack




     of them—permit  over  50 percent of our population to burn some type of




     household waste in their backyards.  About  45 percent of commercial and




     other establishments are also allowed to practice controlled open burning




     of some type.  Thus, although the amount of waste material that has to be
                                    3-63

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Table 3-12.  AVERAGE SOLID WASTE COLLECTED
            (Pounds per person per day)
                                               56
Solid wastes
Household
Commercial
Combined

Industrial
Demolition, construction
Street and alley
Miscellaneous
TOTALS
Urban
1.26
0.46
2.63

0.65
0.23
0.11
0.38
5.72
Rural
0.72
0.11
2.60

0.37
0.02
0.03
0.08
3.93
	 	
National
1.14
0.38

2.63
0.59
0.18
0.09
0.31
5.32
                     3-64

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     collected is staggering in itself,  the amount of material that is actually



     generated and could pose potential collection problems is even more im-



     pressive.  Conservative estimates indicate that 7 pounds of household,



     commercial, and municipal wastes are presently generated per person;



     this totals  over 250 million tons per year.  To this must be added our es-



     timate of over 3 pounds per person per day for industrial wastes, amount-



     ing to an additional 110 million tons per year.  Thus,  estimates for 1967



     indicate that over  10 pounds of household, commercial, and industrial



     wastes are being generated in this country for every man,  woman, and



     child, totalling over 360 million tons per year.



           "To these figures we must add over 550 million tons  per year of



     agricultural waste and crop residues, approximately 1. 5 billion tons per



     year of animal wastes, and over 1. 1 billion tons of mineral wastes.



     Altogether, over 3. 5 billion tons of solid wastes are generated in this


                        56
     nation every year.



3.6.3.1  Disposal Methods to Minimize Air Pollution— Many areas  of the



country have adequate land available for sanitary landfills.  A properly oper-



ated sanitary landfill in which solid waste is buried daily without burning can



turn a worthless piece of property into a valuable recreation area.   The cost of



a landfill operation, in most cases, is less than incineration, not considering


                           fin
hauling costs in either case.     Expanded use of landfills,  of course, may re-



quire an efficient municipal pick-up system.   At present,  only about 6 percent



of municipal solid waste, not including industrial and agricultural waste,  is dis-



posed of in a sanitary landfill.


                                    3-65

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      Some solid wastes such as automobile bodies, paper and wood chips have



a salvage value or reclamation potential. If a market exists in an area for part



of all of the waste  currently being burned, it can be developed and used to re-



duce or eliminate air pollution.  Frequent collection of municipal refuse and the



pickup of leaves in the fall will deter the citizen from open burning.  Disposal



methods  other than combustion are, in many cases, economical.  These meth-



ods can be put to use,  however, only with the execution of adequate planning.



      In  metropolitan areas in which land is becoming scarce for landfill opera-



tions, combustion processes are being used to reduce refuse volume by as much



as 90 percent before disposal in a landfill, increasing the life expectancy of



the landfill site.    Incineration is often used to sterilize pathogenic or con-



taminated waste and reduce its volume before burial.  Our expanding society



may have to resort to more extensive incineration in many areas as  an alterna-


               62
tive to landfill.



      Of the total amount of municipal solid waste produced, not counting agri-



cultural  or industrial solid waste, 86 percent is ultimately disposed  of in open

                                                p~ /?

dumps where open burning is frequently practiced.     Such methods  of volume



reduction normally do not meet health and esthetic  standards that usually are

                                   /-> f)

desired by a progressive community,   because of the large amount of particu-



late matter (as much  as 16 pounds per ton of solid waste burned) released to the



atmosphere with virtually no possibility of controlling emissions.1  Open burn-



ing has been banned in at least  six states. 65
                                    3-66

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     Even today many apartment house, commercial, and municipal incinerators


being built do not meet requirements of good air pollution control standards.


Some incinerators can operate with a minimum of air pollution; however, these


units are costly to operate and maintain, and if poorly operated will create


noticeable air pollution.  The trend today is toward multiple-chamber incinerators


of adequate design that are equipped with efficient control devices and full  instru-


mentation, and well as towards controlled municipal size units. Municipal units


now proposed in this country are of the water-wall type that produce steam as a


saleable product and collect more than 99 percent of the particulate matter emit-


ted from the incinerator itself by means of electrostatic precipitators.


3.6.3.2  Disposal Methods Without Incineration— Disposal and volume-reduction


methods that do not  use incineration are most desirable from an air pollution


standpoint. In many cases they may be more economical and may prove to be


more acceptable to a community than methods using incineration.


     Sanitary landfill—The sanitary landfill, which should not be confused with

                                                           d G.
an open dump, is an acceptable means  of solid waste disposal.    Almost any


kind of material can be disposed of by this method of systematically dumping


solid waste on the ground or in trenches, compacting the waste by driving  a


bulldozer or other heavy equipment over it,  and covering the waste at the end of


each day with a  layer of compacted earth to prevent rodent and insect infestation


and to confine odors.  When completely filled, land so used may be made into


parks and recreation areas.  A properly operated sanitary landfill is operated


without open burning.  Air pollution emissions are limited to material entrained


                                    3-67

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in the air by earth-moving equipment.   Even these emissions, however, can be



kept to a minimum by wetting the fill material.



      Choice of a site and method of operation of a sanitary landfill is essen-



tially dependent on the topography and availability of land. In addition, other



factors  such as length of haul, land drainage, source of cover material, and



quantity of land needed to handle future  waste generation must be considered



before choosing a final site.  Some  factors that must be considered are:



      1.   Land requirements.  About  1 acre-foot  of land is  required for each



           1000 persons for one year operation when the production of waste


                                           67
           is  4. 5 pounds per day per capita.    In  addition,  cover material



           totaling at least  20 percent by volume of the compacted waste



           is  required.  Such material may be supplied from the site or trans-



           ported from nearby areas.   Normally, sites are designed for 10-



           to  20-year service periods.



      2.   Topography.   Depressed areas such as  ravines and abandoned pits



           where the grade must be raised are usually considered desirable



           for sanitary landfill sites.   Flat land can be used by applying

                                                                        r> /»

           progressive excavation  or the cut and cover method of operation.



      3.    Operation. Proper operation of a sanitary landfill requires contin-



           uous use of heavy earthmoving equipment to compact and cover



           the waste with fill material.  It is essential that waste be



           covered by no less than a 6-inch layer of material at least
                                    3-68

-------
          once a day.  An intermediate layer of cover material (about 1



          foot deep) is usually spread over completed sections of the site.



          An additional 2 feet of final cover is required as a minimum for



          the entire site on completion of the operation.



     4.   Cost.  Costs of site,  site preparation, and operation must be



          computed to judge the true cost of sanitary landfill operation.



          In addition, the final  value of the land when reclaimed must be



          balanced against the initial cost of the land. Sanitary landfill



          equipment and operating costs usually range from $0. 80 to $1. 50


                                                    /? o

          per ton of solid waste placed in the landfill.    (Transportation of



          waste to the site is not included in this figure.)



     Composting - Composting,  as applied to waste disposal, is the biological



decomposition of the organic component of waste.  Stable organic residue is the



ultimate product.  The  residue is usable as a low-grade soil  conditioner.  The



market for compost, however, has not been very good,  because equivalent



commercial products are available at less cost.



     Composting requires  separation of non-organic material from the waste.



To be economical, a market for such scrap is necessary.



     Composting costs are the same or higher than those of  incineration.


                                                                    69
Consequently,  only a few plants are operating in the United States today.



Actually, however, in the case of a composting plant operated by a municipality,



there is no more reason to  expect such a plant to be profitable than an
                                   3-69

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incinerator, as both perform essentially the same service for the citizens of




the municipality: that of getting rid of solid wastes.  In areas where commercial




fertilizer is not readily available and the scrap market is good, composting




could be a suitable method for handling organic wastes with little or no




particulate air pollution.  However, some compost plants have odor problems.




      Shredding - Disposal of bulky waste can be facilitated by shredding.  Auto




tires, for instance,  can be shredded and placed in a sanitary  landfill instead




of being burned.  Bulky wood waste, such as  driftwood and combustible




demolition waste, which has heretofore been  burned openly because of the




difficulty of incinerating it, can be shredded and incinerated in a conventional




incinerator provided it is mixed with conventional  refuse so that it does not




blind the grates. It can also be disposed of in a landfill site.




      Each year more than six million automobiles are junked in the United




States.  Automobile body  disposal, therefore, is one of the growing solid waste




problems. The most promising solution to the problem appears to be to step




up the reuse for autobody metal scrap in the domestic steel and foundry




industry, so that the large portion  of the available supply now being discarded




each year can be remelted.





      Air pollution arising from disposal of automobile bodies results, how-




ever, when they are burned to remove upholstery, grease, and paint. Such




burning is apparently required to produce a useable  scrap that is competitive




with other available material.  Open burning  of automobile bodies has proven
                                     3-70

-------
entirely unacceptable from an air pollution standpoint.  Large quantities of
particulate matter are generated by such burning.  Metallic particles con-
taining cadmium,  nickel, and lead may also be released by this method of
disposal.
      Open burning  of junk automobiles has been replaced by controlled
                          70
incineration in enclosures.    Emissions from such practices have been
successfully controlled by afterburners, wet scrubbers,  and electrostatic
precipitators.  Unfortunately, however,  because of the low market price paid
for automobile scrap, the cost of purchasing, operating,  and maintaining such
control equipment is prohibitive in many areas.  It would appear therefore,
that these control techniques need to be reapplied,  perhaps in conjunction with
process changes, to lower operating and maintenance costs, and allow the
higher installation costs resulting from more sophisticated designs to be
amortized over the  life of the  installation. Such designs might attempt to
minimize inlet air flow so that the control devices could be made as small and
                       71
inexpensive as possible.     Also,  where afterburners are used, heat recovery
might be considered.
      A possible solution to the air pollution problem is the expanded use of
mechanical devices  which can disintegrate and shred a whole car (minus the
block,  rear axle, and seats),  remove contaminants by a series of mechanical
separations, and produce a relatively useable scrap with little or no
            72
incineration.    Such processes can be used by most larger cities.  Cost of
                                    3-71
   331-716 O - 69 - 9

-------
equipment for a unit capable of handling from 200 to 300 cars per day is



$500, 000.  Cost for a unit capable of handling 1200 cars per day ranges from


                       73
$1 million to $3 million.


      In many locations, however, the low market price paid for shredded


scrap has restricted the area from which shredders can draw junk auto-bodies.


Although it, too, is restricted by  low scrap prices, the practice of flattening



junk autos and delivering them from outlying areas to a centralized shredder


results in some cars being processed without generating as much air pollution



as if they were burned in the open.


      Compaction - Compaction, although not a disposal method, has the


potential of reducing on-site refuse volume to a point that large storage areas


are not required and transfer to final disposal at landfills or municipal


incinerators  is easier.  Compaction devices are now being marketed for


installation in larger apartment complexes.  In some instances,  these units


have replaced chute-fed incinerators.



      Compaction installations are similar to chute-fed incinerator installations.


Normally,  refuse is charged by tenants through a door located on each floor of


the building.  Refuse builds up to a predetermined level in a receiving hopper,


usually in the basement, then is forced by hydraulic ram into a storage con-


tainer or bag.  Compaction of refuse in the storage container is claimed to



be accomplished up to 3 to 1.  Recent investigations indicate, however, that


much higher compaction ratios may be obtained.
                                     3-72

-------
     Metal containers with capacities up to two cubic yards have been used.




It has been reported that one container is required for every fifty apartments,




with removal two to fives times per week.




     Installed cost of a compactor is reported to be $3500, plus $175 per floor




for the metal chute.  Hauling cost  of the compacted refuse for a 100-unit




apartment building in one area of the country is $85 per month.  Incineration  of




the same refuse would cost $50.




     Widespread use of compaction units could place a heavy burden on pick-




up and disposal facilities of a municipality and could cause an accumulation of




refuse should scheduled pick up be prevented.  Another disadvantage of such a




disposal method is the high cost of installing such units in older buildings.




3.6.3.3    Disposal Methods With Incineration - Incineration, as a means of




volume reduction,  may be justified in areas where land for sanitary land-




fill is scarce or hauling costs are  prohibitive.  That well designed and well




operated equipment be used to minimize the discharge of particulate matter to




the atmosphere is of utmost importance in the use of incinerators.




     Emissions of particulate air pollutants from combustion of solid waste,




including open burning,  can range  from 3 to 28 pounds per ton of refuse,




depending on the degree of combustion and control of emissions.    Reduction




of these emissions to the desired level requires either that  the incinerator




be designed for control of fly ash or that a separate control system be used.




Table 3-13 summarizes the collection efficiency of various  control devices




when applied to incinerators.





                                    3-73

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      Open burning—The results of the National Solid Wastes Survey show that


open burning is widespread.  Eighty-six percent of the 190 million tons of solid


waste collected in 1967 went into land disposal sites, 75 percent of which re-

                                    j- r*
suited in some form of open burning.    The Bureau of Solid Waste Management


of the Environmental  Control Administration sees even a higher percentage of


the sites as undesirable as indicated by the following quotation:


            "This country has over 12,000 land disposal sites being utilized by


      collection services, control of 94 percent of which is unacceptable and


      represents disease potential, threat of pollution,  and land blight.  By no


      stretch of the imagination do these sites  resemble a sanitary landfill.  The


      waste management field must face the challenge of studying and evaluating


      these sites to determine their suitability for conversion to sanitary landfills


      We must develop the necessary plans, finances, and action programs to


      convert those sites that can function as a sanitary landfill.  In many in-


      stances it will be necessary to close and abandon many of these sites.


      Local government then must locate and develop new sites for immediate


      now and to provide necessary capacities  for the increase of the future.


            "To  eliminate open dumps, and the air pollution that results from


      open burning in them, as well as other environmental pollution, may cost

                                                  Cf*
      as much as $230 million per year for 5 years.    This represents about
use

56
                                     3-74

-------
Table 3-13.  MAXIMUM DEMONSTRATED COLLECTION EFFICIENCY
            OF INCINERATOR CONTROL EQUIPMENT74'75
     Collection device
                                        Collection efficiency, percent
 Settling chamber

 Wetted baffles

 Cyclones

 Impaction scrubbers  (with

     pressure drop less than

     ten inches of water)
 Electrostatic precipitators

 Bag filters
   35

   53

75 to 80

94 to 96
  99+

  99+
                                3-75

-------
      5 percent more than is currently being spent annually for solid



                       4.  U56
      waste management.



      Open Top Incinerators— A refractory-lined rectangular chamber with a



full, open top and forced overfire air has been used to incinerate a variety of


                                                      76
wastes including liquids,  solids with high caloric value,   general trash,  and



municipal refuse.  This design, because of its relatively low cost, has been ap-



plied to waste disposal by both municipalities  and industries. Tests of a pilot




unit conducted by the National Air Pollution Control Administration have shown



excessive particulate emissions for high-ash materials and for low-ash materi-



als under certain operating conditions.  Low emissions were realized for  a low-



ash (0. 5 percent by weight) material incinerated under carefully controlled con-


        77
ditions.    Operation of full-scale units on certain high-Btu low-ash wastes are



being conducted without visible emissions of smoke,  but no quantitative test data



are yet available.  Before applying this technique, careful consideration should



be given to the ash content and physical characteristics of the waste, and tests



should be conducted on the specific waste.  As with all combustion sources,



this type of unit requires  control of charging and  air flow to prevent the emission



of smoke and excessive fly ash.  All installations  should be equipped with  ap-



propriate instrumentation to ensure operation within allowable air pollution limits.



Additional tests are contemplated to further define significant parameters which



can be used to estimate performance on any waste material.




      Conical metal burners— Conical  metal waste burners are used in the lum-



ber industry  to incinerate wood wastes.  This single-chamber incinerator




                                      3-76

-------
is not properly designed to minimize atmospheric emissions, and is usually

not operated or maintained properly.  Consequently, large amounts of particulate

matter are emitted from such units.   Some areas of the country, in fact, have

banned all new construction of these burners.  Conical metal burners are not
                                          n n
satisfactory  for other types of refuse  either.

      Domestic Incinerators—Domestic incinerators  may  include such units as

single-chamber backyard units with no auxiliary fuel to dual chamber incinerators

having a primary burner section followed by an afterburner section.

      Many air pollution control agencies have banned installation and use of

backyard incinerators.  A  few air pollution  agencies have in the past prohibited

the installation of some or all types of domestic incinerators  because of the

inability to meet various local standards pertaining to emissions of particulates,

organic compounds,  or odors.  Such action  may be due  in part to excessive

emissions caused by negligent operation of such units and the fact they can

be operated  without using the gas burners.

      Commercial and industrial incinerators - Commercial and industrial

incinerators for burning general refuse range in capacity from  50 to several

thousand pounds of refuse per hour.   These units may be classified into two

general designs,  single- and multiple-chamber incinerators. A single-

chamber unit is  so designed that admission, combustion, and exhaust to a  stack

take place in one chamber. The multiple-chamber incinerator  has separate

chambers for admission and combustion of  the solid refuse,  mixing and
                                     3-77

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further combustion of the fly ash and gaseous emissions, and settling and



collecting of the fly ash.  Industrial wastes other than general refuse require



special designs based on characteristics of the particular waste.



      Single-chamber incinerators  have generally proven inadequate to meet




most emission regulations.   Emissions from such units have been reported to


                                                                    64
be as much  as 25 pounds of particulate matter per ton of refuse burned.



Multiple-chamber incinerators, however,  when designed,  operated, and main-



tained properly, reduce the  volume of refuse sufficiently and produce a minimum



of particulate  emission.   Emissions from  such units have been reported to  be



as little as 3 pounds per ton of refuse burned.   Even well-designed multiple-



chamber incinerators may require  a good gas washer to meet more stringent



regulations.  The National Air Pollution Control Administration has tentatively



found that scrubbers having at least 1/2 inch HO pressure drop and a water rate
                                            Zj


of 4 gallons per 1, 000 scfm are required for Federal incinerators to meet emis-


                                    79
sion standards for Federal facilities.



      To keep particulate emissions to a minimum,  design standards for any


                                                             QA

incinerator must include means to  satisfy  the following criteria:



      1.   Air and fuel must be in proper proportion.



      2.   Air and fuel must be mixed adequately.




      3.   Temperature must be sufficient for combustion for both the solid fuel



          and gaseous products.




      4.  Furnace volume must be large enough to provide the retention time



          needed for complete combustion.




                                    3-78

-------
     5.   Furnace proportions must be such that ignition temperatures are


         maintained and fly ash entrainment is minimized.


     Even an incinerator of proper design must be operated and maintained


properly to minimize particulate emissions.  Where charging  and operation


cannot be closely supervised, scrubbers and auxiliary burners can  minimize


emissions.  Periodic cleaning and adjustment of burners can minimize emis-


sions.  Periodic cleaning and adjustment of burners,  spray nozzles, fans,


and other appurtenant devices are also necessary to minimize emissions.


     Initial incinerator cost depends mainly on the capacity of the unit and

                                                    01
the degree of air pollution control desired. Figure 3-2    shows typical costs


for incinerators without scrubbers,  with low-efficiency  scrubbers,  and with


high-efficiency  scrubbers.  Presumably, these costs data are for the approxi-


mate time the information was presented,  December  1966.  To meet the most


stringent emission standards and to minimize visible emissions and fly ash,


most incinerators must be equipped with scrubbers.


     Design criteria and operating  practices previously described  for general


refuse incinerators  should also apply to units burning pathological waste.


Primary factors that affect particulate emissions from pathological incinerators


include:


     1.  Gas burner rates should be  sufficient to maintain at least 1400°F in


         secondary chamber.
                                     3-79

-------
      2.   Burner placement should be such that all waste in primary chamber




          is covered by flame from burner.




      3.   Preheating should be accomplished with secondary burners prior





          to charging of waste.




      Many air pollution control agencies review on a routine basis all plans




for future incinerator installations to ensure that these units meet emission




standards.  Details that are  usually checked in such a review include:




      1.   Plot plans to see if unit is located in a suitable area.




      2.   Unit capacity to see if it is adequate for the expected daily waste




          generation.




      3.   Gas burner placement and fuel rates.




      4.   Scrubber water flow rate.




      5.   Materials of construction for resistance to heat,  stress, and




          corrosion.




      6.   Air port sizes.




      Recognizing the fact that emissions from incinerators are, to a great




extent, a function of operation, some air pollution control agencies conduct




training  courses and publish literature to be used by incinerator operators or




their supervisors.  Once  aware of the factors  influencing atmospheric emis-




sions, it is possible for operators to contribute greatly to the  reduction of




particulate emissions by  such simple practices as regularly cleaning out the




ash pit or preheating the unit prior to operation.
                                     3-80

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                                             Apartment house incinerators -


                                        Apartment house incinerators are an


                                        important pollutant source in urban


                                        areas of the country.  Smoke and fly


                                        ash from these units cause many


                                        complaints.


                                             Emissions  are usually higher


                                        than other incineration systems be-


                                        cause of low combustion temperatures
       100   500     1000     isoo    2000    and improper air regulation.  Adequate

        CAPACITY OF INCINERATOR, Ib/hr
igure 3-2.  Costs of incinerator at three levels
         of control of paniculate emissions.
                                        control of this source in most cases
                                        has not been achieved, although


 stricter air pollution regulations are inspiring the application of new control


 measures.


      The most common apartment house incinerator is the flue-fed or single-


 flue,  single-chamber model.  In this unit refuse is charged down the same


 passage that the products of combustion use to leave the unit.  Refuse dropped


 onto the fuel bed during burning smothers the fire  and causes incomplete com-


 bustion.  Improvements in design have been made  to the single-flue, single-


 chamber unit.   There are now chute fed units that  are multiple-chamber


 incinerators with separate passages for the refuse  and products of combustion.


 This design provides improved combustion and air  regulation but emissions would
                                     3-81

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still exceed most emission standards.  Inherent in the design of flue or chute-


fed models is the high natural draft in the flues of a tall apartment building


which is a major cause of high particulate emissions.


      Air pollution agencies have approached the control of these units in


different ways.  New York has prohibited the installation of new apartment


house incinerators and has issued specific criteria for upgrading existing units,


Washington,  D.  C., and Atlanta do not allow flue or chute-fed units to be in-


stalled.  Detroit and Philadelphia have set emission  standards at a level that


requires  efficient collection equipment, usually water scrubbers,  on apartment


house incinerators.


      In upgrading existing units and designing new units,  several techniques


are used to overcome the problems of excessive emissions from apartment


house incinerators. A gate at the base of the charging chute is used to prevent


refuse from  entering the  incinerator during burning and to prevent the products


of combustion from leaving through the charging flue.  This approach is prefer-


 able to locking the hopper doors because these locks eventually either fail on


their own or are broken by occupants of the building.  For single-flue units, a


bypass  or separate flue must be constructed for the products of combustion.


Auxiliary burners are placed in the primary and/or secondary chambers of the

                                                                   Q O
incinerator to increase burning temperature and improve combustion.


      Draft control has been used in New York  to reduce entrainment of fuel


bed material in  the effluent gas stream.  A sensor is placed in the primary
                                     3-82

-------
chamber to monitor draft.  When a preset draft level is exceeded a damper



located in  the breeching at the incinerator outlet is activated and decreases



the amount of air entering the incinerator.



     An important step is the addition of efficient gas scrubbers to the in-



cineration system.  Scrubbers designed to increase the velocity of the gases



and contact them with low-velocity water appear to be preferable to spray



nozzle units because plugged nozzles reduce collection efficiency.  A  final



improvement is the  establishment of definite burning periods.   Burning cycles



depend on  the relative size of the apartment house and incinerator,  and are



quite variable.  The intent of such cycles is to systematically destroy the



refuse without overloading the incinerator, and to minimize smoldering refuse



by destroying all waste charged during any one cycle. Employment of the



above techniques should reduce emissions to a level of 2 to 6 pounds per ton



of refuse burned.



     Municipal incinerators - In 1966,  254 municipal-size incinerators were



in operation in the United States.   The average capacity of these units is 300



tons per day.  Most installations  are old (70 percent were installed before  1960)



and not designed to minimize air  pollution.



     "It is estimated that approximately $150 million is required to construct



lew incinerators for replacement of existing inadequate incinerators  and conical



turners.  An additional $75 million is required for air pollution control equip-


                                                           56
nent to  upgrade or replace existing inadequate incinerators."
                                     3-83

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      Approximately 8 percent of all municipal solid waste, not including


                                                                    56
agricultural and industrial waste, is burned in municipal incinerators.



      Design criteria for municipal incinerators - Municipal incinerators may



be classified as either batch-fed or continuously fed units.  Continuously fed



units  are preferable because operating parameters,  such as combustion



chamber temperatures that affect particulate emissions, can be closely con-



trolled.  Grates must be of proper design to ensure complete burnout of



material.  At the same time,  however, grates should mix or tumble the refuse



as gently as possible to minimize entrainment of material in the exhaust gas.



      Most municipal incinerators in this country are of the refractory-lined



furnace type.   Water-wall  furnaces  are more common in Europe.   This type



of unit offers the advantage of steam generation.  As a consequence of heat



recovery in the steam generation process,  flue gas temperatures are lower



than those of refractory-lined units.  Lower flue gas temperatures cause



smaller flue gas volumes,  which in turn require smaller, less costly air



pollution control equipment. In addition, water-wall units can be operated with



less excess air, which further reduces stack gas  volume.



      Air pollution control equipment - Most municipal incinerators in the



United States are equipped with some form of fly ash control system.  Generally,



this system consists of a simple baffle-type spray chamber.   These spray



chambers prevent hot cinders and large particles from being emitted to the



atmosphere,  but they do not effectively control finer material.
                                     3-84

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     More efficient collection devices will be required for municipal incinera-



tors to meet reasonable air pollution control codes.  The medium pressure drop



(6 inches of water) scrubber and the electrostatic precipitator are two control



devices capable of effective particulate control.  No precipitator has yet been



installed on any American municipal incinerator,  but several have been in-



stalled and successfully operated in Europe.   Several devices with collection


                                                                     84
efficiencies of over 95 percent are  scheduled  for new and existing units.



High efficiency scrubbers,  in  contrast to precipitators, might also control



emissions of potentially odorous and toxic  gas.



     Cost of municipal incineration and control devices— Current costs of



constructing municipal incinerators may range from $6,000 - $13,000 per ton


                        85
of rated 24 hour capacity.    Costs in the low end of the range represent in-



cinerators of relatively simple design with minimal controls, such as a



settling chamber.  Costs for incinerators of complex design, equipped with



sophisticated controls such as electrostatic precipitators, would be near the



high end of the range.  Between 30  and 40 percent of this cost is usually spent



on operating equipment and the remainder  is spent on building and land.  Oper-



ating costs (not including plant amortization) range from $4 to $8 per ton of


                  84
refuse  incinerated.     Precipitator (95 percent efficiency) cost for two 250-


                                                              86
ton-per-day incinerators is reported at approximately $430,000.
                                     3-85

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3. 6.4  Air Pollution Potential From Solid Waste Disposal Methods

                                                                       r/?

      There are approximately 12,000 land disposal sites in this country.



Such sites may be defined as locations,  either privately or publicly owned,



on which there is dumping of solid wastes by public or private contractors.



Only 6 percent of these sites may be termed sanitary landfills,  in that they



have daily cover, no open burning, and no water pollution problems.    On



three-quarters of the remaining 94 percent of the land disposal  sites, some



form of open burning is practiced.   This type of ultimate disposal accounts



for a large share of the particulate emissions  estimated to arise from the



burning of solid wastes.



      Some amounts of construction, institutional, industrial and agricultural



waste are also burned.  Emissions from field burning to remove weeds or



residue, incineration of wood waste, and burning of car bodies for salvage



can contribute significantly to local and  even regional air pollution problems.



In some areas of the country these sources may,  in fact, be the greatest cause



of particulate air pollution.



_3. 6. 5  Public Health Service Programs  and Assistance in Solid Waste Disposal



      With passage of  the Solid Waste Act of 1965, the Federal Government



made a commitment to support and assist in a coordinated national effort to


                           87
solve solid waste problems.   The Solid Wastes Program of the Environmental



Control Administration presently supplies technical and financial assistance re-



lating to methods for handling solid wastes. The National Air Pollution Control
                                     3-86

-------
Administration also provides technical assistance on air pollution emissions
and control techniques for solid waste disposal methods.  Public Health Service
regional office directors should be contacted in regard to specific services
available.  In addition, where problems of solid waste disposal arise in connec-
tion with mining industries, the Solid Waste Research Group of the Bureau of
Mines may also be consulted.
                                    3-87
  331-716 0-69-10

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                       REFERENCES FOR SECTION 3

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 6.   Venezia, R. and Ozolins, G.   "Interstate Air Pollution Study,  Phase
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      Div.  of Refining,  May 1967, p.  36.
                                     3-f

-------
11.   "The Automobile & Air Pollution:  A Program for Progress, Part II. "
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22.   Reese, J. T.  and Greco, J.  "Experience with Electrostatic  Fly-Ash
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                                   3-89

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23.   Katz,  J.  "The Effective Collection of Fly Ash at Pulverized Coal-Fired
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29.   Schueneman,  J. J. ,  High, M. D. , and Bye, W.  E.  "Air Pollution
      Aspects of the Iron and Steel  Industry. "  U.S. Dept. of Health,
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30.   "Directory of Iron and Steel Works  of the United States and Canada. "
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31.   Von Bergen, J. M.   "Profile  of Industry Costs for Control of
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32.   "A Marketing Guide to the Metal Casting Market. " Pentan Publishing
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33.   "Statistical Abstract of the United States. "  85th edition, U.S.  Dept. of
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34.   "Standard Industrial  Classification Manual. "  Bureau of the Budget,
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                                     5-90

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35.   Kreichelt,  T. E. , Kemnitz,  D. A. , and Cuffe, S.  T.   "Atmospheric
     Emissions  from the  Manufacture of Portland Cement. " U. S. Dept.  of
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36.   Kenline, P. A. and Hales, J. M.   "Air Pollution and the Kraft Pulping
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37.   "Atmospheric Emissions  from Sulfuric Acid Manufacturing Processes."
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38.   "Control and Disposal  of  Cotton Ginning Wastes. "  U.S. Dept.  of Health,
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39.   Drogin, I.   "Carbon Black. "  J. Air  Pollution Control Assoc. , Vol. 18,
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40.   Brandt, A.  D.  "Current  Status and Future Prospects - Steel Industry
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41.   McGannon, Harold E.   "The Making,  Shaping, and Treating of  Steel. "
     U. S.  Steel Corporation,  8th edition,  1964, p. 404.

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                                    3-91

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46.   Schueneman,  J.  J. ,  High,  M. D. , and Bye,  W. E.   "Air Pollution
      Aspects of the Iron and Steel Industry. "  U.S.  Dept.  of Health, Education,
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47.   Schueneman,  J.  J. ,  High,  M. D. , and Bye,  W. E.   "Air Pollution
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48.   Sterling, M.  "Current Status and Future Prospects - Foundry Air
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49.   Doherty, R. E.  "Current Status and Future  Prospects - Cement Mill
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53.   Brandt, A.  D.  Private communication,  June 11,  1968.

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77.   Burckle,  J. O. , Dorsey, J. A., and Riley, B.  T.   "The Effects of the
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                                    3-94

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78.   Kreichelt, Thomas  E.   "Air Pollution Aspects of Tepee Burners Used
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79.   Sable ski, J. J. , Knudson,  J.  C. ,  Cote, W. A., and Kowalczyk, J.  F.
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     (Presented at the Annual Meeting of the Air Pollution Control Association,
     St. Paul, Minnesota, June 23-27,  1968).

80.   Williamson, J. E. , Me Knight, R.  J. , and Chass, R. L.  " Multiple -
     Chamber Incinerator Design Standards for Los Angeles County. "  Los
     Angeles County Air Pollution Control District, Los Angeles,  California,
     Oct. 1960.

81.   Voelker, E. M. "Control of Air Pollution from Industrial and Household
     Incinerators. " In:  Proceedings of the 3rd National Conference on Air
     Pollution, Washington,  D. C. , 1967,  pp.  332-338.

82.   Feuss, James V. and Flower,  Franklin B.  "The Design  of Apartment
     House Incinerators  - the State of Art. " (Presented at the Annual Meeting
     of the Air Pollution Control Association, June  23-27, 1968.)

83.   Duprey, R. L.  "Compilation of Air  Pollutant Emission Factors. " U.S.
     Dept. of Health, Education, and Welfare,  National  Center for Air
     Pollution Control, Durham, North Carolina,  PHS-Pub-999-AP-42, 1968,
     67pp.

84.   Bogue, M.  DeVon   "Municipal Incinerators. "  U.S. Public Health Service,
     Office of Solid Wastes,  1965.

85.   Hickman,  H.  L. Private communication, Technical Services, Bureau of
     Solid Waste Management, Rockville,  Maryland, Nov. 1, 1968.

86.   Fife, James A. and Boyer, Robert H. , Jr.   "What Price Incineration
     Air Pollution Control ?"  In: Proceedings of  1966 National Incinerator
     Conference, American Society of Mechanical Engineers,  New York,
     1966, pp.  89-96.

87.   Vaughan, R. D.  "Assistance Available under the Solid Waste Disposal
     Act. " In:  Proceedings of the  Surgeon General's Conference on Solid
     Waste Management, Washington, D. C.  U.S.  Dept. of Health, Education,
     and Welfare,  National Center for Urban and Industrial Health, 1967,
     pp. 155-162.
                                    3-95

-------
                      4.  GAS CLEANING DEVICES



4.1    INTRODUCTION



      Gas streams contaminated with particulate matter may be cleaned



before the gas is discharged to the atmosphere. Gas cleaning devices take



advantage of certain physical,  chemical, and/or electrical properties of the



particulate matter and gas stream.   Selection of a gas cleaning device will



be influenced by the efficiency required, nature of the process gas to be



cleaned,  characteristics  of the particulate and gas  stream, cost of the



device's use, availability of space,  and power and water  requirements.



Other basic considerations  include maintenance, dependability, and waste



disposal.  It has been estimated  that total expenditures in 1966 of industrial



air pollution control equipment in the United States were  about $235 million.



Value of shipments  of the industrial gas cleaning  equipment industry in 1967



was double the 1963 figure,  and the backlog of orders recently nearly equalled



a year's productive output.   Undoubtedly legislative pressure and local



pollution  control regulations have supplied the impetus for such rapid growth


              2
in this industry.   Table  4-1 shows  an up-to-date list of the types and values


                                                   2
of control equipment being sold to various  industries.



      This chapter discusses the wide array of commercially available gas



cleaning devices and summarizes published operating characteristics, including
                                  4-1

-------
                               Table 4-1.  MANUFACTURERS' SHIPMENTS OF INDUSTRIAL GAS
                                          CLEANING EQUIPMENT BY END USE IN 1967
                                                        (thousands of dollars)

Iron and steel
Utilities
Chemicals
c
Rock products
Pulp and paper
Mining and metallurgical
Refinery
All otherd
Exports
Total shipments
Electrostatic
precipitators
5,783
15,506
1,207
2,760
a
a
a
687
a
36,509
Fabric
filters
4,536
a
5,344
3,602
122
1,855
a
4,959
1,081
21,730
Mechanical
collectors
2,300
2,476
3,130
1,038
802
389
a
8,408
a
22,381
Scrubbers
particulate
7,423
a
3,709
1,142
989
825
a
3,901
651
19,229
Scrubbers
gaseous
4,275
a
1,479
a
193
394
a
114
72
6,770
Gas incinerators
and adsorbers
b
a
1,001
a
a
a
282
2,137
79
3,976
Total
shipments
b
24,317
18,481
15,870
8,966
6,753
6,160
4,098
20,206
5,744
110,595
I
to
        Not published to avoid disclosure.
        Ga-s incinerators and adsorbers purchased by iron and steel companies are included in "all others" category to avoid disclosure.
       ' "Rock products" includes cement and asbestos plants.
        "All other" includes shipments to distributors where end use cannot be identified.

-------
efficiencies, and information that will help determine the gas cleaning devices

suited for a specific application.  Information presented includes:

      1.  Introductory material (definitions and theoretical principles).

      2.  Equipment description and design (variations, arrangements,  and

          performance).

      3.  Typical applications (including efficiency data).

      4.  Operational factors (power requirements, pressure drops,

          temperature limitations, corrosion and maintenance problems,

          and waste disposal).

     Cost factors for each major type of control device are discussed in Section

6 of this report.  Capital, installation, and operating costs  are provided for

settling chambers, cyclones,  scrubbers, electrostatic precipitators, fabric

filters,and afterburners.

4. 1.1  Preliminary Selection of Equipment

     The selection of gas cleaning equipment is far from an exact science and

must be based on particle and carrier gas characteristics,  and process,

operating, construction, and economic factors.

     Important particle characteristics consist of size distribution,  shape,

density, and such physio-chemical  properties as hygroscopicity, agglomerating

tendency, corrosiveness, "stickiness",  flowability,  electrical conductivity,
                         o
flammability, and toxicity. °

-------
       Test methods for determining some of the properties of fine particulate




matter cited above are outlined in the American Society of Mechanical Engineers'




Power Test Code Number 28.




       The process  factors affecting selection of a gas cleaner are volumetric




flow rate,  variability of gas flow, particle concentration, allowable pressure




drop, product quality requirements, and the required collection efficiency.




Required collection efficiency is based  on the value of the material being




collected,  the nuisance or damage potential of the material, the physical




location of the exhaust, the geographical location (i.e. , the air pollution




susceptibility of the  area), and present and future local codes and ordinances.




       Ease of maintenance and  the need for continuity of operation are




operating factors which should be considered.  Important construction factors




include available floor space and headroom and construction material




limitations imposed  by the temperature, pressure, and/or corrosiveness of




the exhaust stream.  Economic factors consist of installation,  operating,




and maintenance costs.




       Information on the particle size gradation in the inlet gas stream is




very important in the proper selection of gas cleaning equipment.  Particles




larger than 50 microns may be removed in inertial and cyclone separators




and simple, low-energy wet scrubbers.   Particles smaller than 50 microns




require either high-efficiency (high-energy) wet scrubbers, fabric filters,




or electrostatic precipitators.
                                   4-4

-------
     Wet collectors operate at variable efficiencies directly proportional to the



energy expended and can handle changing effluent flow rates  and characteristics.



Disadvantages of wet scrubbers are (I1)  scrubber liquor may require treatment.



^2) power cost is high,and (3) a visible plume may be emitted. Fabric filters



more readily permit reuse of the collected material and can collect combustible



and explosive dusts. They do. however, have temperature limitations and are



sensitive to process conditions.   Electrostatic precipitators can  operate at



relatively high temperatures, have low  pressure drop, low power requirements.



and few moving parts.  They are.  however, sensitive  to variable dust loadings



or flow rates and.  in some cases, require special safety precautions.



     The performance of various gas cleaning devices may  differ widely



depending upon the particular application.  Grade efficiency  curves  for selected



gas cleaning devices are shown in Figure -i-1 as an illustration of a method for


                                                              5 6
describing collection equipment performance for one application.  '    The per-



formance of the various gas cleaning devices shown could differ significantly



lor other applications.
                                    4-5

-------
100
                                   BAG FILTERHOU5E
                               A '  VENTURI SCRUBBER (6-INCH THROAT, 30-INCH WATER GAIICF)
                                   SPRAY TOWER (22-FOOT DIAMETER)                  E>
                                 'DRY ELECTROSTATIC PRECIPITATOR (3-SECOND CONTACT TlMF'
                                 /MULTIPLE CYCLONES (12 INCH DIAMETER TUBES)
                               B <  SIMPLE CYCLONE (4-FOOT DIAMETER)
                                   INERTIAL COLLECTOR
            10
                                 30         40         50

                                   PARTICLE SIZE, microns
    Figure 4-1.  Composite grade (fractional) efficiency curves based on test silica dust.



        As a further aid in the selection of particulate matter collection equip-

  ment, the areas of application of the various cleaning devices  are given in

  Table 4-2.1  Other areas of application have been summarized at the end of

  each  equipment section.  The reader should refer to those sections and to the

  material referenced therein.

-------
   Table 4-2.  USE OF  PARTICULATE COLLECTORS BY INDUSTRY
Industrial
Classification
Utilities and industrial
power plants





Pulp and paper




Rock products






Steel












Process
Coal
Oil
Natural gas
Lignite
Wood and bark
Bagasse
Fluid coke
Kraft
Soda
Lime kiln
Chemical
Dissolver tank vents
Cement
Phosphate
Gypsum
Alumina
Lime
Bauxite
Magnesium oxide
Blast furnace
Open hearth
Basic oxygen
furnace
Electric furnace
Sintering
Coke ovens
Ore roasters
Cupola
Pyrites roaster
Taconite
Hot scarfing

EP
0
0
-
0
+
-
0
0
0
-
-
-
0
0
0
0
0
0
-i-
0
0
0

4~
0
0
0
T
0
-i-
0

MC
0
0
-
0
0
0
T
-
-
-
-
0
0
0
0
0
0
0
+
-
-
-

-
0
-
0
-
0
0
-

FF
_
-
-
-
-
-
-
-
-
-
-
-
0
0
0
0
+
-
-
-
-
-

0
-
-
-
~r
-
-
-

\YS
_
-
-
-
+
-
-
0
0
0
0
-
+
0
0
+
-
-
-
0
+
0

0
-
-
T
0
0
-
+

Other
_
-
-
-
-
-
+
-
-
-
-
+
-
-
-
-
-
-
-
+
+
-

-
-
~r
-
-
-
-
-
                                   4-7
331-716 0-69-11

-------
Table 4-2. USE OF PARTICULATE COLLECTORS BY INDUSTRY (Continued)
Industrial
Classification
Mining and
metallurgical













Miscellaneous

















Process
Zinc roaster
Zinc smelter
Copper roaster
Copper reverb.
Copper converter
Lead furnace
Aluminum
Elemental phos.
Ilmenite
Titanium dioxide
Molybdenum
Sulfuric acid
Phosphoric acid
Nitric acid
Ore beneficiation
Refinery catalyst
Coal drying
Coal mill vents
Municipal incin-
erators
Carbon black
Apartment incin-
erators
Spray drying
Machining opera-
tion
Hot coating
Precious metal
Feed and flour
milling
Lumber mills
Wood working

EP
0
0
0
0
0
-
0
0
0
+
+
0
-
-
+
0
-
-
+

+
-

-
-

-
0
-

_
-

MC
0
-
0
-
-
-
-
-
0
-
-
-
-
-
+
0
0
+
0

+
-

0
0

-
-
0

0
0

FF
-
-
-
-
-
0
-
-
-
0
-
-
-
-
+
-
-
0
-

+
-

0
0

-
0
0

_
0

ws
-
-
-
-
-
0
0
-
-
-
-
0
0
0
+
_
-
-
0

-
0

+
+

0
-
_

-
-

Other
_
-
-
-
-
-
+
-
-
-
-
0
o !
0
+
-
-

+

-
-

-
+

0
-
-

-
	 1
                                4-J

-------
Table 4-2. USE OF PARTICULATE COLLECTORS BY INDUSTRY (Continued)
                                 KEY

        0 = Most common                      Other -
        + = Not normally used                   Packed towers
      EP = Electrostatic                        Mist pads
           Precipitator                        Slag filter
      MC = Mechanical                         Centrifugal
           Collector                             exhausters
      FF = Fabric Filter                        Flame incineration
      WS = Wet Scrubber                        Settling chamber
                                 4-9

-------
4.2  SETTLING CHAMBERS




 4. 2.1 Introduction




      Gravitational settling chambers use the force of gravity to separate dusts




 and mists from gas streams.  Such collectors are simple in design and opera-




 tion, but have low  collection efficiency.   The principal disadvantages are low




 collection efficiency for small particles and large space requirements.




 4.2.2 Discussion  of Terms




      To assist in  understanding the operation of settling chambers, the




 following terms are discussed:




      1.  Terminal Settling Velocity.  A dust particle falling under the influ-




 ence of gravity attains a constant terminal velocity,  which is  dependent on the




 physical properties of the gas through which the particle is falling, as well as


                                                                   7

 the physical properties of the particle, including its size and  shape.  Terminal




 settling velocities  in air of spheres of different particle densities were calcu-


                                                  7

 lated and are presented graphically in Figure 4-2.




      2.  Pick-Up  Velocity.  Gas flow velocities in a settling  chamber must be



                                                                  8  9
 kept below velocities at which reentrainment or "pick-up"  occurs,  '   or




 collection efficiency will be decreased.




      3.  Collection Efficiency.   Collection efficiency  is represented by the




 weight fraction of the dust  retained in the collector.  Theoretical collection




 efficiency may be represented by the ratio of particle  retention time to  theoret-




 ical settling time and cannot exceed unity.
                                     4-10

-------
        THEORETICAL

        SCREEN MESH
EQUIVALENT STANDARD

 TYLER SCREEN MESH
u
o
o
z
Z

i
UJ
I-
102

10°
10-1
10-2
in-3
in-*

n C





io-6
§ § S
0 m 1M
1 1





















1
/.
\n
m

Jj
f/<
*+
P—





























-J
^

/
7
?
-i
ft
/
r






F



















—
t
i_
//
r ''
j j
/'(
f/
/!'
^"
r^


--
— i


'A

in
iO 'T r\j










<^
<~
f
/

w
f/ A
' r /
1' //
- i -/- —
17=
1
J





















cV

#
ulk or apparent) specific gravity of partic es-'
e ative to water at 4° C. "
?. Stokes • Cunning ham correction factor s
ncluded for fine partic es settling in air.
3. Physica properties used:
luid Temp. Viscosity Density :
°F centipoise Ibmass/rt^ • •
Mr 70 0.0181 0.0749









10


100






1,000 10,0
               PARTICLE DIAMETER, microns
     Figure 4-2.  Terminal velocities of spherical

                            in air. (Adopted from reference 7)
                         4-11

-------
4. 2. 3  Design Considerations


      A gravitational settling chamber consists essentially of a chamber in


which the velocity of the carrier gas is decreased so that particles in the gas


settle out by gravity.  Velocity of a gas is reduced by expanding the ducting


into a chamber of suitable dimensions  so  that a low gas velocity is obtained.


      The settling chamber may consist of a simple balloon duct (Figure 4-3),


an expansion chamber with dust hopper (Figure 4-4), or dust settling chamber


(Figure 4-5).


                                         The multiple-tray settling chamber


                                         (Figure 4-6) represents  one of the


                                         first attempts to increase collection


                                         efficiency by  reducing the vertical

       Figure 4-3.  Balloon duct.
                                         settling distance (time) by using


multiple shelving.  Vertical distance between shelves may be as little as 1 inch.


The gas must be uniformly distributed laterally upon entering the  chamber;


verticle distribution is not critical.  Uniform distribution is achieved by the


use of gradual transitions,  guide vanes, distributor screens, or perforated


plates.



      Because the settling rate of dust decreases with increasing turbulence of


the gas,  the velocity of the gas stream is  usually kept as low as possible.  For


practical purposes,  the velocity must not  be so great that settled particles are


reentrained,  or so low that equipment  size becomes excessive.  Gas  velocities


are normally from 1  to 10 feet per second.



                                     4-12

-------
            Figure 4-4. Baffled expansion chamber with dust hopper.







     In practice, gravitational settling velocities used in design must be based





on experience or on tests conducted under actual conditions,  because terminal




settling velocity may be influenced by such factors as agglomeration and





electrostatic charge.





4.2.4 Typical Applications





     Settling chambers are usually installed as pre-cleaners to remove large





particles and agglomerated particles, which can clog small-diameter cyclones






                                    4-13

-------
                 INLET
                 AIR PIPE
                          BAFFLE
                         Figure 4-5.  Dust settling chamber.
                 -. C
3-
                            £
                    Figure 4-6.  Multiple-tray dust collector.


and other dust cleaning equipment.  Because of space considerations, dust

                                                              H
chambers are usually limited to particles larger than 43 microns  (325 mesh).


      Dust settling chambers are most frequently used on natural draft exhaus-


from kilns and furnaces because of their low pressure drop and simplicity of


design.     Other areas of application are in cotton gin operations and alfalfa


feed mills.
                                    4-14

-------
4.3 DRY CENTRIFUGAL COLLECTORS



4.3.1 Introduction



     Dry centrifugal collectors are gas cleaning devices that utilize the



centrifugal  force created by a spinning gas stream to separate particulate



matter from the carrier gas.  Spinning motion is imparted to the carrier gas



by a tangential gas inlet, vanes,  or a fan.  The dust particles, by virtue of



their inertia,  move outward to the separator wall, from which they travel to


           12
a receiver.



     Three important forces that act on individual dust particles during the



separation  process are gravitational,  centrifugal, and frictional drag.  The



force of gravity (F ), which causes the particulate matter to settle, is  equal
                 &


to the product of the  particulate mass (M ) and acceleration caused by gravity



(G).



                               F   =  M   X G
                                 g      P



     The major force causing  the separation of  particulate matter in a



cyclone separator is the centrifugal (radial) force caused by a uniform  change



in linear velocity caused by rotation.  The centrifugal force (F )  is equal to



the product of the particulate mass (M ) and centrifugal acceleration



(V2/R).13'14
  P


                            F   =  M  x  V 2/R
                              c       p      p



Where V is the particle velocitj^ and R is the radius of motion (curvature).

        P
                                    4-15

-------
      The ratio of centrifugal force to the force of gravity is often called the


                     15
separation factor (S):
                            S =  F  /F   = V 2/RG
                                  eg      p
In practice, S varies from 5 for large-diameter,  low-resistance cyclones to


                                                16
2500 for small-diameter, high-resistance units.



      The frictional drag on a dust particle is caused by the relative motion



of the particle  and gas,  and acts to oppose the centrifugal force on the particle.



The frictional drag (F )  is directly proportional to the product of (C ), a drag



coefficient, the projected cross-sectional area of the particle (A ), particle



density (p), the square of the particle velocity relative to the gas stream


   o
(V  ), and an inverse function of the acceleration due to gravity G.
                          Ff  - (Cf)(A )(p)(Vr2)/2G
                                      P


      The gravitational, radial,  and frictional forces combine to determine the



path of the particle and collection efficiency.



4.3.2  Types of Centrifugal  Collectors



      Centrifugal collectors, commonly called cyclones, are made in a wide



variety of designs, which generally fall in the following categories:



      1.   Conventional reverse-flow cyclones



          a.  Tangential inlet.



          b.  Axial inlet.



      2.   Straight-through-How  cyclones.



      3.   Impeller collectors.
                                    4-16

-------
Figure 4-7 shows a typical cyclone of conventional reverse-flow design with a





tangential inlet.  Dust laden gas enters the tangential inlet and flows in a





helical vortex path that reverses at the base of the cyclone to  form an inner





cone.   Dust particles are forced to the wall by centrifugal action and drop to





the bottom of the cyclone.   There, dust must be removed without disturbing




the vortex of gas flow in the cyclone.   Any disruption of the gas  stream reduces





collection efficiency and causes particle reentrainment in the  gas  stream.




      Tangential inlet cyclones are categorized as either high-efficiency or




high-throughput collectors.  The high-efficiency design features a narrow  gas




inlet which enhances collection because of the shorter radial settling distance





and large cross-sectional  area between the  wall and the dust-laden vortex.





These features are typical of many small diameter cyclones.  The high-




throughput cyclone sacrifices  efficiency for volume flow  rate  and is typical of





larger-diameter cyclones.





      Although most cyclones  use a cone to  reverse the gas direction and




to deliver the collected dust to a central point for removal,  a  simple cylinder





can be used.  Because the cylinder requires a greater  axial distance than  the





cone and thereby adds height and weight to the collector,  it is  not commonly




used.





      The axial inlet cyclone is shown  in Figure 4-8.   Like the tangential





inlet cyclone, both the efficiency and pressure drop of  axial inlet units are





affected by the dimensions  of the gas inlet.
                                   4-17

-------
                                                                                          CLEANED GAS
I
I—1
00
               ZONE OF INLET
               INTERFERENCE
                TOP VIEW
                         INNER
                         VORTEX
                         GAS
                         INLET
                SIDE VIEW
   OUTER
   VORTEX
GAS OUTLET
  BODY

  INNER
  CYLINDER
  (TUBULAR
  GUARD)
                           OUTER
                           VORTEX
                            INNER
                            VORTEX
                                               CORE
                                              DUST OUTLET
                                                                                                        -DUST-LADEN GAS
                   Figure 4-7.  Conventional reverse-flow cyclone.
                                                                                Figure 4-8.  Axial  inlet cyclone.

-------
     In cyclones with straight-through flow (Figure 4-9),  particulate matter is



collected  around the periphery of the base and is bled off to a secondary collec-



tor that may be a cyclone or dust settling chamber.   This  type of cyclone is



used frequently as a fly ash collector and as a precleaner  (skimmer) for other



types of dust cleaning equipment.  The chief advantages of this design are low



pressure  drop and high gas handling capacity.



     In the impeller collector (Figure 4-10),  the particulate-laden gas enters



the throat of the impeller and passes through a specially shaped  fan blade where



the dust is thrown into an annular slot leading to the collection hopper.



     The principal advantage of this unit is its  compactness, which may be



of concern in a plant  requiring a large number of collectors.  The major



limitation is a tendency toward plugging and rotor imbalance from the buildup



of solids on the rotating impeller.   Temperature limitations also exist because



of the use of bearings and seals in the device.



4.3.3 Design



     High-efficiency, dry centrifugal collectors require that the separation



factor be  high, and the number of gas revolutions large, and that collected dust



be removed to avoid reentrainment.  Cyclone dimensional  factors, gas


                                                        15
characteristics, and dust properties affect dust  collection.



     Collection efficiency increases with:



     1.  dust particle size,



     2.  particle density,
                                    4-19

-------
                           TOP VIEW
                              SWIRL VANES
                            SIDE VIEW




                          PURGE

                          DEFLECTOR RING
Figure 4-9.  Straight-through-flow cyclone.
             (Courtesy of the Americon Petroleum In-
             stitute)
               4-20

-------
  Figure 4-10.  Dynamic cyclone showing  method by which dust  is dynamically
              precipitated  and delivered  to the storage  hopper.
              (Courfesy of American' Air Filter Company)
     3.   inlet gas velocity,

     4,   cyclone body length,

     5.   number of gas revolutions,

     6.   smoothness of cyclone wall.

Collection efficiency decreases with increased:

     1.   gas viscosity,

     2.   cyclone diameter,

     3.   gas outlet duct diameter,

     4.   gas inlet area.
                                    4-21

-------
      Cyclone efficiencies are commonly classified as low,  medium, and high,





corresponding to weight collection efficiency ranges of 50 to 80,  80 to 95, and



                              14
95 to 99 percent, respectively.    A given cyclone design can fall into more





than one class, depending upon the mode of operation  and  the particle size being




collected.  For example, a cyclone nominally considered  a high-efficiency




cyclone could operate in the low  collection efficiency range if it were used on a





gas stream containing a significant quantity of submicron  particles.




      In addition  to the overall collection efficiency, based on the weight of




entrained particulate entering and leaving the collector, performance is  also




related to cut size.  Generally, cut size is defined as  the  particle diameter




collected with 50 percent efficiency on a weight basis.




      Particle cut size may be estimated from the Rozin,  Rammler, and




Intelmann   formula:
                          Dpc
where:
      D   = diameter of particle collected with 50 percent efficiency,
       pc



      „   - gas viscosity,





      b   - width of cyclone inlet,





      N   --- number of effective turns within the cyclone,
                                    4-22

-------
     V   = inlet gas velocity,
      i

     p   = density of the particulate matter, and


     g   = density of the gas.


     Well-designed,  large-diameter, conventional cyclones may be expected


to provide high collection efficiency for particles from 40 to 50 microns and


typically have cut sizes of S microns.    High-efficiency cyclones having


diameters of less than 1 foot operate efficiently on particles of 15 to 20 microns


in size and have cut sizes of 3 microns.  Typical efficiencies for various


particle size ranges are shown in Table 4-3.


     Collection efficiency of small-diameter cyclones will be low if much of


the suspended material is smaller than 5 microns.  In special cases in which


the dust shows a high degree of agglomeration or high dust concentrations are


involved (over 100 grains per cubic  foot),  cyclones will remove dust particles


smaller than 5 microns in diameter.  The size of the agglomerates  is many


times larger than the original particles.  Efficiencies of as high as  9S percent


have  been attained on agglomerated  dusts having original particle sizes of


from 0.1  to 2.0 microns.


     Factors that commonly cause  a reduction in cyclone collection efficiency


include infiltration of air at the bottom of the cyclone and the buildup of dust


on the cyclone walls.   A variety of dust removal methods is  available (Figure


•4-11).  The buildup of dust may be reduced by means of vibrators and flexible

             IS
rubber cones.    Special valves may be used to discharge dust without


admitting air.

-------
Table 4-3.  RELATIONSHIP BETWEEN PARTICLE SIZE RANGE
           AND CYCLONE EFFICIENCY RANGE14
  Particle size range,
        microns
  Conventional
cyclone efficiency
      High
cyclone efficiency
   Less than 5
   5  to 20
   15 to 50
   Greater than 40
   Low
   Medium
   High
    Low

    Medium

    High

    High
                          4-24

-------
REMOVABLE
CONNECTION
                       DOWNSPOUT
                       FROM
                       CYCLONE
                         MANUAL
                         SLIDE GATE
                          CLOSED
                          DRUM
         SIMPLE CLOSED DRUM
         PERIODIC DUMP
                          DOWNSPOUT
                          FROM
                          CYCLONE
                                          ,_,    MOTOR-
                                          ED    OPERATED
                                                VALVE
                                  MOTOR-OPERATED
                                  VALVE
     DOWNSPOUT
     FROM
     CYCLONE
  DUST COVER
             \
    DUST
    BIN  '
>*SCOUNTER
   WEIGHT
                         AUTOMATIC
                         FLAP
                         VALVES
                                                    DOWNSPOUT
                                                    FROM
                                                    CYCLONE
                                               MECHANICALLY
                                               OPERATED
                                               SPHERICAL
                                               SEGMENT
                                               VALVES
                                               OUT OF PHASE
                                                                           TO DUST
                                                  SPHERICAL SEGMENT VALVES
                                                  FOR HIGH-PRESSURE DIFFERENTIAL
        AUTOMATIC FLAP VALVES
                                              DOWNSPOUT
                                            * FROM
                                           " CYCLONE
                                        TO DUST BIN'
                                                      I

                         CHOKE DISCHARGE SCREW FEEDER
                                                                SPRING-LOADED
                                                                CHOKE ON
                                                                SCREW
                                                                DISCHARGE
                Figure 4-11.  Various types of cyclone dust discharge.
                             (Courtesy of the American Petroleum Institute)
                                         4-25

-------
4.3.3. 1  Operating Pressure Drop - The pressure drop across a cyclone


depends on a number of variables, but usually ranges from 1 to 8 inches of

                                                          14
water.  Efficiency increases with increasing inlet velocity,   but at a lower


rate than that at which the pressure drop increases.  For a given cyclone and


dust combination, an optimum velocity exists, beyond which turbulence increases


more rapidly than separation efficiency,  and efficiency decreases.


      Pressure drop in a cyclone is due to both frictional and  dynamic energy


losses, which are interdependent.  Frictional losses are determined by cyclone


surface roughness,  gas velocity,  and the physical properties of the gas and


aerosol.  Dynamic  energy loss, on the other hand,  is caused by the  energy


stored in the high-velocity rotating centrifugal gas stream. Part of this energy


is lost in the rotating gas leaving the cyclone.


      Internal surface roughness can cause an increase in  frictional pressure


drop, and result in a decrease in overall pressure drop by causing a decrease


in rotational gas  velocity (dynamic pressure loss) along the outer circumference


of the cyclone, with a resultant decrease in  collection efficiency.


      To lower the  pressure drop through a  given collector, either a reduction


of the rotational velocity  (dynamic pressure  loss) of the clean exit gas or re-


duction of internal rotational energy  (dynamic pressure gain) is used.  Pressure


recovery from the exit gas may be accomplished by the use of deflection cones,


baffles, inverted cones,  vanes, or drums and scrolls, but usually at the ex-


pense of reduced collection efficiency.   Pressure reduction values reported in
                                      4-26

-------
the literature vary from 10 to 25 percent of the total pressure drop across


           14
the cyclone.


     Pressure reduction may also lie accomplished by the use of inlet vanes


which reduce pressure drop and rotational velocity, and hence collection


efficiency.  Vanes arc used when gas handling capacity is to he increased and/


or when normal collection efficiency is  so high that loss in efficiency is


insignificant.


     In the impeller collector, pressure drop and collection efficiency may be


increased by restricting the gas outlet.   Pressure drop may be as low as 1/2


inch of water, and pressure gains may  even be realized with some units because


of the pumping action of the  motor-driven  impeller.


4.:i.o.2 Dust Loading - A cyclone can  lie designed to handle practically any


amount of material that can  be moved by gas flow   In general, cyclone


efficiency increases with increasing dust  load.  Since these characteristics


are not possessed by other types of collectors with inherently higher efficiencies


cyclones are frequently used as preclcaners where dust loadings are too high


for the  final collector.


     Because cyclone efficiencies decrease with decreasing dust load and


other types of collectors can operate efficiently at lower dust loadings, cyclones


are usually used (1) for dust loadings of more than 10 grains per cubic foot,


(2) for coarse or easily flocculated  dust loadings of less than 10 grains per


cubic foot, or (3)  if such factors as high temperature and  corrosion exert an


overriding influence.



                                      4-27

-------
4.
Other Design Considerations - Cyclones may be operated in parallel
as shown in Figures 4-12 and 4-13.  In both configurations,  gas distribution




becomes critical and collection efficiency is usually lower than the corresponding




single-unit efficiency, even in well-designed systems.
                     Figure 4-12.  Cyclones arranged in parallel.




      Series operation is sometimes justified if the dust is subjected to




fragmentation and deflocculation as a result of bouncing within the cyclone, if




large particles must be removed  to prevent clogging,  if abrasion is a problem,




or if the primary cyclone loses efficiency.  In these cases,  the primary cyclone




is usually of large-diameter, low-pressure-drop design followed by progres-




sively smaller-diameter cyclones,  each with  increased efficiency and pressure




drop.




      Erosion effects increase exponentially with increasing gas velocity.




Maximum erosion occurs at an impingement angle of from 20 to 30 degrees,




and is approximately twice the erosion occurring at 90 degrees.1   The effects of
                                      4-28

-------
                                      erosion may be minimized by the use



                                      of special alloys, abrasion-resistant



                                      refractories, thicker walls,   rubber



                                      lining,  and by reducing gas velocity.



                                      4. 3.4  Typical Applications



                                            Cyclones are  frequently used



                                      in both primary and secondary gas



                                      cleaning operations.  They are used  in



                                      feed and grain mills, cotton gins, ferti-



                                      lizer plants,  petroleum refineries,



                                      asphalt mixing plants, metallurgical



                                      operations, and chemicals, plastics,


                                                               20, 21
                                      and metals manufacture.



                                            Cyclones designed for the collec-
Figure 4-13.  Cyclones arranged  in parallel,  tion of mist are  sometimes modified by

     (Courtesy of Western Pre c I p itot i on Division)

placing an outer skirt on the gas outlet to prevent liquid carryover.  Repre-




sentative performance and applications of centrifugal collectors are listed in


                  99
Tables 4-4 and 4-5.
                                     4-29

-------
                     Table 4-4.  REPRESENTATIVE PERFORMANCE OF CENTRIFUGAL COLLECTORS
                                                                                                        20
Collector
type
Series cyclone
Cyclone
Cyclone
Cyclone
Cyclone
Impeller
collectors
Impeller
collectors
Process
Fluid- catalytic
cracking
Abrasive Cleaning
Drying
Grinding
Planing mill
Grinding
Rubber dusting
Material
Catalyst
Talc
Sand and Gravel
Aluminum
Wood
Iron scale
Zinc stearate
Airflow,
ft3/min
40,000
2,300
12,300
2,400
3,100
11,800
3,300
Pressure drop,
in. H20
High
0.33
1.9
1.2
3.7
4.7
9.0
Efficiency,
wt %
99.98
93.0
86.9
89.0
97.0
56.3
88. 0
Inlet load,
gr/ft3
2800
2.2
38.0
0.7
0.1
0.15
0.6
Inlet mass
median size, |j.
37.0
—
8.2a
	
	
3.2b
0.7
I
CO
o
        Outlet mass median size = 3.2 microns

        Outlet mass median size = 2.5 microns

-------
Table 4-5.  APPLICATIONS OF CENTRIFUGAL COLLECTORS
Operation or process
Crushing, pulverizing, mixing,
screening
Alfalfa feed mill

Barley feed mill
Wheat air cleaner
Drying, baking
Catalyst regenerator (petroleum)
Detergent powder spray drier
Orange pulp feed drier
Sand drying kiln
Sand and gravel drying
Stone drying kiln
Mixing fluids
Asphalt mixing
Bituminous concrete mixing
Polishing, buffing, grinding,
chipping
Grinding (aluminum)
Grinding (iron)
Grinding (machine shop)
Surface coating
Rubber dusting
Surface treatment - physical
Abrasive cleaning
Abrasive stick trimming and
shaping
Casting cleaning with metal
shot, sandblasting and tumbling
Foundry tumbling
Truing and shaping abrasive
products
Woodworking, including plastics
rubber, paper board
Mill planing
Air contaminant


Alfalfa dust

Barley flour dust
Chaff

Catalyst dust
Detergent powder
Pulp dust
Silica dust
Silica dust
Silica dust

Sand and gravel dust
Sand and stone dust


Aluminum dust
Iron scale and sand
Dust

Fluffy zinc stearate

Talc dust
Silicon carbide and
alumina dust
Metallic and silica dust

Dust
Silicon carbide and
alumina dust


Wood dust and chips
Type of air
cleaning
equipment


Cyclone, settling
chamber
Cyclone
Cyclone

Cyclone, ESP
Cyclone
Cyclone
Cyclone
Inertial collector
Cyclone

Cyclone
Cyclone, scrubber


Cyclone
Cyclone
Impeller collector

Impeller collector

Cyclone
2 parallel cyclones

Impeller collector

Impeller collector
Cyclone



Cyclone
Collector
efficiency,
wt %


85

85
85

95
85
85
78
50
86

50-86
95


89
56
91

78-88

93
51

97-99+

99
58



97
Reference


23

23
23

23
23
23
24
25
24

24
22


26
25
27

26

26
24

27

27
24



26
                         4-31

-------
 4.4 WET COLLECTORS AND MIST ELIMINATORS


 4.4.1 Introduction


      Wet collectors use a liquid, usually water, in the separation process


 either to remove particulate matter directly from the gas stream by contact


 or to increase collection efficiency by preventing reentrainment.


 4.4.1.1  Collection Theory - Wet collectors increase particle removal efficiency


 by two mechanisms: (1)  fine particles are "conditioned" so that their effective


 size is  increased,  enabling them to be collected more easily and (2)  re-


 entrainment of the collected particles is minimized by trapping them in a

                                  O O  OQ
 liquid film and washing them away.   '


      The effective size of  the particle may be increased by promoting con-


 densation on fine particles,  which act as nuclei when the vapor passes through


 its dew point.  Condensation can remove only a relatively small amount of


 dust because the amount of condensation required to remove high concentrations


 is usually greater than can  be readily achieved.


      Forced conditioning or trapping of dust particles on liquid droplets is


 usually  accomplished by impact using inertial forces. Wetting agents do not


 significantly increase collection efficiency, but they do help to prevent re-


 entrainment of collected dusts that are not easily wetted by water.30 Solubility


of the particle in the droplet is  usually not a factor in increasing collection


effectiveness.
                                    4-32

-------
     The principal mechanisms by which participate matter is brought into


                         29
contact with liquid droplets   are:



       1.  Interception.  Interception occurs when particles are carried by



       a gas in streamlines around an obstacle at distances of less than the



       radius of the particle.



       2.  Gravitational Force. Gravitational force causes a particle,  as



       it passes an obstacle,  to fall from the streamline and settle on the



       surface of the obstacle.



       3.  Impingement.  Impingement occurs when an object, placed in



       the path of a particle-laden gas stream, causes the gas to flow



       around the obstacle.  Larger particles, however, tend  to continue



       in a straight path because of inertia and may impinge on the obstacle



       and be collected.  (The impingement target efficiency is represented



       by the ratio of the cross-sectional area of the liquid droplets to the



       area of the gas stream cleared of particles.)



       4.  Diffusion. Diffusion results from molecular collisions and,



       except for submicron particles, plays little part in separation of



       particles from a gas stream.



       5.  Electrostatic Forces.  Electrostatic forces result  when particles



       and liquid droplets  become  electrically charged.  An electrical charge



       may be induced by flame ionization or friction,  or by the presence of



       charged matter.  Electrostatic forces may affect collection



       efficiency significantly.



                                  4-33

-------
       6.  Thermal Gradients.  Thermal gradients are important to the



       removal of matter from a particle-laden gas stream because parti-



       culate matter will move from a hot area to a cold area.  The motion



       is caused by unequal gas molecular collision energy on the surfaces



       of the hot and cold sides of the particle, and is directly proportional



       to the temperature gradient.



4.4.1.2  Efficiency - Efficiencies of wet-scrubbing devices are compared on


                                                      31
the basis of "contacting power" and  the "transfer unit. "    Contacting power



is that portion of useful energy expended in producing contact of the particulate



matter with the  scrubbing liquid, as well as  in producing turbulence and mixing



in the scrubber  device.  The contacting power represents the kinetic energy or



pressure head loss across the scrubber, kinetic energy or pressure head drop



of the scrubbing liquid, and other forms of energy dissipated in the gas stream,



such as sonic energy or energy supplied by a mechanical rotor.



      The transfer  unit,  which is expressed  as  the numerical value of the



natural logarithm of the reciprocal of the fraction of the dust passing through



the scrubber, is a measure of the difficulty of separation of the particulate



matter.



      Dust collection efficiency is believed by some investigators  to be  directly



related to contacting power and the properties of the aerosol and to have litte
                                   4-34

-------
                                            31
relationship to scrubber design and geometry.    Others believe design details



are important in the effort to achieve maximum collection efficiency for a



given pressure drop.



     Gas cleaning equipment is usually selected on the basis of required col-


                 32
lection efficiency.    There  are other factors such as gas temperature and



humidity and dust stickiness and abrasiveness that  may exert an overriding



influence on the final choice.  In the following discussion principal design



features of the various groups  of wet collectors are reviewed from the point



of view of general suitability under  different operating conditions.



     In general, particle size distribution and operating conditions will de-



termine collection efficiencies, which, in turn,  will determine power require-



ments for a given unit.



4.4.2  Equipment Description and Design



     Collection efficiencies, operating pressure drop, water  requirements,



and other operating characteristics reported herein were obtained from



manufacturers' equipment bulletins  and other literature sources.



4.4.2.1  Spray Chamber -  The  simplest type of wet scrubber is a round or



rectangular spray chamber  into which water is introduced by means of spray


    .   33
nozzles.
                                    4-35

-------
      When spray chambers are used to remove coarse particles from hot



gases, they perform the additional functions of gas cooling and humidification.


Spray chambers also effect preliminary conditioning of the particulate matter



by causing condensation of moisture on particles, thus increasing collection



efficiency by increasing the size of  the particles.


     The principal three configurations in a spray chamber are cocurrent


                                          34
flow, countercurrent flow,  and cross now .


      In  cocurrent flow, both the spray droplets and the gas containing par-



ticulate matter flow through the spray chamber in the same direction.  The


relative  velocity of the water droplet and gas stream causing effective


collision and capture of the particulate matter is at a minimum, as is col-


lection efficiency.  Part of the kinetic energy of the  spray droplets  is expended


in inducing gas circulation and motion within the  scrubber.



      Countercurrent flow occurs when the liquid and gas flow in opposite


directions,  as in a spray tower in which the liquid is introduced in the top of


the tower and falls against the rising gas stream.  The relative velocity of the


liquid droplets and particulate matter in the gas stream is at a maximum, as


is collection efficiency.



      In  cross flow operation, the liquid is introduced at right angles to the



direction of gas  flow and falls across the gas stream.  The relative velocity



of the particulate and liquid droplet  and the impaction efficiency lie between



the cross flow and countercurrent flow methods  of operation.
                                     4-36

-------
     For a given spray chamber design, mixed flow usually occurs because of



turbulence,  liquid droplet inertia, and gravitational  force.  Liquid droplets



travel in the direction of the liquid stream until inertial forces are overcome



by air resistance.   Large droplets settle under the influence of gravity while



smaller droplets may be swept along with the gas stream.



     Liquid droplets and particulate matter may be  separated from the gas



stream by gravitational settling, impaction on baffles, filtration through



shallow packed beds, or by cyclonic action.



     Spray chambers are used  in exhaust systems for light dust cleaning,



electroplating fume control, and preconditioning dust from  acid phosphate


          34
fertilizers,    as well as for providing a final cleanup of exhaust gases from


                                                            8
the recovery furnaces in the kraft pulp manufacturing process.


                                                                     33
     Figure 4-14 shows a spray system installed in the base of  a stack.



When the  system is properly adjusted and operated,  60 to 80 percent of the


                                                                            Q /?

solids entering the spray zone may be collected during soot-blowing operations.



Approximately 1/2 gallon of liquid per minute per square foot of stack cross



sectional  area is required.



     The smokestack soot wet-out surface area may also be increased by



packing the smokestack (Figure 4-14).  The pieces of packing are usually



stacked and of large diameter to minimize pressure drop and fouling of the bed.



Extra draft fan capacity must be available to make up for the decrease in draft



caused by lower flue  gas temperature and by packing.  The bed must be cleaned



periodically by flooding with water.



                                   4-37

-------
                                                                                                                FULLJET NOZZLE
CO
00
                       16 FULLJET NOZZLES.
                       13 REQUIRED IN TWOBANKS.
                       MATERIAL TYPE 303 STAIN-
                       LESS   STEEL.  PRESSURE
                       DROP 58  TO 62 p s i
                      rNOTE:  NOZZLES TO PITCH
                              10° TOWARDCENTER
                              OF STACK
8 FULLJET NOZZLES.
26  REQUIRED  IN   FOUR
BANKS.  MATERIAL   TYPE
303    STAINLESS   STEEL.
PRESSURE  DROP   55  TO
65 p s i

NOTE: NOZZLES TO PITCH
          TOWARDCENTER
      OF STACK
            I
                                                                                                         SECTION A-A

                                                                                                                 FULLJET NOZZLE
                                                                                       INLET PIPE
                                                                                                         SECTION B-B
                                                                                              EXPECTED VARIATION OF LIQUID LOAD
                                                                                              PER SQUARE FEET A PPROX IMATEL Y 10%
                            PACKED STACK
                                                           UNPACKED STACK
                                        Figure 4-14.  Arrangement of  nozzles  in smoke stack spray system.
                                                      (Courtesy of Sproying Systems Company)

-------
4 4.2.2  Gravity Spray Towers - One of the simplest types of wet scrubbers



is the gravity spray tower.  Liquid droplets, produced by either spray nozzles



or atomizers, fall downward through a countercurrent rising gas stream con-



taining dust particles.  To avoid  spray droplet entrainment and carryover, the



terminal settling velocity of the spray droplets must be greater than the velocity



of the rising gas  stream.  In practice,  the vertical gas velocity usually ranges



from 2 to 5 feet per second.  For higher velocities, a mist eliminator must be



used in the top  of the  tower.



      Collection impingement target efficiency in a gravity spray tower is in-



fluenced by the difference between the free-falling velocity of these particles



and the velocity of the rising gas stream.  Droplet collection efficiency increases



with decreasing droplet size and  increasing  relative velocity.  In a gravitational



settling chamber these two conditions are mutually exclusive.  Hence, there is


                                                           37
an optimum droplet size for a maximum collection efficiency.    In practice,



this optimum size is from 500 to 1000 microns.



      Spray towers are often used  as  precoolers where large quantities of gas



are involved. Operating characteristics include low pressure drop (usually



less than 1 inch of water, exclusive of  mist  eliminator section and gas dis-



tribution plate), ability to handle spray liquid  having a high solid content (us-



ing water recirculation because of large spray nozzle clearance and spray drop-



let size),  and moderate liquid requirements (from  5 to 20 gallons per 1000 cfm).



Their chief disadvantages are low scrubbing efficiencies for dust particles in
                                    4-39


   331-716 0-69-13

-------
the 1- to 2-micron range and large space requirements.  Spray towers are


usually limited to  the collection of particles of 10 microns or larger.

                                                      33
       Figure 4-15 shows  a typical spray tower layout.    Gas  entering the


base of the spray tower passes through inlet conditioning  sprays, through a


distribution plate, through one or more banks of spray nozzles, and through a


mist eliminator section.  The mist eliminator is usually necessary in a tower


operating at gas velocities of over 6 feet per second.


       The base gas distributor plate may consist of a perforated plate with


uniform hole distribution or a support plate covered with from 6 to 12 inches of


tower packing.


4.4.2.3 Centrifugal Spray Scrubbers - The efficiency of collection of


particles smaller  than those  recovered in a gravitational spray tower can be


improved by increasing the relative velocity of the droplets and gas stream.


This may be achieved by using the centrifugal force of a spinning gas stream.


       Centrifugal spray scrubbers are of two types.   In the first type the


spinning motion is imparted to the gas stream by a tangential entry such as


shown in Figure 4-16a.  The principal benefit is derived from the wetted walls,


which prevent  reentrainment of separated material.  Best collection is obtained


by spraying countercurrently to gas flow in the inlet duct at water rates of from


5 to 15 gallons per 1000 cubic feet of gas  and at pressure  drops  in excess of

                  37
3 inches of water.     Figure 4-16b shows this principle employed with a


tangential base gas inlet.   The liquid spray is directed outward from sprays
                                    4-40

-------
GAS IN
               / \/\
               /v\
                 /\  \
    Figure 4-15. Typical layout for spray tower.


               (Courtesy of Spraying Systems Company)
                                             -MIST ELIMINATOR
                                              GAS DISTRIBUTOR PLATE
                           4-41

-------
DUSTY
GAS  "
CLEANED GAS


      f   ANTI-CARRYOVER BAFFLE


                   SPRAY RING
                  "WATER SUPPLY
                                                                          CLEAN  GAS OUT
  a.  LARGE-DIAMETER IRRIGATED CYCLONE
                CLEAN GAS
                OUT
                               TOWER NOZZLES,
                               DIRECTED
                              .CROSS FLOW
                                RECTANGULAR
                               -INLET
                               FRESH WATER
                               SUPPLY
   FLUSHING JETS
   DIRECTED
   DOWNWARD

                WASTE OUT


        c. CYCLONIC SPRAY SCRUBBER.

         (Courtesy of Buffolo Forge Compony)
                                                       GAS IN
                                                        CORE BUSTER DISK


                                                         SPRAY MANIFOLD


                                                            DAMPER
                                                                        WATER WATER
                                                                        OUT    IN
                                                     b. PEASE ANTHONY  CYCLONIC SCRUBBER

                                                       {Courtesy of Chemicol Construction Corporotion)
                                                    SEPARATOR
                                                     WATER OUT


                                                d.  MULTI-WASH SCRUBBER.

                                              (Courtesy of Cloude B. Schneibl* Compony)
                        Figure 4-16.  Centrifugal spray scrubbers.
                                               4-42

-------
set in a central pipe.  An unsprayed section above the nozzles is provided so



that the liquid droplets containing the collected particles will have time to reach



the walls of the chamber before coming into contact with the gas stream.



      In the scrubber design illustrated in Figure 4-16c water is sprayed



tangentially inward from the wall as an aid in imparting centrifugal motion to



the gas stream.   The scrubbing liquid is introduced through nozzles at a pres-



sure of 400 pounds per square inch (gauge).



      Water requirements are approximately 5 gallons  per 1000 cubic feet



of gas.  Operating pressure drop ranges from 1.3 to 2.3 inches of water with

                                                                    O Q

removal efficiencies as high as 96 percent for 2- to 3-micron particles.



      In the second design, (Figure 4-16d) the rotating  motion is given to the



gas stream by fixed vanes  and impellers,  and the scrubbing liquid is introduced


                                          39
centrally either as a spray or liquid stream.



      This type  of scrubber is used as  a  final cleanup after spray dryers,



calciners,  coolers, crushers, classifiers, and cupolas.



4.4.2.4  Impingement Plate Scrubbers - Impingement plate scrubbers,



shown in Figure 4-17a,  consist of a tower equipped with  one or more impinge-


                                                      37
ment stages, mist removal baffles,  and  spray chambers.   The impingement



stage (Figure 4-17b) consists of a perforated plate that has from 600 to 3000



holes per square  foot and a  set of impingement baffles so arranged that a baf-



fle is located directly above each hole.   The perforated plate is  equipped with



a weir to control  the level of scrubbing liquid on the plate.  The liquid flows



over the plate and through a downcomer to either  a sump or the  lower stage.


                                   4-43

-------
       The dust-laden gas enters the lower section of the scrubber and passes



up through a spray zone created by a group of low-pressure sprays. As the



dust-laden gas passes through the impingement stage, the high gas  and particle



velocity (from 75 to 100 feet per second) effectively atomizes the liquid at the



edges of the perforations.  The spray droplets, about 10 microns  in size,



enhance collection of fine dust.



       Overall efficiency for a single plate may range from 90 to  98 percent



for 1-micron  particles or larger, with pressure drops of from 1 to 8 inches of



water  and water requirements of from 3 to 5 gallons  per 1000 cubic feet of


    37
gas.


4.4.2.5  Venturi Scrubbers - Obtaining high collection efficiency of fine



particles  by impingement requires a small obstacle diameter and high relative



velocity of the particle as it  impinges on the obstacle. In a venturi scrubber



this is achieved by introducing the scrubbing liquid at right angles to a high



velocity gas flow in the throat (vena contracta) of the  venturi. Very small



water droplets are formed by the gas flow, and high relative velocities  are



maintained until the droplets are accelerated to their  full speed.



       In the  venturi scrubber the velocity of the gases alone causes the dis-



integration of the liquid.  The energy expended in the  scrubber is  accounted



for by the gas stream pressure drop through the scrubber, except for the



small amount used in the sprays  and mist separation  chamber.



       A  second factor which plays  a part in the effectiveness of the venturi



scrubber  is the conditioning  of dust particles by condensation. If the gas in




                                    4-44

-------
                      TARGET .
                      PLATE  \
     IMPINGEMENT
     BAFFLE STAGE
ORIFICE
PLATE
                                   GAS FLOW

     ApG.Sr°^E.l;lA_TING    ARRANGEMENT OF "TARGET PLATES'
     iLUlilAbb        IN IMPINGEMENT SCRUBBER
                          WATER DROPLETS ATOMIZED
                          AT EDGES OF ORIFICES
                                DOWNSPOUT TO
                                LOWER STAGE
 IMPINGEMENT SCRUBBER    b.  IMPINGEMENT PLATE DETAILS
Figure 4-17.  Impingement plate scrubber.
                4-45

-------
the reduced-pressure region in the throat is fully saturated,  or (preferably)



supersaturated, some condensation will occur on the particles  in the throat due to



the Joule-Thompson effect.  Condensation will be more pronounced if the gas is



hot, due to the cooling effect of the scrubbing liquid.   This helps the particle to



grow, and the wetness of the particle surface helps agglomeration and separation,



      Gas velocities of from 200 to 600 feet per  second are attained in the



venturi throat.    Water is either injected into the throat of the venturi as a



spray (Figure 4-18a) or  by means of a weir box  (Figures 4-18b and 4-18c) in



quantities of from 5 to 7 gallons per  1000 cubic feet  of gas.



      Figures 4-18b and 4-18c show  a scrubber  that uses an overflow weir  on



the walls upstream of the venturi.  This method of water injection has  the ad-



vantage of allowing the scrubbing water to be recirculated to much greater



extent than is possible with systems  using small jets.



      Recent developments have taken the form  of finding methods of injecting



water to reduce nozzle wear and pump requirements,  and in maintaining pres-



sure drop with varying gas flows.  Methods of maintaining pressure  drop and



scrubbing efficiency with varying gas flow rates have been centered in the



development of variable  venturi throats.



      The flooded disk (variable-throat-orifice scrubber) illustrated in Figure


                                     41
4-19 is a relatively new  development.    Scrubbing liquid is fed to the center



of the orifice plate, which serves to  distribute the liquid across the orifice



throat.   The pressure drop and efficiency performance is comparable  to other
                                    4-46

-------
Figure 4-18.  Venturi scrubber may feed liquid through jets (a),
              over a weir (b), or swirl them on a shelf (c).
              (Courtesy of UOP Air Corroction Division)
                           4-47

-------
venturi scrubbers.  The scrubbing efficiency and pressure drop may be ad-


justed by changing the position of the disk.
                                                         CLEAN GAS OUTLET
                       DUSTY GAS
                       INLET
CYCLONE MIST
SEPARATOR
   ADJUSTABLE DISK
           STUFFING BOX —


SCRUBBING WATER INLET-
                                       TANGENTIAL

                                       INLET
                             DISK-POSITIONING ROD
                                                       SCRUBBING WATER OUTLET
              Figure 4-19.  Flooded disk (variable throat orifice) scrubber.

                          (Courtesy of Research Cottrell Incorporated)
       The operating pressure drop across the unit ranges from 6 to 70 inches

 of water.  Water recirculation rate is about 5 gallons per 1000 cubic feet of

 gas; make-up water required is about a gallon per 1000 cubic feet.
                                       4-48

-------
      In the venturi jet scrubber the scrubbing liquid may be supplied in the
form of a high-velocity jet directed along the axis of a venturi throat.  The
ejector venturi scrubber uses the velocity of the contacting liquid to pump,  scrub,
and/or absorb the entrained gas.
      The mechanical efficiency of the venturi jet  stream in pumping the gas
may range as high as 16 to 17 percent of the total energy input.   The energy
requirements range  from 1 to 5 horsepower per 1000 cubic feet per minute.
Corresponding  liquid requirements range from 20 to 50 gallons per 1000 cubic
feet of gas.  Increased collection efficiency requires increased energy ex-
         42,43
penditure.
      In the multiple-venturi jet scrubber (Figure 4-20),  a nozzle sprays
a hollow cone of water into the belled venturi entrance so that the spray strikes
the throat wall  and rebounds in the form of a fine spray at right angles  to the
gas  stream.  The water passes through the gas stream twice before passing
through the venturi diffuser section.  Features of the design are  low water
                           44
usage and low pressure drop.
     The vertical venturi differs from the conventional venturi scrubber in
that the gas flow is directed upward to produce a turbulent  mixing action of the
gas  stream and suspended scrubbing liquid in the diffuser section of the venturi
(Figure 4-21).  Liquid recirculation occurs both internally by eddy mixing
action in the diffuser and externally by return  of the scrubbing liquid, after
partial solids separation, to the venturi throat.  The carryover slurry, when
                                    4-49

-------
Figure 4-20.  Multiple-venturi jet scrubber.
              (Courtesy of B ue 11 Corporation)
                     4-50

-------
                         MIST ELIMINATOR
                         SECTION
                     CUTAWAY VIEW OF
                     AEROMIX SHOWING
                     FLOW PATTERN. NOTE
                     RECIRCULATION ZONE.
Figure 4-21.  Vertical venturi scrubber,
           (Courtesy of UOP Air Correction
           Division)
separated by the centrifugal action

of the gas stream caused by the sta-

tionary impeller, returns by gravity

to the solids concentrator.  The

principal advantages of this design

are high solids content of slurry,  low

water usage (1 to 3 gallons per f 000
                                       cubic feet of gas), elimination of a
recirculation pump, relatively low

pressure drop,  and low operating

      45
costs.

4. 4. 2. 6  Packed Bed Scrubbers - A

tower or box packed with such pack-

ing as Raschig rings,  saddles, tile,

and marbles may be used for dust

and mist collection as well as for gas

absorption (Figure 4-22).   Two basic

packed bed designs, cross-flow

(Figure 4-23a) and countercurrent

flow (Figure 4-23b) exist.  The

packed bed may be held in place

(fixed),  free to move (fluid),  or
                                   4-51

-------
  PALL RING
TELLERETTE
 MASPAC
                                               PLASTIC INTALOX
                                                   SADDLE
                                 RASCHIG
                                   RING
LESSING
  RING
CROSS-PARTITION
     RING
                               SINGLE SPIRAL   DOUBLE SPIRAL   TRIPLE SPIRAL
                                   RING             RING             RING
                                         BERL
                                         SADDLE
          INTALOX
          SADDLE
                                            CERAMIC PACKINGS
                 Figure 4-22.  Wet scrubber packings.
                              4-52

-------
                                                                                       GAS OUTLET
f
CJl
CO
                                   LIQUID
                                   DISTRIBUTION    UNWETTED
                         PACKING  HEADERS        , SECTION FOR
                         SUPPORT-,     /        ,-' MIST ELIMINATION
                         C" t? i r^
                                                   -PACKING SUPPORT
                                                          GRID
DIRTY

GAS IN
                                                           CLEAN GAS
                      FRONT     /
                      CLEANING "
                      SPRAYS
                                                                         GAS INLET —
                       "SUMP
                                                                                                             MIST
                                                                                                             ELIMINATOR
                                                                                                             SECTION
                                                                                        LIQUID
                                                                                        INLET

                                                                                        'V WEIR
                                                                                        DISTRIBUTOR

                                                                                        PACKED
                                                                                        SCRUBBING
                                                                                        SECTION
                                                                                                             . PACKING
                                                                                                              SUPPORT
                                                                                         LIQUID
                                                                                         OUTLET
                                 a.  CROSS-FLOW  SCRUBBER
                                                                               b. COUNTERCURRENT-FLOW  SCRUBBER
                                                     Figure 4-23.  Packed-bed scrubbers.
                                                                   (Courtasy of Chemical Engineering Magazine)

-------
covered with water (flooded).  The irrigating liquid serves to wet, dissolve,




and/or wash the entrained particulate matter from the bed.  Dry beds may be




used for the elimination of mists.  In general,  smaller-diameter tower packing




gives a higher particle target efficiency than larger-sized packing for a given




gas velocity.



       The cross flow, fixed bed,  packed scrubber (Figure 4-23a) operates




with the gas stream moving horizontally through the packing while the irriga-




ting liquid  flows by gravity vertically through the packing.  This type of scrub-




ber operates with a very low pressure drop and water requirements, both of




which are about 40  percent of that required for counter flow operation.  The




leading face of the packed bed is usually slanted from 7 to 10 degrees  (depend-




ing on gas  velocity) in the direction of the oncoming gas stream to ensure com-




plete wetting and washing of the face of the bed by the falling irrigation liquid.




Inlet sprays are usually included in this design to condition the inlet gas and




scrub the face of the packed bed.  The first few inches  of the bed may be irri-




gated more heavily to prevent build-up of solids.   The back of the bed is usually



                                         46
operated dry to act as  a demisting  section.




       Liquid requirements range  from 1 to 4 gallons per 1000 cubic feet of




gas, with pressure drops of from 0. 2 to 0. 5 inch of water per foot of bed.




Collection efficiency in excess of 90 percent may be achieved when collecting




particles of 2 microns or larger, with dust loadings  as high as 5 grains


              47
per cubic foot.    Higher dust loadings may be handled if the dust is readily



soluble.




                                     4-54

-------
      Countercurrent flow (Figure 4-23b) is the most common design used in
packed beds.  Gas is forced upward through the packing against gravity flow of
the liquid.
      Countercurrent flow works best at a pressure drop and gas velocity
that cause the buildup of water in and on top of the bed,  usually 0.5 to 1.0
                                             4ft
inch of pressure drop per foot of packing depth.    Pressure drop in excess
of this amount will usually result in excessive liquid entrainment and reduced
efficiency.  Liquid flow rates of from 10 to 20 gallons per 1000 cubic feet of
gas are common.  Water efficiency will then be at a  maximum and bed clogging
at a minimum.
      In cocurrent, or  parallel  flow, the gas stream and liquid pass through
the bed in the same direction.  In this type of operation the irrigation liquid
keeps the packed bed from being  clogged,  and the gas and liquid both assist in
washing solids through the bed.   The advantage of this type of operation is the
small liquid requirement,  7 to 15 gallons per 1000 cubic feet of gas.  The
operating pressure drop is on the order of 1 to 4 inches of water per foot of
packed bed.
      The flooded-bed packed scrubber is operated as  a counterflow packed tower
(Figure 4-24).  The packing consists of a 6-inch thick bed of spherical packing.
Dust- and fume-laden air enters  below the bed of glass marbles and passes through
a spray section and up through the flooded bed of spheres.  Bubbles  formed in
the bed  create a turbulent layer approximately 6 inches  in depth. The marbles
                                    4-55
  331-716 0-69-14

-------
have a constant,  gentle rubbing action which makes them self-cleaning.  En-



trained moisture is removed by impaction or inertial separation in a mist



elimination section.  The scrubber is reported to be 99 percent efficient in re-



moving particles 2 microns  and larger with a pressure drop of from 4 to 6


                49                                                /
inches of water.     Scrubbing  liquid requirements are from 2 to 2-1/2 gallons



per 1000 cubic feet of gas.   Liquid with a high solid content can be recirculated.



The scrubber is capable of handling dust loads of up to 40 grains per standard



cubic foot.  Flooded bed packed scrubbers may be used to control emissions



of acid vapors, carbon black,  ceramic frit,  chlorine tail gas, cupola gas, and



ferrite dusts.



       Fluid bed packed scrubber (Figure 4-25) packing consists of low density



polyethylene or polypropylene  spheres about 1-1/2 inches in diameter that are


                                                               45
continually in motion between the upper  and  lower retaining grid.



       The scrubbing liquid  is sprayed downward over the balls in a counter-



current  flow of dirty gas.  Gas and  liquid are brought into contact on the sur-



face  of the wetted spheres and  in the spray between them.



       The spheres are continually cleaned  by constant motion, and the bed is



not readily plugged.




       Pressure drop ranges from  6 to  8 inches of water, and collection



efficiencies are in excess of  99 percent for particles of 2  microns and larger.49




Liquid and dust handling capacities  are comparable to the flooded bed packed



     uu    45
scrubber.
                                     4-56

-------
GLASS SPHERES
       SPRAY
       WATER INLET
                                                                                          MIST
                                                                                          ELIMINATOR
                                                                                         TURBULENT
                                                                                         LAYER
                              Figure 4-24.   Flooded-bed  scrubber.
                                           (Courtesy of National Dust Collector Corporation)
                                             4-57

-------
                                         CLEAN GAS
 MIST ELIMINATOR
FROM
RECIRCULATION
PUMP
SCRUBBING LIQUOR
RETAINING GRID
FLOATING BED OF LOW
DENSITY SPHERES
RETAINING GRID
MAKEUP LIQUOR
TO
RECIRCULATION
PUMP
                                 c>  O~u u
                                  oo \poooooo
O. OlONO  O, O O O
                                                                                 TO DRAIN
                                                                                 OR RECOVEF
                  Figure 4-25.  Floating-ball (fluid-bed) packed scrubber.
                                (Courtesy of UOP Air Correction Division)
                                         4-58

-------
4.4. 2.7  Self-Induced Spray Scrubbers -  The particle collection zone of the
self-induced spray scrubber is a spray curtain that is induced by gas flow through
a partially submerged orifice or streamlined baffle.  Mist carryover is minimized
by baffles or swirl chambers.  In the submerged orifice scrubber (Figure 4-26a)
the impingement gas velocity of about 50  feet per second creates droplets in the
                         50
300- to 400-micron range.    Blaw Knox (Figure 4-26b) and Doyle  (Figure
4-26c) scrubbers operate with impingement velocities of from 120 to 180 feet
        A  51
per second.
     Pressure drop ranges from 2 to 15 inches,  and water requirement is
about 1 gallon per 1000 cubic feet of gas when water is recycled.
     The chief advantages of the self-induced spray scrubber design are
its ability to handle high dust concentration and concentrated slurries.
     Sludge removal may be accomplished by drag chains or by sluicing the
sludge to suitable  separators.
4.4.2.8 Mechanically Induced Spray Scrubbers - In the mechanically induced
spray scrubber (Figures 4-27a and 4-27b) high-velocity sprays are generated
at  right angles to the direction of gas flow by a partially submerged rotor.
Scrubbing is achieved by impaction because of both high radial droplet velocity
and vertical gas velocity.  Liquid atomization occurs at the rotor and at the
          52
outer wall.
                                   4-59

-------
                                                                                                                          GAS OUTLET
 I
OJ
o
                   a.  SCHMIEG     SWIRL-ORIFICE   DUST   COLLECTOR

                      (Courtesy of United Sheet Metal Co., Inc.)
                                                                                                                                           SEPARATOR
                                                                                                                                           PLATES
                                                                                                                                           PRIMARY
                                                                                                                                         -' SEPARATOR
b.  LIQUID VORTEX  CONTRACTOR

   (Courtcfly of Blow Kno> Co.)


                 DIRTY GAS
RECYCLE TO
PROCESS
                                                                                                                                     DOYLE SCRUBBER
                                                                                                                                     (Court.,y at W..r.,n Pr,
                                                                 Figure 4-26.  S©l f- induced—spray scrubbers.

-------
      Power and liquid requirements range from 3 to 10 horsepower and from



4 to 5 gallons per 1000 cubic feet of gas for the high-velocity design (Figure


                                                                            53
4-27b), depending on particle size and the desired level of scrubbing efficiency.



      Advantages of this type of scrubber are relatively low  liquid requirements,



small space requirements,  high  scrubbing efficiency, and high dust load capac-



ity.  The rotor, however,  is susceptible to erosion from large particles



and abrasive dusts,  and high-energy scrubbing applications may require



the use of additional mist elimination equipment.



4.4.2.9 Disintegrator Scrubbers - A disintegrator scrubber consists of a



barred rotor within a barred stator.  Water is injected axially through the rotor



shaft and is separated into fine droplets by the high relative velocity of rotor  and



stator bars.  Dust particles are  impacted by the high velocity liquid droplets.



      Water and power requirements range from 4 to 9 gallons per minute



and from 7 to 11 horsepower, respectively, for each 1000 cubic feet per minute of



gas handling capacity.  Scrubbing efficiency is about 95 percent for 1-micron



particles and may be improved by increasing either the water rate or the num-



ber of stator and rotor bars.  Scrubbing efficiency is independent of dust load-



ing, and exit dust concentrations range as low as 0. 004 grain per standard cubic


* 4. 54
foot.



      Advantages of this scrubber are high collection efficiency for submicron



particles and low space requirements.  The principal disadvantage is  its large



power requirement.
                                     4-61

-------
4-

-
L:
                 a.  SCHMIEG  VERTICAL-ROTOR  DUST  COLLECTOR

                    (Courtesy of United Sheet Metal Co., Inc.)
b.  CENTER  SPRAY  HIGH-VELOCITY SCRUBBER

   (Courtesy of Air Engi neer i ng Mag a z i ne)
                                        Figure 4-27.  Mechanically induced  spray scrubbers.

-------
4.4.2.10  Centrifugal Fan Wet Scrubbers—This type of scrubber,  (Figure



4-28) consists essentially of a multiple-blade centrifugal blower.





     Design pressure drop is about 6-1/2 inches with a maximum pressure



drop of 9 inches.  Water requirements range from 3/4 to 1. 5 gallons per  1000



cubic feet of gas and power  requirements range from 1 to 2 horsepower per


                         55
1000 cubic feet per minute.



     The chief advantages are low space requirements, moderate power



requirements,  low water consumption, and a relatively high scrubbing effici-



ency.



4.4. 2.11  Inline Wet Scrubbers—In this axial-fan-powered gas scrubber



(Figure 4-29),  a water spray and baffle screen wet the particles, and centrifugal



fan action eliminates the wetted particles through concentric louvers.



     Pressure drop is about 5 inches of water, and water consumption is



about 1 gallon per 1000 cubic feet of gas.  The moisture removal capacity of



the eliminator  section is sensitive to changes in gas flow rate.  Average re-



moval efficiency is in excess of 99 percent for particles ranging in size from



5 to 10 microns.



     Advantages of the inline wet scrubber are low installation space re-



quirements and low installation costs.  Coal and metal mining industries use



inline  scrubbers.
                                  4-63

-------
DIRT AND WATER
DISCHARGED AT
BLADE TIPS
                                                                           DIRTY GAS
                                                                           INLET
                                            CLEAN GAS
                                            OUTLET
          WATER AND
          SLUDGE OUTLET
                   Figure 4-28.  Centrifugal fan wet scrubber.

                                (Courtesy of American Air Filter Company^
                                     4-64

-------
Figure 4-29.   Inline wet scrubber.
       (Courtesy of Joy Manufacturing Company)
                 4-65

-------
4.4. 2.12 Irrigated Wet Filters - Irrigated wet filters (Figure 4-30a) con-

sist of an upper chamber, containing wet filters and spray nozzles for clean-

ing the gas,  and a lower chamber for storing scrubbing liquid.  Liquid is re-

circulated and sprayed onto the surface of the filters on the upstream side of the

bed.  Two or more  filter stages constructed in  series are used.  A dry bed

containing small diameter fibers may be added  as a final cleanup stage to re-
                 r.f7 IT Q
move spray mist.   '    A wetted impingement  plate may be used in the first com-
                                                                       rq /?A
partment to reduce the particle load  on the following stage (Figure 4-30b).   '

       The number  of cleaning stages to be used is determined by the character-

istics of the gas stream and cleaning requirements.  Gas velocities range from

200 to 300 feet per  minute with a liquid requirement of approximately three

gallons per minute  per square foot of filter area (8 to 10 gallons  per 1000 cubic

feet of gas).   Pressure drop,  which ranges from 0. 2 to 3 inches  of water per

4-inch bed depth, is dependent on the gas loading,  liquid loading, and fiber bed

density.  Normal bed thickness may  range  from 1 to 4 inches,  based on

scrubbing requirements.

       The chief mechanism of irrigated wet filters  involved in the capture of

particulate matter is interception by individual filaments in the filter.  Both

particle removal and gas  absorption  can be accomplished,  and the irrigation

feature aids in removal of solid particulate matter.

4. 4. 2.13 Wet Fiber Mist Eliminators - Two mechanisms, Brownian diffu-

sion and  inertial impaction, are involved in the  separation of mist and dust

particles in wet fiber mist eliminators.

                                     4-66

-------
                                           SPRAY HEADER CONNECTION
                                                                 FLOAT VALVE
                                                                 QUICK FILL
                                                                OVERFLOW
                                                       LIQUIDLEVELINDICATORS
                                         SUCTION CONNECTION
                         a.  WETTED FILTER
IMPACTION
                   DUST-LADEN GAS
  WATER FILM
                                                  VENA CONTRACTA
WATER FILM
                      WATER DROPLETS
                     b.  IMPINGEMENT PLATE FILTER

           Figure 4-30.  Wetted and impingement plate filters.
                          (Courtesy of Buffalo Forge Company)
                                   4-67

-------
      Brownian diffusion dominates in mist collection in which fiber beds with




large specific surface areas are used, gas velocities range between 5 and 30




feet per minute, and the mist consists largely of submicron particles.  A char-




acteristic of Brownian diffusion control is that collection efficiency increases




with decreasing gas velocity because of increased filter bed retention time.




This collection mechanism has some effect on the collection of 3-micron parti-




cles and a major effect on the collection of 0. 5 micron  particles.  Brownian




motion is an important factor in particle capture by direct interception.




      Inertial impaction dominates in  particle collection above 3 microns in




size at gas velocities in excess of 30 feet per second in coarse filter beds.




Inertial impaction efficiency increases with increasing  gas velocity.




      Fiber diameter and the distance between adjacent fibers are important




in determining collection efficiency and pressure drop.   Because high mechani-




cal bed stability is necessary for operation in the high pressure  drop range,




design of mounting and support structures becomes critical.




      Wetted filters are  available in two designs, low-velocity (5 to 30 feet




per minute),  illustrated  in Figure 4-31, and high-velocity (30 to 90 feet per




minute),  illustrated in Figure 4-32.  The low-velocity design consists of a




packed bed of fibers retained between two concentric screens.  Mist particles




collect on the surface of the  fibers, coalesce to  form a liquid film that wets




the fibers, and are moved horizontally and downward by gravity and the drag

-------
of the gases.  The liquid flows down the inner screen to the bottom of the



element and through a liquid seal to a collection reservoir.  Collection effi-



ciencies  are reported to be in excess of 99 percent on particles smaller than



3 microns at operating pressure drops of from 5 to 15 inches of water.  Effi-



ciencies  increase when  the scrubber is operated below design capacity.



     The high-velocity filtering element (Figure 4-32a)  consists of a packed



fiber bed between two parallel screens. A multiple mounting is shown in



Figure 4-32b.  Liquid flow patterns are similar to those of the  low-velocity



filter,  and removal efficiencies range from 85 to 90 percent for 1- to 3-micron


                                                          62
particles and pressure drops of from 5 to 10  inches of water.



     This type of wet filter finds  application in the collection of sulfuric,



phosphoric, and nitric acid mists  and in the separation of moisture and oil



from compressed gases.  Disposable filters are used in  the recovery of



platinum catalysts used in nitric acid manufacture and in the collection of


                                                   63
viruses and bacteria, and radioactive and toxic dusts.



     The wire mesh filter consists of an evenly spaced knitted wire  mesh



and is usually mounted in horizontal beds (Figure 4-33).   The principal



collection mechanism is inertial impaction.  Rising mist droplets strike  the



wire surface,  flow down the wire to a wire junction, coalesce,  and flow to the
                                   4-69

-------
                                                    CLEAN
                                                   GAS OUT
                        SUPPORT PLATE

                            SCREENS
                           FIBER PACKING
f
                           LIQUID DRAINAGE
                                                              LIQUID
                                                              SEAL
                                                              POT
                                              LIQUID BACK TO PROCESS


                              a. LOW-VELOCITY FILTERING ELEMENT
                                                                                             CLEAN GASES
                                                                                               TO STACK
                                                                                                  i?=xl
                                                                              ACID-LADEN
                                                                                GASES
                                                                                                              TUBE SHEET
                                                                                                               BRINK MIST
                                                                                                               ELIMINATOR
                                                                                                               ELEMENTS
                                                                                                              RECOVERED
                                                                                                                 H2S04
                                                                          b.  MULTIPLE MOUNTING OF LOW-VELOCITY FILTER-
                                                                             ING  ELEMENTS
                                               Figure 4-31.   Low-velocity filtering elements.
                                                             (Courtesy of Monsanto Company)

-------
                                                                MANHOLES
                                                                    X
                                                  DIRTY GAS
                                                      IN
                                                                                              CLEAN
                                                                                              GAS
                                                                                              OUT
                                                                                          FIBER
                                                                                          ELEMENTS
                                                                                            LIQUID
                                                                                            LEVEL
                                                                                         __ACID
                                                                                           OUT
a.  HIGH-VELOCITY FILTERING ELEMENT
                                                   b.  MULTIPLE MOUNTING OF HIGH-VELOCITY FILTER-
                                                      ING ELEMENTS
                       Figure 4-32.  High-velocity filtering elements.

                                     (Courtesy of Monsanto Company)

-------
-q
to
                                        STACK
                                                         WIRE MESH
                                                         WIRE MESH
                                                     ACID DRAIN
                                  EFFLUENT FROM

                                     ABSORBER
                         a. MIST  ELIMINATOR   ARRANGEMENT   IN  VESSEL

                           ABOVE ACID  PLANT ABSORBER


                             (Courtesy of Chemical Engineering Progress  Magazine)
  fa.  ONE-PIECE  DEMISTER(RJ

(Courtesy of Otto H. York Co., Inc.)
                                                         Figure 4-33.  Wire mesh mist eliminators.

-------
bottom surface of the bed,  where the liquid disengages in the form of large


droplets and returns by gravity to the process equipment.


      Operating pressure drop is usually less than 1 inch of water with gas


velocities of from 10 to 15 feet per second.  Recent development has centered


on the area of high energy filtration in which pressure drops of from 35 to 40


inches of water gauge have been used.


      Factors governing maximum allowable gas velocities include gas and


liquid density,  surface tension, viscosity, bed specific surface area, liquid

                                    f1"1 I
loading,  and suspended solids content.


      Advantages in the use of fiber  filters and wire mesh mist collectors


are high removal efficiency, simplicity of operation,  low maintenance in dust-


free service,  low initial cost,  and recovery of valuable products without dilu-


tion.


4.4.2.14 Impingement Baffle Mist Eliminators - Baffle  mist  eliminators


offer one of the simplest methods  of controlling large-diameter solid and


liquid particulate emissions.  A variety of designs  are in use.   Figures 4-34,


4-35, 4-36,  and 4-37 show the arrangement of baffles successfully used in the


reduction of emissions from coke  quenching operations.    An S5 to 90 per-


cent reduction of emissions was achieved on particulate matter which ranged


from 16 to 200 mesh at gas velocities ranging to a high of 36 feet per second.


A significant reduction in water droplet fallout was  also achieved.  The  baffles


were operated dry with short spray periods to prevent the buildup of solids.
                                   4-73

-------

A
4_
WATER SPRAY
MANIFOLD


HANGER— >.=


BAFFLES^--
SECTION A-A-*.






1 ^f"
l~^^
.Y ~^y\ x a-
»*)jj.* \ , ' . * V l ' \ % * / ' 1 \ '
^^^~~

A
_J
TOP VIEW
TOP OF

=? TOWER
.- SPRAY
NOZZLES


SIDE VIEW
                                                        b. MIST  ELIMINATOR BAFFLES
a.  DIAGRAM  OF BAFFLE SYSTEM SHOWING CLEAN-
   ING WATER SPRAYS AND BAFFLE ARRANGEMENT
   LIP
   FLOW
                  Figure 4-34. Coke quench mist elimination baffle system.
                                  (Courtesy of U. 5. Steel Corp.)
                               Figures 4-35, 4-36, and 4-37 show the common lay-

                               outs of mist eliminator baffles used in spray chamber

                                         35,66
                               scrubbers.
                  Mist removal efficiencies of as
          60° BENT PLATE UNIT
high as 95 percent may be achieved for the removal

of 40-micron spray droplets up to a maximum gas

velocity of 25 feet per  second and pressure drops of

from 1 to 2 inches of water.  Velocities in excess of

25 feet per second result in the re-entrainment of

liquid droplets.
  Figure 4-35.  Details of baffle
              design.
     (Cou,,.sy Of chemicoi Engineering   4. 4. 2.15  Vane-Type Mist Eliminators - Vane-
          Progress Magozine)
                               type mist eliminators (Figure 4-36) have a range


                               of operation of from 10 to 50 feet per second, with
                                        4-74

-------
     AAAAAAA
    AAAAAAAA
     AAAAAAA
    AAAAAAAA
     AAAAAAA
    AAAAtAAAA
GAS
FLOW
Figure 4-36. Streamline mist eliminator baffles.
FLUE
GAS
     \
          16 GAUGE PLATE
        317 STAINLESS     /40C
        WIRE MESH ~ '
Figure 4-37. Screen and mist eliminator details.
      (Courtesy of Paper Trade Journal)
         4-75

-------
collection efficiencies reported to be as high as 99 percent for 11-micron par-



ticles and   with pressure  drops  from    0.1 to 2 inches of water.  The prin-



cipal advantage of vane type over baffle mist eliminators is the wider range of


                                              67
operation at comparable collection efficiencies.




4. 4. 2.16 Packed Bed Mist Eliminators - Figure 4-38 shows a packed bed



stack mist eliminator.  Removal efficiencies of such devices may range to as



high as  65 percent at gas velocities  of from 7 to 10 feet per second.  Mist re-



entrainment occurs at higher gas  velocities because of the turbulent nature of



gas flow in  packed beds.  This type  of mist eliminator is often used for tail



gas cleanup in sulfuric and phosphoric  acid manufacture.



4. 4. 2.17 Mist and Vapor Suppression - Mist formation from bubbling



solutions, such as plating baths and acid pickling baths,  may be reduced by the



addition of wetting agents.   Foaming and non-foaming types are presently used


                                              71-74
to reduce both surface tension and bubble size.        Smaller bubbles escape



the treated bath with less violence and with a corresponding reduction in the



formation of mist particles.   Foaming agents reduce mist formation by reduc-



ing bubble escape energy and by trapping the mist particles in a dense foam.



The use of surfactants in chrome plating baths can reduce chromic acid losses



by as much  as 45 percent with a corresponding  reduction  in air and water pol-



lution.




     Foam, which has the disadvantage of trapping hydrogen gas,  can create



a fire hazard  and must be continually replaced.  Floating plastic objects such
                                    4-76

-------
                             BERL SADDLES
  Figure 4-38. Bed of Berl saddles added to

             discharge stack.

   (Courtesy of Chemicol Engineering Progress Magazine)
as polyethylene balls,  hollow rods,


                             75
and cylinders are also used.



The floating plastic used to



cover the surface serves  as  a



tank top and mist eliminator and



reduces heat losses and ventila-



tion requirements.



      In one case the use  of 3/4-



inch balls to cover 90 percent of



the surface area of sulfuric acid



solutions used in the electro-re-
                              75
fining of copper resulted in a 90 percent reduction in evaporation losses and a



 70 percent reduction in heat loss.      The savings from the reduction in loss



of methylated spirits (an addition agent) over a  2- week period paid for the



balls. In addition to a 90 percent reduction in air pollution from sulfuric acid



mist, there was a noticeable reduction in corrosion rates.   The approximate



cost of the ball cover is $1. 50 to $2. 00  per square foot of tank surface area.



4. 4. 2. 18  Liquid Distribution - Wet scrubbers require a uniform and con-



sistent liquid distribution pattern for the maintenance of high scrubbing effici-



encies at minimum water rates.  Liquid distribution in wet scrubbers is ac-



complished by spray nozzles or spinning disk atomizers.  Weir box or sieve



plate  distributors may be used for packed towers.
                                    4-77

-------
4.4.£.19 Spray Nozzles - Spray scrubbers require liquid droplets that are
closely sized in order to avoid liquid entrainment at maximum gas flow rates.
Since the scrubbing liquid is often recirculated, the spray nozzles must be
capable of handling liquids with fairly high solids content.
         The basic functions of liquid  spray nozzles and atomizers are to
create small droplets with large surface areas, to distribute the liquid in a
specific pattern,  to control liquid-flow metering, and to generate high-velocity
         76-79
droplets.      At least one of the above functions is involved in every  industrial
spraying process, and spray nozzle selection depends on the specific function
to be  performed.  The spray devices used in wet scrubbers may be classified
as pressure nozzles (hollow and solid cone and  impingement and impact),
rotating nozzles (spinning atomizers), and miscellaneous  nozzles.
         In hollow-cone spray nozzles, the fluid is fed to a whirl chamber—
a tangential inlet (Figure 4-39a) or a fixed spiral (Figure  39b) — so that the
fluid acquires rapid rotation.   The  orifice is on the  axis of the chamber, and
the  fluid exits as a hollow conical sheet and  then breaks up into droplets.
The angle of the spray is determined by the  dimensions  of the swirl chamber
and the  pitch of the nozzle.   A spiral  with a short pitch produces a wide-
angle  spray; conversely, a long pitch produces  a narrow-angle spray.
The spray angle may range from 15 to 135 degrees.
                                   4-78

-------
j. HOLLOW CONE SPRAY
  NOZZLE
Courtssy  of Spray  Systems
Company)
  d.  SOLID  CONE  SPRAY
     NOZZLE
  (Courtesy  of Spray Engineer-
  ing Company)
  h. SPINNING DISK SPRAY
    NOZZLE
  (Courtesy   of   Schutte   &
  Koerting)
b.  HOLLOW CONE SPRAY
   NOZZLE
(Courtesy    of   Schutte   &
K oert i ng )
                                       B.  SOLID  CONE  SPRAY
                                          NOZZLE
                                       (Courtes y  of Bete  Company)
                                       i. MONOFAN NOZZLE
                                      (Courtes y of Spray  Engmeer-
                                      i ng Company)
*-. HOLLOW CONE SPRAY
   NOZZLE
(Courtesy   of   Schutte   &
K oert i ng)
                                                                       f.   CLUSTER SPRAY  NOZZLE
                                                                          (Courtes y of Spray Eng ineer-
                                                                          i ng 'Company)
                                      g. PINJET IMPINGEMENT
                                         SPRAY NOZZLE
                                      (Courtes y of Spray E ng ineer-
                                      ing  Company)
                  Figure 4-39.  Spray nozzles commonly used in wet scrubbers.
                                               4-79

-------
      Hollow cone spray nozzles with cone angles of from 15 to 20 degrees




(Figures 4-39b and 4-39c) are used in venturi jet scrubbers for maximum



turbulence and mixing in the throat and diffuser section.   Larger nozzle angles




are used in air washers and humidifiers.



      The solid cone nozzle  (Figure 4-39d) is a modification of the hollow cone



nozzle used when complete coverage of fixed area is desired.  The nozzle is



essentially a hollow-cone  nozzle with the addition of a  central axial jet.  The



jet strikes the outer rotating fluid inside the  nozzle orifice and is broken into



droplets.   The angle of the spray is a function of nozzle design and is nearly



independent of pressure.   A second type of solid  cone  spray nozzle (Figure 4-39el



consists of an orifice and external  helical spiral.  The nozzle is essentially non-



clogging and finds use in packed column distributor design.  Commercial solid



cone nozzles are available with included  angles  of from 30 to 100 degrees.



Wet scrubbers nearly always use nozzles  with large angle sprays.  Solid-cone



spray nozzles are frequently mounted in clusters (Figure 4-39f).  Liquid dis-



tribution is enhanced by using several small  sprays instead of one large spray



of the same capacity.  Liquid distribution is  also improved by the proper sel-


                            78
ection of pipe manifold  size.




      In the impingement-type nozzle  (Figure 4-39g),  a high-velocity liquid



jet is  directed at a solid target  or a liquid stream.  Proper orientation and



shape of the target or control of the size and shape of  the two fluid streams



produces a hollow cone, fan,  or dish-shaped spray pattern.  The  nozzles are
                                     4-80

-------
robust and simple in shape, and  despite higher cost, they are frequently used


in wet scrubbing towers because  of their more uniform distribution of droplet


size.


     Rotating nozzles (spinning atomizers)  are a type of liquid distributer


(Figure 4-39h) less frequently used  in gas scrubbing than either hollow cone


or solid cone nozzles.  The droplets produced by rotating nozzles are uniform


in size and can be controlled without regard to liquid feed rate by changing the


disk speed. Spinning atomizers are used in some wet scrubbers and have the


advantage of being able to handle slurries  that  could clog conventional nozzles.


Among miscellaneous atomizers,  the fan jet (Figure 4-391) is used in wetting


and light humidification operations.


     In packed tower and cross flow scrubber liquid distributor design,  spray


nozzles and drilled pipe headers  may be used to distribute liquid.   Most packed


tower liquid distributors are of the weir box V-notch type (Figure 4-40a).  For


low rates of gas  flow, weir risers  (Figure 4-40b) may be used.  Submerged


orifice plate distributors (Figure 4-40c) are also used.  Liquid distribution

                                              79
is critical in determining scrubber performance.


     Because spray nozzles frequently wear or clog and produce  an uneven


liquid pattern, they require frequent replacement and maintenance.  Weir box


distribution, on the other hand, is dependable and requires little maintenance


after initial leveling.  Pumping heads are  also lower and result in lower power


requirements and less maintenance.
                                  4-81

-------
          o.  PACKED TOWER  WEIR  BOX LIQUID DISTRIBUTOR

                     (Courtesy of Koch Engineering Compony)
b.  PACKED   TOWER   "WEIR   RISER"   LIQUID  DISTRIBUTOR

                  (Courtesy of U. S. Stonawore Compony}
 I
00
to
                                                  c.  "SUBMERGED  ORIFICE"   PLATE   DISTRIBUTOR

                                                             
-------
     Liquid distribution within a packed bed is  also very important.  Initial

distribution of liquid onto the top of the bed is often enhanced by the use of

small sized packing in the top of the bed.

     Normal drip point requirements for weir box distribution range from 8

to 10 points per square foot for vertical packed  beds  and from 15 to 30  points

for cross flow scrubbers.

     Cross flow scrubbers normally contain baffles  or corrugated walls

around the periphery of the packed bed to prevent gas channeling.   Packed beds

above 15 feet in height frequently require liquid  redistribution.

4.4.3 Typical Applications of Wet Scrubbers

     Typical applications of wet scrubbers are tabulated in Table 4-6.

4.4.4 Water Disposal

     Water usage and waste disposal may become critical factors  in the final

selection of a wet scrubber.  Waste quantity,  particle size distribution  in the

slurry, recovery value, corrosiveness of the  solutions, and materials  of con-

struction are important factors.  The final selection  of a water treatment or

disposal system should not result in water,  soil, or air pollution.  Refer to

references 80 through 92  for additional information.

4.4.4.1  Settling Tanks and Ponds - This method of disposal may be applied

to scrubber discharges containing solid particulate matter  that  readily settles

or is  easily flocculated by chemical treatment.  Tank or pond size may be
                                                   Q rj
easily determined by  laboratory sedimentation tests.    Separation by
                                    4-83

-------
       Table 4-6.  TYPICAL  INDUSTRIAL APPLICATION OF WET  SCRUBBERS
            Scrubber type
                                                                         Typical application
Spray chambers


Spray tower

Centrifugal


Impingement plate

Venturi
 Venturl throat
 Flooded disk
 Multiple jet

Venturi jet

Vertical venturi

Packed bed
 Fixed

 Flooded
  Fluid (floating) ball


Self-induced spray

Mechanically-induced spray

Disintegrator

Centrifugal fan
  Inline fan

Wetted filters

Dust, mist eliminators
  Fiber filters


  Wire mesh

  Baffles

  Packed beds
Dust cleaning,  electroplating, phosphate fertilizer,  kraft paper, smoke
  abatement

Precooler, blast furnace gas

Spray dryers, calclners, crushers, classifiers,  fluid bed processes, kraft
  paper,  fly ash

Cupolas, driers, kilns, fertilizer, flue gas
Pulverized coal, abrasives, rotary kilns, foundries, flue gas, cupola gas,
  fertilizers, lime kilns, roasting, titanium dioxide processing,  odor
  control, oxygen steel making,  coke oven gas, fly ash

Fertilizer manufacture,  odor control,  smoke control

Pulverized coal, abrasive manufacture


Fertilizer manufacturing, plating, add pickling

Acid vapors, aluminum inoculation,  foundries, asphalt plants, atomic
  wastes, carbon black, ceramic frit,  chlorine tall gas, pigment manufac-
  ture, cupola gas,  driers, ferrlte,  fertilizer

Kraft paper, basic oxygen steel,  fertilizer, aluminum ore reduction,
  aluminum foundries,  fly ash,  asphalt manufacturing

Coal mining, ore mining, explosive  dusts,  air conditioning, Incinerators

Iron foundry, cupolas, smoke,  chemical fume control, paint spray

Blast furnace gas

Metal mining, coal processing, foundry, food, Pharmaceuticals


Electroplating, acid pickling, air conditioning, light dust


Sulfurlc, phosphoric, and nitric acid mists; moisture separators; house-
  hold ventilation; radioactive and toxic dusts, oil mists

Sulfuric, phosphoric, and nitric acid mists; distillation and  absorption

Coke quenching, kraft paper manufacture, plating

Sulfurlc and phosphoric acid manufacture, electroplating spray towers
                                                      4-84

-------
sedimentation is usually limited to particles larger than 1 micron or to particles


that readily flocculate. Advantages are that waste products to be disposed of


may be sluiced to a burial pit, waste water may be chemically treated and re-


used, operational costs are low, and abrasive solids can be handled.  Disadvan-


tages are that a large  area is required for the settling of small particles, ground


water contamination from ponds  is possible, and natural evaporation to  the


atmosphere occurs.

4.4.4.2 Continuous Filtration - This method of slurry treatment is usually


applied where the solids have some recovery value or  are  porous or incom-

         es 1
pressible.    Advantages are a dewatered waste product and moderate space


requirements.   Disadvantages are high initial  cost and relatively high mainten-


ance and operational costs.


4.4.4.3 Liquid Cyclones - The wet cyclone has come  into prominence in the


last few years as a method for concentrating solids.   The advantages are low


initial cost, low maintenance,  ability to handle abrasive solids,  and low space


requirements.   Disadvantages are the production of high solids filtrate or over-

                                          82
flow and relatively high power requirements.


4.4.4.4 Continuous Centrifuge - This method of solids separation can some-

                                                                         Q O
times be applied to submicron slurries at fairly high collection efficiencies.


The advantages  are low space requirements and a large variety of designs for


special requirements.   Disadvantages are high  capital and operating costs and


susceptibility to abrasion and corrosion.
                                     4-85

-------
4.4.4.5  Chemical Treatment - Chemical treatment of liquid wastes includes



treatment with chlorine,  lime, soda ash,  carbon dioxide, ammonia, corrosion


                                                 84-93
inhibitors, coagulants, and/or limestone soak pits.
                                  4-86

-------
4.5  HIGH-VOLTAGE ELECTROSTATIC PRECIPITATORS





4. 5.1  Introduction




     The high-voltage electrostatic precipitator (ESP) is used at more large





installations than any other type of high-efficiency particulate matter collector.





For many operations, such as coal-fired utility boilers,  the high-voltage elec-





trostatic precipitator is the only proven high-efficiency control device available





today.  High-voltage single-stage  precipitators have been used successfully to





collect both solid and liquid particulate matter from smelters, steel furnaces,





petroleum refineries, cement kilns, acid plants, and many other operations.




Figures 4-41 and 4-42 show typical electrostatic precipitator  installations.




     Electrostatic precipitators are normally used when the  larger portion of




the particulate matter to be collected is smaller than 20  microns in mean diam-





eter.  When particles are large,  centrifugal collectors are sometimes employed





as precleaners.  Gas volumes handled normally range from 50, 000 to 2, 000, 000




cubic feet per minute. Operating  pressures range from  slightly below atmos-





pheric pressure to  150 pounds per square inch gauge and operating tempera-





tures normally range from ambient air temperatures to 750" F.





4.5.2  Operating Principles





     Separation of suspended particulate matter from a gas stream by  high-





voltage electrostatic precipitation requires three basic steps:





     1.  Electrical charging of the suspended particulate matter.





     2.  Collection of the charged particulate matter on a grounded surface.





     3.  Removal of the particulate matter to an external receptacle.




                                   4-87
   331-716 0-68-16                            ° '

-------
Figure 4-41.  Multiple  precipitator  installation  in basic oxygen furnace plant.
             (Courtesy of Koppers Co. Inc.)
                                        4-88

-------
Figure 4-42.  Detarrer precipitators  installed  in  steel  mill.
              (Courtesy of Koppers Co. Inc.)
                             4-89

-------
      A charge may be imparted to particulate matter prior to the electrostatic



precipitator by flame ionization or friction; however, the bulk of the charge is



applied by passing the suspended particles through a high-voltage, direct-cur-


            94
rent corona.     The corona is established between an electrode maintained at


                                             *

high voltage and a grounded collecting surface.    Particulate  matter passing



through the corona is subjected to an intense bombardment of negative ions




that flow from the high-voltage electrode to the grounded collecting surface.



The particles thereby become highly charged within a fraction of a second  and



migrate toward the grounded collecting surfaces.  This attraction is opposed



by inertial and friction forces.



      After the particulate matter deposits  on the grounded  collecting surface,



adhesive, cohesive, and primary electrical forces must be  sufficient to resist



any gas stream action and counter electrical forces that would cause reen-



trainment of  the particulate matter.  Free flowing liquids are removed from



the collecting surface by  natural gravity forces.  Successful removal of other



particulate matter depends on a complex interrelationship of particle size,



density,  and  shape and electrical, cohesive, adhesive,  aerodynamic, and rap-



ping forces.  This particulate matter is dislodged from the  collecting surfaces



by mechanical means such as by vibrating with rappers or  by flushing with



liquids.  The collected material falls to a hopper, from which it is removed.
* The terms "collecting electrode" and "grounded collecting surface" are often

  used synonymously.
                                   4-90

-------
4. 5.3  Equipment Description




     Two major high-voltage electrostatic precipitator configurations are




used:  the flat surface and tube types.  In the first, particles are collected on




flat,  parallel collecting surfaces spaced from 6 inches to 12 inches apart with




wire  or rod discharge electrodes equidistant between the surfaces.  In tube-




type high-voltage electrostatic precipitators, the grounded collecting surfaces




are cylindrical instead of flat with  the discharge electrode centered along the




longitudinal axis.  Figures 4-43 and 4-44 show typical electrode and collecting




surface layouts for both types of high-voltage electrostatic precipitators.  A




complete  precipitator consists of many  of these units as shown in Figures 4-45




and 4-46.




4.5.3.1   Voltage Control  and Electrical Equipment— High-voltage electro-




static precipitators operate with unidirectional current and with  voltages of




from 30 to 100 peak kilovolts.  Transformers are used to provide high-voltage




current.   Rectifiers convert the alternating current to unidirectional current.




In addition,  precipitators are usually equipped for automatic power control.




Electrical power energization and control equipment is usually furnished in




the form of  several packaged units  complete with instrumentation.




     Transformers are  usually oil cooled and are integrally connected to




silicon rectifiers.  The transformer single-phase output may be rectified to




either double-half-wave or full-wave direct current.   Earlier types of high-




voltage sets consisted of separate transformers using either vacuum tube or
                                 4-91

-------
             CHARGING FIELD
CHARGED ( - ) PARTICLES
               HIGH-VOLTAGE DISCHARGE ELECTRODE).
                          COLLECTING BAFFLE
                                                    GROUNDED (+) COLLECTING SURFACE
                                                 DISCHARGE ELECTRODE TENSION WEIGHT
            PARTICLE PATH
          Figure 4-43.  Schematic view of a flat surface-type electrostatic precipitator.
                                                       GROUNDED
                                                       COLLECTING SURFACE
                                                       CHARGED PARTICLES
DISCHARGE
ELECTRODE
                                                            HIGH-VOLTAGE
                                                        DISCHARGE ELECTRODE
                                                             (NEGATIVE  )
                                                      . GROUNDED COLLECTING  SURFACE
        Figure 4-44.  Schematic  view of tubular surface-type electrostatic precipitator.

                                           4-92

-------
 I
CO
CO
                                                                                             SAFETY RAILING

                                                                                             HIGH VOLTAGE TRANSFORMER/RECTIFIER


                                                                                             RAPPER - H. V. ELECTRODE

                                                                                             RAPPER - COLLECTING SURFACE

                                                                                             PENTHOUSE ENCLOSING INSULATORS AND GAS SEALS


                                                                                             ACCESS PANEL


                                                                                             INSULATOR



                                                                                             H. V. WIRE SUPPORT


                                                                                             H. V. DISCHARGE ELECTRODE



                                                                                             PERFORATED DISTRIBUTION BAFFLE



                                                                                             GROUNDED COLLECTING SURFACE
                                                                                             SUPPORT COLUMNS


                                                                                             QUICK OPENING DOOR
                                                                                             (INSPECTION PASSAGE BETWEEN STAGES)
                                                                                             WIRE WEIGHTS



                                                                                             HOPPERS
                                    Figure 4-45.   Cutaway view of a flat surface-type  electrostatic precipitator.
                                                    it--       t i >r\r> A :. r-	 _*:__r\-	:-_\
                                                   (Courtesy of UOP Air Correction Division)

-------
                                                GAS INLET
              GAS OUTLET
HIGH-VOLTAGE
 CONDUCTOR
 DIFFUSER
  VANES
INSULATOR COMPARTMENT

HIGH-VOLTAGE SYSTEM
SUPPORT INSULATOR
                                                                         ELECTRIC HEATER
                                                                         WATER SPRAYS
                                                                         DISCHARGE ELECTRODE
                                                                         SUPPORT FRAME
                                                                        WEIR PONDS
                                                                        DISCHARGE ELECTRODES
                                                                         TUBULAR COLLECTING
                                                                         SURFACES
                                                                        CASING
                                                                         WEIGHTS
                                                                         DISCHARGE SEAL
          Figure 4-46.  Cross-sectional  view of irrigated tubular blast furnace precipitator.
                       (Courtesy of Koppers  Co. Inc.)
                                           4-94

-------
mechanical rectifiers.  Silicon rectifier conversion equipment is available for




modernizing existing vacuum tube or mechanical rectifiers.




     Figure 4-47 shows one type of transformer-rectifier unit, and Figure 4-48




shows one type of power control unit.




4.5.3.2  Discharge Electrodes—The discharge electrodes,  which are almost




always negatively energized, provide the corona.  Although round wires about




1/8-inch in diameter are usually used, discharge electrodes can be twisted




rods,  ribbons, barbed wire, and many other configurations.   Steel alloys  are




commonly used;  other materials include stainless steel, silver,  nichromey'




aluminum,  copper, Hastelloy^, lead-covered iron wire, and titanium alloy.




Any conducting material with the requisite tensile strength that is of the proper




configuration is a feasible discharge electrode.  Figure 4-49 shows some  com-




mon discharge electrode configurations.




4.5.3.3  Collecting Surfaces— A variety of flat collecting surfaces is available.




The use of smooth  plates,  with fins to strengthen them and to produce quiescent




zones, has become common in recent years.  Special shapes are designed pri-




marily to prevent reentrainment of dust.   Figure 4-49 shows some types of




collecting surfaces. Essentially all tubular collecting surfaces are standard pipe.




4.5.3.4  Removal  of Collected Particulate Matter— Collected particulate mat-




ter must be dislodged from the collecting surfaces and discharge electrodes and




moved from the electrostatic precipitator hopper to a storage area.
                                   4-95

-------
       \
Figure 4-47.  Typical  double half wave  silicon
             rectifier with twin output bushings.
                     4-96

-------
                                                 Ui
Figure 4-48.  Internal view of one type of recti-
            fier control  console showing com-
            ponent parts.
            (Courtesy of Koppers Co. Inc.)
                    4-97

-------
                           EXPANDED METAL
                                                       ROD CURTAIN
VEE POCKET
                                   a. COLLECTING PLATES
                                                                     if
                                                                                        r/
                                                                                        I/
                                                                                         17
SQUARE
ROUND                 BARBED
                                    b. DISCHARGE ELECTRODES
                                                                    STAR
     PUNCHED
     RIBBON
         Figure 4-49. Electrostatic  precipitator collecting plates and discharge electrodes.
                                             4-98

-------
     Liquid collected participate matter flows down the collecting surfaces and




discharge electrodes naturally and is pumped to storage.




     Solid collected particulate matter is usually dislodged from collecting




surfaces by pneumatic or electromagnetic vibrators or rappers.  At times,




motor driven hammers  are used  for this purpose or sprays are used to flush




materials from collecting surfaces.  Solid materials are transferred from the




hopper to storage by air,  vacuum,  or screw conveyors.  Swing valves, slide




gates, or rotary vane-type valves are installed at the hopper outlet.  Figures




4-50 and 4-51 show some types of hopper valves and rapper  mechanisms.
         ROTARY VALVE
                                b. SWING VALVE
    Figure 4-50.  Hopper discharge valves,  (a) Rotary valve and (b) swing valve.







4.5.4   High-Voltage Electrostatic Precipitator Equipment Design




     Design of high-voltage electrostatic precipitator equipment is a highly




complex and specialized field.  It  is therefore important that design decisions




be made only by those qualified by extensive knowledge  and experience.






                                   4-99

-------
t
l->
o
o
                        Figure 4-51.  Electrostatic precipitator rapper mechanisms,  (a) Pneumatic  impulse  rapper,


                                     (b) Magnetic impulse rapper, and (c) pneumatic reciprocating rapper.

                                      (Courtesy of Koppers Co. Inc.)

-------
     The basic elements of design of electrostatic precipitators involve both



performance requirements and physical requirements.  Voltage, electrical



energy, gas velocity,  flow distribution, sectionalization, collecting surface



area, treatment time, number and type of discharge electrodes,  number and



type of collecting surfaces,  collecting surface and discharge electrode spacing,



and number and type of rappers are  some performance requirement factors to



consider.  Layout,  structure, materials handling, and construction material



requirements are some physical factors to consider.



     Information on the design of high-voltage ESP is reported by Ramsdell,


        , .   „  ., 94-96
White, and Archbold.



4.5.4.1  Conditioning Systems —Conditioning systems that change the  pro-



perties of the gas stream or the particulate matter are sometimes installed



ahead of the electrostatic precipitator.  The need for such a system depends



on the application.  Conditioning may involve  gas  cooling, gas humidification,



air dilution, or the  injection of agents  such as sulfur trioxide and ammonia.



4.5.4.2  Voltage, Electrical Energy, and Sectionalization Requirements —



Voltage,  electrical  energy,  and sectionalization are interrelated.  The design
                                   4-101

-------
of the high-voltage electrostatic precipitator should provide for a peak voltage


sufficient for consistent operation of the unit within required performance limits.


The design should also provide for automatic power control and sufficient elec-


trical power to handle all load conditions.  When necessary, the design should


provide for sectionalization so that voltage may be adjusted to compensate for


different conditions in different sections of the  electrostatic precipitator.


      The peak voltage requirements of a high-voltage electrostatic precipita-


tor depend on the application and design,  and usually range from 30 to 100 kilo-


volts.  Peak voltage requirements depend largely on the spacing of


electrodes and collecting surfaces.   The  composition,  pressure, and tempera-


ture of the gas  stream and the concentration  of particulate matter in the gas


stream also influence peak voltage  design requirements.


      For continuous high-efficiency performance,  sectionalization usually is


required.  The power supply and controls for each precipitator section are


energized separately to prevent power fluctuations from spreading from section


to section.  The power controls regulate  current, voltage, and sparking.   The


number of sections required depends on performance requirements and the


application.  For some applications sparking is not desirable.  Where sparking


is desirable, there is often an optimum spark rate that will give the best  per-

                                                            qn
formance.  An  example of this effect is shown in Figure 4-52.


4.5.4.3   Gas Velocity,  Treatment Time, and Flow Distribution— Gas  veloci-


ties range from 3 to 15 feet per second.  Low linear gas velocities promote
                                   4-102

-------
                   85
                z u
                Jli UU 75
                — on

                y^
                u- z

                u-070
                   65
                              50        100        150


                              SPARKS PER MINUTE
              Figure 4-52.  Variation of precipitator efficiency

                          with sparking  rate for a given fly-

                          ash precipitator.
deposition and help minimize re-entrainment of particulate matter.  The cross-




sectional area of the electrostatic precipitator determines the linear gas




velocity for a given gas  volume.  Longer treatment time promotes more ef-




fective deposition  of particulate matter.   The length of the treatment section of




the electrostatic precipitator determines the treatment time for a given linear




gas velocity.




     Uniform flow distribution is an important design factor. Perforated




plates are installed at the inlet and sometimes at the outlet of the electrostatic
                               installed in the inlet and outlet ductwork to




                                   .  When it is necessary to install bends or




                                                helpful.   Experimental gas
precipitator, and vanes are often




distribute the flow of the gas stream




elbows near the inlet or outlet,  turning vanes are




flew models are most useful as an aid to flow distributor design.




4.5.4.4   Collecting Surfaces and Discharge Electrodes—The number,  type,




size, and spacing of collecting surfaces and discharge electrodes required is
   331-716 0-69-17
                                   4-103

-------
dependent on the application and desired performance.  For a given application,




an increase in the total collecting surface area will usually improve perform-




ance provided adequate corona power is supplied.




4.5.4.5   Materials of Construction— Choice of materials for shells,  collecting




surfaces, electrodes, hoppers, and other surfaces is governed by cost and




serviceability.  Corrosion and temperature resistance are the two most im-




portant factors to  consider.  Steel construction is  used wherever possible;




however, aluminum,  lead, concrete, wood, ceramics, plastics,  plastic




coated metals, and many other materials can be employed.




4.5.4.6   Collected Particulate Matter Handling Systems—Electrostatic pre-




cipitator hopper walls should be  sloped to promote free flow of collected




material.  When materials stick or bridge  in the hopper,  vibrators or rap-




pers should be attached to the outside of the hopper walls  at strategic locations.




      Hopper outlet valves should be  designed to operate freely under all con-




ditions.  The hopper  discharge system should also be designed to minimize gas




leakage into or cut of the electrostatic precipitator to prevent re-entrainment of




the collected particulate matter.




4.5.4.7   Controls and Instruments— Useful controls and  instruments  are:




      1.  Individual electrical set controls  and indicators.




      2.  Spark rate indicators.




      3.  Rapping  cycle, frequency, intensity, and duration controls and in-




         dicators.
                                   4-104

-------
     4.  Outlet opacity indicator.




     5.  Line voltage indicators.




     Recorders are useful for providing a permanent record of performance.




Alarms are used to signal  when control variables deviate from normal and when




control valves, gates, or conveyors fail to function properly.




4.5.4.8   Layout—An electrostatic precipitator system should be designed to




conserve space and to minimize costs.  Other factors to consider are provision




for future additions of equipment and the  effect of the layout on gas flow distribu-




tion.




4.5.5  Specifications and Guarantees




     Little published information is  available on design criteria for electro-




static precipitators.  It is  therefore advisable for persons without extensive




knowledge of and experience  with the application of electrostatic precipitators




to rely on several  different vendors or consultants to furnish  specifications.




Forms used by members of the Industrial Gas Cleaning Institute are helpful




for reporting and tabulating necessary information.  These forms specify the




information that the vendor needs to make a comprehensive proposal.  This




form includes information  on:




     1.  The purchasing company.




     2.  The proposal.




     3.  The application.




     4.  Operating and design conditions.
                                  4-105

-------
      5.   Properties  of the particulate matter and the gas stream.




      6.   Inlet particulate matter loadings.




      7.   Desired outlet loadings.




      8.   Desired efficiency.









      When the purchaser lacks sufficient information to complete the form,




the vendor can often draw on his knowledge and experience to supply missing




information or can advise the purchaser on further action.  The purchaser may




also retain consultants for guidance.




      Industrial Gas Cleaning Institute publication No. EP-4 is useful for bid




evaluation.  Major sections of this form relate to:




      1.   Operating and performance data.




      2.   Precipitator arrangement.




      3.   Collecting system.




      4.   Electrical systems.




      5.   Other auxiliary equipment and services.




      The purchaser should select specifications  from the information sub-




mitted by the several vendors.  Any differences in equipment or services




proposals should be reconciled by consultation with the vendors or other ex-




perts. The specifications selected should be used to  solicit final bids.
                                   4-106

-------
      The purchase agreement should include a performance guarantee (when




 deisrable), conditions for measuring performance,  and specifications. In-




 formation that may be used  for guidance in the preparation of purchase agree-




 ments is published by the Industrial Gas Cleaning Institute.




 4.5.6  Maintaining Collection Efficiency




      A well designed precipitator properly maintained and operated within




 design limits will perform consistently at  or above design efficiencies through-




 out its serviceable life.




      Loss of efficiency is commonly caused by  overloading,  process changes,




 or inadequate maintenance.   Increasing output or process  gas flows




 without adding precipitator sections usually reduces electrostatic precipitator




 efficiency.  Changes in raw materials, products, fuels,  and gas stream con-




 ditions can also lead to poor performance.   If these factors are anticipated in




 the original design, loss of  efficiency can  often be avoided.




      It is not always possible to anticipate changes in the properties of




 particulate matter and the gas stream. It is therefore important that collec-




: tor performance be monitored frequently by sampling the outlet gas stream.




 When inspection and maintenance fail to bring performance to within design




.limits and overloading is not  a factor, the cause of poor performance is usually




 traceable to changes in properties of  the particulate matter or the gas stream.




 Should this occur, consultation with the manufacturer of the equipment or with




 other experts is in  order.
                                  4-107

-------
4.5.7.  Improvement of Collection Efficiency




      Process changes or changes in air pollution control requirements may




make it necessary to improve the efficiency of an electrostatic precipitator.




When no provision has been made for future additions, it may be less costly to




scrap the older unit and to install a modern,  more efficient unit.  If provision




has been made originally for  layout and installation of additional units to




increase capacity, the changes  may be made at nominal  cost.




      Before action is taken to improve efficiency, all of the elements of design




mentioned in Section 4. 5.4 should be considered and compared with process re-




quirements.  The modifications required will depend on  the degree of improve-




ment required and the application.




      When process conditions have changed, changing the voltage or power




supply of the unit may improve the performance.   Increasing the number of




high-tension bus sections may at times improve performance.   The installation




of automatic power controls alone seldom results in significant improvement;




however,  use of this technique in  conjunction with other  techniques such as in-




creased sectionalization is often effective.




      Installing additional high-voltage electrostatic precipitator sections  is




the most common technique for improving collection efficiency.  At times  ef-




ficiency may be improved sufficiently by distributing the flow more uniformly




within the unit or in the ductwork  leading to the unit.  In exceptional cases,




modification of material handling systems may bring about the necessary




improvement.






                                    4-108

-------
     Changing the temperature of the gas stream or injecting other materials


                                 ,,.  .      101, 102   „
into the gas stream may improve efficiency.           Whenever



foreign materials are injected the air pollution aspects of these materials



should be considered.



4.5.8  Typical Applications



     High-voltage electrostatic precipitators have been used sucessfully to



collect a wide variety of solid and liquid particles.   Various applications  for



high-voltage electrostatic precipitators are included in Table 4-2.



4.5.8.1  Pulverized Coal-Fired  Power Plants—The arrangement in Figure 4-53



depicts a pulverized coal unit.  Typical of older systems, the mechanical



precleaner (multiple cyclone) and the  electrostatic  precipitator are located



downstream of the air heater.  Gases range in temperature from 220°  to



350° F.  The best precleaners seldom exceed 80 percent efficiency.  Assuming



an 80 percent  cleanup, the electrostatic precipitator would have to collect 95



percent of the remaining particulate matter to achieve an overall efficiency



of 99 percent.  When soot is blown,particulate matter concentrations are  well



in excess of average emission levels.



     A recently installed collection system locates the electrostatic preci-



pitator before, instead of behind, the  air heater on a large steam generator.
                                 4-109

-------
                                                                               STEEL SUPPORT LEVEL

                                                                                 FAN
                                                                                   ASH CONVEYOR
                                                                                   ROOF LEVEL
Figure 4-53.  Electrostatic precipitator installed after air heater in power plant steam generator system.
                                               4-110

-------
The collector is rated at 99 percent efficiency and handles gases at from



600° to 700°  F.  In this temperature range resistivity of particles is favorable



for collection; particularly for fly ash generated from low sulfur coals and



residual fuel oil.  Installations of this type must handle greater volumes of gases



and, therefore,  are more expensive.  Long-term evaluations are necessary to



compare the performance of this unit with cold-side electrostatic precipitators



of the same rating.



4.5.8.2  Integrated Steelmaking Operations— High-voltage electrostatic pre-



cipitators are frequently used in integrated  steel plants.   A common application



is the detarring of coke oven gas.  Wet-type electrostatic precipitators are



used for final cleaning of blast furnace gases.  Exit loadings as low as 0. 005


                                                                   "1 (~\ Q  1 n C

grain per standard cubic foot have been reported for this application.



High-voltage electrostatic precipitators applied to sintering strands reportedly



reduce particulate emission  concentrations  to less than 0.04 grain per standard


  , .  ,  .  107-109
cubic foot.



     Precipitator equipment applied to oxygen-lanced  open hearths,  basic



oxygen furnaces, and electric arc furnaces  reduces particulate emission levels



io less than 0. 05 grain per standard cubic foot.    '



j, 5.8. 3  Cement Industry— Electrostatic precipitator system efficiencies in



excess of 98 percent have been reported for dry-process rotary cement kiln


            1 1 £
Applications.     Efficiencies exceeding 99  percent  have been reported for



electrostatic precipitator systems applied to wet-process rotary cement



.ilns.116
                                   4-111

-------
4.5.8.4  Kraft Pulp Mills— The electrostatic precipitator is a common gas



cleaning device used on kraft mill recovery furnaces.  A survey of 50 plants



indicated that the rated efficiency of electrostatic precipitators installed


                             117
ranged from 90 to 98 percent.      In some applications efficiencies of at least


                              1 I Q

99 percent have been reported.      Electrostatic precipitators have been ap-



plied to emissions from kraft mill lime kilns.



4. 5. 8. 5  Sulfuric Acid— The efficiency of electrostatic precipitators in re-



moving  acid mist from contact-type sulfuric acid manufacturing processes


                                119
ranges from 92 to 99. 9 percent.
                                  4-112

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•4.6 LOW-VOLTAGE ELECTROSTATIC PRECIPITATORS
     The low-voltage,  two-stage, electrostatic precipitator is a device



.originally designed to purify air,  and is used in conjunction with air-



conditioning systems.   Cleaning of incoming air at hospitals and industrial



and commercial installations is also a major use for the low-voltage



precipitator, and it is sometimes called an air conditioning precipitator or


                   120
electronic air filter.      As an industrial particulate matter collector, the



device is used for the control of finely divided liquid particles



discharged from such sources as meat smokehouses,  asphalt paper saturators.



pipe coating machines,  and high-speed grinding machines.



     Low-voltage precipitators are limited almost entirely to the collection



of liquid particles, which will drain readily from collector plates.   Two-



stage precipitators cannot control solid or sticky materials, and become



ineffective if concentrations exceed 0.4 grain per standard cubic foot.



     There is a limited number of ways of removing collected materials



from the two-stage precipitator.  This limitation causes the primary use of



the equipment to be restricted to  systems with low grain loadings in which



the collector plates need to be cleaned only at infrequent intervals.  This has



been a deterrent to widespread use of two-stage precipitators in air pollution



control. Also, electrostatic precipitators do not collect or remove gases



or vapors responsible for objectionable odors and eye irritation.
                                   4-113

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4. 6.2  Major Components of Low-Voltage Electrostatic Precipitators


      The feature of the low-voltage precipitator (Figure 4-54) that distin-


guishes it from the high-voltage electrostatic precipitator is the

                                                            121
separate ionizing zone located ahead of the collection plates.     The ionizing stags


consists of a series of fine ( 0. 007-inch diameter) positively charged wires


equally spaced at distances of from 1 to 2 inches from parallel grounded


tubes or rods.  A corona discharge between each wire and a  corresponding


tube charges the  particles suspended in the air flowing through the  ionizer.


The direct-current potential applied  to the wires amounts to 12 or 13  kilovolts.


Positive polarity is regularly used to minimize  the formation of ozone.


      The second stage consists of parallel metal plates usually less  than an


inch apart.  In some designs, alternate plates are charged positively and


negatively, each  to a potential of 6 or 6-1/2 kilovolts direct current,  so that


the potential difference between adjacent plates  is 12 or 13 kilovolts.


      In other cases, plates are alternately charged  to a positive potential


of 6 to 13 kilovolts and grounded.  (The lower voltages are used with  closely


spaced plates.)  This  arrangement is shown in Figure 4-54.  The illustration


shows particles entering at the  left,receiving a positive charge in the ionizer,


and being collected at the negative plates in the  second stage.  Liquids drain


by gravity to a pan located beneath the plates.  Rapping or shaking  is not


employed,  primarily because of the  close spacing of plates.
                                    4-114

-------
        GAS
        FLOW-
FIELD
RECEIVER
ELECTRODE
                          IONIZER
                           STAGE
                                         DUST
                                         PARTICLE
                                         PATH
                                                COLLECTOR
                                                  STAGE
1st STAGE
EMITTER WIRES AND
ELECTROSTATIC  FIELDN
10,000-12,000 VOLTS
                                                                    2nd STAGE
                                                                    EMITTER PLATES (+)
                                                                    6,000-8,000 VOLTS
                                                               GROUNDED
                                                               COLLECTOR PLATES (-)
ITTER WIRE (+)
     GAS
     FLOW
                 DUST-
                           DUST
                           PATH
                           O •
                                         EMITTER PLATE
                                         6,000-8,000 VOLTS (+)
                            FIELD RECEIVER
                            ELECTRODES (-)
                                                                        GROUNDED
                                                                        COLLECTOR PLATES (-)
       Figure 4-54.  Operating principle of two-stage electrostatic preclpitator.

                                        4-115

-------
      The package unit shown in Figure 4-55 is used to collect oil mist from


                  122
grinding machines.     Oil droplets agglomerate on the plates and drain to



the bottom.  Because solids or viscous liquids will not drain freely,



systems removing such materials have to be shut down occasionally for




cleaning of the plates to prevent arcing.



      Semiviscous materials can be collected by the low-voltage precipitator




if an adequate washing system is provided. The frequency of washing will



depend on the  inlet loading and the characteristics of the collected participate




matter.



4. 6. 3  Auxiliary Equipment



      Pretreatment of particles may be required to improve their electrical



properties before they enter the precipitator.  The system shown in Figure 4-56




includes a low-pressure scrubber, mist eliminator, and tempering coil to



control temperature and humidity.   Removal of large particles by the scrubber



allows longer  operating periods without shutdown for cleaning of the electrostatic



precipitator.  Mist eliminators remove water droplets and prevent excessive



sparkover.  Heating coils allow flexibility in setting optimum conditions.  For



many materials, a relative humidity greater than 50 percent in the gas stream



is beneficial.




4.6.4  Design Parameters




      When a low-voltage electrostatic precipitator is  used in conjunction with



air conditioning, velocities range between 5 and 10 feet per second (fps).



However, for  pollution control purposes, where the particulate loadings are





                                     4-116

-------
 I
I—'
I—I
-
-------
                  MIST
               ELIMINATOR
 l
i-*
i—i
oo
 DIRTY
  GAS
 FLOW
   LOW
PRESSURE
SCRUBBER

JK
/
^™






PERFORATED 	
PLATE /
A°
/ ;

A A ".
v
;\
\ G \

TEMPERING \
C01L IONIZER\
STAGE








\ .
COLLECTOR _\
STAGE
                                                                                        CLEAN
                                                                                          GAS -
                                                                                         FLOW
                                                                                      COLLECTED
                                                                                        OILS OUT
Figure 4-56.  Two-stage electrostatic precipitator with auxiliary scrubber, mist eliminator, tempering
             coil, and gas distribution plate   (top view).

-------
much higher, the superficial gas velocity through the plate collector section



should not exceed 1. 7 fps.  The relationship between air velocity and collection



efficiency is illustrated by the Penney equation which assumes streamline flow.



The Penney (1937) equation for two-stage precipitators is:
                                       wL
                                       vd
where:



     F = efficiency expressed as a decimal.



     w = drift velocity,  feet per second.



     L = collector length, feet.



     v = gas  velocity through collector, feet per second.



     d= distance between collector plates,  feet.



The upper limit for streamline flow through these two-stage precipitators is



600 feet per minute (fpm). Mechanical irregularities in units now manufactured



may reduce this  upper limit.
                                   4-11 Q
   331-716 O - 69 - IB

-------
The effect of gas velocity on collection efficiency for several industrial opera-





tions  is shown in Figure 4-57.  Efficiencies of 80 percent and greater are




shown for the collection of oil mist at asphalt paper saturators and for air




conditioning applications.  Collection efficiencies ranging from 60 to 80





percent are possible for meat smokehouses at a velocity of I. 5 fps.  For




smokehouses, collection decreases  rapidly at higher velocities.   Test data for





typical installations are shown in Table 4-7.




      The practical voltage limit for low-voltage precipitators is  18 kilovolts.




Most  units operate at 10 to  13 kilovolts.  Current flow under these conditions




is small (4 to 10 milliamperes).  The collecting plates are usually energized




at 5. 5 to 6. 5 kilovolts,  but  potentials up to 13 kilovolts are  possible. Actual




current flow  is small because no corona exists between the  plates.




      The degree of ionization may be increased by increasing the number of




ionizing electrodes, either  by decreasing spacing or by installing a second




set of ionizing wires in series.  Because decreased spacing requires reduced




voltage to prevent sparkover, there appears to be an advantage in





the series arrangement.  Decreased spacing, however, lowers first cost and




space requirements.





      Low-voltage precipitators of standard design  for capacities up to




20, 000 cfm are supplied by manufacturers in preassembled units  requiring





only external wiring and duct connections.  The installed weight of the




precipitator is approximately 80 pounds per square foot of cross-sectional
                                    4-120

-------
 I
H1
(S3
   100



   90
-  80
c
(J
u
   70
   60
   50
O  40

H
U
O
U
                         30



                         20



                         10



                         0
              A. SMOKEHOUSES, EXTRAPOLATED WITH PENNEY  EQUATION (OPERATING TEST DATA
                 FOLLOW CLOSELY).
              B. ASPHALT SATURATOR, OPERATING TEST DATA.
             C,D. AIR CONDITIONING, MANUFACTURER'S RECOMMENDATION.


            	I	I	I	I          I  	I    _L
                      1.5
                                            GAS VELOCITY, ft/sec
    Figure 4-57.  Efficiency of two-stage precipitator as function of velocity for several industrial
                  operations.

-------
                       Table 4-7.  INDUSTRIAL OPERATION OF TWO-STAGE PRECIPITATORS
                                                                                        121
Contaminant
source
Tool grinding
Meat smokehouse
Meat smokehouse
Deep fat cooking
Asphalt saturator
(roofing paper)
Muller-type mixer
Contaminant
type
Oil aerosol
Wood smoke,
vaporized fats
Wood smoke,
vaporized fats
Bacon fat aerosol
Oil aerosol
Phenol-formal-
dehyde resin
Ionizing
voltage
13,000
13,000
10,000
13,000
12,000
13,000
Number of
ionizer
banks
1
2
1
2
1
1
Collector
voltage
6,500
6,500
5,000
6,500
6,000
6,500
Efficiency,
wt %
90
90
50
(75% opacity
reduction)
85
87
Velocity,
fpm
333
60
50
68
145
75
Inlet
concentration
gr/scf
	
0.103
0.181
	
0.384
0.049
to
to

-------
area measured perpendicular to the gas flow.   These standard units are




usually sized so that the air flow for air pollution applications is about 100 fpm.




4.6.5  Materials of Construction




     The standard material used in the construction of low-voltage precipita-




te r collector cells is aluminum.   The precipitator housing is usually made of




galvanized steel and frames are of aluminum.  Where washing is  to be frequent




and even mildly corrosive conditions exist,  ionizer wires should be made of




stainless steel.




4. 6. 6  Typical Applications of Low-Voltage Electrostatic Precipitators




     Applications of low-voltage  precipitators to air pollution control have




developed slowly since  1937 when the  first installation was successfully used




to collect ceramic overspray from pottery glazing operations.  Other applica-




tions have been the collection of oil mist from high-speed grinding machines and




the cleaning of gases from deep fat fryers, asphalt saturators,  rubber curing




ovens,  and carpet mill  dryers. See Table 4-7  for operational data.




4. 6. 6.1 Machining Operations —High speed grinding machines generate mist




from cutting oils, which must be vented from the working area.  Package




units of the type shown  in Figure 4-55 are used to collect the mist.  A filter




is provided ahead of the precipitator to remove metal chips and any other




large particles.  Concentrations of solids and tars are usually low enough to




be flushed from the plates with the collected oil droplets.
                                  4-123

-------
 4.6.6.2 Asphalt Saturators—In the manufacture of roofing paper,  low-voltage




 electrostatic precipitators are used to remove the steam-distilled  organic




 materials from hot liquid asphalt.  Moisture evolved from the paper carries




 oil from the process.  Oils that are collected flow readily from the plates of the




 electrostatic precipitator; only  occasional cleaning is required.




 4.6.6.3 Meat Smokehouses—Smokehouses are used by meat packing houses to




 cook and smoke a variety of products.  During the cooking cycle, exhaust




 products are reasonably innocuous and exhaust gases can be discharged directly




 to the atmosphere.  Smoke generated from hardwood sawdust  contains liquid




 aerosols, most of which are partially oxidized organics.  In addition to aerosols,




 odorous, eye-irritating gases and vapors are discharged in exhaust products.




      Two-stage precipitators have been used with limited success  to control




 visible aerosols from smokehouses.  All  such operations use the design of




 Figure 4-56 with a scrubber,  mist eliminator, and tempering coil.  Under




 optimum operation, these units have reduced visible emissions to about 10




 percent opacity.  Maintenance is a problem, however and the exhaust gases




have a strong odor and a lachrymose  character.




      The collected particles are principally tars and gums.  When  the unit is




warm (120 to 180° F),  at least some of these tars drain from the plates.
                                    4-124

-------
When the plates are not cleaned regularly, arcing occurs in the collector




section, particularly near the lower edges of the plates.




4. 6. 6.4 Other Applications —Two-stage precipitators offer the promise of a




low-cost control device for such operations as  rubber curing and carpet mill




drying, where oil mists are generated.  Conceivably,  these devices can be used




wherever the liquid separates easily from the plates and wherever other




considerations such as odors and eye irritants  are not a problem.




4. 6. 7 Air Distribution




     Proper air distribution through the precipitator is essential for efficient




collection.  Precipitators are usually installed with horizontal air flow and




frequently  in positions requiring abrupt changes in gas flow preceding the




unit.  Installations of this type can result in  turbulent and uneven flow with




high local velocities, leading to low  overall efficiencies.




     Where a  straight section of at  least 8 duct diameters is  not available




ahead of the precipitator,  mechanical means for balancing the air flow must




be used.  Several types of distribution baffles and turning vanes have been




devised.  The most effective device  has been found to be one or more  perfor-




ated sheet  metal plates fully covering the cross section of the plenum preced-




ing the ionizers. The optimum open area for the plate is about 40 percent of




the cross-section.
                                    4-125

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4. 6. 8  Maintenance




      To assure optimum performance, the internal parts of the precipitator




must be kept clean enough to prevent arcing.  In addition,  voltages have to be




held within proper ranges, and plate and wire spacings have to be maintained




within  reasonably small tolerances.




      The frequency of internal washing will depend on the application.




High particulate loadings in the gas stream and sticky materials




present the greatest problems.  On the other hand, two-stage precipitators




can be operated indefinitely where  relatively clean, free-flowing oils are




collected.
                                   4-126

-------
4.7  FABRIC FILTRATION



4.7.1 Introduction



     One of the oldest and most positive methods for removing solid particulate


                                                                  123
Contaminants from gas streams is by filtration through fabric media.     The



fabric filter is capable of providing a high collection efficiency for particles as



small as 0. 5 micron and will remove a substantial quantity of particles as


                    124
small as 0.01 micron.



     With a fabric filter,  the dust-bearing  gas is passed through a fabric in



such a manner that dust particles are retained on the upstream or dirty-gas



side of the fabric while the gas passes through the fabric to the downstream or



clean-gas side.  Dust is removed from the fabric by gravity and/or mechanical


      125
means.     The fabric filters or bags are usually tubular or  flat.



     The structure in which the bags hang is known as a baghouse.  The  number



of bags may vary from one to several thousand.  The baghouse may have  one



compartment or many so that one may be cleaned while others are still in



service.   Figure 4-58 illustrates one type of baghouse.



4.7.1.1  Range of Application—Approximately 80 percent of all manufacturing



plants contain operations that produce dust and particles of such a small size


                                                                          123
that use of a highly efficient collection device such as a baghouse is desirable.


In many cases, a fabric collector is an integral component of the plant operation.
                                  4-127

-------
CLEAN AIR
 OUTLET
                                                          *— CELL PLATE
                                                          s
              Figure 4-58.  Typical  simple  fabric  filter bag-
                           house design.
                                  4-128

-------
For example, filters are used to collect metal oxides, carbon black,  and



dehydrated milk, and to recover reusable materials such as nonferrous


        i     126
grinding dusts.



     In other cases, fabric collectors are used to  reduce equipment maintenance.



to improve product quality,  to filter ventilation air entering a clean room, to



prevent physical damage to the plant or equipment, and usually to collect mists,

                                                                  1 O/"*
fumes or particulate matter that contribute to atmospheric pollution.



     The initial selection of gas cleaning equipment for a given plant frequently



is made on the basis of past performance of the  equipment.  However, in making



a choice, the ability  of the equipment to continue satisfactory operation under



anticipated conditions must also be considered.  In short,  design collection



efficiency is not the sole criterion of performance.  The ability of the equip-



ment to continue high collection efficiency throughout its lifetime is also



important.  Other parameters considered in the selection  are the costs of



purchase, operation, and maintenance  (detailed  in Section 6),  as well as a



variety of technical factors (listed in Section 4. 7. 4).



4.7.2 Mechanisms of Fabric Filtration



     The particulate matter is removed from the air or gas  stream by
                                    1 9V
impinging on or adhering to the fibers.    '      The filter fibers are usually



woven with relatively large open spaces, sometimes 100 microns or larger.



The filtering process is not simple fabric sieving, as can be seen by the fact that
                                  4-129

-------
high collection efficiency for dust particles 1 micron or less in diameter has



been achieved.  Small particles  are initially captured and retained on the



fiber of the fabric by direct interception, inertial impaction, diffusion,



electrostatic attraction, and gravitational settling.  Once a mat or cake of



dust is accumulated, further collection is accomplished by mat or cake



sieving as well as the above mechanisms.  Periodically the accumulated



dust is removed, but some residual dust remains and serves as an aid to



further filtering.



4. 7.2.1  Direct Interception — Air flow in fabric filtration is usually laminar.



Direct interception occurs whenever the fluid streamline, along which a particle



approaches a filter element, passes within a distance from the element equal



to or less than one half the particle diameter.  If the particle has a very



small mass it will not deviate from the streamline as the streamline  curves



around the obstacle,  but because of van der Waal forces it will be attracted



to and adhere  to the obstacle if the streamline passes sufficiently close to


            130
the obstacle.     (See path A in  Figure 4-59 for  illustration.)



4. 7. 2. 2  Inertial Impaction —  Inertial  impaction occurs when the mass of the



particle is so  great that it is unable to follow the streamline rapidly curving

                                                               1 OA
around the obstacle and continues along a path of less curvature,    so that the



particle comes closer to the filter element than it would have come if it had



approached along the streamline.  Collision  occurs because of this inertia
                                    4-130

-------
     A DIRECT
     INTERCEPTION
B INERTIAL IMPACTION
c  ELECTROSTATIC ATTRACTION     effect even when flow line intercep-
                                           tion would not take place.  (See path

                                           B in Figure 4-59).  Impaction is not

                                           a significant factor  in collecting par-

                                           ticles of 1 micron diameter or less.

                                           Impaction is considered significant

                                           for the collection of particles of two
Figure 4-59.  Streamlines and particle trajectories
          approaching filter elements.  (Df repre- microns diameter and becomes the
          sents the filter element diameter; Dp
          the diameter of the particles; Vo is the
          velocity of the  gas stream.)           predominant factor  as particle size

                                                      131
                                           increases.

    4.7.2.3  Diffusion—For particles ranging in size from  less than 0.01 to

    0.05 micron diameter,  diffusion is  the predominant mechanism of deposi-

    tion.  Such small particles do not follow the streamline because collision

    with gas molecules  occurs, resulting in a random Brownian motion  that

    increases the chance of contact between the particles and the collection

    surfaces.  A concentration gradient is established after the collection of a

    few particles,  and acts  as a driving force to increase the rate of deposition.

    Lower air velocity increases efficiency by increasing the time available for

                                                                       131
    collision and therefore the chance of contacting a collecting surface.
                          4-131

-------
4.7.2.4  Electrostatic Attraction —  Electrostatic precipitation will result from




electrostatic forces drawing particles and filter element together whenever either




or both possess a static charge.  (See path C in  Figure 4-59.)  These forces




may be either direct,  when both particle and filter are charged; or induced,




when only one of them is charged.  Such charges are usually not present un-




less deliberately introduced during the manufacture of the fiber.  Electrostatics




assists filtration by providing an attraction between the dust and fabric, but it




also affects particle agglomeration,  fabric cleanability, and collection efficiency.




A triboelectric series of filter fabrics may be useful in selecting fabric with


                                  132
desirable electrostatic properties.




4.7.2.5  Gravitational Settling — Settling of particles by gravity onto the filter




surface may result from particle weight as the particle passes through the




filter. A simple method of judging the usefulness of a mechanism, based on



                                    133
particle size, is shown in Table 4-8.




4.7.3  Filter Eesistance




      Two forms of resistance,  clean  cloth resistance and dust mat resistance,




affect the design of baghouses containing fabric  filters.




4.7.3.1  Clean Cloth Resistance — The resistance to air flow offered by clean




filter cloth is determined by the fiber  of the cloth and the manner  in which the




fibers are woven together.  A tight weave offers more resistance  than a loose




weave at the same air flow rate  and, because the air flow is laminar, resistance




varies directly with air  now.  One of the characteristics of filter fabrics
                                      4-132

-------
    Table 4-8.  CONTROL MECHANISM FOR PARTICLE SIZE COLLECTION
                                                                           133
 Primary collection mechanism
 Direct interception




 Impingement




; Diffusion




 Electrostatic




 Gravity
Diameter of particle,  microns
          0.001 to 0.5





           0.01 to 5
                                    4-133

-------
frequently specified is the American Society for Testing and Materials (ASTM)
permeability, which expresses the air volume in cubic feet per minute passing
through a square foot of clean new cloth with a pressure differential of 0.50 inch
water gauge.  The usual range of values is from 10 to 110 cfm per square foot.134
With normal design conditions, the resistance of the clean cloth does not exceed
0. 10 inch of water gauge and is often less.  The average flow rate in use for an
operating cloth is 1. 5 to 3.0 cubic feet per minute per square foot of woven cloth.
This is known as the air-to-cloth ratio or the filtering velocity in feet per
        134
minute.
4.7.3.2 Dust Mat Resistance —  The pressure drop of the dust mat at the end of
any elapsed time is related to the concentration of dust in the gas stream, the
mass density of the gas, and the  face velocity of the gas  through the fabric  by
the equation:
      where:
          (Ap )    , = pressure drop of the dust mat, inches of water
             t  Ulclt
                   t - elapsed time,  seconds
                   G = dust concentration in gas stream,  Ib/ft
                   P = mass density of gas, slugs /ft3
                   g = acceleration of gravity,  ft/sec
                   v = face velocity of gas through the fabric, ft/sec.
                  K = resistance coefficient
                  C = dimensional constant
The values of K, the resistance coefficient modified to include a factor for con-
version of dust cake thickness to mass with constant viscosity, must be deter-
mined experimentally.  C is a dimensional constant adjusted as required for the
                 101  1 QR
actual units used.   '
      K values  are  usually determined by means of a scale model unit either in
the laboratory or in the field.  Care must be exercised  in applying such
                                     4-134

-------
                         1 O C*

results to a full-scale unit.      If a vertical bag is used, elutriation of par-



ticles may occur so that the true value of K varies with time and position on

       -I o/2
the bag.     The measured value of K is an average value that may not be the



same when the scale or the  configuration is changed.  This is borne out by failure



of some full-scale units to function as anticipated  on the basis of pilot studies.


                                                    135
     Table 4-9 gives K values for a number of dusts.      These data were



obtained by laboratory experiments using an air flow of 2 cubic feet per



minute through 0. 2 square foot of cloth  area (equivalent to  a filtering velocity



of 10  ft/mm).   The tests were terminated at  a maximum  pressure differen-



tial of 8 inches of water column.



     Investigators have found that K varies as a power function of the filter


       137
velocity,    and velocities greater than 2. 3 ft./min. seriously affect the K

                               I O Q

value of the fly ash being studied.  °   These recent studies indicate that K



values listed in Table 4-9 should be used only for  estimates.  Further research



is needed to define more precisely the factors  affecting the resistance



coefficients of filter cakes.   The values in Table 4-9 may be used when such



limitations are considered.



     The pressure drop across the collected dust increases uniformly with



time,  indicating a linear relationship between resistance and the thickness of



the accumulated dust mat.  The data clearly show a trend of increasing resist-



ance with  decreasing particle size.  In a full-scale baghouse,  particularly if



•relatively long vertical bags are used, a substantial amount of elutriation can
   331-716 0-69-1
                                   4-135

-------
         Table 4-9.  FILTER RESISTANCE COEFFICIENTS (K) FOR
             INDUSTRIAL DUSTS ON WOVEN FABRIC FILTERS135
Dusts
Granite
Foundry
Gypsum
Feldspar
Stone
Lampblack
Zinc oxide
Wood
Resin (cold)
Oats
Corn
Filter resistance coefficients (K)
for particle size smaller than
20 meshb> c
1.58
0.62


0.96




1.58
0.62
140 meshb> c
2.20
1.58






0.62


375 meshb'd

3.78
6.30
6.30






1.58
90 nd'e




6.30


6.30

9.60
3.78
45/nd'e









11.0
8.80
20 £
19.8

18.9
27.3




25.2


2Mf
— - —




47.2
15. 7g




a
 K = inches water gauge per pound of dust per square foot per foot per minute of
   filtering velocity.
b
 U.  S. standard sieve.
 Coarse,  smaller than 20 mesh or 140 mesh.
 Medium, smaller than 350 mesh, 90 \± or 45 p..
 Theoretical size of silica; no correction made for materials having different
   densities.
 Fine, smaller than 20 (j. or 2 (i.
 Flocculated material, not dispersed,  size actually larger.
                                       4-136

-------
           139
be expected.     The dust-laden gas usually enters the filter bag at the bottom



and travels upward.  As the gas filters through the cloth,  its upward velocity



decreases so that only very fine dust remains airborne to be deposited on the



upper portion of the bag.  Because the actual pressure loss through the bag



must be the same through all areas, the volume and filtering velocity through


                                                       1 Q C

some portions of the bag reach high values.  Investigators    found that local



filtering velocities vary by a factor of 4 or more throughout a single filter


                                                                    139
bag.  This,  in turn, may lead to collapse or puncture of the filter cake.



Punctures (small holes in the dust mat) are usually self-repairing because the



increased air flow through the small area  of low resistance brings  more dust



with it. Collapse of the filter cake, on the other hand, is a shift in cake



structure to a more compacted condition with a greater resistance.



     Collapse  and puncture of the filter cake are phenomena caused by



excessive filtering velocities.  Some dust  is embedded and remains in the



interstices of the cloth when puncture or collapse occurs so that normal



cleaning does not completely remove this dust.  The embedded dust "blinds"



or plugs the fabric pores to such an extent that  the fabric  resistance becomes



permanently excessively high.  Once begun, blinding becomes worse rapidly.



For example,  transient local filtering velocities of 100 ft/min through areas of


                                                                          139
puncture were found when the average filtering  velocity was only 0. 75 ft/min.



jj.3.3  Effect of Resistance on Design  — Resistance of the cloth filter and



dust cake cannot be divorced from the total exhaust system.   The operating
                                  4-137

-------
characteristics of the exhaust blower and the duct resistance determine the





ways in which increases in the baghouse  resistance affect the gas rate.  If the




blower performance curve is steep, the gas flow rate may be reduced only



                                                               131
slightly when the resistance of the filter bags changes markedly.     Some varia-




tion in resistance and air volume  occurs  normally in all baghouses.  Proper




design requires  that the volume be sufficient to capture the emissions at the




source when the system resistance is maximum and the gas volume minimum.




To prevent blinding of fabric from particle impaction,  the  filter ratio must




not be excessive  immediately after cleaning when the pressure drop is at a




minimum and the air volume at a  maximum.




4.7.4  Equipment Description and Design




      The selection or design of industrial dust collection equipment requires




consideration of many factors.   Figure 4-60 illustrates the complex nature of




the final selection of a fabric collector.   Exhaust system design considerations




include:





      1.   Determination of the minimum volume to be vented from the basic




      equipment.





      2.  Estimation of the maximum desirable resistance.




      3.  Selection of the blower operating point that will provide the




      minimum required volume at the  maximum system resistance.





      4.  Estimation of the minimum resistance for the condition immediately




      after a thorough cleaning  of the filter bags.
                                     41 OQ
                                    -loo

-------
                     BAG ECONOMICS
 I
i—i
to
                     DUST AND GAS CHEMISTRY-
DUST AND GAS TEMPERATURE-»J


PHYSICAL CHARACTERISTICS
OF DUST AND GAS STREAM
                     DUST PARTICLE
                     SIZE DISTRIBUTION"
                     DESIRED COLLECTION
                     EFFICIENCY
                     GAS DEW POINT
                     GAS TEMPERATURE•
 EQUIPMENT
 MAINTAINABILITY'
                     ECONOMICS
                                                    •FABRIC SELECTION-
                                                                             PROCESS FACTORS-
                               .AIR TO CLOTH.
                                RATIO
 . FILTER SURFACE
  AREA
                                                       BAGHOUSE
                                                       HOUSING
                                                                      FILTRATION CYCLE
 FABRIC FILTER
"COLLECTOR DESIGN
                                                                                                     -PRECLEANERS
                                                                                                       VOLUME
                                                                                                       • INLET DUST
                                                                                                        LOADING
           PRODUCT
          "REQUIREMENTS


             DESIRED
          	COLLECTION
             EFFICIENCY
                                                                          CLEANING.
ENERGY ECONOMICS-


 BAG ECONOMICS	


 PRODUCT HANDLING-
                                       Figure 4-60.  System analysis for fabric filter collector design.

-------
      5.  Determination of a second operating point on the blower character-




      istic curve for the clean bag condition.



      6.  Determination of the minimum filtering area required by the



      maximum filtering velocity permissible for the particular dust or




      fume being collected.



      7.  Rechecking of the calculations,  with the filtering area thus




      determined, to assure compatibility.



      The rule of thumb for air-to-cloth ratios for conventional baghouses



with woven-cloth,  fabric filters is 1.5 to 3. 0 cubic feet per  minute per



square foot for dusts and  1. 0 to 2. 0 cubic feet per minute per square foot for



fumes.  The pressure  drop for the woven cloths normally ranges from 2 to 8



inches of water.  Physical characteristics of bag fabrics tested in a pilot



plant are given in Table 4-10.  Typical relationships between filter ratio and


                                                           140
pressure drop across bags for the three fabrics in Table 4-10    are shown


               140
in Figure  4-61.



      Typical filter ratios and dust conveying velocities for  various dusts and



fumes collected in woven  cloth bags  are shown in Table 4-11.



      The rule of thumb for air-to-cloth ratios for reverse jet  baghouses with



felted or napped woven fabric filters is 10 to 16 cubic feet per  minute per



square foot of cloth for dust, and 6 to 10  cubic feet per square foot of cloth



for fumes.  Table 4-12 shows typical filter ratios of fabrics used for various



dusts and fumes being collected in reverse jet bag-houses.
                                    4-140

-------
Table 4-10.  PHYSICAL CHARACTERISTICS OF BAG FABRICS
             TESTED IN PILOT PLANT140
Material
Thread count
Yarn type
Warp
Fill
Weave
Weight, oz/sq yd
ASTM permeability
Fabric
A
Silicon! zed glass
54 X 52

Filament
Filament
Crowfoot
9.36
15-20
B
Siliconized Dacron
73 X 68

Filament
Filament
Twill
4.59
25-35
C
Siliconized glass
65 X 35

Filament
Staple
Twill
9.00
60-80
                          4-141

-------
Table 4-11.  RECOMMENDED MAXIMUM FILTERING RATIOS AND DUST
   CONVEYING VELOCITIES FOR VARIOUS DUSTS AND FUMES IN
       CONVENTIONAL BAGHOUSES WITH WOVEN FABRICS141
Dusts or fumes
Abrasives
Alumina
Aluminum oxide
Asbestos
Baking powder
Batch spouts for grains
Bauxite
Bronze powder
Brunswick clay
Buffing wheel operations
Carbon
Cement crushing and grinding
Cement kiln (wet process)
Ceramics
Charcoal
Chocolate
Chrome ore
Clay
Cleanser
Coca
Maximum filtering
ratios,
cfm/ft" cloth area
3.0
2.25
2.0
2. 75
2.25 - 2. 50
3.0
2.5
2.0
2.25
3.0 - 3.25
2. 0
1. 5
1.5
2.5
2.25
2.25
2. 5
2.25
2.25
2.25
Branch pipe
velocity,
fpm
4500
4500
4500
3500 - 4000
4000 - 4500
4000
4500
5000
4000 - 4500
3500 - 4000
4000 - 4500
4500
4000 - 4500
4000 - 4500
4500
4000
5000
4000 - 4500
4000
4000
                              4-142

-------
Table 4-11.  RECOMMENDED MAXIMUM FILTERING RATIOS AND DUST
   CONVEYING VELOCITIES FOR VARIOUS DUSTS AND FUMES IN
   CONVENTIONAL BAGHOUSES WITH WOVEN FABRICS (Continued)
Dusts or fumes
Coke
Conveying
Cork
Cosmetics
Cotton
Feeds and grain
Feldspar
Fertilizer (bagging)
Fertilizer (cooler, dryer)
Flint
Flour
Glass
Granite
Graphite
Grinding and separating
Gypsum
Iron ore
Iron oxide
Maximum filtering
ratios,
cfm/ft^ cloth area
2.25
2.5
3.0
2.0
3. 5
3.25
2. 5
2.4
2. 0
2.5
2. 5
2. 5
2.5
2. 0
2.25
2. 5
2. 0
2.0
Branch pipe
velocity,
fpm
4000-4500
4000
3000-3500
4000
3500
3500
4000-4500
4000
4500
4500
3500
4000-4500
4500
4500
4000
4000
4500-5000
4500
                            4-143

-------
Table 4-11.  RECOMMENDED MAXIMUM FILTERING RATIOS AND DUST
   CONVEYING VELOCITIES FOR VARIOUS DUSTS AND FUMES IN
   CONVENTIONAL BAGHOUSES WITH WOVEN FABRICS (Continued)
Dusts or fumes
Lampblack
Lead oxide
Leather
Lime
Limestone
Manganese
Marble
Mica
Oyster shell
Packing machines
Paint pigments
Paper
Plastics
Quartz
Rock
Sanding Machines
Silica
Soap
Maximum filtering
ratios,
cfm/ft cloth area
2.0
2.25
3.5
2.0
2.75
2.25
3.0
2.25
3.0
2.75
2.0
3.5
2.5
2.75
3.25
3.25
2.75
2.25
Branch pipe
velocity,
fpm
4500
4500
3500
4000
4500
5000
4500
4000
4500
4000
4000
3500
4500
4500
4500
4500
4500
3500
                           4-144

-------
Table 4-11.  RECOMMENDED MAXIMUM FILTERING RATIOS AND DUST
  CONVEYING VELOCITIES FOR VARIOUS DUSTS AND FUMES IN
  CONVENTIONAL BAGHOUSES WITH WOVEN FABRICS (Continued)
Dusts or fumes
Soapstone
Starch
Sugar
Talc
Tobacco
Wood
Maximum filtering
ratio,
cfm/ft^ cloth area
2.25
2. 25
2.25
2.25
3.5
3.5
Branch pipe
velocity,
fpm
4000
3500
4000
4000
3500
3500
                          4-145

-------
Table 4-12.  RECOMMENDED MAXIMUM FILTERING RATIOS AND FABRIC
  FOR DUST AND FUME COLLECTION IN REVERSE-JET BAGHOUSES142
Material or operation
Aluminum oxide
Bauxite
Carbon, calcined
Carbon, green
Carbon, banbury mixer
Cement, raw
Cement, finished
Cement, milling
Chrome, (ferro) crushing
Clay, green
Clay, vitrified silicious
Enamel, (porcelain)
Flour
Grain
Graphite
Gypsum
Lead oxide fume
Lime
Fabric
Napped cotton
Cotton sateen
Napped cotton, wool felt
Orion felt
Wool felt
Cotton sateen
Cotton sateen
Cotton sateen
Cotton sateen
Cotton sateen
Cotton sateen
Napped cotton
Cotton sateen
Wool felt, cotton sateen
Wool felt
Cotton sateen, orlon felt
Orion felt, wool felt
Napped cotton
Filtering
ratios, cfm/ft2
11
10
8a
7
8
9
10
8
10
10
12
12
14a
16
7a
10
8a
10
                               4-146

-------
Table 4-12. RECOMMENDED MAXIMUM FILTERING RATIOS AND FABRIC
 FOR DUST AND FUME COLLECTION IN REVERSE-JET BAGHOUSES
                           (Continued)
Material or operation
Limestone (crushing)
Metallurgical fumes
Mica
Paint pigments
Phenolic molding powders
Poly vinyl chloride (PVC)
Refractory brick sizing
(after firing)
Sandblasting
Silicon carbide
Soap and detergent powder
Soy bean
Starch
Sugar
Talc
Tantalum fluoride
Tobacco
Wood flour
Wood sawing operations
Fabric
Cotton sateen
Orion felt, wool felt
Napped cotton
Cotton sateen
Cotton sateen
Wool felt
Napped cotton
Napped cotton, wool felt
Cotton sateen
Dacron felt, orlon felt
Cotton sateen
Cotton sateen
Cotton sateen, wool felt
Cotton sateen
Orion felt
Cotton sateen
Cotton sateen
Cotton sateen
Filtering
ratios , cf m/ft
10
ioa
11
10
10
ioa
12
6-8a
9-11
12a
14
10
ioa
11
6a
12
10
12
                            4-147

-------
  Table 4-12.  RECOMMENDED MAXIMUM FILTERING RATIOS AND FABRIC

     FOR DUST AND FUME COLLECTION IN REVERSE-JET BAGHOUSES

                                   (Continued)
      Material or operation
      Fabric
   Filtering

ratios,
Zinc, metallic



Zinc oxide



Zirconium oxide
Orion felt, dacron felt
Orion felt
Orion felt
      11
a                 2
 Decrease 1 cfm/ft  if dust concentration is high or particle size is small.
                                 4-148

-------
         123456

         FILTERING RATIO, ft3/ff2 . mjn


 Note:  A and C are siliconized glass fabrics, B is a
 siliconized Docron fabric.
      A typical range of dust


loading for woven bag filters is


from 0.1 to 10 grains per cubic


foot of gas.  Higher concentrations


of particulate matter in some


industries are removed by a pre-


cleaning device, such as  a low


efficiency cyclone.   Maximum dust


loading reported for felted bag
Figure 4-61. Pressure drop versus filter  ratio   filters with reverse jet or pulse
          for  fabrics  on 60-minute cleaning
          cycle for electric furnace dust.

          (Courtesy of the Journol of the Air Pollution
          Control Associotion)
jet cleaning is 80 grains per cubic


foot.  Figure 4-62 presents dust

      143
loading versus filter ratio data for typical products.


4.7.4.1 Baghouse Design—Many design considerations for handling waste gases


from various operations are the same regardless of the process involved.   How-


ever, this is not necessarily true of baghouse type - a most important design


decision - which ranges from the open-pressure type to the closed, welded,


fully insulated baghouse.  Generally the type of baghouse  required is dictated


by the moisture in the waste gas.  The higher the dew point, the greater the


precaution that must be taken to prevent condensation which can moisten the


filter cake,  plug the cloth,  and corrode the housing and hoppers.   Three


designs, open pressure, closed pressure, and closed suction are used in


fabric filter baghouse construction.     The cost of the open pressure system


is the least of the three; that of the closed suction system is the greatest.

                                    4-149

-------
           5     10     IS     20     25

            FILTERING RATIO, ft3/ft2 - min
                                         30
 KEY
                       6.  KAOLIN
                       7.  CEMENT OR
                          LIMESTONE DUST
                       8.  COAL DUST
                                                    Open pressure — An open


                                              pressure baghouse,  in which the


                                              fan is located on the dirty gas


                                              side of the system, can be oper-


                                              ated with open sides as long as


                                              protection from  the weather is


                                              provided.  Under some circum-


                                              stances, a completely open bag-
 1.  MAGNESIUM
    TRISILICATE
 2.  CARBON BLACK
 3.  STARCH DUST
 4.  RESINOX             9.  LEATHER BUFFING
 5.  DIATOMACEOUS EARTH    DUST
 FOR NUMBERS  i THROUGH 6, 99.94   99.99  PER-     allows hotter inlet gas tempera-
 CENT PASSING 325  MESH. FOR  NUMBERS 7 AND
 8, 95 PERCENT PASSING 200 MESH.  NUMBER 9,60
 MESH AVERAGE.
Figure 4-62.  Typical performance of reverse-jet
            baghouses using  felted fabrics on    cooling is better in an open bag-
            a variety of dusts (dust load versus
            filtering  ratio  at  3.5  in.  w.c.
            pressure drop).
            (Courtesy of the Industrial Chemist Magazine)
                      144
house is satisfactory,     and
                                              tures to be used because the
                                              house.  Better cooling allows
                                              lower temperature filter media to

                                                                            1 Q1
be used with higher inlet gas temperatures than might otherwise be possible.


In an open pressure system, the blower must handle the entire dust load, which


causes the blower to wear substantially.   Thus, maintenance cost is higher than


that for a blower  on the clean gas side of a baghouse.  Because air flows from


the inside of the filter bags, bag replacement is facilitated because a leaky bag


is easier to locate.   The open pressure unit is normally constructed with cor-


rugated steel or asbestos  cement walls.  It may have open gratings at the cell


plate level and may not require hopper insulation.  Figures 4-63 and 4-64


illustrate the open pressure baghouse.144'145
                                     4-150

-------
                    CLEANED GAS
                    OUTLET
/
>


>
>
(I.
i
V
'-/
y
'-
V
t'

^

f


A


\:


/


^
r


^
,
'
V



f
1



n


\
t


\
\




A
'
\


/
P


^
•<
fit
                         CORRUGATED
                         HOUSING
                           OPEN
                          "GRATING
                      OUTSIDE AIR

                        SIDE VIEW
Figure 4-63.  Open pressure baghouse.
      Closed pressure —A closed


pressure baghouse is  also constructed


with the fan on the dirty gas side of


the system, but the structure is


closed.


      The closed pressure unit is


used for gases with high dew points


and for toxic gases, that cannot be


released at low elevations.  Blower


maintenance problems are identical
to those of the open pressure baghouse.  Asbestos cement walls without insula-


tion are sometimes used to construct closed pressure baghouses.  The floor of


such a unit is closed and the hoppers are insulated.   Figures 4-65 and 4-66

                                     144  145
illustrate the closed pressure baghouse.


     Closed suction —A closed suction baghouse is one in which the fan is


located on the clean gas side of the closed,  all-welded,  air tight structure.  The


closed suction unit is used for gases with dew points between 165  F and 180  F.


The floor of  such a unit is closed and the structure walls and hopper are


insulated,  particularly for dew points in the  upper range. Blower maintenance


is cheaper because the blower is on the clean gas side of the system.  The


inspection for holes in the bag is difficult.
   331-716 0-69-20
                                  4-151

-------
Figure 4-64.  Open pressure baghouse unit showing installation without a separate clean gas
             housing.

             (Courtesy of the Wheelobrotor Corporation)
                                           4-152

-------
                     CLEANED GAS

                     OUTLET
Figures 4-67 and 4-68 illustrate




+u   i    i         K   u     144,145
the closed  suction baghouse.








      Structural considerations —
                          CORRUGATED

                          HOUSING        Metal used to construct the baghouse
                            CLOSED
                        SIDE VIEW
Figure 4-65. Closed pressure baghouse.
walls and hoppers must be strong




enough to withstand the pressure




differentials involved.  A pressure




differential of 8 inches water




column represents approximately
42 pounds per square foot.  The total air pressure exerted on a side panel of



                                                  131
a closed suction baghouse may be in excess of 2 tons.




     Easy access to the baghouse interior must be provided to change bags




and to perform maintenance.  The open pressure unit has  easy access to the




cell plate at the bottom of the baghouse, even when the  unit is operating.  How-




ever, at the bag top level, the hot and possibly toxic  gases prevent bag changing




without taking the unit off stream.  To overcome this difficulty, many units  are




furnished with internal partitions between compartments so an individual




compartment can be isolated.  Thus, the remaining compartments continue  to




filter while the one removed from service is maintained.




     Hoppers are sized to hold  the collected dust while or until it is  removed




for disposal.  The slope of the sides of the hopper  must be steep enough to
                                 4-153

-------
Figure 4-66.  Closed  pressure   baghouse  unit.
              (Courtesy of the Wheelobrator Corporation)
                       4-154

-------
         CLEAN GAS
         TO FAN
-7T — r~n — ST3T '
AaL .aL/jL jfeAviA

>

*
/
\

\
y

f


\





^

'

\
f
\
1


\


\


^

\
/
\
r \



   DIRTY
   GAS
   FRO
   PROCESS
                           CLOSED
                           ALL WELDED
                           HOUSING
SIDE VIEW
permit the dust to slide or flow

freely.  The designer must also

consider the possibility of bridging.

Continuous removal of dust will help

to prevent bridging of material, and

will prevent  operating difficulties

with materials that become less

fluid with time.
                                                4.7.4.2  Fabric  Filter Shape -

   Figure 4-67.  Closed suction baqhouse.      ,-,.,,,     ,        ,     i. ......  .u
                                          Filter shape is dependant on  the use

 to which the filter will be put.  Two major bag shapes, the envelope (flat) and
 the tube, are used.
                                                The envelope bag is illustrated

                                                         145
                                          in Figure 4-69.     Dust is collected


                                          on the outside of the bag, which is
                                                         J

                                          prevented from collapsing by the use


                                          of internal screens or  frames.  How-

                                          ever, the internal screen complicates


                                          bag changing and the contact of the


                                          screen and fabric reduces cloth life.


                                          The envelope bag has the advantage
•igure4-68.  Closed suction concrete baghouse  of providing more filtering surface
          unit.
          {Courtesy of the Wheelobrotor Corporation)
                                    4-155

-------
                          TOP VIEW
                           SIDE VIEW
Figure 4-69.  Typical  flat  or  envelope  dust

            collector bag.
per volume than the tubular bag



because of the close spacing of



the envelopes.  If the dust has a



tendency to bridge, every other



bag may be removed to prevent



plugging.



      The tubular bag,  illustrated



in Figure 4-70, is open at one


                          145
end and closed at  the other.
 Tubular bag design is more varied than flat bag design.  Multi-bag and bottom



 or top entry uni-bag filters are in widespread use.  Air flow may be either



 from the outside or inside.



      A multi-bag is a group of either three  or six tubular bags sewn together


                         145
 as shown in Figure 4-71.      Multi-bag suspension is limited to a top loop



 suspension. A disadvantage of the top loop suspension is the difficult  adjustment



 required occasionally because of the multi-bag dimensional instability.



      The uni-bag is a single  tubular bag,  not attached to other bags,  into



 which gas may enter from  the top or bottom.  Bottom entry allows  gas to



 enter from the hopper  section and flow upwards into the filtering area as shown


                145
 in Figure 4-72.



      Bottom entry allows  pre-separation  of the coarse particles in the hopper,



 and the fabric  handles  the suspended dust.  Gas flows down in a top entry unit
                                    4-156

-------
\


\

__,

^


\
»

f
\


H



\

t

^

^

H



,

f
^




H



x

f
                                SIDE VIEW
                                          into the filtering area as shown in



                             TOP VIEW     Figure 4-73.145  The entire dust



                                          load passes through the entire  tube



                                          of the top entry design before dust



                                          reaches the hopper.  A cell plate



                                          ceiling, as well as a cell plate



                                          floor, increases the difficulty of



                                          adjusting  top entry bags.  The  top


Figure 4-70. Typical round  or tubular dust col-        ,                    ,   ,
           lector bag.                      entry baghouse creates a dead  gas



                                          pocket in  the hopper that can be a



                                          source of trouble because of con-



                                          densation of water vapor in  mois-



                                          ture-laden gases.



                                                The direction of gas flow in



                                          tubular bags can be either inside



                                          out or outside in.  If the direction



                                          is outside in,  then a frame is



                                          inserted in the bag to  prevent



                                          the bag from collapsing.  Collecting



                                          the dust on the outside of the bag



                                          requires that the unit be inspected on



                                          the dirty gas side and increases
                                TOP VIEW



\


l\






f







' i
' i
' I
i i '
1 i
. 1
1 |
1 1
. ' 1 t


X




                                SIDE VIEW
Figure 4-71.  Typical  multi-bag  dust collection
          system.
                                     4-157

-------
— 1

b/

^
rr
'
\



\
•


•V
'

1 '

\
'
N
•

r-
H

*
INSIDE OUT
FILTERING



^r




      INSIDE OUT

      FILTERING
SIDE VIEW
                                                             SIDE VIEW
Figure 4-72.  Bottom entry design uni-bag.     Figure 4-73. Top entry design  uni-bag.



the difficulty of bag replacement.  Also, shorter bag life is experienced because



of bag and frame contact.



4.7.4. 3  Cloth Type — Two basic types of cloth are used in fabric filters.  They



are woven cloth or "cake" filter  media, and felted cloth or "fiber" filter


       146,147
media.



     Woven fabric acts as a support on which a layer of dust is deposited to



form a microporous layer capable of removing additional particles by sieving


                                      123
and other basic filtration mechanisms.  "  Cake filtration is the most important removal



mechanism  when new filter cloth becomes thoroughly impregnated with dust.  A



wide variety of woven and felted  fabrics are used  in fabric filters.  Clean felted



fabrics  are  more  efficient dust collectors than clean woven fabrics, but woven materials



are capable of giving equal filtration efficiency after a dust layer accumulates on



the surface.  When new woven fabric is placed in service,  visible penetration of



dust may occur until the cake builds up.  This takes a period of a few hours to a few days
                                       4-158

-------
for industrial applications, depending on the dust loading and the nature of the



particles.  When dealing with extremely low grain loadings and fine dusts, fabrics



may be precoated with asbestos floats or similar materials to form an artificial



filter cake  to prevent dust leakage.



     Another method of reducing dust leakage in fabrics is based on the use of



electrostatics.  Electrostatic forces used in dust collecting mechanisms are



explained in Section 4.7.2.4.  Electrostatics not only assists filtration by pro-



viding an attraction between the dust and fabric but also may affect particle



agglomeration,  fabric cleanability and collection efficiency.



     Electrostatic charges are induced in both fabrics and dusts by friction.



The maximum charge and the charge dissipation rate are measured for each



fabric and dust.  Fabrics are arranged in relation to each other in a triboelectric


      132
series.     Attempts to develop such a series  for dusts have not been successful.



     Agglomeration of some charged dusts may be aided by selection of a fabric



with an opposite charge.   For example, a negatively charged dust would agglom-



erate with a positively charged fabric.



     Dust  leakage through a fabric  may be reduced by maximizing the electro-



static differential between dust and fabric, thus maximizing the  electrostatic



attraction forces.  Leakage may also be  reduced by selecting a fabric with a



low dissipation of electrostatic charge.  A fast dissipation of charge reduces  too



quickly the  electrostatic  attraction between fabric and dust.  When this occurs,



fabric  overcleaning during the cleaning cycle is possible with no residual dust



remaining on fabric to act as a precoat.



                                  4-159

-------
      Electrostatic charging has been introduced in some bonded fiberglass



fabrics used for air conditioning installations.   However, until more informa-



tion is available for large industrial fabric filters, the relative importance of



electrostatics in determining the best filter fabric for a specific installation



cannot be evaluated.  Certainly, if one fabric does not work effectively, other



fabrics should be tried.   Both the physical characteristics  and the electrostatic


properties of the fabrics may serve as guides.




      Woven fabrics — Woven fabric filters in conventional baghouses usually


                                    126  130
have air-to-cloth ratios of 1:1 to 5:1.    '     Woven fabric permeability can be



varied, which, in turn, varies the operating air-to-cloth ratio.  Permeability



and air-to-cloth ratio have been discussed in Section 4.7.3.1.



      Woven fabric permeability or porosity is varied by using different yarns,



fabric count,  cloth weights (expressed as ounces per square yard),  and weave



patterns.  The three basic forms  of yarn used for woven fabrics are monofila-


                                     147
ment,  multifilament, and  spun-staple.     Monofilament yarn is  a synthetic



fiber made in a  single, continuous filament.  Multifilament yarn is made by



twisting two  or more monofilaments together.  Spun-staple yarn is made by



twisting short lengths of natural or synthetic fiber into a continuous strand.



Warp is the yarn that runs lengthwise in a cloth and fill (pick) is the yarn that


                                                 147
interlaces with warp yarn to form a woven fabric.     The  count  of a fabric is



the number of warp and fill yarns per  square inch in a woven fabric.



    Another  method for decreasing woven fabric  porosity  is to  weave cloth



from napped  yarn or plied yarn.  The napped yarn is made  by abrading the



                                    4-160

-------
                                                               148
surface of the filament yarn to produce a fuzzy, fibrous condition.     The




plied yarn is made by twisting lighter weight yarns together in a single,  con-


                    149
tinuous strand of yarn.    For example,  a fabric made from 800 denier yarn




(weight in grams of a single continuous strand of yarn, 9000 meters long) may



be made from plied yarn by using four strands  of 200 denier yarn.  These four



200 denier strands of yarn may be twisted together to  give the plied strand of



yarn which may be used to weave the 800 denier cloth.   The weight of the cloth



remains unchanged while its dust retentivity is improved.



     The basic weaves usually used for fabric filters are plain, twill,and


    149
sateen. These are illustrated in Figure 4-74.  The plain weave has a simple



"one up and one down" construction. This construction permits maximum  yarn



interlacing per square inch, and, if woven tightly, allows high impermeability.



If the count is lowered, this weave can be as open as desired.  The plain weave


                                                           149
is common in certain cotton ducks and many synthetic fabrics.



     The twill weave is recognized by the sharp diagonal "twill"  line formed by



the passage of a warp yarn over two or more fill or pick yarns with the inter-



lacing advancing one  pick with each warp.  In equivalent construction, twills




have fewer interlacings than the plain weave and,  hence, greater porosity,



although this naturally depends  on the count. Cotton and synthetic filter twills


                 149
are commonly used.




   The sateen weave with even fewer  pick  interlacings, spaced widely and




regularly, provides a smooth surface with increased porosity.  These qualities
                                 4-161

-------
make them particularly valuable in dust collection.  Cotton fabrics in this



weave are commonly known as sateens.   Cotton sateen is probably more com-



monly used than any other fabric in fabric filters operated at ambient tempera-
tures.
                                                          m

       PLAIN
                                      TWILL
SATEEN
              Figure4-74. Basic fabric weaves used for woven filter bags.

                         (Courtesy  of West Point Pepperell, Industrial Fabrics Division)




      Dimensional stability is an important factor in filter fabric.  Cotton and



wool fabrics must be preshrunk, and synthetics are usually given a corre-


                                            131
spending treatment known as "heat-setting".      This process contributes to a



more even balance of warp and filling yarn tension,  controls  porosity, and



virtually eliminates  shrinkage.   Dimensional stability may be lost if the fabric



is subjected to temperatures near that used in the original heat-setting process.



Excessive temperatures in operation can cause a shrinkage of 3  or 4



percent.  Shrinkage  may cause a bag to pull loose from its connection to the



floor plate or the upper support structure.
                                     4-162

-------
      Woven natural fabrics may be treated with flameproofing, moldproofing,



shrinkproofing, and/or dust-releasing coatings, such as silicone to increase


           131
service life.    Woven synthetic fibers  are often treated with flameproofing



and dust-releasing coatings.



      Woven fabric bags are made from cotton, wool, Dacron, Nylon, Orion,



Nomex, polypropylene,  Teflon,  and fiberglass.



      Fiberglass fabric bags are treated with silicone, mixtures of silicone



and collodial graphite, and Teflon lubricants to provide protection against



abrasion and flex failures caused by fiber-to-fiber rubbing.     These lubri-



cants are effective at temperatures of from 100U F to 550° F.



      Felted fabrics — Felted fabrics serve as filter media and are used in


                                                                       126
reverse jet and pulse jet baghouses with air-to-cloth ratios of 6:1 to 16:1,


                    131
or ratios 5 to 6 times     those  woven fabric filters.



      Felted bags are more expensive than woven bags. Wool is the only



fiber that will produce a true felt.  However, synthetic fibers can be needled



to function as a felt filter fabric.  Hence, felt is limited to wool and such



synthetic fibers as Dacron, Nylon, Nomex,  polypropylene,  and Teflon.  Cotton



and fiberglass fibers do not make  felted fabrics.



      Felted fabrics are complex, labyrinthine masses of randomly oriented



fine fibers.  The relative thickness provides the advantages of maximum dust



impingement and changes of direction of flow to entrap small  dust and fume



particles. Felted fabric filters operate with extremely high collection efficiencies.
                                   4-163

-------
      In some cases, felted bags do not function well in the collection of



extremely fine fumes because the fine particles are embedded in the felt and are



very difficult to remove in the cleaning cycle.  In general, felted bags are cleaned



by high-pressure reverse jet and jet pulse devices that operate at frequent inter-



vals.   In one unit,  each felted bag is  cleaned individually by reverse air flow



from  a pressure blower and a burst of compressed air released when the bag has



U          J  J  151
been expanded.



      Principal considerations for proper selection of the most economical felt


         ..  . .           ...   150
for a  particulate process include:



      1.  Necessary characteristics of the fiber to meet chemical and



      thermal resistance needs.



      2.  Type of construction.



      3.  Such physical properties of  the felt as density,  breaking strength,



      elongation, bursting strengh,  air permeability, and particle size



      retention.



4.7.4.4 Fabric Cleaning — Fabric flexing and reverse air flow through the



cloth  are  two methods of cleaning collected particulate  matter from fabric filters.



      Fabric flexing — Manual shaking, mechanical shaking,  and air shaking are



three  methods of fabric flexing used in cleaning filters.  Air shaking is further



broken into four methods:  air bubbling, jet pulsing, reverse air flexing and  sonic



vibration.
                                    4-164

-------
    Manual shaking is used in baghouses of about 500 to 600 square feet of



cloth.  A rap is transmitted to the framework from which the filtering  bags are



suspended.  Vibration from the rap shakes the dust loose.   Thorough cleaning



is rarely achieved because  the shaking action  is dependent on the operator's


     131
vigor.     This method is the least expensive and least desirable.



    Mechanical shaking (Figure 4-75) removes dust from woven fabrics in a


                                                   126
manner similar to that achieved by hand shaking a rug.     The  shaker mecha-



nism provides  a gentle but effective cleaning action on the bags without exerting



undue stresses on the fabric.



    The shaker design must allow for easy installation, alignment, and main-



tenance.  Shaking is usually used  for inside out filtering and is considered too



vigorous for fiberglass bags unless special provisions are made  for  reducing


                     145
the intensity of shaking.



    Air shaking (Figure 4-76) is done by flowing air  between rows  of  bags,


                                                      139
windwhipping the bags to make a dancing,  cleaning action.      Bags  are over-



cleaned near the orifice or jet  and undercleaned in blind areas out of the wind-



whipping action.  This method  requires a  minimum of  hardware but is usually



too vigorous for fiberglass bags.



    Air bubbling is  done by releasing a traveling air  bubble at the top of the



bag during the cleaning cycle,as shown in  Figure 4-77.  The bubble travels down



the bag during repressuring and causes it to ripple,  thus cleaning the bag by



shaking.  The compressed air requirements are high and cleaning at higher
                                 4-165

-------
 air-to-cloth ratios has not been fully proven.  This method is used for inside

 out filtering and sometimes for fiberglass bags.

      The jet pulse method employs a jet action of compressed air through a

                                              venturi section at the top of the bag

                                              (Figure 4-78).  Smaller diameter

                                              tubular bags are held in place

                                              over a supporting screen,  and

                                              dust is collected on the outside of
      INSIDE OUT
      FILTERING
                             SIDE VIEW
an open-end-up tubular bag.  Com-

pressed air released at frequent
Figure 4-75.  Mechanical shaking of bottom entry   intervals to a row of bags causes
            design uni-bag dust collector.
                                              the bags to pulse outward,  thus
vibrating the fabric, and removing

the dust. The dust is cleaned off by

a flicking action on the collection

surfaces rather than a reverse

flow through the fabric.  Felted

fabrics usually are used with out-

side in filtering.  The jet pulse

provides uniform pressure drop

and continuous and automatic

cleaning with no moving parts and
               O) PRESSURE BLOWER
                        TOP VIEW
                        AIR JETS
                        FOR SHAKING
                    SIDE VIEW
Figure 4-76.  Air shaking wind-whip cleans dust
            collector bags.
                                     4-166

-------
permits higher air-to-cloth ratios, resulting in smaller units for equivalent



capacity.  The cost of a supporting frame and higher replacement costs of


                                                                145
felted fabrics over woven fabrics are disadvantages of this method.



     Reverse air flexing is achieved by a double  or triple cycle deflation of the



bags followed by gentle inflating through low-pressure reverse flow,  as shown in



Figure 4-79.  The  cloth cleaning is not exclusively shaking, because some back-



washing occurs.  This method is used for inside out filtering with fiberglass



bags.



     Occasionally, sonic generators are used to  provide  additional fabric vibra-


                       145
tions for cleaning action.     Sonic generators vibrate the dust loose from the



collecting fabrics as shown in Figure 4-80.   They are sometimes used  to



supplement repressuring and reverse flow cleaning.   Some carbon black and



zinc oxide installations are using repressuring and sonic horns to clean fiber-


 i    u    145
glass bags.



     The second cleaning  category, reverse air flow, is  divided into three



methods:  repressuring  cleaning, atmospheric cleaning, and reverse jet



cleaning.



     Repressuring cleaning is a low-pressure, high-volume, reverse  flow of



air through the bags as shown in Figure 4-81.  It  is used for woven or felted



bags.



     Atmospheric cleaning is used in closed suction baghouses.  An atmos-



pheric vent is placed into the damper of the fan so that when the compartment



damper valve closes, the vent opens to the atmosphere allowing a backwash of
   331-716 0 - 69 - 21
                                  4-167

-------
                            JET
       UNI-BAG
     INSIDE OUT
     FILTERING
                                  SIDE VIEW
Figure 4-77. Bubble cleaning of dust collector
             bags.
                                                                                      COMPRESSED AIR
                                                                                      OUTSIDE IN
                                                                                      FILTERING
                                                                                   SIDE VIEW
                                                                                Figure 4-78. Jet pulse dust collector bag cleaning.
 I
I—>

00
                           \
                          \
                             #
           REPRESSURING
              VALVE
                                       EXHAUST
r1
I
[
^
                                 SIDE VIEW

                         FILTERING
                                                                             SIDE VIEW

                                                                   COLLAPSING
                                                                                             INLET
                                                                                             VALVE
       SIDE VIEW

CLEANING
                Figure 4-79. Reverse air flexing to clean dust collector bags by repressuring.

-------
                                      AIR HORN
                  FILTER BAG
                                      SOUND WAVES


                                        SIDE VIEW
           Figure 4-80.  Sonic cleaning of dust collector bags.
                        S7A
—1


4


4

1

r
\




n



*

4
M


\



,
rt
^

k
*


ui
n

^



*
u
\
\

\

<


_

A

^

i
1
                                     INSIDE OUT
                                     FILTERING
                                    SIDE VIEW
          Figure 4-81.  Repressuring cleaning of dust collector bags.


air to clean the cloth,as shown in Figure 4-82.   This action is gentle and is only

used with fiberglass cloth and easily removed dust.  Sonic horns may be used to

supplement the cleaning action.  The amount of backwash air is dependent on

doth resistance.  If the resistance is high the amount  of backwash air is

diminished, thus reducing the cleaning action.
                                 4-169

-------
                               TO FAN
                                                   VENT OPEN
                       SIDE VIEW
                                                   EXHAUST CLOSED
                                                        TO NEXT

                                                       COMPARTMENT
                                                   SIDE VIEW
            OPERATING
CLEANING
            Figure 4-82.  Cloth cleaning by reverse  flow of ambient air.




      Reverse jet cleaning uses a traveling compressed air ring which moves up



and down the outside of a tubular filter bag, thus blowing the  dust back through



the cloth and off the inside of the bag with compressed air as shown in Figure



4-83.  Re-entrainment of fine dust during cloth cleaning has caused high pressun



drops across some baghouses collecting fine fumes.  The design is used success'



fully with felted bags  with high air-to-cloth ratios collecting relatively coarse,



nonabrasive dusts. The replacement costs of bags is somewhat high.  The unit


                             145
allows a compact installation.



      The volume of air blown through the slot of the blow ring usually ranges


                                                            -I O 1

from 1.0 to 1.5 cubic feet per minute per linear inch of slot.  °  Slot widths


                             152
range from 0. 03 to 0.25 inch.
                                    4-170

-------


Jf
\
4
-4
r
.*•

TOP ENTRY
^-A— /-^
,/ \
r "(
_ x
X"^ ^^S;


^
HIGH PRESSURE
' *-AIR BLOW
RING
P
INSIDE OUT
FILTERING
CROSS-SECTION
           Figure 4-83.  Reverse jet cleaning of dust collector bags.
4.7.4.5  Fabric Selection — Fabrics that are presently applied in commercially
                                          123 147  153
available baghouses are shown in Table 4-13.    '    '     The finish applied to
these fabrics is described in Section 4.7.4.3.
     When comparing fabric cost ranks given in Table 4-13,  other factors also
should be considered.   Use of a high-temperature fabric reduces the amount of
dilution cooling required.   A high-temperature fabric requires less filtering
area. For example, when cooling gases from 400° F to 250° F with ambient air
at 90° F, the final gas volume is  increased by 60 percent.  The filter operating
at 400° F requires only  62. 5 percent as much cloth  area as at 250°  F.  These
                                                          154
reductions will also lower power  costs for operating the  filter.
     Fabric materials  less commonly used are carbon, metals and ceramic
fibers that will filter gases at temperatures up to 1600° F.      Beta fiberglass,
                                  4-171

-------
                          Table 4-13.  FILTER FABRIC CHARACTERISTICS
                                                                             123, 147,  153
Fiber
Cotton
Wool
Nylond
Orlond
Dacrorid
Polypropylene
Nomexd
Fiberglass
Teflond
Operating
exposure
•F
Long
180
200
200
240
275
200
425
550
450
Short
225
250
250
275
325
250
500
600
500
Supports
combustion
yes
, no
yes
yes
yes
yes
no
yes
no
Air
permeabilitya
cfm/ft2
10-20
20-60
15-30
20-45
10-60
7-30
25-54
10-70
15-65
Composition
Cellulose
Protein
Polyamide
Polyacrylonitrile
Polyester
Olefin
Polyamide
Glass
Polyfluoroethylene
Resistance
Abrasion
G
G
E
G
E
E
E
P-F
F
Mineral
acids
P
F
P
G
G
E
F
E
E
Organic
acids
G
F
F
G
G
E
E
E
E
Alkali
G
P
G
F
G
E
G
P
E
Costc
rank
1
7
2
3
4
6
8
5
9
Win/ft2 @ 0.5 in. W. G.
bP= Poor, F = Fair, G = Good, E = Excellent.
cCost rank, 1 = lowest cost, 9 = highest cost.
 Dupont registered trademark.

-------
a relatively new product, is more flexible than regular fiberglass and abrades


              149
less in service.



4.7.4.6  Auxiliary Equipment—Auxiliary equipment that is selected during



the original design includes dust handling equipment and precooling equipment.



     Dust handling equipment — For collectors that are regularly cleaned and



re-used, such dust handling equipment as  hoppers must be provided for the



collected dust.  Hoppers empty  through a dust gate,  rotary lock or  trickle


                                                             130
valve into a screw or belt conveyor, a  truck body, or a tote bin.     The dust



is then conveyed to the final disposal point.



     Careful consideration must be given to the dust handling system at the


                                             130
time the fabric collector is originally designed.     Failure to do so may result



in leakage in the system that will redisperse the collected dust and  create air



pollution problems.  Inaccessability of the handling equipment for servicing will



make maintenance difficult.  Undersizing of the dust disposal mechanism may



block the upstream flow of process materials.



     Precooling equipment — The application of cloth filtration to the cleaning



of furnace gases in most cases requires that the gases be cooled in order to



protect the filter fabric and to ensure economical bag life.  The following three


                                                              1 R G.

cooling methods are  employed singly or in various combinations:



     1.  Radiation and convection cooling, this requires a relatively large



     investment in U-tube coolers, or heat exchangers.
                                  4-173

-------
      2.  Admission of outside air for cooling, this results in relatively



      large filtration volumes with a resultant increase in the size of the



      gas cleaning equipment.



      3.  Spray cooling, this  is the most economical with respect to



      capital investment, but requires careful control of cooling water



      sprays in order to keep the temperature of gases high enough (75° F



      above dew point) to prevent condensation, which causes plugged filters.



      Radiation and convection cooling,and spray cooling cannot be used for a



gas of high moisture  content.  Only the tempering air method can be used to



avoid condensation of the moisture.  Regulation of  temperature is  accomplished



easily by this method, however, the outside air used for cooling also mustpass



through the filter,  so the filter must be considerably larger than a filter used



with U-tubes or spray cooling methods.



      Spray cooling of hot gases is the least expensive method because the



initial cost is reasonable, the maintenance is relatively easy, and the increase



in gas volume to be filtered is nominal.  However,  careful control of cooling is


                                                                            145
needed to hold the temperature of hot gases 50° F to 75° F above the dew point.



4.7.4.7  Individual Collectors Versus Large Collecting Systems — The individual



fabric collector has several advantages over a large central collecting system

                                                                           157
in manufacturing plants where relatively few dust sources must be controlled.


The unit collector is  self-contained,  and has a lower erection cost because the



unit is shipped erected, or nearly so,  and because  it can be installed at the



point  of need with minimum duct work.  The unit collector's mobility is often



                                   4-174

-------
economically important in a plant with idle batch processes where idle unit



collectors maybe moved to sites requiring dust control.  The large central



collecting system requires considerable floor space and is often erected outdoors.



Outdoor erection of a central system may require insulation and even supple-



mentary heat input to avoid chilling the gas to the dew point.  The large central



system is preferred in large manufacturing plants where  many dust sources  of



continuous processes must be controlled.



4.7.5 Typical Applications



     The following examples of fabric collector  application are presented to



show how  the}' may be applied to  control particulate matter from various sources.



The use of fabric filters has been extended by the introduction of fiberglass



bags capable of operations  at temperatures up to 550"  F.  The use of synthetic



fabric bags has resolved many problems  associated with corrosive or moderate



temperature dust emissions.



4.7.5.1  Cement Kilns —The collection of the dust from rotary cement kilns has



long been  a difficult problem.  The difficulty arises from the  large volumes  of



gas involved, the heavy loading of very fine particles, the high gas temperatures,



and in the case of wet-process  kilns, the presence  of a large  amount of water


     158
vapor.




    The conventional cyclone will collect a high percentage  of the dust,  but



beyond this point the electrostratic precipitator is the only device besides  the



fabric collector capable of final and  complete cleanup.  '        Efficiencies  as
                                   4-175

-------
high as 99. 5 percent, outlet loadings below . 02 grains per standard cubic foot,




and plume opacities less than 10 percent have been reported for fabric filter




                      i  ,    16°
applications to cement kilns.




4. 7. 5. 2 Foundry Cupolas—Emissions from a gray iron cupola are a prime





example of particulate matter than can be controlled with high temperature




fabric filtration.  Cupola exhaust temperatures range from 1000  F to 2200° F



                                                              162

with an average effluent loading of about 1 grain per cubic foot.     Much of




the emission is fine metal  oxide  fume less than 0. 5 micron in diameter.  Gas




cooling and high-temperature fabric filters are required.  Evaporation cooling




by water sprays is the most common technique used in gas cooling.  Off-gas




temperatures are reduced  to about 450" F before filtration through fiberglass





bags.  In a typical installation the  gas is filtered at rates of about 2. 5 feet


       2

cfm/ft through tubular bags that are 11-1/2 inches in diameter and 15-1/2




feet long.  A bag life of one or two years can be expected if bags are used





continuously.  In noncontinuous service, averaging 20 to 40 on-stream hours



                                                            1 62
per week, bags have been  reported to last four or five years.




4.7.5.3 Electric Arc Steel Furnaces—The electric arc steel furnace  presents




an emission control problem that is characterized by fine particulate matter




containing a high percentage of oxides of iron, dispersed in a gas stream that





is highly variable in temperature,  loading, and volume  during the different





process cycles.  Effluent volume is dependent on the type of hooding arrange-





ment employed because the dilution air flow is adjusted to provide for gas
                                   4-176

-------
cooling and in-plant dust control.  Stack temperatures may reach 750° F or

                               1 C* *3
higher with closed, hooded units.



     The first large-scale fiberglass filter in the steel industry was  installed

                            1 C* O
in 1959 at a Seattle steel mill.      This unit handles 105, 000 cfm at tempera-



tures up to 500° F using fiberglass  bags 11-1/2 inches in diameter and 25 feet



long that operate at an air-to-cloth ratio of 1.4.  The fiberglass bags are



cleaned by collapsing.



     Another example is a furnace melting 45 tons of steel scrap in four hours



and using an Orion fabric filter to handle a volume of 60, 000 cfm at 200° F.



The bag replacement costs are approximately $1400 per  year with a five year


,   ...  163
bag life.



4.7.5.4  Open Hearth Furnaces—A major steel company conducted a study



which found that iron oxide fumes generated by an oxygen-lanced open hearth


                                                      164
furnace could be collected efficiently by fiberglass bags.



     The 10-compartment baghouse used in the  study handles 145, 000 cfm at


                                       2
500° F, based on a filter ratio of 2  cfm/ft when nine of the ten compartments



are in operation.  Each of the ten compartments contains 80 fiberglass bags,



11-1/2 inches in diameter and 34 feet long (or 8070 square feet of filter surface



per compartment).  Reverse  air flex cleaning, supplemented by sonic horns,



is used.  The efficiency of the baghouse is well over 99 percent under all con-



ditions of inlet gas volume and dust loading.   Inlet particulate loading  has been



as high as 20  grains per cubic foot  during periodic cleaning of heat regenerative
                                  4-177

-------
surfaces.  The outlet dust loading has been measured at 0. 007 grains per


  u-  t   . 165
cubic toot.


4.7.5.5  Nonferi-ous Metal Furnaces—One of the largest secondary lead smelters


in the country has converted  from synthetic fiber to fiberglass bags to permit


fume collection at temperatures higher than 400° F.  This installation cleans the


combined effluent from a reverberatory furnace and a lead blast furnace.  Higher


filtering temperatures were desired in order to eliminate the  deposition of


organic tars on the bags. After 16 months' experience with fiberglass bags,

                     2
operated at 1.2 cfm/ft  and cleaned by shaking, results are reported as


  *•  t   +    162
satisfactory.


      After completion of pilot-scale  studies with both synthetic and  fiberglass


media at an integrated smelter producing primary  copper and  zinc, a baghouse


equipped with  222, 000 square feet of fiberglass bags was constructed to clean

                                                                       162
the  effluent streams from a reverberatory furnace and copper converters.


Fiberglass fabric was selected because of its corrosion resistance and because


operation at 450' F reduced by 50  percent the radiation-convection heat trans-


fer  area that would have been required for cooling  to temperatures safe for

                                                   2
organic media.  The average filter ratio is 1.6 cfm/ft  .  Bags 5 inches in


diameter and 10 feet long are vised.  Bag cleaning involves collapse every half


hour supplemented by mechanical  shaking every eight hours.  Sonic cleaning


equipment has been tried experimentally.  Based on present knowledge, an


average bag life in excess of two years is anticipated.
                                   4-178

-------
A. 7.5.6 Carbon Black Plants—Baghouses equipped with fiberglass bags are


reported to be in use for the final cleaning in 35 of the 37 carbon black plants

                  ~\ f C*
in the United States.     Earlier baghouses used synthetic bags  and kept the


filtration temperature below 2503 F to protect the media.  However, the


temperature was regulated by evaporative cooling, which brought the gas stream


close to the acid dewpoint and caused serious corrosion of fabric.   The intro-


duction of fiberglass in 1953 minimized this  problem by allowing operation at


temperatures of 400° F to 500° F.  Bag collapse, with some supplementary vibra-


tion from  sonic horns or other gentle means is the most common technique


used for cleaning the fiberglass  filters.  Air-to-cloth ratios are usually 1. 5:1.


The average baghouse capacity is around 50, 000 cfm, and bag life is  12 to 18

   «.  166
months.


4.7.5.7 Grain Handling Operations—The important sources of grain dust


emissions are cleaning, rolling, grinding, blending,  and the loading of trucks,


rail cars, and ships.  Conveying and storing grains also cause dust emissions.


     Low- and medium-efficiency cyclones  only have been used because of the


increased operating costs  and maintenance problems  associated with high-


efficiency multiple cyclones.   For grain dusts larger than 10 microns in


diameter,  medium-efficiency  cyclones are satisfactory.  For grain dusts


smaller than 10 microns,  the  fabric filter is preferred.     Often, air  streams


containing large amounts of dust are passed  through a cyclone to remove coarse


Particles before being directed to a fabric filter.  This technique relieves the
                                  4-179

-------
fabric filter from handling a high volume of large particles.  Receiving,



handling,  and storing operations require hooding the emission source and



conveying the dust-laden air to dust collection equipment.  For receiving



hoppers used in unloading rail cars and trucks, a method of control is to



exhaust air from below the grating.  The indraft velocity required will range



from 100 to 300 feet per minute depending on whether the hopper is in a building



or outside and exposed to winds.



      The fabric filters with the open pressure or closed pressure baghouse


with mechanically shaken woven cotton bags are reported to remove 99. 9 per-


                                                        123
cent of grain particles in the size range of 1 to 5 microns.     The air-to-cloth



ratios are about 5:1.


      Reverse jet filters which use felted fabrics are reported to remove 99,9


percent of grain particles in the size range of 1 to 5 microns with an air-to-

                                                                   i fis
cloth ratio as high as 15:1,  although ratios  of 12:1 are  more common.



4.7.6 Operational Practices



      Operational practices are somewhat different for woven fabrics and


felted fabrics.   The bag life  of woven fabrics  is related to cleaning frequency.



The more often a fabric, especially fiberglass, is cleaned, the shorter the


bag life; this assumes that cleaning is conducted often  enough to avoid fabric



blinding by a dust overload.  Fabric cleaning may be done when the pressure


drop across the baghouse, or one of its compartments, increases to 6 inches of

      131
water.     In large baghouses, fabric cleaning is scheduled by compartment


based on previous operating  experience.



                                    4-180

-------
     To avoid plugging of woven fabrics because of condensation,  the gas tem-



perature in the baghouse should be 50° F to 75°  F higher than the dew point of



the gas.     In some cases,  insulated duct work and baghouses are needed to



maintain gas temperatures.  In some installations, a small auxiliary heater is



used to prevent condensation in a baghouse when it is shut  down.


                               131
     The bag life of felted fabrics    is prolonged by reducing the frequency of



cleaning.  The cleaning cycle may be scheduled  to hold the pressure drop across


                                                           169
a reverse jet baghouse with felted bags to 3-5 inches  of water.     Figure 4-84



illustrates the effect of pressure control on filter resistance in a reverse jet


                       152
filter for dusts and fumes.



     To avoid plugging of felted fabrics when handling gases with high moisture


                                                                        131
content, the use of preheated air for reverse jet cleaning may be necessary.



4.7.7  Maintenance Procedures



     Maintenance  of a fabric collector is often related to  adequacy of the



original design.  The installation  of filters with  high air-to-cloth ratios is often



responsible for rapid replacement of bags.  The replacement may be needed



because of blinding of fabric or excessive bag wear.



     An unusually heavy grain loading may cause excessive wear or blinding



of a woven fabric.  As a rule of thumb,  particulate loadings above 10 grains per



cubic foot are often handled by a precleaner such as a medium- or low-efficiency


      130
cyclone.     The cyclone will remove a large amount of particulate matter
                                  4-181

-------
greater than 10 microns in diameter.  Reverse jet and pulse jet collectors
can
handle, without a precleaner,  dust loadings up to 80 grains per cubic foot for

                                     131
particulates larger than 60 microns.
                    UJ
                    OL
                       70
                       60
                       50
                       30
                    UJ
                    >s> 20
                    <
                    LU
                    a:
                    u
                       10
                                        DUST AT 5 TO 10 gr/ft3

                                        OR METALLURGICAL FUME
                                        AT \ gr/ft3
                         TYPICAL DUST AT
                         0.5 gr/ft3
                        0      20     40      60       80     100

                             REVERSE JET OPERATION, percent

                  Figure 4-84.  Effect  of  cleaning  frequency  on
                               filter   resistance  in  reverse-jet
                               baghouse.
                               (Courtesy of  Air Conditioning, Heating, and
                               Ventilating Magazine)



      Many baghouses are designed with compartments so that one compart-


ment can be shut down while the  rest  of the dust collector  continues operating.


Means for easy access to the bags should be included in the original design.


      Leakage through the filter  is perhaps the most important service problem.


Each bag must be regularly inspected for holes or tears.  Regular measurement
                                      4-182

-------
of down-stream dust concentration should be made either manually or with an


                                                                141
electronic-eye,to warn of an increase in dust content of the stream.



     Bag spacing is important.  Sufficient clearance must be provided so that



one bag does not rub another.  A minimum clearance of 2  inches is needed


                             131
between bags 10 or 12 feet long,     while longer bags require greater clearance



distances.



     The fan motor and bearings,  shaking device, reverse jet blow rings, valves,


                                                             130
and dampers must be lubricated regularly and checked for wear.     To avoid



extended downtime, worn parts should be replaced before they fail in service.



     Regular inspection of ducts,  hoods,  framework, and housing for signs of



wear from corrosion, erosion,  excessive heat,  and excessive moisture should



     A 13°
be made.



     Pressure gauges,  thermocouples, flow meters,  and all other instruments


                                                                     130
must be checked regularly to ensure that they are functioning accurately.



     A preventive maintenance program should be established and followed.



Regular routine inspection of major lubricant locations is needed.  The  schedule


                                                         130
maybe altered to fit specific installations of dust collectors.



1.7.8  Safety



    Whenever dust is  a combustible material,  the principal hazard in the



operation of fabric collectors is that of explosion and fire.  Other hazards may



arise in special cases,  depending upon the toxicity or  abrasiveness of the dust,
  331-7160-69-22                        4-183

-------
i.e., human health hazards such as metal poisoning and silicosis.




Continuous  monitoring of discharge effluents is needed to avoid any mishaps. 30





4.8  AFTERBURNERS




4.8.1  Introduction




      Afterburners are gas cleaning devices which use a furnace for the combus-




tion of gaseous and particulate matter.  Combustion is accomplished either by




direct flame incineration or by catalytic combustion.




      The disposal of particulate matter by combustion is limited to residue-free




vapors,  mists,  smoke,  and particulate  matter which is readily combustible,




as well as to particle sizes which require short furnace retention time and small




furnace size. Afterburners are usually used to dispose of fumes, vapors, and




odors when relatively small volumes of gases and low concentrations of partic-




ulate matter are involved.




4.8.1.1 Definition of Terms-




      Direct flame combustion—The use of a separately-fired burner in direct




flame  contact with the particle-laden gas to sustain rapid oxidation.  Heat




transfer occurs by conduction,  convection, and radiation.




      Catalytic  combustion—A method of oxidizing combustible gases  and




vapors on the surface of a catalyst,  without flame and at a lower temperature




than corresponding flame temperatures.




      Catalyst—A  substance which increases the combustion rate and theoret-




 ically is unchanged by the combustion process.
                                    4-184

-------
    Flash point temperature—The lowest temperature at which the vapors



above a volatile combustible substance ignite momentarily in air, tested



usually by applying a small flame under specific test conditions.  Flash point



temperatures are dependent on the geometry of the vapor-filled space, and differ



from open and closed containers.



    Auto-ignition temperature—The lowest temperature at which a volatile


                                                     170
flammable substance will ignite and sustain combustion.



4.8.1.2 Advantages and Disadvantages of Afterburners—The advantages and



disadvantages of direct flame and catalytic afterburners are cited to allow



a comparison to be made of the two types of gas cleaning devices.



    Direct flame—Advantages of the direct flame incineration afterburner



include: (1) High removal efficiency of submicron odor-causing particulate



matter, (2) simultaneous disposal of combustible gaseous and particulate



matter, (3) compatibility with existing combustion equipment, (4) relatively



small space requirements,  (5) simple construction, (6) and low maintenance.



    Disadvantages include:  (1) high operational costs including fuel and



instrumentation,  (2) fire hazards,  and (3) excessive weight.



    Catalytic—Advantages of the catalytic afterburner include:  (1) reduced



fuel requirements,  (2) and reduced temperature, insulation requirements,  and



fire hazards.
                                  4-185

-------
      Disadvantages include: (I) high initial cost, (2) sensitivity to catalytic

poisoning, (3) inorganic particles must be removed  and organic droplets must

be vaporized before combustion to prevent damage and plugging of the catalyst,

(4) catalysts may require frequent reactivation, and (5) lower efficiency at

the usual catalytic  afterburner operation temperature.

      Catalytic afterburners frequently require a  direct flame air preheater

to initiate and sustain catalytic  combustion, thereby further reducing the relative

advantage of the catalytic afterburner.   Methane from the incomplete combustion

of the direct flame  preheater fuel is not oxidized at low temperature in the

 catalyst bed.  Incomplete  combustion and the formation of oxygenated com-

 pounds may be prevented by operating the catalyst bed at elevated temperatures

 with a consequent reduction in the thermal advantage and fuel savings over

 direct flame combustion.

      Catalytic afterburners frequently are unable to meet local code

 requirements as to combustion efficiency at the usual catalytic afterburner

 operating temperature. *

 4.8.1.3  Combustion Theory — Combustion is the chemical reaction of a fuel

 with an oxidant, involving the disappearance of the  original reactants and the
 *Los Angeles County Rule No. 66: 90 percent or more of the carbon in the
 organic material being incinerated must be oxidized to carbon dioxide.
                                     4-186

-------
production of heat and oxides.  Combustion usually takes place in a thin



reaction zone.



     When solid fuels burn,  the reaction zone is confined to the surface of the



particle.  At low temperatures the combustion rate is limited  by the chemical



reaction rate, whereas at higher temperatures the chemical-reaction rate is  so


                                                           171 172
rapid that the rate of air supply controls the combustion rate.    '



     Combustion of liquid droplets and volatile solids occurs away from the



surface of the particle and combustion rate may be dependent on the rate of



heat transfer to the surface,  which causes evaporation and thermal decom-



position of the solid.  Combustion is  influenced by the gas velocity, the rate



of mixing, and the supply of oxygen.     '



     The temperature in the combustion zone  surrounding the particulate



matter may  exceed the temperature at the interior of the particle and in the



surrounding gas by several hundred degrees.   Heat transfer is largely by



radiation from the incandescent surface of the  particle,  or from the incan-


                                                                        175
descent carbon formed as an intermediate step in the combustion process.



     Catalytic combustion—The mechanism of surface catalysis  is very



complex.  The catalytic combustion process occuring on the surface of the



catalyst involves diffusion of the reacting molecules to the surface of the



catalyst through a stagnant gas film which surrounds the surface of the



catalyst,  adsorption of the reactants  on the surface, chemical combination of



the reactants,  desorption of the combustion products,  and diffusion of the
                                   4-187

-------
combustion products from the surface of the catalyst to the main gas stream.
The rate of catalytic oxidation is usually controlled by adsorption, chemical
combination,  desorption,  or a combination of these.
      Catalytic combustion occurs at a lower temperature than direct flame
oxidation by substituting catalytic adsorption energy for thermal energy of
activation (energy necessary for chemical combination) and by increasing the
concentration of the reactants on the surface of the catalyst.
      The chemical union of the oxygen with the organic compounds occurs
without flame on the surface of the catalyst,  with the transfer of the  heat of
combustion from the catalytic bed to the gas stream.
      Many substances exhibit catalytic properties,  but metals  in the platinum
family are recognized for their ability to produce combustion at minimum tem-
peratures.  Because catalysis is a surface phenomenon, relatively small
amounts  of metal are used and supported to expose a maximum of surface area.
Other catalysts include copper chromite,and the oxides of copper, chromium,
                                         176 177
vanadium,  manganese, nickel, and cobalt.    '
       Catalysts may be subject to poisoning from such materials
as zinc,  arsenic,  lead,  mercury, copper, iron, antimony, and phosphates.
Other materials which commonly suppress catalysis include halogen, and
                  178 179
sulfur compounds.    '      Poisoned catalysts may be reactivated by
periodically washing the  catalyst with acid solutions.
                                    4-188

-------
4 «_2 Afterburner Design Criteria


/t.8.2.1  General — Variables which must be considered in the selection and/or


design of afterburners for particle-containing gaseous wastes are heat transfer,


reaction temperature,  particulate size, mixing, flame contact, residence time,


inlet gas temperatures, and composition.  The  variables are interdependent and,


as a consequence, design criteria are semi-empirical because of the large


range of materials dealt with,  the lack of  design data, and the  relatively loose


control of operating conditions.


4.8.2.2 Heat Transfer — The transfer of  heat from burner flame to gaseous


and particulate matter is  an important factor in determining the furnace size,


operating temperatures, and fuel requirements of direct flame contact incin-


erators.  Heat transfer is best achieved by mixing when gases  are burned,

                                                                        180,181
and best achieved by radiant heat transfer when particulate matter is burned.

      For purposes of burning particulate matter, radiant heat transfer and


furnace temperature uniformity may be increased by  increasing the emissivity


of the burner flame.  This can be accomplished by limiting the air supply  to


produce a sooty flame,  by using high carbon-to-hydrogen ratio (C/H) fuels,


by adding soot or fuel oil  (by carburetion)  to gas flames, by using low-velocity

,                                                                        182-184
burners,  through poor mixing of air and fuel, and by  altering furnace design.


18.2.3  Reaction Temperature — Most direct flame burners  operate in the


1200  F to 1500° F temperature range in order  to obtain  maximum combustion

                                                                         185
within the limits of flame  contact, mixing, and  residence time  in the furnace.
                                 4-189

-------
                                                                         186-1
  O  11

     1000    1200   1400    1600   1800   2000   2200


                TEMPERATURE (° K)
      Figure 4-85 illustrates



the effect of air velocity and



particle diameter  on the



combustion rate of carbon.



The effects of particle size,



reaction temperature,  combus-



tion gas composition, and gas



velocity on the combustion rate



of carbon, coal,  and a number of



other compounds have been in-


         , 171-174,  189-191
vestigated.



      Adsorption catalysts are



used in fume burners operated
 Figure 4-85.  Effect of air velocity and particle   in the 800 °F to 1200 °F tempera-

             diameter on the combustion rate of

             carbon. (Dn = particle diameter)   L             _         ,  , ,  ,
                    v D                        ture range.   Furnace and catalyst



temperatures,  space,  velocity, and bed depth are used to achieve the desired


                                                       192-194
level of combustion efficiency (Figures 4-86 and 4-87).



      Compounds  such as methane, which are difficult to oxidize, require a



catalytic bed temperature approximately 200°F higher than ethane, propane,



butane, and other members of the paraffin series.      Carbon monoxide, which



is difficult to oxidize by direct flame combustion at low temperatures,  is easily
                                     4-190

-------
  100


   90


   80


   70


   60


  i 50
  I

  !40

   30


   20


   10
F—I	1	1     nr-^q
oxidized by platinum at a temperature of approximately 300 °F and by hopcalite


                             176,  196
catalysts at room temperature.



4 8.2.4  Retention Time —Pre-heat (induction) and combustion times will



                                            dictate the overall residence time



                                            of the  particulate matter in the



                                            afterburner.  Residence time



                                            requirement will determine  both



                                            combustion chamber dimensions



                                            and efficiency.



                                                  The time required to heat



                                            the waste gas to  peak furnace



                                            temperature is dependent on the
                                  1
   700    800     900   1000   1100   1200

              TEMPERATURE, ° F
 Figure 4-86. Combustion efficiency of catalytic    burner combustion chamber
          afterburner.


                                            dimensions and efficiency.



     The time required to heat the waste gas to peak furnace  temperature is



dependent on the burner combustion intensity and inlet gas temperature and may



be computed as follows:

                                                 2
!,„,   ,.          ,  ,   heat capacity of gas (Btu/ft -°F) x temperature rise (°F) n.
heat up time seconds)  =	—.   ..   .  .    ., '„. /£*	:	  (l>
                   '              combustion intensity  (Btu/ft'J-sec)



     Values of combustion intensity will vary from 1 Btu per  cubic foot per



second for low-pressure gas jet mixers to 500 Btu  per cubic foot per second for
                                   4-191

-------
     100
 is  80
 H o
 3 a
 to uj  60

 §1
 UH
 _|Q-  40
 o u-
 HO  20
            I      II
          SPIRAL-WOUND
          METAL FOILS
         '4 in. DEEP
          BED
       O1—
       212
                               30,000 SV
                               70,000
                              100,000
                 I     I     I     I      I
premix mechanical burners.  A


typical value is 140 Btu per


cubic foot per second for premix


high-pressure gas jet multiple-


port burners.


      The time required to heat
                 392       572         752

           REACTOR INLET TEMPERATURE, ° F

                                               a gas with a heat capacity of
 Figure 4-87.  Effect of temperature and velocity
             on abatement effectiveness: spiral-   0. 0182 Btu/ft  - °F  from
             wound metal foils catalyst support.                      '
             (Courtesy of the Journal of the Air  Pollution
             Control Association)                     200° F to  1800° F in  a. furnace


with a combustion intensity  of 140 Btu per cubic foot per second would be:


          Time (seconds) = 0.0182 x (1800 - 200)/140  = 0.208  seconds


      Combustion time required is dependent on particle  size, oxygen content


of the furnace  atmosphere,  furnace temperature, particle composition, gas


velocity,  and mixing of combustibles.   Combustion times for a number of


different materials have been determined and correlated  on the basis of
the following equations:
                       196
                    2
      id =  PR'Tm  X0/ (960D pj  for diffusion-controlled combustion rate  (2)



      ic = PX0/ <2KsPg)  for chemical reaction-controlled cumbustion rate  (3)


      Where:  td - diffusion-controlled combustion time (seconds);



              tc = chemical reaction rate-controlled combustion time (seconds):
                                    4-192

-------
                                                         3
            p = density of carbon residue or coke (gm/cm );


                                                         3
            R' = universal gas law constant (82.06 atm cm /mole/°K);



          T  = mean temperature of stagnant gas film (°K);



           x  = original diameter of particle  (cm);



            0 = combustion mechanism = 1 for CO and 2 for  CO  formation;
                                                             Lj

                                                                        2
            D = diffusion coefficient of oxygen at temperature T   (gm/cm );



           p  = partial pressure of oxygen in combustion air (atm); and
            o
                                                       2
           K  = surface reaction rate  coefficient (gm/cm  sec atm).
            S


    K may be calculated by means of the following equations:
      S



    K  ^L.085xl04xT-1/2xe-39'30°/RTs(forsoot)       (4)
      S                  S

                 -35 700/RT
    K  =  8710 x e    '        s (for coke and carbon residue)    (5)
      S


    Where:  T  = surface temperature of the carbon.




    Equation 2 holds at high temperature, zero gas velocity, and large particle



sizes.  The equation can be corrected for the effects of gas velocity and turbu-



lence by use of the dimensionless Nusselt conventional heat transfer relationship



t    i.   •  i          181
tor spherical particles:


                                            1 /2
              N    = 2 + 0. 68 N      x N
               Nu             Pr        Re



    Where:  N    = Nusselt Number;
             Nu


            N    = Prandtl Number, a function of the physical properties of


                   the gas; and



            N    = Reynolds Number, a function of the physical properties of
             XX C

                   the gas, particle diameter, and gas velocity.
                                  4-193

-------
      The Nusselt Number N    - h x/k = 2 at zero gas velocity where: h = con-
                                         2
vectional heat transfer coefficient (cal/cm  °C sec); x = particle diameter (cm).

h is an inverse function of the stagnant gas film thickness, x/2, surrounding the

particle and directly proportional to the thermal conductivity of the furnace at-
                    2
mosphere, k (cal/cm  °C cm sec).
      The film thickness decreases with increasing velocity  and decreasing particle
size to such an extent that the combustion rate for particles  smaller than 100

microns is limited only by chemical kinetics at normal afterburner temperatures.

      Equation 2 is of limited value in afterburner design because particles

larger than 100 microns are easily collected by  other gas cleaning devices and

would require excessive retention time and furnace volume.
      Equation 3 holds for particle sizes smaller than 100 microns and for tem-
peratures at which the combustion rate is  determined by chemical kinetics.

      Total combustion time for a carbon residue-forming particle then becomes:

                            t  = t.  + t   •  K   + t                     (7)
                             r    i    d    v    c

      where:     t  = total residence time (sec);

                t. = induction  time (sec); and

               K^ = volatile matter correction factor determined by the equation:

                        KV  =  (1  + E/100)  / (1 + E/100 -  V/100)       (8)
      where:     E - percent excess air and

                V = percent volatile matter.
                                    4-194

-------
     The combustion time for hydrocarbon liquid droplets larger than 30 microns

                                                              -| O Q

at zero gas velocity may be computed using the following equation:




                    t  = (29,800/p  )    M   T~1-75  .x2               (9)



     where-   M   = molecular weight and
               w


               T  = furnace temperature (°K)



     The combustion time of particles smaller than 30 microns is dependent on



the combustion rate of the hydrocarbon vapors.

                                      r*

     The time required to burn a 5 x 10   cm  soot particle of 2 grams/cubic



centimeter density in a furnace atmosphere containing 0. 20 atmosphere of oxygen



at 1800 °F can be computed using equations 3 and 4.  The time required would be



0.51 second.



     Total residence time in the furnace,  including heat up time from 200 °F,



would be induction time + combustion time = total time, or:



                    t  = 0.208 + 0. 510 = 0. 718 second
                     r


     In practice,  minimum gas furnace retention time is  about 0. 30  second at



a temperature of 1200 °F.  Particle retention time may be increased by design-



ing the combustion chamber in the shape of a cyclone  using a small tangential

                                                               -| n p-

inlet, and by introducing the gases at a high velocity (Figure 4-88).



     Cyclone furnace dimensions are chosen using a  gas velocity of from 15 to



30 feet per second.   '     Good mixing is attained by using appropriate design



parameters to provide turbulent flow in the afterburner.



    A tangentially fired, portable hood,  smoke  afterburner is shown in



Figure 4-89.



                                  4-195

-------
                             REFRACTORY
                             LINED
                             STEEL SHELL
                              REFRACTORY
                              RING BAFFLE
 GAS BURNER
 PIPING
                        GA5 STREAM
                                                     The combustion constants


                                               for a number of organic compound!


                                               are presented in references 171


                                               through 175,  186 through 191, and


                                               195 through 197.


                                               4. 8. 2. 5  Heat Recovery — Inlet


                                               waste gas temperatures should


                                               be as  high as possible to mini-


                                               mize additional fuel and preheat

                                                             198-201  ,
                                               requirements.         The


                                               maximum recoverable energy
                                 CONTAMINATED  in afterburner stack gases as a
Figure 4-88.  Typical  direct-fired  afterburner
            with  tangential  entries  for  both
            fuel and contaminated gases.
                                               function of exhaust gas tempera-


                                               ture is shown in Figure 4-90,


with waste gas energy content and temperature as parameters.


      Heat recovery equipment used to recover heat from the flue gas may be


grouped under two classifications:  recuperative and regenerative. Recuperative


(recovery) heat exchangers recover heat on a continuous basis and include cross


flow, countercurrent flow, and cocurrent flow heat  exchangers (Figures 4-91


through 4-93). For a given heat flow and temperature drop, heat exchanger sur-


face requirements will be at a minimum in the counterflow heat exchanger (Figure


4-91). 2°2


      Cocurrent flow heat exchangers  are  often used where a moderate level of


heat recovery is  required.  Countercurrent flow heat exchanger construction

                                      4-196

-------
            Figure 4-89.  Portable canopy hood with stack afterburner.
                        (Courtesy of Eclipse Fuel Engineering Company)


maybe more costly than that for cocurrent flow,  because of operation at lower

temperatures (near the clewpoint), which may require use of special alloys or

alloy steels.


      Regenerative heat exchangers recover heat by intermittent heat exchange

by the alternate heating and cooling  of a solid.   Heat flows alternately into and


out of the same  exchanger, as air and flue  gas flow are periodically reversed.


Regenerative heat exchangers are of fixed and moving bed types.
                                    4-197


-------
z ^
  u
LL 10
o  \
O 2
   00
 "• o
 >- H
 O "°
 UJ <
 5 x
 ZUJ
 ill t-
 H £
 O <
 CL
            .AFTERBURNER TEMPERATURE
                       1350 "F
              A fixed bed,  pebble-stove,
        regenerative afterburner is
        shown in Figure 4-94.  When
        gas is passed through the pair
        of pebble-type regenerators
  ]3500   connected back to back, the gas
                                                is heated on the upstream side
  242
  1135
  028   and cooled on the downstream
  927
  8i4   side.  When the upstream bed
            100    200    300    400   500
         PROCESS EXHAUST TEMPERATURE, °F
  707

600
                                               and gas temperature drop, gas
                                               flow is reversed and the heat
   Figure 4-90. Afterburner  energy  requirements   transfer process is repeated.
              with fume energy content and tem-
              perature  parameters.                Particulate matter is effectively
retained and incinerated.  Heat recovery efficiencies in excess of 95 percent
    ,     , .    , 203
can be achieved.
       A commonly used rotary regenerative heat exchanger consists of a
partitioned rotating cylinder containing heat sink and heat transfer surface area.
The cylinder is  partitioned along its axis by appropriate gas seals so that hot
flue gas and cold waste gas may be passed through the heat exchanger on opposite
sides of the cylinder.   Heat is absorbed from the hot flue gas by the heat
exchanger surface and transferred by the continuous rotation of the heat exchange
                                     4-198

-------
          STACK GASES
                                                             STACK GASES
                                                                         7
                                                                        r~\
                           JJ
                       AIR
                                                       AIR
                                                                         AIR
Figure 4-91.  Counter-flow  type.
Figure 4-92.  Parallel-flow type.
                             STACK GASES
                   AIR
                         Figure 4-93. Cross-flow  type.
                                       NATURAL GAS
                                              '/?/v'.'';':" '         "A 'iv.-V.'>
                                              7*.-;.Y                '-'.': ~;'
                                              '•/•'•-'                 • •':' '
                                              h|   PEBBLE BED   Q
                                              V -'v.
                                                  •-•.•--.•.•-..	.-./-
             TO CHIMNEY
                                                    BLOWER
                                                                            FROM KILN
          Figure 4-94.   Fixed-bed, pebble-stone, regenerative destencher.
                        (Courtesy of Research Cottrell)
   331-716 0-69-23
                                        4-199

-------
surface to the cold waste gas side where the heat is absorbed by the incoming
                                                                  203
cold gases.   Heat recovery efficiency ranges from 85 to 95 percent.
4.8.2.6  Fuel Requirements — Maximum fuel consumption for one-pass catalytic
afterburners may be as high as 10 Btu per standard cubic foot of waste gas flow,
while systems with heat exchangers can economically reduce heat requirements
                                     199
to about 4 Btu per standard cubic foot.    The heating value of the waste gas
stream is usually limited by insurance underwriters to combustible  vapor con-
centrations of less than one-fourth of the lower explosive limits of the gas mix-
ture.  For organics,  this is equivalent to about 13 Btu per standard  cubic foot
and represents a total temperature rise  of approximately 675° F,  equivalent to
52° F to 55° F per Btu per standard cubic foot. Catalytic combustors are usually
equipped with automatic safety controls when treating high organic concentrations.
      The heat generated by the combustion of solvent and paint fumes may be
directly recovered by recirculating the combustion gases to the oven (Figure
4-95), or indirectly recovered by means of heat exchangers (Figure 4-96).
Direct heat recovery  may be advantageous in the case of catalytic  combustion
because of lower oxygen requirements in the catalytic combustion  zone.    '
This can be  advantageous with  materials having a low explosive limit.
      Fuel savings from the use of the heats of combustion of paint bake-oven
solvent vapors  may be large enough to provide a 50 percent return on invest-
ment in the case of catalytic combustion.204
                                    4-200

-------
          ALL-METAL
          CATALYST ELEMENTS
                                             FRESH MAKE-UP AIR
 PREHEAT
 BURNER
                                                                             SUPPLY
                                                                             FAN
     FROM SOLVENT
     EVAPORATION ZONE
                                                      HEATED DECONTAMINATED
                                                      AIR RETURN TO OVEN
                                PAINT BAKE OVEN
          Figure 4-95.  Direct recirculation of combustion gases to recover heat.
CLEAN GASES
                                 COLD
                                 FRESH
                                 AIR
                                                        /////A////////////////
                                                                             SUPPLY FAN
         HEATED MAKE-UP AIR
                                 PAINT BAKE OVEN
        Figure 4-96.  Heat exchanger to recover heat from combustion gases.

                       (Courtesy of Universal Oil Products Co.)
                                       4-201

-------
      Fuel requirements and burner capacity may be determined by means of



a heat balance, using the heat of combustion of the fuel and the sensible heat



needed to raise the temperature of the waste gas and the products of combustion



up to the desired combustion temperature.  The heating value of the contaminant


                                 .   ,      .       .  185,205-208
must be deducted to determine net fuel requirements.



4.8.2.7  Modified Furnace Afterburners —Existing boilers,  rotary kilns, and



furnaces have been successfully modified and used for direct flame incineration.



Requirements for successful operation are:



      I..  Contaminants must be  combustible and non-corrosive.



      2.  The oxygen content of the contaminated gas must be high, or of such



      volume that it does not upset or reduce furnace capacity.



      3.  The furnace must be operated continuously  or modulated to ensure



      adequate furnace temperatures.



      4.  The furnace must be large  enough to ensure adequate residence time.



      5.  Conditions must be such that there is little  or no deposition of par-



      ticulate matter on the burner or furnace walls.



      Furnace modifications, design calculations, and proven methods for


                                                 -i o (-

introducing waste fumes are given in the literature.



      Odors from kraft pulp manufacture have been successfully disposed of by



introduction into a modified furnace kiln with fuel  savings of over $450 per


    .,  209,210
month.
                                   4-202

-------
A.8.2. 8 Hood and Duct Design Considerations — Furnace inlet gases, and vapors




from paint and varnish cooking kettles,  as well as from other sources, must be




maintained at temperatures above condensation to avoid exhaust duct fouling.




Collection ductwork is usually insulated and may be heated by means of an ex-




ternal duct which serves to recover heat from the flue gas, effecting a reduction


                                            208
in combustor fuel requirements (Figure 4-97).




     Duct gas velocities are usually high, ranging from 4000 to 5000 feet per




minute, to prevent the settling of particulate matter, to effect a high heat re-




covery rate between the  flue gas and furnace feed gas,  and to minimize the



                                  211  212
danger of flashback and fire hazards.    '




     Other safety devices to minimize fire hazards may include diluting




vapors to below the lower explosive limits, using flame arresters,  and




including a wet scrubber between the direct flame combustor and the vapor




source. Dilution of the vapors may be accomplished by recirculation of a por-




tion  of the flue gas, with a substantial reduction in fuel requirements,  as shown



        .  ._ 208-213
in Figure 4-97.




     Flame arresters may consist of a packed bed of pebbles, metal tower




packing, aluminum rings (Figure 4-98), or corrugated metal gridwork (Figure




4-99),  in conjunction with a blast gate or other pressure release device.  Flash-




back through the  bed is prevented by bed gas velocities in excess of flame pro-




pagation velocities,  by pressure drop,  as well as by cooling the flame to below


                       o 1 q  914

combustion temperatures.    '
                                  4-203

-------
      Other types of flame arresters include  spray chambers, wet seals, and



dip legs (Figure 4-100).  Wet flame arresters have the disadvantage of cooling



and humidifying the exhaust gas, with a consequent increase in fuel requirements.



Wet sprays are capable of removing up to 80  percent of the solids involved in


                                                          185
paint  making; there is no noticeable reduction in odor level.



      Other safety devices include high- and low-temperature combustion and



flame-out control instruments.



      Exhaust hoods should be close fitting to minimize ventilation requirements.



Guidance on hood design and  ventilation rates is  offered by the American Con-


                                             215
ference of  Governmental Industrial Hygienists.



4.8.2.9  Gas Burners — Figure 4-101 shows  a crossectional view of an open-



type inspiration (venturi mixer) premix burner.  This mixer uses the energy



of the gas to induce primary  air in proportion to the gas flow and is limited to



cases in which high pressure gas (5 to 10 pounds per square inch) is available.


      Luminous flames may  be produced by conventional burners by operation



at low capacity and by restricting air supply.  Minimum burner capacity  is


                                                                    212  216 217
determined by the burner throat velocity at which flashback can occur.    '   '



The turndown ratio (ratio of  maximum to  minimum flow rate for satisfactory


burner operation) will range  from 3:1 to 5:1.



      Pressure-type burners, illustrated in Figure 4-102, permit a higher rate



of heat release within a relatively small space and are available in a multitude



of designs for special applications.  They are characterized by a single mixing
                                   4-204

-------
 I
to
o
Ul
1  EXHAUSTER
2  PREHEAT BURNER
3  CATALYST
4  RECYCLING DAMPER
5  HEAT EXCHANGER
                                                                        STACK
                                                                        DISCHARGE
                                                                      COLD OUTSIDE
                                                                      AIR
                                                                                                     PREHEATED
                                                                                                     FACTORY
                                                                                                     SUPPLY AIR
                                          \utt\\\u\\\\\\\
                                                            COOLING
                                                            STATION
                                                       COOKING
                                                       STATION
                       Figure 4-97.  Integration of fume disposal from a kettle cooking operation with  factory make-up air
                                    heating.  (Courtesy of Cotolytic Combustion Co.)

-------
              ////////S'A
               PACKING
              rrrrrrrrrr/
              //////
              '/// /t /
                                       WASTE GAS
                                 BLAST GATE
   TO
COMBUSTOR
Figure 4-98.  Packed bed flame arrester.
                    a:
                    O
                    03
                    O
                    (J
                   t
                                                                              BODY
                                                                              TUBE BANK
                                                                              TUBE BANK
                                                                              SHELL
                                                                              HANDLE
Figure 4-99. Corrugated  metal  flame arrester
             with  cone removed and  tube bank
             pulled partly out of body.
             (Courtesy of Generol Precision Systems, Inc.)
                 OIL
                 OR
                WATER
                                      WASTE GAS
   Figure 4-100.  Dip leg flame arrester.
                                      4-206

-------
port or nozzle which produces a short hot flame.  Gas premixing is accomplished



by use of forced inlet combustion air, usually supplied by a fan.  This type of



burner has a high turndown ratio and is capable of producing an accurate control



of the gas combustion mixture.



     Waste gas may be used as a source of primary and secondary air, with a



consequent reduction in fuel requirements, if the oxygen content is high and the



gas  is free from deposit-forming solids.



     Burners of the cyclone design, shown in Figure 4-88, are usually mounted



to fire tangentially into the combustion chamber and to assist in the cyclonic



motion and mixing of the furnace atmosphere.  Burners  must be capable of con-


                                                                 IR1") /* O/* PI'S
tinuous modulation to accommodate changes in waste gas flow rates.    '    '   '



     To prevent the emission of smoke when the flame is operated to produce



a luminous flame,  secondary air or waste gas may be introduced  above the burner



     Combustion intensity may be further increased by  the use of forced air,



premixing, multiple-port burners of the type  shown in Figure 4-103.  Combus-



tion intensities as high as  500 Btu per cubic foot per second have  been obtained



using a combination of multiple port burners and flame impingement on the sur-


                                                      -109

face of refractory brick which acts as a catalytic surface.     Typical uses and



combustion characteristics for a number of burners are listed in  Table 4-14.



     The combustion  intensity of a given burner is related to the furnace  tem-


                                                       198
perature and fuel composition as indicated in the equation:
                                  4-207

-------
     NUT AND STUD
DISC
BODY
GAS INLET
          SPIDER   LOCK~\    SPUD
                    NUT  AIR INLET
      Figure 4-101. Cross-sectional view of open-type
                    inspirational premix burner.
  RATIO DIAL    COMBUSTION
       MS INLET AIR INLET
    RATIO VALVE
         HOLE FOR PILOT TIP  (.-MOUNTING PLATE
   Figure 4-102.Cross-sectional view of forced air,
                 premix, multiple-port burner.
                         4-208

-------
                                 Table 4-14.  GAS BURNER CLASSIFICATIONS





Classification
Atmospheric
or low-pressure
burner system












Blast or high-
pressure burner
system













Extent of mixture
of air and gas
Partial, usually
less than 50%
of air required
for combustion


Air and gas not
mixed; low-veloc-
ity stratified or
diffused in com-
bustion chamber
Air and gas not
mixed; turbulent
mixing close to
nozzle but in com-
bustion chamber

Completely mixed
or nearly so before
reaching nozzle







Velocity
of
mixture
through
nozzle.
ft/min
50
to
1,200



400
to
10,000


400
to
36,000



1,200
to
36,000











Mixing
method
Gas jet mixer
or injector using
low-pressure gas



Not mixed until
in combustion
zone


Not mixed until
in combustion
zone



Premixed by air
jet mixer

Gas jet mixer
HP gas

Mechanical
mixer
Combination
of the above



Required
gas
pressure
Under
1 Ib.




Under
4 oz.



4
to
16 oz.



4 oz.


1
to
25 Ib.
4 oz.






Required
air
pressure
0





Under
4 oz.



4
to
32 oz.



4
to
32 oz.
0


0







Temperature
range, °F
100°
to
1200°



600°
to
2400°


1000°
to
2800°



1200°
to
3000°











Combustion
speed
Very
slow




Slow




Fast





Very
fast








Combustion inten-
sity, approximate
maximum heat re-
lease per cubic foot
of combustion
chamber space
10 Btu/ft3/sec





28 Btu/ft3/sec




70 Btu/ft3/sec





70 Btu/ft3/sec





555
to
1400
Btu/ft3/sec




Typical burner
assemblies
Ring burners
Pipe burners
Torch burners
Box burners
Immersion burners
Wheel burners
Diffusion burners
Radiant flame burners
Variflame burners
Radiant tube burners
Static pressure burners
Nozzle mixing
burner




Open burners





Tunnel burners



 I
to
o
ID

-------
                            2     -3/2            -A/RT
                  CI = k •  p  • T  •    C  •  C  •  e  "" """ a        (10)

                                              3
      Where:  CI = combustion intensity (Btu/ft  sec atm);


              k is a constant;


              p = atmospheric pressure;


              T  = furnace atmosphere temperature "absolute;
               a

              C ,  C  = fuel and oxygen concentration,


              e = natural log base;


              A - energy of activation (approximately 42, 000 calories/gm atom);

                  and


              R = universal gas law constant.



      A heat loss of approximately 5 percent from the combustion gas can re-



duce combustion gas temperature and reduce combustion intensity by as much



as 20 percent,  with a consequent  reduction in afterburner combustion efficiency.



Hence it is important that combustion zone heat losses be kept at a minimum.



Heat losses can be reduced by proper insulation and by shielding the burner



from  cold objects,  such  as  ironwork,  heat exchangers, masonry,  or even the



sky.

    ma^salfiimmtmtiiumgKggm^

                                                     Combustion efficiency is



                                               improved  if combustion takes



                                               place at the base of the furnace



                                               and the waste gases pass upward,



                                               This  minimizes opportunity for



                                               channeling and  bypassing.

    Figure 4-103. Multiple-port high-intensity prernix

              burner.

              (Courtesy of Maxon Premix Burner Company)
                                    4-210

-------
4,8.2.10_ Construction Materials — Afterburner surfaces exposed to high tem-



peratures and erosive or corrosive conditions must be constructed of alloys



capable of withstanding high temperatures or must be lined with refractory



materials.



     Metals — Temperatures at which alloy steels are used are limited by



Underwriters'  Laboratories, Inc. to approximately 200° F below the temperature



atwhich scale  formation occurs. Martensitic and ferritic stainless steels are



recommended for use in areas that are exposed to wide ranges of temperature


                          218
and to corrosive conditions.     Temperature limitations for other metals and


                                                             207
alloys are determined by design stress and  safety requirements.



     Refractories—Refractories used in direct flame afterburners increase



radiant heat transfer, insulate,  act as a support structure,  and resist abrasion



and corrosion.  In so doing, they must be capable of withstanding thermal shock.



Fire clay refractories are commonly used in incinerator and afterburner con-



struction because of low cost, spall resistance,  and long service life.  Fire



clay refractory bricks are classified (Table 4-15) into maximum service  classes


                                                                        202
according to American Society for Testing and Materials standards (ASTM).



Their softening points, as determined by pyrometric cone equivalent (PCE) help


                                      O 1  Q
determine their maximum service class.      Other requirements include limits



on shrinkage, spalling loss, and deformation under load.  Castable fire clay


                                                                /M 7
refractories commonly used (Table 4-16) are of  two ASTM classes.
                                  4-211

-------
 Table 4-15.  ASTM CLASSIFICATION OF FIRE CLAY REFRACTORIES
Refractory type
Low heat duty
Intermediate heat duty
High heat duty
Super duty
PCE
19
29
21-32
33
Temperature, °F
2768
2984
3056-3092
3173
Table 4-16.  COMMONLY USED CASTABLE FIRE CLAY REFRACTORIES
ASTM No.
24
27
Temperature, °F
2400
2700
Density,
lb/ft3
70-85
110-125
Special properties
Insulating light weight
General purpose

-------
    Service temperature range and physical properties of various refractories



for corrosive conditions are shown in Figures 4-104 and 4-105 and in Table 4-17.


                                         202 203 219
The literature contains further information.    '     '



4.8.2.11 Typical Applications —A summary of the afterburner applications is



presented in Table 4-18.  The information was taken from published literature



and manufacturers' bulletins.
                                  4-213

-------
 I
to
                          5000
                          4500
                          4000
                          3500
                          3000
                              _  ACIDIC
                      Q.
                         2500 —
                         2000 -
                          1500 —
                                           NEUTRAL
                               FIRECLAY
                                                                                  BASIC
                                                                                                         GRAPHITE, 6400° F
                                                                                                              m.
                         1000
SILICA  CASTABLES, INSULATING    HIGH      CHROME,   ZIRCONIA, GRAPHITE
        MORTARS,      BRICK     ALUMINA   MAGNESITE   ZIRCON   CARBIDES,
        PLASTICS                                                  BORIDES,
                                                                  NITRIDES
                                             Figure 4-104.  Service temperature ranges for refractories.

                                                            (Courtesy of McGraw-Hill Book  Co.)

-------
 I
to
                         cc
                         UJ
                         CL
                         UJ
                         I-
•z.
UJ
t-
u_
o
                         x
                         O
                             2000
                             1900 —
                             1800 —
                             1700
                             1600
SILICA i  SILICIOUS |                  i
—    "T"         *T~ FIREBR!CK---4«-
 BRICK     BRICK
                                                                                    ALUMINOUS BRICK --
                        %A1203
                         %Si02  TOO
                 10
                90
                 20
                 80
30
70
40
60
50
50
60
40
70
30
80
20
                                                                                          , ALUMINA
                                                                                             BRICK"'
90
10
100
  0
                                                                     COMPOSITION BY WEIGHT
                                         Figure 4-105.  Degree of refraction for alumina-silica system products.
                                                         (C ourte s y of C hem tea I Engineering Magozi ne }

-------
 Table 4-17.   GENERAL PHYSICAL AND CHEMICAL CHARACTERISTICS
                OF CLASSES  OF REFRACTORY BRICK
Type of b.-lck
Silica
Hlgh-dut>
fireclay
Super-duty
fireclay
Acid- resistant
(lype HJ
Insulating
brick
High-alumina
Extra-high
alumina
Mulllte
Chrome- fired
Magneslte-
ohrome bonded6
Magnesl te-
ch rome fired
Magneslte-
chrome
high-fired
Magneslte-
bondedb
Magneslte- fired
Zircon
Zlrconla
(stabilized)
Silicon-carbide
Graphite
Typical
chemical
composition
SltVj, 05%
3102. 54%
AI^O;,, 40%
SI02, 52%
AlsOj, 42%
81O2. 69%
A1203, 34%
Varies
Al20g,
A1203,
90-99%
AI2O3. 71%
Chrome ore.
100%

MgO, 60-«0%
8IO2. 1.2-5%

MgO, 95%,
ZK>2. 67%
Si O2, 3.1%
ZrOs, 94%
CaO, 4%
SIC, 80-907
C, 97%
bulk
density,
u./rt3
115
1.14
140
142
30-75
170
186
153
195
190
180
180
181
178
200
245
160
105
point,
*!•
3100
3128
3170
3040
Varies
3200-
3400
3000-
3C50
3290
Varies

Varies


3900
3100"
4800
4175
6400
Chemical
nnture
Acid
Acid
Acid
Acid

Slightly
acid
Neutral
Slightly
acid
Neutral

Bas'c


Basic
Acid
Sltghtlv
acid
Slightly
acfd
Neutral
Defor-
mation
under
hot
loading
Excellent
Fair
Good
Poor
Poor
Good
Excellent
Excellent
Fair
Good
Excellent
Excellent
Good
Good
Excellent
Excellent
Excellent
Excellent
Apparent
poroiilly,
21
18
16
7
35-85
20
23
20
20
12
20
18
11
19
26
23
15
16
Perme-
ability
High
Moderate
High
Low
High
Low
Low
Low
Low
Very Low
High
High
Low
Moderate
Very low
Low
Very low
Low
Hot
strength
Excellent
Fair
Fair
Poor
Poor
Good
Excellent
Good
Good
Good
Good
Excellent
Good
Good
Excellent
Excellent
Excellent
Excellent
Thermal
shock
resistance
Poor3
Fair
Good
Good
Excellent
Good
Good
Good
Poor
Excellent
Excellent
Excellent
Good
Good
Good
Excellent
Excellent
Excellent
Chem ual resistance
to acid
Good
Good
Good
Insoluble In acids
except HF and
boiling phosphoric
Poor

Good except for
HF and aqua regla
Insoluble In
most acids
Fair to good

Fair except
to utrong acids

Soluble In
most acids

Very alight
Very slight
Slight re-
action with HF
Insoluble
t° alkali
Good al low lemjwraturBi
Good al low lemperalurei
Good at low temperaturw
Very resistant In
moderate concen-
trations
Poor

Very slight attack
with hot solutions
Blight reaction
Poor

Fair resistance it
low temperatures

Good resistance at
low temperatures

Very slight
Very Slight
Attacked at high
temperatures
Insoluble
Good above 1200°F.
Chemically bonded.
Dissociates above 3100'F.
                                      4-216

-------
                             Table 4-18.   SUMMARY  OF AFTERBURNER APPLICATIONS AND LITERATURE  REFERENCES
 I
to
Applications
Aery late
polymerization
Asphalt blowing and
saturating
Automotive paint
baking
Bakellte manufacturing
Bonding and burn-off
Burnoff ovensa
Carbon furnacesa
Chemical processing
Coffee roastinga
Coil and strip coating
Corn popping4
Cupola gasa
Deep fat frying2
Fabric curing
Fish and vegetable
oil processing3
Food processing
Foundry core baking2
Fungicide manufacture2
Grinding wheel
sintering
Hardboard coating
and curing
Incinerators2
Kraft paper manufacture
Metal decorating2
Metal chip drying
References
Catalytic

204
204

227b. 204, 195

204, 225
204
204, 223
194
204, 224
204
204

204
185
204
204
185, 204
204

124

204


185, 204
204
Flame

178



225

178
178
192. 201
209. 224
179

209

185








228
209. 222
178

Applications
Nut roasting
Oil hydrogenationa
Oil quenching2
Oil sulfurizatlon
Paint and varnish
cocking2
Paper coating
Pharmaceutical
manufacture
Phthalic and maleic anhy-
dride manufacture3
Potato chip cooking3
Printing2
Rendering3
Resin manufacturing
and aery late
polymerization3
Rice browning3
Sewage treatment
Smoke abatement3
Smoke houses3
Stationary diesel engines
Synthetic rubber
manufacture

Tar coating
Textile finishing
Vitamin manufacture
Wax burnout,
investment casting3
Wire enameling2
References
Catalytic
204
204
204
204

204, 227
204
204

185, 204. 227
204
204. 221
204

204
204
204


194, 227
204

204

204

185, 204
194. 204, 227
Flame




178, 195, 220
209, 220, 225, 226



178. 220
178
178
178, 185

178. 220

203, 229
228, 230
185, 209

200


198



178. 226
                                      alnvolves discharge of particulate matter.

                                      ^Underscored references contain quantitative data.

-------
                       REFERENCES FOR SECTION 4

 1.   Wilson, E. L. "Statement on Air Pollution. "  In:  Hearings before
     Subcommittee on Air and Water Pollution of the Committee on Public
     Works,  United States Senate, 90th Congress,  Part 4, "Air Pollution,
     1967," p.  2637.

 2.   "Industrial Gas Cleaning Equipment Shipments and End  Use - 1967."
     U.S. Dept. of Commerce, Washington,. D. C. ,  1968.

 3.   Stephan, D. G. "Dust Collector Review. "  Trans. Foundrymen's
     Soc. ,  Vol. 68, pp. 1-9, 1960.

 4.   Stairmand, C. J. "Removal of Grit,  Dust, and Fume from Exhaust
     Gases from Chemical Engineering Processes." Chem. Eng., pp. 310-
     326, Dec. 1965.

 5.   Stairmand, C. J. "The Design and Performance of Modern Gas-Cleaning
     Equipment."   Inst. of Fuel,  Vol.  29, pp.  58-76,  Feb. 1956.

 6.   Duprey, R. L. "Particulate Emission and Size Distribution Factors."
     U.S. Dept.. of Health, Education, and Welfare, National Center for
     Air Pollution Control, Durham,  North Carolina,  May 1967. (Prepared
     for: New York-New Jersey Air Pollution  Abatement Activity.)

 7.   Lapple, C. E. "Fluid and Particle Mechanics. "  University of Delaware,
     Newark, 1951, pp. 292-324,  353.

 8.   Strauss, W. "Industrial Gas Cleaning."  Pergamon Press, New  York,
     1966,  pp.  144-160, 171.

 9.   "Engineering Data on Dust Collecting Systems. "  Bulletin No.  63,
     Schmieg Industries, Detroit,  Michigan, 14 pp.

10.   Jackson, R.  "Survey of the Art  of Cleaning Flue Gases. "
     British  Coal Utilization Research Assoc.,  Leatherhead-Surrey,
     England, 1959, 427 pp.

11.   "What We Know about Air Pollution Control. "  Special Bulletin No.  1,
     Texas Cotton Ginners' Association, Dallas, Texas, March 1965, 43pp.
                                    4-218

-------
12.  Lapple,  C.  E.   "Fluid and Particle Dynamics. "  University of Delaware,
    Newark, 1952, 353 pp.

13.  Strauss, W. "Industrial Gas Cleaning. " Pergamon Press, New York,
    1966,  471 pp.

14.  "Cyclone Dust  Collectors. "  American Petroleum Institute, Engineering
    Dept., New York, 1955, 65pp.

15.  Danielson,  J. A. (ed.)  "Air Pollution Engineering Manual. "  U.S. Dept.
    of Health,  Education, and Welfare, National Center for Air Pollution
    Control, Cincinnati,  Ohio, PHS-Pub-999-AP-40,  1967, 892 pp.

16.  Rosin, P.,  Rammler, E. , and Intelmann, W.  "Grundlagen, und
    Grenzen cler Zyklonentstaubung" (Principles and Limits of Cyclone-
    Dust Removal), V.D.I. Zeits, No.  76, pp. 433-437, April 1932.

17.  Perry, R. H. , Chilton, C.  H. , and Kirkpatrick, S. D. "Chemical
    Engineers Handbook, " 4th edition, McGraw-Hill,  New York, 1963.

18.  Hughson, R. V.  "Controlling Air  Pollution. " Chem.  Eng. ,  Vol.
    70, pp.  71-90, 1966.

19.  Stoker,  R.  L.  "Erosion Due to Dust Particles in a Gas Stream. "
    Ind. Eng. Chem., 41(6):1196-1199, June 1949.

20.  Stern, Arthur C.  (ed.) "Air Pollution. " Vol. II, Academic Press,
    New York,  1962, p. 291.

21.  "Plugging $8,600 Leak."  Chem.  Proc., pp.  13-14, June 1967.

22.  "Inventory of Air Contaminant Emissions. "  New York State Air
    Pollution Control Board,  Albany, N. Y. ,  Appendix C, Table 9, p. 22.

23.  Larson, G. P., Fisher, G.  I. , and Hamming,  W.  J.  Evaluating
    Source of Air Pollution.  Ind.  Eng. Chem. ,  Vol. 45,  pp.  1070-1074,
    1953.

24.  Friedlander, S. K. ,  Silverman, L. , Drinker, P. , and First, M.  W.
    "Handbook on Air Cleaning. "  U.  S. Atomic Energy Commission,
    Washington, D. C. , Sept.  1952, 89pp.
                                 4-219

-------
25.    Dennis, R.,  Johnson,  G. A., First,  M. W.,  and Silverman, L.  "How
      Dust Collectors Perform. " Chem. Eng. ,  Vol.  59, pp. 196-198, Feb.
      1952.

26.    Silverman,  L.,  First, M. W. , Reichenbach,  G. S.,  Jr., and Drinker, P.
      "Investigation of Aerosol Aggregation and  Collection." Final Progress
      Report NYO-1527,  U.  S.  Atomic Energy Commission,  Washington, B.C.
      Feb.  1, 1950, 65 pp.

27.    First, M. W., Silverman, L., Dennis, R., Rossano, A.  T.,  Billings,
      C., Conners, E. , Moschella, R.,  Friedlander,  S.,  and Drinker, P.
      "Air Cleaning Studies."  Progress Report NYO-1586 for Feb. 1, 1951-
      June 30, 1952, U.S. Atomic Energy Commission, Washington,  B.C.,
      Feb.  16, 1953.

28.    Perry, J. H.,  (ed.) "Chemical Engineers' Handbook." 3rd edition,
      McGraw-Hill, New York, 1950, pp. 1013-1050.

29.    Gilbert,  N.   "Removal of Particulate Matter from Gaseous Wastes -
      Wet Collectors. "  American Petroleum Institute, New York, N. Y.,
      1961,  47 pp.

30.    "Air Tumbler. "  Bulletin No. 661, Dust Suppression and  Engineering
      Co.,  Lake Orion,  Michigan, 1956, pp. 19-20.

31.    Semrau, K.  T.  "Dust Scrubber Design - A Critique  on the State of the
      Art."  J.  Air Pollution Control As soc. ,  13_(12):587-594, Dec. 1963.

32.    Wilson, Earl L.  "Statement Presented at Subcommittee on Air and
      Water Pollution of the  Committee  on Public Works. " U.S. Senate,
      90th Congress,  First Session on S. 780, Part 41. Government
      Printing Office, Washington, D.C., 1967, 2630pp.

33.    "Pollution Abatement Manual.  Spraying Nozzles and Accessories."
      Spraying Systems Co., Bellwood,  Illinois,  1966, 18 pp.

34.    Teller, A. J.  "Control of Gaseous Fluoride Emissions. " Chem. Eng.
      Prog., 63_(3):75-79, March 1967.

35.    Blosser, R.  O.  and Cooper, H. B. H., Jr.  "Trends in Reduction of
      Suspended Solids in Kraft Mill Stack. "  Paper Trade  J., 151(11):46-51,
      March 13, 1967.
                                  4-220

-------
36.  "Stack Sprays to Reduce Dust Emissions During Soot Blowing. "
    Bituminous Coal Research, Inc.,  Pittsburgh, Pennsylvania,  1957,
    4 pp.  (Aid to Industry 500-330).

37.  Stairmand, C. J. "The Design and Performance of Modern Gas
    Cleaning Equipment."  J. Inst.  Fuel,  Vol.  29,  pp. 58-76, Feb.  1956.

38.  "Hydraulic Scrubbing Towers."  Bulletin AP525A,  Buffalo Forge Co.,
    Buffalo, N.Y.,  1957.

39.  Montross, C. F.  "Entrainment Separation. "  Chem.  Eng., Vol. 60,
    pp. 213-236,  Oct. 1953.

40.  "Pease-Anthony Gas Scrubbers."  Bulletin M 102,  Chemical  Construction
    Corp., New York, N.Y., 1950.

41.  Walker, A. B.  and Hall, R. M.  "Operating Experience with a Flooded
    Disk Scrubber - A New Variable Throat Orifice Contactor. "  J.  Air
    Pollution Control Assoc. ,  18(5):319-323, May 11,  1968.  (Presented
    at the Annual Meeting,  Air  Pollution Control Association, Cleveland,
    Ohio, June 11-16, 1967.  Paper #67-147)

42.  Harris, L. S.  "Fume  Scrubbing with the Ejector Venturi System. "
    Chem.  Eng. Prog.,  62_(4):55-59,  April 1966.

43.  Kristal, E.,  Dennis, R., and Silverman,  L.  "A Study of Multiple
    Venturi Wet Collector."  J. Air Pollution Control Assoc.,  10_(4):204-
    211, Feb. 1957.

44,  Pallinger, J.  "A New Wet Process for Separation of Very  Fine Dust. "
    Staub,  22_(7):270-275, 1962.

45.  "U.O.P.  Wet Scrubbers."  Bulletin 608, U.O.P. Air Correction Div. ,
    Greenwich, Connecticut, 1967,  pp.4-5.

46.  Sheppard, S.  V. "Control on Noxious Gaseous  Emissions. "  In:
    Proc. Metropolitan  Engineers Council on Air Resources Symp.  "New
    Developments in Air Pollution Control, " New York, N.Y. ,  1967,
    pp. 21-28.

47.  Teller, A. J.  "Crossflow  Scrubbing Process. " U.S. Patent No.
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                                 4-221

-------
48o   Eckert, J. S.  "Use of Packed Beds for Separation of Entrained
      Particles and Fumes from an Air Stream. "  J. Air Pollution Control
      Assoc.,  16_(2):95-9S, Feb. 1966.

490   "Hydro Filter, "  Bulletin N-20, National  Dust Collector Corp.,
      Sicokie, Illinois.

50.   "Schmieg Swirl - Orifice Dust Collectors."  Schmieg Industries
      Catalog 100A,  Detroit, Michigan, 1963.

51.   Doyle, H., and Brooks,  A. F.  "The Doyle Scrubber. "  Ind. Eng.
      Chem. , 49_(12):57A-62A5  Dec. 1957.

52.   "Schmieg Vertical - Rotor Dust Collector."  Schmieg Industries
      Catalog 101A,  Detroit, Michigan, 1963.

53.   Jamison,  R.  M., Hanson, V. W., and  Arnold, O. M. "Performance
      Testing Data on Mechanically Energized Spray Wet Type Dust
      Collectors."  Air Eng.,  7_(6):26-28,  30-31,  37, June 1965.

54,   Rice, O. R.,  and Bigelow, C. G. "Disintegrators for Fine Cleaning
      Blast Furnace Gas." Amer.  Inst, of Mining and  Metall.  Eng.,
      Feb.  1950.

55=   "Roto-Clone  Dynamic Precipitator Type W. "  American  Air Filter
      Bulletin 274-F, Louisville, Kentucky, 1965,  pp.  1-15.

56.   "The Joy Microdyne Dust Collector."  Western Precipitator Co.
      Bulletin J110,  Los Angeles,  California, 1966, 7 pp.

57,   "Gas absorbers. " Buffalo Forge Co.  Bulletin AP 225, Buffalo, N.Y.

58.   First, M. W., Moschella, R., Silverman, L., and Berly, E.
      "Performance of Wet Cell Washers for  Aerosols."  Ind.  Eng. Chem.,
      43_(6):1363-1370, June 1951.

59.   "Neva-Clog Metallic Medium."  Multi-Metal Wire Cloth, Inc.
      Bulletin 613A, Tappan, N.Y., 1961.

      Morash, N., Krouse,  M., and Vasseller, W. P.  "Removing Solid
      and Mist Particles from  Exhaust Gases. " Chem. Eng.  Prog.,
      63(3):70-74,  March 1967.
                                  4-222

-------
gl.   Brink,  J. A.,  Jr.  "Air Pollution Control with Fiber Mist Eliminators.
     Can. J. Chem. Eng.,  Vol. 41,  pp.  134-138,  June 1963.

62.   Brink,  J. A.,  Jr., Burggrabe, W.  F.,  and Rauscher, J. A. "Fiber
     Mist Eliminator for Higher Velocities. "  Chem. Eng. Prog., 60(l):68-73,
     Nov. 1964.

63.   Blasewitz, A.  G.  and  Judson,  B. F.  "Filtration of Radioactive
     Aerosols by Glass Fibers." Chem. Eng.  Prog., 51^(1):6-ll, Jan. 1955.

64.   York, O. H. and Poppele, E. W.  "Wire Mesh Mist  Eliminators."
     Chem.  Eng.  Prog., 59_(6):45-50, June 1963.

65.   Fullerton, R.  W.  "Impingement Baffles to Reduce Emissions from
     Coke Quenching. "  U.S. Steel Corp. Paper 67-93, Applied Research
     Lab., Monroeville,  Pennsylvania,  1967.   Also:  J. Air Pollution
     Control Assoc., 17_(12):S07-9,  Dec. 1967.

66.   Houghton, H.  G. and Radford,  W.  H.  "Measurements on Eliminators
     and the Development of a New Type for Use at High Gas Velocities, "
     Trans. Amer. Inst. Chem. Eng.,  Vol. 35, pp. 427-433, May 1939.

67.   Perry, R. H.,  Chilton,  C. H., and Kirkpatrick,  S.  D.  "Chemical
     Engineers' Handbook.  "  4th edition, McGraw-Hill, New York, 1963,
     pp. 18-85.

68.   Massey,  O. D. "How Well do  Filters Trap Stray Stack Mist?"
     Chem.  Eng.,  pp.  143-146, July 13, 1959.

69.   Storch,  H. L.   "Product Losses Cut with a Centrifugal Gas Scrubber."
     Chem.  Eng.  Prog., 62_(4):51-54, April 1966.

70.   Powers,  E. D. "Control and Collection of Industrial Dusts."  Rock
     Prod.,  Vol. 48, pp. 92-94, June 1945.

71.   Jackson, J,  "Gas Cleaning by the  Foam Method. " Brit. Chem. Eng.,
     8(5):319-321,  May 1963.

72.   Pozin,  M. E.,  Mukhlenov, I. P.,  and Tarant,  F.  Ya. "The Foam
     Method of Treating Bases and Liquids."  Goskhimizdat, 1955.
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73.   "Anti-Spray. "  R. O.  Hull and Co., Bulletin 717, Cleveland, Ohio,  1964.

-------
74.   "Rohco No-Cro-Mist. " R. O. Hull and Co., Bulletin 706,  Cleveland,
      Ohio, 1964.

75.   Scheldhammer,  A.,  (ed.)  "Allplas System is Simple Cure for Acid
      Fumes."  Air Eng., 10(1) :12, Jan. 1968

76.   Tate, R. W. "Sprays and Spraying for Process Use - Part I.  Types
      and Principals." Chem. Eng., pp. 157-162, July 19, 1965.

77.   Tate, R. W. "Sprays and Spraying for Process Use - Part  II.
      Application and Selection."  Chem. Eng., pp. 111-116,  August 2, 1965.

78.   Senecal, J. E.  "Fluid Distribution in Process Use." Ind.  Eng. Chem.,
      49j6):993-997, June 1957.

79.   Eckert, J. S., Foote,  E. H., and Huntington, R. L.  "Pall Ring -
      New Type of Tower Packing. Chem.  Eng.  Prog., 54_(l):70-75,
      Jan. 1958.

80.   Conway, R. A. and Edwards, V.  H.  "How to Design Sedimentation
      Systems from Laboratory Data. " Chem. Eng.,  68(10):167-170,
      Sept. 18,  1961.

81.   Rickles, R. W.  "Waste Recovery and Pollution Abatement. " Chem.
      Eng., pp.  133-152, Sept. 27, 1965.

82.   Zhevnovatyi, A. N.  "The Influence of the Basic Parameters of
      Hydrocyclone-Thickeners on their Operating Efficiency."  Ind.  Chem.
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83.   Busch,  A.  W. "Liquid-Waste Disposal System Design." Chem. Eng.,
      pp. 83-86, March 29, 1965.

84.   Brooke, M.  "Corrosion Inhibitor Checklist. " Chem. Eng., pp. 134-
      140, Feb.  5, 1962.

85.   Jacobs, H.  L.  "In Waste Treatment, Know Your Chemicals, Save
      Money."  Chem.  Eng., pp. 87-92,  May 30,  1960.

86.   Dickerson,  B. W.,  and Brooks,  R. M.  "Neutralization of  Acid
      Wastes."   Ind. Eng. Chem.,  42_(4):599-605, April, 1950.
                                  4-224

-------
87.   "Manual on Disposal of Refinery Wastes."  Vol. II.  "Waste Gases and
     Particulate Matter."  5th edition,  American Petroleum Institute, Div.
     of Refining,  New York, N.Y.,  1957,  68pp.

88.   "Manual on Disposal of Refinery Wastes. "  Vol. III.  "Chemical Wastes, "
     4th edition, American Petroleum Institute,  Div. of Refining,  New York,
     1960, 28 pp.

89.   "Manual on Disposal of Refinery Wastes."  Vol. VI, "Solid Wastes, "
     1st edition, American Petroleum Institute,  Div.  of Refining, New York,
     1963, 51 pp.

90.   Warner, D.  L.  "Deep-Well Disposal of Industrial Wastes." Chem.  Eng.
     72_(l):73-78, Jan. 4,  1965.

91.   Betz, W. H.,  and  Betz,  L. D. "Handbook of Industrial Water  Condition-
     ing. " 4th edition, W.  H. and L. D. Betz Co.,  Philadelphia, Pa.,  1953,
     248 pp.

92.   Air Pollution Control Equipment.  Ceilcote Co. Bulletin 12-1, Berea,
     Ohio, 1967,  23 pp.

93.   Jackson,  R. and Waple,  E. R.  "The Elimination of Dust and  Drizzle
     from Quenching Towers." Gas World,  pp.  75-84, May 7, 1960.

94.   White, H.  J.  "Industrial Electrostatic Precipitation."  Addison-Wesley,
     Reading,  Massachusetts,  1963.

95.   Ramsdell, R.  G.,  Jr. "Design Criteria for Modern Central Station
     Power Plants." Consolidated  Edison Co. of New York, Inc.,
     April 1968.

96.   Archbold,  M.  J.  "Combustion Observations and Experience Resulting
     from a Precipitator Improvement  Program. "  In:  Proc.,  American
     Power Conference, Chicago, Illinois, March 1961, Vol. 23,
     pp. 371-390.

97.   White, H.  J.   "Electrostatic Precipitators for Electric Generating
     Stations." Trans, of American Institute of Electrical Engineers,
     Paper 72,  pp.  229-41, 1953.

98.   "Terminology  for Electrostatic Precipitators. "  Industrial Gas Cleaning
     Institute,  Pub-EP-1,  Rye, New York, Oct.  1967, 4 pp.
                                  4-225

-------
 99.  "Procedure for Determination of Velocity and Gas Flow Rate. "
      Industrial Gas  Cleaning Institute,  Pub-EP-2, Rye, New York ,
      June 1965,  6 pp.

100.  "Criteria for Performance Guarantee Determinations."  Industrial
      Gas Cleaning Institute, Pub. EP-3,  Rye, New York, Aug. 1965.

101.  Reese,  J.  T.,  and Greco, J.   "Experience with Electrostatic Fly-Ash
      Collection Equipment Serving Steam-Electric Generating Plants."
      J. Air Pollution Control Assoc., _18(8):523-528, Aug. 1968.

102.  Baxter, W. A.  "Recent Electrostatic Precipitator Experience with
      Ammonia Conditioning of Power Boiler Flue Gases. "  (Presented at
      the 61st Annual Meeting of the Air Pollution Control Association,
      St. Paul,  Minnesota, June 23-27,  1968, Paper 68-67.)

103.  O'Mara, R. F.  "Dust and Fume Problems in the Iron and Steel
      Industry."  Iron-Steel Eng. , Oct.  1953.

104.  "Air Pollution  in the Iron and Steel Industry. "  Organization for
      Economic Cooperation and Development, McGraw-Hill, New York,  1963
      135 pp.

105.  Dunn, C.  W.   "Modern Blast Furnace Blowing and Recovery Systems."
      Iron-Steen Eng. , Oct. 1962.

106.  Howell, G.  A.   "Air Pollution Control in Steel Industry. " Iron-Steel
      Eng., Oct.  1953.  Also: Air Repair,  3_(3):163-166, Feb.  1954.

107.  Brandt, A.  D.   "Air Pollution Control in the Bethlehem Steel Co. "
      Air Repair, 3J3):167-69,  Feb.  1954.

108.  Punch,  G.  and Young,  P. A.  "Gas Cleaning in the Iron and Steel
      Industry. "  In:  Fume Arrestment,  Iron and Steel Institute, Spec.
      Report 83, London, 1963, pp.  1-23.

109.  Frame, C.  P.   "The Effects of Mechanical Equipment on Controlling
      Air Pollution at No. 3  Sintering Plant,. Indiana Harbor Works, Inland
      Steel Company. " Preprint.  (Presented at the 56th Annual Meeting
      of the Air Pollution Control Association,  Detroit, Michigan, 1963.)
                                  4-226

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110. Lloyd, H.  B.  and Bacon, N. P.  "Operating Experiences with Oxygen-
    Assisted Open Hearth Furnaces."  In:  Fume Arrestment, Iron and
    Steel Institute, Spec. Report 83, London, 1964, pp. 65-70.

111. Elliot, A.  C.  and Lafreniere,  A. J.  "The Collection of Metallurgical
    Fumes from an Oxygen Lanced Open Hearth  Furnace. "  J. Air Pollution
    Control Assoc.,  14_(10):401-406, 1966  and J. Metals  (Japan), 18_(6): 743-
    747,  1966.  (Presented at the Air Pollution  Control Association Annual
    Meeting, Houston, Texas, 1964.)

112. Smith, W.  M. and Coy,  D.  W.   "Fume Collection in  a Steel  Plant. "
    Chem. Eng. Prog., j>2(7):119-123, July 1966.

113. "Dust Removal in Oxygen Steel Making. " Stahl u.  Eisen, Nov. 1959.
    (Translated and abstracted  from report of meeting of the Eisenhlitte,
    Osterreich.)

114. Mitchell, R. T.  "Dry Electrostatic Precipitators  and Waagner-Biro
    Wet Washing Systems. "  In: Fume Arrestment, Iron and Steel Institute,
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    pp. 80-85.

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120.  Magill, P. L.,  Holden,  F. R., and Ackley, C.  (eds.) "Air Pollution
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127.  "Control of Particulate Emissions. "  Training  Manual, U.S.  Public
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128. Spaite, P. W.,  Stephan, D.,  and  Rose,  A., Jr.  "High Temperature
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129. Rosebush, W.  H. "Filtration of Aerosols. "  In:  Handbook on Aerosols,
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130.  Licht, W. "Removal of Particulate Matter from Gaseous Waste-
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                                   4-228

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132. Frederick,  E.  R.  "How Dust Filter Selection Depends upon Electro-
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                                 4-229

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144. Adams, R.  L.  "High Temperature Cloth Collectors. "  Chem.  Eng. Proc.,
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149. "Engineering Fabrics for Industry. "  Wellington Sears Co., West
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                                   4-230

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157.  Chase,  F.  R.  "Application of Self-Contained Dust Collectors. " (Pre-
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158.  "Southwestern Portland Filters Hot Kiln Gases. "  Pit and Quarry, Oct.
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159.  Jones,  A.  H.  "How to Get Your Money's  Worth When Buying and Install-
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160.  Kreichelt,  T. E., Kemnitz,  D. A., and Cuffe,  S.  T.  "Atmospheric
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161.  Harrison,  B. P., Jr.  "Baghouse  Cleans  500°  F Cement Kiln Gases. "
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162.  Spaite, P. W., Stephan,  D.  G.,  and Rose A. H., Jr.  "High Tempera-
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163.  Adams, R. L. "Application of Baghouses to Electric Furnace Fume
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164.  Herrick, R.  A.  "A Baghouse Test Program for Oxygen Lanced Open
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165.  Herrick, R.  A.,  Olsen,  J.  W., and Ray,  F. A.  "Oxygen-Lanced Open
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166.  Drogin, I.  "Carbon Black. " J.  Air Pollution Control Assoc.,  18(4):
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167.  Cote. W. A.  "Grain Dust Emissions  and Our Atmosphere. " Proc.
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    1967, pp.  65-74.
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168.  Noland, R.  "Technological Developments in Plant and Equipment Designs
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169.  "Aerotron Dust Collectors. Type B. "  Buffalo Forge Co.  Bulletin
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170.  Thomas,  N. J.  "Auto-Ignition Temperatures of Flammable Liquids."
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171.  Kobayashi, K.  "Combustion of a Fuel Droplet. "  In:  Fifth Symposium on
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172.  Spaulding, D.  B.  "Heat and Mass Transfer in the Combustion of Liquid
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173.  Hottel, H. C., Willians, G. C.,  and Simpson, H. C.  "Combustion of
     Droplets of Heavy Liquid Fuels. " In: Fifth Symposium on Combustion,
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174.  Nishiwaki, N.  "Kinetics of Liquid Combustion Processes.  Evaporation
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175.  Orning, A. A.  "Combustion of Pulverized Fuel—Mechanism and Rate of
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176.  Griffiths, J.  C., Thompson, C. W., and Weber,  E. J.  "New or Unusual
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177.  Innes, W. B.,  and Duffy, R.  "Exhaust Gas Oxidation on Vanadia-
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     Aug. 1961.

178.  Decker, L.  D.  "Odor Control by Incineration. "  Universal Air Products
     Div.  Form No. 5-048,  p.  16.   (Presented at Middle States Air Pollution
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179. "Catalyst Deactivation and Poisoning Agents. " Universal Oil Products,
    Air Correction Div. Form No. 5-039.

180. Topper, L.  "Radiant Heat Transfer  from Flames in a Turbojet Combus-
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181. Eckert,  E. R.  G.  and Drake, R. M., Jr.  "Heat and Mass Transfer."
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182. Trinks,  W. and Keller, J. D.  "Tests of Radiation from Luminous
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183. Sherman, R. A.  "Radiation from Luminous and Non-Luminous Natural
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184. Thring,  M. W.  "The Radiative Properties of Luminous Flames. "  In:
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185. Danielson, J. A. (ed.)  "Air Pollution Engineering Manual. " U. S.  Public
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186. Yagi,  Sakae and Kunii, D.   "Combustion of Carbon Particles in Flames
    and Fluidized Beds. "  In:  Fifth Symposium on Combustion,  Pittsburgh,
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187. Browning, J.  A.,  Tyler,  T. L., and Kran, W.  G.   "Effect of Particle
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188. Godsave, G. A. E.  "Studies of the Combustion of Drops in a Fuel
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189. Gregory, C.  A., Jr.  and Calcote, H. F.  "Combustion Studies of
    Droplet-Vapor Systems. "  In:  Proceedings of the 4th Symposium on
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190.  Smith, D. F.  and Gudmundsen, A.  "Mechanism of Combustion of
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191.  Parker,  A.  S. and  Hottel,  H.  C.   "Combustion Rate of Carbon." Ind.
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192.  Krenz, W. B., Adrian, R. C., and Ingels,  R. M.  "Control of Solvent
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193.  Miller, M.  R. and  Wilhoyte,  H. J.  "A Study of Catalyst Support Systems
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194.  Volheim, G.  "The Catalytic Afterburning of Industrial Effluents. "
     25_(ll):20-26,  Nov.  1965.

195.  Gamble,  B. L.  "Control of Organic Solvent Emissions in Industry. "
     Paper 68-48,  61st Annual Meeting, Air Pollution Control Assoc., St.
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196.  Field, M. A., Gill, D.  W., Morgan,  B. B.  and Hawksley,  P.  G. W.
     "Combustion of Pulverized Coal." British Coal Utilization Research
     Association, Leatherhead,  England,  1967,  413 pp.

197.  Mills, J. L.,  Hammond, W.  F.,  and Adrian, R. C.  "Design of After-
     burners  for Varnish Cookers.  " (Presented at the 52nd Annual Meeting
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198.  Thring,  M.  W.  "The Science  of Flames and Furnaces. "  2nd edition
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199.  Benforado,  D. M.,  Pauletta,  C. E.,  and Hazzard, N. D.  "Economics
     of Heat Recovery in Direct-Flame Fume Incineration. "  Air Eng.,
     Vol. 9, pp.  29-32,  March 1967.

200.  Sandomirsky,  A. G.,  Benforado,  D. M., Grames, L. D. and Pauletta,
     C.  E. "Fume Control in Rubber Processing by Direct-Flame Incinera-
     tion. " J. Air Pollution Control Assoc., ^6(12):673-676,  Dec.  1966.
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201. Myers, F. D.,  and Waitkus,  J.  "Fume Incineration with Combustion
    Air at Elevated Temperatures. " J. Air Pollution Control Assoc.,
    16(7):378-382, July 1966.

202. Trinks, W. and Mawhinney, M.  H.  "Industrial Furnaces," 5th edition
    Vol. I, John Wiley and Sons,  1961,  486 pp.

203. Perry. R. H., Chilton, C. H. and Kirkpatrick, S. D.   "Chemical
    Engineers' Handbook. "  4th edition, McGraw-Hill, 1963, 1911 pp.

204. "Catalytic Combustion  Systems for Ovens and Dryers. "  Universal Oil
    Products Bulletin 602,  Air Correction Division, llpp.

205. Goodel,  P. H.  "Industrial Ovens Designed for Air Pollution Control. "
    J. Air Pollution Control Assoc., Vol.  10, pp.  234-238,  1960,  (Presented
    at the 52nd Annual Meeting of the Air Pollution Control Association, Los
    Angeles,  Calif., June 22-26, 1959).

206. Vandaveer, F. E.  and  Sedeler,  C. G.  "Combustion of Gas. "  American
    Gas Assoc., Inc., New York, 1965,  53 pp.

207. Ingels, R. M.  "The  Afterburner Route to Pollution Control. "  Air Eng.,
    No. 6, pp. 39-42,  June 1964.

208. Ruff,  R.  J.  "Profits from Waste Gases. " Reprint.  Catalytic Combus-
    tion, Detroit, Mich., 4 pp.

209. Caplan,  K. J. (ed.) "Air Pollution Manual—Part  II—Control Equipment.'
    American Industrial  Hygiene  Association, Lansing, Mich.,  1968, pp.
    112-135.

210. DeHaas,  G.  G., and  Hansen, G. A.  "The Abatement of Kraft  Pulp Mill
    Odors by Burning. "  TAPPI,  3_8(12): 732-738, Dec. 1955.

211. Industrial Air Pollution Control.  Sly Manufacturing Co.,  Cleveland,
    Ohio, Bulletin 204, 1967,  35  pp.

212. Weil, S.  A.   "Burning  Velocities of Hydrocarbon Flames. " Inst. Gas
    Tech., Chicago, Illinois,  Research Bulletin 30, 1961, 48pp.

213. "Standards for Ovens and Furnaces. "  National Board  of Fire Under-
    writers, " NBFU No. 864, Aug.  1963.
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214.  Radier,  H. H.  "Flame Arresters. " J. Inst. Petr., Vol. 25, pp.
      377-381, 1939.

215.  "Industrial Ventilation—A Manual of Recommended Practice. "  10th
      edition,  American Conference of Governmental Industrial Hygienists,
      Lansing, Mich., 1968, 150 pp.

216.  Barr, J.  "Diffusion Flames. " In:  Proceedings of the 4th Symposium
      on Combustion, Cambridge, Mass.  Williams and Wilkins Co.,  Balti-
      more, Maryland,  1952, pp.  765-771.

217.  Griffiths,  J. C. and Weber, E. V.  "Influence of Port Design and Gas
      Composition on Flame Characteristics of Atmospheric Burners."
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      Bulletin 77,  1958,  63 pp.

218.  "Standards for Safety—Commercial—Industrial Gas Heating Equipment—
      UL. 795."  Underwriters Laboratories, Nov. 1952,  Revised 1960.

219.  Burst, J.  F., and Spieckerman, J.  A.  "A Guide to Selecting Modern
      Refractories."  Chem. Eng., 74(16): 85-104, July 1967.

220.  Benforado, D. M.  "Air Pollution Control by Direct Flame Incineration
      in the Paint Industry. " J. Paint Tech., 3£(508):265-266, May 1967.

221.  Wallach, A.  "Some Data and Observations on Combustion of Gaseous
      Effluents from Baked Lithograph Coatings. " J. Air Pollution Control
      Assoc.,  12(3): 109-110, March 1962.

222.  Benforado, D. M.  and Cooper,  G.   "The Application of Direct-Flame
      Incineration as an Odor Control Process in Kraft Pulp Mills." Preprint.
      (Presented at the 22nd Engineering Conference, Process Systems and
      Controls,  Water and Air Pollution,  TAPPI, Atlanta,  Ga., Sept.  19-22,
      1967.)

223.  Banner,  A. P., and Ilgenfritz,  E. M.  "Disposal of Coal Tar Pitch
      Distillate Obtained from Carbon Baking Furnace by Catalytic Combus-
      tion." J. Air Pollution Control Assoc., ^3(12):610-612,  Dec. 1963.

224.  Sullivan, J. L.  "An Evaluation of Catalytic and Direct Fired After-
      burners  for Coffee and Chicory Roasting Odors.  J.  Air Pollution Con-
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                                  4-236

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225. Jares,  J.  "Fume Oil and Varnish Disposal by Combustion. "  Chem.  Eng.,
    Vol. 56, pp. 110-111, Jan. 1949.

226. Benforado,  D. M.  and Waitkus,  J.  "Exploring the Applicability of
    Direct-Flame Incineration to Wire Enameling Fume  Control." Wire
    Prod., Vol. 42,  pp.  1971-1978,  1967.  (Presented before the Electrical
    Conductor Division of the Wire Association, Chicago, Illinois, Oct. 23,
    1967.)

227. Moody, R.  A.  "Examples of Catalytic Afterburning  in Stationary Installa-
    tions and Motor Vehicles. "  Staub, 2J5(11):26-30,  Nov. 1965.

228. Truitt, S. M.  "The Application of Gas  Burner Equipment for Elimination
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229. McKenzie,  D.  "Burn Up Those  Lift-Station Odors." North American
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230. Bailey, J.  M.  and Reed, R. J.  "Fume Disposal  by  Direct Flame Incinera-
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                                  4-237

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    5. EMISSION FACTORS FOR PARTICULATE AIR POLLUTANTS





    An emission factor is a statistical average of the rate at which pollutants





are emitted from the burning or processing of a given quantity of material.





Emission factors can also be established on the basis of some other meaningful




parameter, such as the number of miles traveled in a vehicle.   To determine





emission factors, available reliable data on emissions from a particular source





or group of sources are gathered and correlated with information on process





use. The individual emission factors derived are tabulated, and either an




average or a range of values  is selected for use.





    Some emission factors  are based on  very limited data; others are based




on extensive data that are highly variable;  and still others are based on ex-




tensive, consistent data.  It is, therefore, important that the accuracy of the





data on which an emission factor is based be evaluated before the factor is





used for estimating emissions.




    In general, the emission factors for  particulate air pollutants are not





precise indicators of what particulate emissions might be from any single





process even though all the details of the process are known.  Emission fac-





tors are more valid when applied to a number of processes.
                                     5-1

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      Emission factors listed in Table 5-1 are taken from Compilation of Air



Pollutant Emission Factors, Public Health Service publication No.  999-AP-42,



except where noted. The factors are for uncontrolled sources except as qualified



in the table.  Examples of how emission factors are  used follow.



Coal Combustion



Given: Source burns 10, 000 tons per year in a  spreader stoker  without fly



       ash reinjection.



       85 percent efficient multiple cyclones



       Ash content— 10 percent (Note:  Expressed as the number 10 in making



       the computation)



From  Table 5-1:



      Emission factor = ISA pounds per ton of coal,  where A equals ash content.



Therefore:



      Particulate emissions = (Process weight)  (Emission factor) (Collection



                             efficiency factor)



      Particulate emissions =  L, 000 tpnS °f C°al1   ["(13) (10) pcunds °f Particulate
                              L           year   J   Lv   ' ^  '      tons of coal
                                                        year



Solid Waste Disposal



Given:  Commercial operation burning 2, 000 tons per year of refuse



        in multiple- chamber incinerator.
                                      5-2

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From Table 5-1:



     Emission factor—3 pound per ton of refuse



Therefore:


           ,  ,     .         r0 nAA tons of refuse] f  pounds of particulate
     Particulate emissions  =2, 000	  3	r—	
                                       year    1 I      ton of refuse
     year     1 I      ton of refuse


pounds of particulate
                          =  6,000
                                          year



Process Industries



Given: Secondary brass and bronze smelting operation with



      fabric filter 99 percent efficient.



      Furnace type—electric.



      Metal charged into furnace—20, 000 tons per year



From Table 5-1:



     Emission factor - 3 pounds per ton of metal charged



Therefore:



     Particulate emissions =


       tons of metal charged]  f    pounds  of particulate]
 iU, 000                      I  I o • 0 ~«'.  \  n      i
              year         J  I    ton of metal charged J


                               pounds of  particulate
                          =  600 —•	•
                                        year
                                    5-3

-------
               Table 5-1.  PARTICUIATE EMISSION FACTORS1
                 Source
Particulate emission ratea
Fuel combustion - stationary sources
  Coal
   Pulverized
     General (anthracite and bituminous)
     Dry bottom (anthracite and bituminous)
     Wet bottom (anthracite and bituminous)
      Without fly ash reinjection
      With fly ash reinjection
     Cyclone (anthracite and bituminous)
     Spreader stoker (anthracite and
      bituminous)
      Without fly ash reinjection
      With fly ash reinjection
     All other stokers (anthracite and
      bituminous)
      Greater than 10 X 106 Btu/hr
      Less than 10 X 106 Btu/hr
     Hand-fired equipment
      (Bituminous coal only)
  Residual oil
   Greater than 100 X 106 Btu/hr
                     /-»
   Less than 100 X 10  Btu/hr
  Distillate oil
   10 to 100 x 106 Btu/hr
   Less than 10 X 106 Btu/hr
16Ablb/ton of coal burned
17A Ib/ton of coal burned

ISA Ib/ton of coal burned
24Aclb/ton of coal burned
2A Ib/ton of coal burned
ISA Ib/ton of coal burned
20AC  Ib/ton of coal burned
5A Ib/ton of coal burned
2Ad Ib/ton of coal burned
20 Ib/ton of coal burned
10 lb/1000 gallons of oil burned
23 lb/1000 gallons of oil burned

15 lb/1000 gallons of oil burned
8 lb/1000 gallons of oil burned
                                     5-4

-------
       Table 5-1 (continued).  PARTICULATE EMISSION FACTORS
                Source
 Natural gas
   Greater than 100 X 106 Btu/hr
   10 to 100 X 106 Btu/hr
   Less than 10 X 106 Btu/hr
 Wood2
Fuel combustion - mobile sources
 Gasoline-powered motor vehicle
 Diesel-powered vehicle
 Aircraft
   Jet (fan-type)
    4 engine
    3 engine
    2 engine
    1 engine
   Jet (conventional)
    4 engine
    3 engine
    2 engine
    1 engine
   Turboprop
    4 engine
    2 engine
   Piston
    4 engine
    2 engine
    1 engine
Particulate emission ratea
15 Ib/million ft3 of gas burned
18 Ib/million ft3 of gas burned
19 Ib/million ft3 of gas burned
10 Ib/ton of wood burned

12 lb/1000 gallons consumed
110 lb/1000 gallons consumed
7. 4 Ib/f light
5.6 Ib/f light
3.8 Ib/f light
1.9 Ib/f light

34.0 Ib/flight€
25.5 Ib/flight
17.0 Ib/flight
8.5 Ib/flight

2.5 Ib/f light6
0. 6 Ib/flight

1.4 lb/flighte
0. 6 Ib/flight
0.3 Ib/flight
                                     5-5

-------
            Table 5-1 (continued).  PARTICULATE EMISSION FACTORS
                    Source
Particulate emission rate
Solid waste disposal
  Open burning of leaves and brush
  Open-burning dump
  Municipal incinerator
On-site commercial and industrial
  multiple-chamber incinerator
  (Los Angeles design)
Single-chamber incinerator
Domestic gas-fired incinerator
On-site residential flue-fed incinerator
Process  industries - (specific examples)
  Chemical industry
    Paint and varnish manufacture
      Varnish cooker
      Alkylresin production - total
        operation
      Cooking and blowing of oils
      Heat polymerization acrylic resins
Phosphoric acid manufacture
  Thermal process absorber tail
    gas with control (acid mist)
Sulfuric acid manufacture - contact
  process (acid mist)
Food and agriculture industries
  Coffee roasting
    Direct fired roaster
    Indirect fired roaster
    Stoner and cooler
    Instant coffee spray dryer - always
     controlled with cyclone and wet
     scrubber
17 Ib/ton of refuse burned
16 Ib/ton of refuse burned
17 Ib/ton of refuse burned
3 Ib/ton of refuse burned


10 Ib/ton of refuse burned
15 Ib/ton of refuse burned
28 Ib/ton of refuse burned
60-120 Ib/ton of feed

80-120 Ib/ton of feed
20-60 Ib/ton of feed
20 Ib/ton of feed

0.2-10.8  Ib/ton of phosphorus
 burned
0.3-7.5 Ib/ton  of acid produced
7. 6 Ib/ton of green beans
4.2 Ib/ton of green beans
1.4 Ib/ton of green beans
1.4 Ib/ton of green beans
                                     5-6

-------
      Table 5-1  (continued).  PARTICULATE EMISSION FACTORS
             Source
Particulate emission ratea
Cotton ginning operation (includes cotton
 gin and incineration of cotton trash)
Feed  and grain mills
 General with 90% efficient cyclones
 Wheat air cleaner with cyclone
 Barley flour mill with cyclone
 Alfalfa meal mill with settling chamber
  and cyclone
 Orange pulp dryer with cyclone
Starch manufacture - natural gas direct-
 fired flash drier
Primary metal industry
 Iron and steel manufacture
  Sintering machine  gases
  Sinter machine discharge
 Open hearth furnace
  Oxygen lance^
  No oxygen lance
 Basic oxygen furnace^
 Electric arc furnace
  Oxygen lance&
  No oxygen  lance&
 Blast furnace
  Ore charging^
  Agglomerate charging^
 Scarfing
 Coking operations - charging, pushing,
  quenching
11. 7 Ib/bale of cotton
        (500 Ib)

6 Ib/ton of product
0. 2 Ib/ton of product
3.1 Ib/ton of product
4. 0 Ib/ton of product

11. 3 Ib/ton of product
8 Ib/ton of starch
20 Ib/ton of sinter
22 Ib/ton of sinter

 22 Ib/ton of steel
 14 Ib/ton of steel
 46 Ib/ton of steel

 11 Ib/ton of steel
 7 Ib/ton of steel

 110 Ib/ton of iron
 40 Ib/ton of iron
 3 Ib/ton of steel processed
 2 Ib/ton of coal
                                   5-7

-------
       Table 5-1 (continued).  PARTICULATE EMISSION FACTORS
              Source
Particulate emission ratea
Secondary metal industry
 Aluminum smelting
   Chlorination - lancing of chlorine gas
    into molten metal bath
   Crucible furnace
   Reverberatory furnace
   Sweating furnace
 Brass and bronze smelting
   Crucible furnace
   Electric furnace
   Reverberatory furnace
   Rotary furnace
 Gray iron foundry
   Cupola
   Electric induction furnace
   Reverberatory furnace
 Lead smelting
   Cupola
   Pot furnace
   Reverberatory and sweating furnace
 Magnesium  smelting
   Pot furnace
 Steel foundry
   Electric arc furnace
   Electric induction furnace
   Open hearth furnace
1000 Ib/ton of chlorine used

1.9 Ib/ton of metal processed
4. 3 Ib/ton of metal processed
32. 2 Ib/ton of metal charged

3. 9 Ib/ton of metal charged
3. 0 Ib/ton of metal charged
26. 3 Ib/ton of metal charged
20. 9 Ib/ton of metal charged

17.4 Ib/ton of metal charged
2. 0 Ib/ton of metal charged
2. 0 Ib/ton of metal charged

300 Ib/ton of metal charged
0.1 Ib/ton of metal charged
154 Ib/ton of metal charged

4.4 Ib/ton of metal charged

15.0 Ib/ton of metal charged
0.1 Ib/ton of metal charged
10. 6 Ib/ton of metal charged
                                   5-8

-------
      Table 5-1  (continued).  PARTICULATE EMISSION FACTORS
            Source
Particulate emission ratea
 Zinc smelting
  Galvanizing kettles
  Calcine kilns
  Pot furnaces
  Sweating furnace
Mineral product industry
 Asphalt saturators
 Asphalt batch plant - rotary drier
 Calcium carbide plant
  Coke dryer
  Electric furnace hood
  Furnace room vents
  Main stack - vents to atmosphere -
   exhaust from furnace hoods always
   passes through impingement scrubbers
 Cement manufacture
  Dry process - kiln
  Wet process - kiln
 Ceramic and clay processes
  Ceramic clay - spray drier with cyclone
  Bisque with scrubber
  Catalytic material - drier,  kiln and
   cooler with cyclone and scrubber
 Concrete batch plant - total operation
 Frit manufacture - frit smelters
 Glass manufacture  - soda-lime process
  with direct fired continuous melting
5. 3 Ib/ton of metal charged
88. 8 Ib/ton of metal charged
0.1 Ib/ton of metal charged
10.8 Ib/ton of metal charged

3.9h Ib/ton of asphalt
5. 0 Ib/ton of mix

0. 2 Ib/ton of product
1. 7 Ib/ton of product
2. 6 Ib/ton of product
2. 0 Ib/ton of product
46 Ib/barrel of cement
38 Ib/barrel of cement

15 Ib/ton of charge
2 Ib/ton of charge
6 Ib/ton of charge

0. 2 Ib/yard of concrete
16.5 Ib/ton of charge
2. 0 Ib/ton of glass
 331-7180-69 - 26
                                  5-9

-------
      Table 5-1 (continued).  PARTICULATE EMISSION FACTORS
             Source
Particulate emission rate3
Lime production
  Rotary kiln
  Vertical kiln
Perlite manufacture - expanding furnace
Rock wool manufacture
  Cupola
  Reverberatory furnace
  Blow chamber
  Curing oven
  Cooler
Rock,  gravel and sand production
  Crushing
  Conveying,  screening,  shaking
  Storage piles  - wind erosion
Petroleum industry
  Fluid catalytic crackers
  Moving bed catalytic crackers
   TCC-type  unit

   HCC-type  unit

Kraft pulp industry
  Smelt tank
   Uncontrolled
   Water spray
   Mesh demister
Lime kiln
Recovery furnace with primary
  stack gas scrubber
                                 5-10
200 Ib/ton of lime
20 Ib/ton of lime
21 Ib/ton of charge

21. 6 Ib/ton of charge
4. 8 Ib/ton of charge
21. 6 Ib/ton of charge
3. 6 Ib/ton of charge
2.4 Ib/ton of charge

20 Ib/ton of product
1. 7 Ib/ton of product
20 Ib/ton of product
0.1 to 0. 21 Ib/ton of catalyst
  circulated

0. 05 to 0. 15J Ib/ton of catalyst
  circulated
0. 15 to 0. 25J Ib/ton of catalyst
  circulated
20 Ib/ton of dry pulp produced
5 Ib/ton of dry pulp produced
1-2 Ib/ton of dry pulp produced
94 Ib/ton of dry pulp produced
150 Ib/ton of dry pulp produced

-------
      Table 5-1  (continued).  PARTICULATE EMISSION FACTORS


aEmission rates are those from uncontrolled sources,  unless  otherwise noted.

Vhere letter A is shown, multiply number given by the percent ash in the
 coal.

cValue should not be used as emission factor.  Values represent the loading
 reaching the control equipment always used on this type of furnace.

 Revised from 5 A.

6Flight is defined as a combination of a landing and a takeofl.

 Depends on type  of control.

gBased on data  from NAPCA Contract No. PH  22-68-65.

 Includes only solid particulate matter.  In addition, about 65  Ib/hr of oil
 mist may be evolved from asphalt saturators.

 Revised from 0.1.

 Revised from 0. 04.
                                  5-11

-------
                      REFERENCES FOR SECTION 5

1.   Duprey, R. L.  "Compilation of Air Pollutant Emissions Factors. " U.S.
    Dept. of Health,  Education, and Welfare, National Center for Air Pollution
    Control, Durham, N.C., PHS-Pub-999-AP-42, 1968.

2.   "Procedure for Conducting Comprehensive Air Pollution Surveys."  New
    York State Dept.  of Health,  Bureau of Air Pollution Control Services,
    Albany, New York, Aug.  18, 1965.
                                  5-12

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     6.  ECONOMIC CONSIDERATIONS IN AIR POLLUTION CONTROL




6.1  SELECTION OF CONTROL SYSTEM




     Most air pollution emission control problems can be  solved in several




ways.  In order to select the best method of reducing pollutant emissions,




each solution should be thoroughly evaluated prior to implementation.  Steps




such as substitution of fuels and raw materials  and modification or replace-




ment of processes should not be overlooked as possible solutions.   Such




emission reduction procedures often can improve more than one pollution




problem. For example, particulate matter and sulfur  oxides emissions both




may be reduced by switching from high-sulfur coal to natural gas or low-




sulfur oil.  Such steps also may have the benefit of reducing or eliminating




solid waste disposal and water pollution problems.  Often it is cheaper to




attack  two air problems together than to approach  each problem individually.




If steps such  as process alterations and substitution of fuels are not feasible,




it may be necessary to use gas cleaning equipment




     Figure  6-1 shows the factors to be considered in selecting of gas clean-




ing system.   The first consideration is the degree of reduction of emis-




sions which may be required to meet emission standards.  The degree of
                                   6-1

-------
                 EMISSIONS AND EMISSIONS
                       STANDARDS
            DETERMINES COLLECTION EFFICIENCY
            CONTROL EQUIPMENT ALTERNATIVES
1
•
FABRIC
FILTER
u_


1
ELECTROSTATIC
PRECIPITATOR




WET
COLLECTOR




'
MECHANICAL
COLLECTOR





AFTER-
BURNER

  y  VOLUME
SJ-  TEMPERATURE
,5s  MOISTURE CONTENT
<* uj  CORROSIVENESS
££  ODOR
£ <  EXPLOSIVENESS
0<  VISCOSITY
  X
  u
                         PROCESS
                                                              u
IGNITION POINT
SIZE DISTRIBUTION
ABRASIVENESS
HYGROSCOPIC NATURE
ELECTRICAL PROPERTIES
GRAIN LOADING          «
DENSITY AND SHAPE      *•*
PHYSICAL PROPERTIES     i
                         O
WASTE TREATMENT
SPACE RESTRICTION
PRODUCT RECOVERY
PLANT
FACILITY
i

ENGINEERING STUDIES
HARDWARE
AUXILIARY EQUIPMENT
LAND
STRUCTURES
INSTALLATION
START-UP





WATER AVAILABILITY
FORM OF HEAT RECOVERY
(GAS OR LIQUID)
t



COST OF
CONTROL



\



POWER
WASTE DISPOSAL
WATER
MATERIALS
GAS CONDITIONING
LABOR
TAXES
INSURANCE
RETURN ON INVESTMENT
t
SELECTED
GAS CLEANING SYSTEM
                  DFSIRED EMISSION RATE


Figure 6-1.  Criteria for selection of gas cleaning equipment.

                             6-2

-------
emission reduction or the collection efficiency required is dependent upon the




relationship between emissions and emission standards as shown at the top of




the figure.   This is an important factor in making the choice among control




equipment alternatives.  Although a control system may include two or more




pieces of control equipment, collection efficiency, as used in this chapter,




applies to individual pieces of control equipment.  The usual ranges of collec-




tion efficiency for  various  equipment alternatives are shown in Table 6-1.  The




important factors to be considered next are the gas stream and particle char-




acteristics of the process itself, as shown in the center of Figure 6-1.  High




gas temperatures without cooling,  for  example,  preclude the use of fabric




filters; explosive gas streams  prohibit the use of electrostatic precipitators;




and submicron particles cannot generally be efficiently collected with





mechanical collectors.  A  number  of factors that relate to the  plant facility




should also be considered, some of which are  listed in Figure  6-1.  Each al-




ternative will have a specific cost associated with it,  and the components of




this cost should be carefully examined.   Those alternatives which meet the




requirements of both the process and the plant facility can then be evaluated




in terms of cost; on this basis, the gas cleaning system may be selected.
                                   6-3

-------
             Table 6-1.  AIR POLLUTION CONTROL EQUIPMENT
                      COLLECTION EFFICIENCIES1'2'3
      Equipment type
                                                 Efficiency Range
                                              (on a total weight basis)
                                             	percent	
Electrostatic precipitator
Fabric filters
Mechanical collector
Wet collector
Afterburner:
           c
   Catalytic
   Direct flame
                                                      80 to 99.5+
                                                      95 to 99.9
                                                      50 to 95
                                                      75 to 99+

                                                      50 to 80
                                                      95 to 99
b
 Most electrostatic precipitators sold today are designed for 98 to 99. 5 per-
 cent collection efficiency.
 Fabric filter collection efficiency is normally  above 99.5  percent.
->
"Not normally applied in particulate control;  has limited use because most
 particulates poison or  desensitize the catalyst.
                                    6-4

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6.2   COST-EFFECTIVENESS RELATIONSHIPS

     Meaningful quantitative relationships between control costs and pollutant

reductions are useful in assessing the impact of control on product prices,

profits, investments, and value added to the product. *  With such relationships

at hand the alternates for solution of an air pollution problem can be evaluated

for more effective program implementation by the user of the control equip-

ment and by the enforcement agency.  These cost-effectiveness relationships

sometimes are applied collectively to a meteorological or air quality control

region,  where they describe the total cost impact on polluters as a result of

controlling sources;  the discussion here, however, centers around cost-

effectiveness as applied to an individual source.  Cost-effectiveness is a meas-

ure of all costs to  the firm associated with a given reduction in pollutant emis-

sions.  For  computing the costs for a given system, one should consider (1) raw

materials and fuels used in the process, (2) alterations in process equipment,

(3) control hardware and auxiliary equipment,  and (4) disposal of collected

emissions.

     Figure 6-2 shows an example of a theoretical cost-effectiveness relation-

ship.   The actual total costs  of control may depart from  this curve because

some cost elements,  such as research and development expenditures and fixed
*Value added is generally considered to be the economic worth added to a prod-
 uct by a particular process, operation, or function. "*
                                    6-5

-------
      QUANTITY OF POLLUTANTS



    Figure 6-2.  Cost of control.
charges  (taxes, insurance, deprecia-



tion) are not directly related to the



operation of the equipment and to the



level of emissions  in a given year.



The cost of control is represented on



the vertical axis and the quantity of



pollutants emitted on the horizontal
axis.   Point P indicates the uncontrolled state, in which there are no control



costs.   As control efficiency improves, the quantity of emissions is  reduced



and the cost of control increases.  In most cases, the marginal cost of control



is smaller at the lower levels of efficiency, near point P of the curve.  The



curve also illustrates that as the cost of control increases, greater increments



of cost usually are required for corresponding increments of emission reduc-



tion.  Process changes sometimes may result in emission reduction without



increased costs. Research and development expenditures resulting in new or



improved equipment design, improved process operations,  or more  efficient



equipment  operations will improve the economics of control.  All these factors



may substantially reduce control costs at most emission levels and shift the



cost of the control curve (CC) as illustrated by CC  in Figure 6-3.  Note that



as control  technology develops, the cost of attaining a desired emission level



will be reduced from C  to C .
                      a     b
                                      6-6

-------
              cc
         QUANTITY OF POLLUTANTS
Figure 6-3. Expected new cost of control.
Cost-effectiveness information is use-




ful in emission control decision-




making.  Several feasible systems




usually are available for controlling




each source of emissions.   In most




cases,  the least-cost solution for




each source can be calculated at




various levels of control.  After
evaluating each alternative and after considering future process expansions and




more rigid control restrictions,  sufficient information should be available on




which to base an intelligent control decision.




     Cost-effectiveness relationships vary from industry to industry and from




plant to plant within an industry.  The cost for a given control system is  signif-




icantly dependent on the complexity of the installation and the characteristics




of the gas stream and pollutant.  Geographical location is another significant




factor that influences the total annual cost; for example,  the  components  of




annual cost, such as utilities,  labor,  and the availability of desired sites for




waste material, vary from place to place.
                                     6-7

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6.3   COST DATA




      It is the purpose of this chapter to develop basic information and tech-





niques for estimating the costs of installing and operating control equipment.





Such information can be useful in developing cost-effectiveness relationships





for application of various control systems.




      The control cost information included in this chapter is based on experi-




ence, a careful study of the literature,  and  a survey of more than 250 sup-




pliers, users,  installers,  and operators of  air pollution control equipment.




The cost information was reviewed by a panel from the gas cleaning equip-





ment industry for reasonableness of data and methodology.  The cost data




reported reflects 1968 prices, except as noted.




6.4   UNCERTAINTIES IN DEVELOPING COST RELATIONSHIPS




      Cost information for control devices is indicated in Section 6.7 where,




for various types of equipment,  operating capacity is plotted against cost.




The upper and lower curves indicate the expected range of costs, with the




expected average cost falling  approximately in the middle.  Although quanti-




tative values for collection efficiency and gas volume capacity are not listed,




higher collection efficiency, which involves  more intricate engineering de-





sign,  results in higher costs.  Control equipment is designed for a nominal




gas volume capacity, but under actual operating conditions the volume may




vary.  Similarly, the efficiency of control equipment will vary from application
                                    6-8

-------
to application as particle characteristics, such as wettability,  density, shape,




and size distribution, differ.  For example, a  control device designed to oper-




ate on 50,000 acfm  of gas with a nominal collection  of 95 percent may have an




effective operating range of from 45,000 to 55,000 acfm, and its collection




efficiency may range from 90 to 97 percent.




     The effect of these independent variations is to make single point esti-




mates of cost versus size and efficiency difficult to  determine.  Based on the




data available,  all estimates must be  constructed over an interval of uncer-




tainty for each of the three variables.   To make the cost estimation problem




manageable in this report, nominal high, medium, and low collection efficien-




cies have been selected for each type  of control equipment, except fabric




filters.   For fabric filters, the nominal high,  medium,  and low curves reflect




construction variations.  The purchase, installed, and total annualized costs




of operation are plotted for each of the three efficiency levels  over the gas




volume range indicated.  Purchase, installed,  and total annualized costs  for




fabric filters  are plotted for variations in filter construction and cleaning




methods.




     Generalized categories of control equipment are discussed rather than




specific designs because of uncertainties in size, efficiency, and cost.  If




required,  more detailed information on the cost of various engineering innova-




tions  (e.g. , packed towers of specific design to accommodate  a corrosive gas




stream) should be requested from the  manufacturers of the specific  equipment.
                                    6-9

-------
Cost variations associated with wet collectors are reported in Table





6-2. 3




      Other difficulties exist in developing cost  information for existing control




devices, especially cost estimates on the maintenance and operation of control





equipment.  Individual firms may remember what a control device cost origi-




nally,  but they may forget what it costs to install and operate.  In addition,





internal bookkeeping and auditing systems often bury these expenditures in




total plant operating costs.  For example, water and electricity used by a




control operation are not always separately metered and accountable as a





specific air pollution control cost item.  Some of these costs  can  be identified




and assessed on the basis  of industrial experience or engineering estimates.





6. 5  DESCRIPTION OF CONTROL COST ELEMENTS




6.5.1   General





      The actual cost of installing and operating air  pollution  control equipment




is a function of many direct and indirect cost factors.  An analysis of the con-




trol costs for a specific source should include an evaluation of all relevant





factors, as  outlined in Figure 6-4.  The control system must be designed and




operated as an integral part  of the process;  this will minimize the cost of con-




trol for a  given emission  level.  The definable control costs are those that are




directly associated with the installation and  operation of control systems.




These  expenditure items from the control equipment user's point  of view have




a breakdown for accounting purposes as follows:
                                    6-10

-------
     Table 6-2.  APPROXIMATE COST OF WET COLLECTORS IN 1965"
	 , 	
o
Tvpe of collector
b,c
Cyclonic:
Small diameter multiples
Single chamber, constant
water level
Single chamber, multiple
stage, overhead line
pressure water feed
Single chamber, internal
nozzle spray
Self-induced spray ' '
b, c
Wet impingement
c,d
Venturi
Variable pressure drop
inertialc>d
c d
Mechanical '
Cost, dollars/cfm
Capacity, cfm
1,000


0.50
1.40

0.95


3.00

0.80
1.00
3.00
1.00

1.75
5,000


0.30
0.45

0.40


1. 50

0.40
0.50
1. 50
-

0.75
20,000


0.20
0.35

0.25


1.00

0.25
0.25
1.20
-

0.35
40,000


0.20
0.25

0.20


0.75

0.25
0.25
0.50
0.30

-
 Basic designs,  mild steel construction.

 Add 30 to 40 percent to base price for fan,  drive, and motor (standard
 construction materials).
Q
 Special materials construction costs for 1000- to 40,000-cfm range units
 are approximately as follows:

    Rubber lining - base increase of 65 to  115 percent.
    Type 304 stainless steel - base increase of  30 to 60 percent.
    Type 316 stainless steel - base increase of  45 to 100 percent.
d
 Add from 10 to  40 percent to base price  per additional stage as in some
 cyclonic and wet impingement designs.
                                  6-11

-------
         OPERATIONAL
         VARIABLES INFLUENCING
         CONTROL COSTS
GAS CLEANING SYSTEM
FACTORS INFLUENCING
CONTROL COSTS
COST AREAS DETERMINING
THE NET COST OF CONTROL
to
                              VOLUME
                            POLLUTANT
                                             GAS CLEANING
                                                 SYSTEM
                                                                         TYPE
                                                                         SIZE
               CONSTRUCTION
                 MATERIAL
                                                                      EFFICIENCY
                                                                    PRESSURE DROP
                                                                    POWER AND FUEL
                                                                                                WASTE
                                                                                              MATERIAL
                                                                                             UTILIZATION
                                                                                                                    ENGINEERING
                                                                                                                      STUDIES
LAND
                                                                    SITE
                                                               PREPARATION
                                                                  CONTROL
                                                                 HARDWARE
                                 AUXILIARY
                                 EQUIPMENT
                                                                                                                     INSTALLATION
                                                               MATERIALS  AND
                                                                   SUPPLIES
                                                                MAINTENANCE
                                                               AND OPERATION
                                                                                                                       CAPITAL
                                                                                                                       CHARGES
                                        Figure 6-4.  Diagram of cost evaluation for a gas cleaning system.

-------
     Capital Investment




          Engineering studies




          Land




          Control hardware*





          Auxiliary equipment*




          Operating supply inventory




          Installation*




          Startup




          Structure modification




     Maintenance and Operation




          Utilities*




          Labor*




          Supplies and materials*




          Treatment and disposal of collected material




     Capital Charges




          Taxes*




          Insurance*




          Interest*




     Of the expenditure items  shown above, only those denoted by an asterisk




were considered in developing the cost estimates used in this chapter.  Other
*Denotes cost items considered in this report
                                  £* -I o



  331-716 0 - 69 - 27

-------
factors,  such as engineering studies, land acquisition, operating supply inven-




tory, and structural modification,  vary in cost from place to place and there-




fore were not included.  Costs for the treatment and disposal of collected




material, while also not included,  are  discussed in some detail in Section 6-8.




6.5.2   Capital Investment




      The "installed cost" quoted by a manufacturer of air pollution equipment




usually is based on his engineering study of the actual emission source.   This




cost includes three of  the eight capital  investment items—control hardware




costs, auxiliary equipment costs, and costs for field installation.




      The purchase cost curves that are shown in Section 6.7 illustrate the




control hardware costs for various types of control equipment.  These purchase




costs are the amounts  charged by manufacturer for equipment of standard con-




struction materials.  Basic control hardware includes built-in instrumentation




and pumps.   Purchase cost usually varies with the size and collection efficiency




of the control device.  The purchase  costs plotted on the curves are typical




for the efficiencies indicated,  but  these costs may vary ±20 percent from




the values shown.  Of  course, equipment fabricated with special materials




(e.g., stainless steel  or ceramic coatings) for extremely high temperatures




or corrosive gas  streams  may cost much more.




      The remaining capital  investment items,  auxiliary equipment and installa-




tion costs, are aggregated together and referred  to as "total installation costs."
                                     6-14

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These costs are shown in Table 6-3, expressed as percentages  of the purchase




costs. These costs include a reasonable increment for the following items:




(1) erection,  (2) insulation material, (3) transportation of equipment,  (4) site




preparation,  (5) clarifiers and liquid treatment systems (for wet collectors), and




(6) auxiliary equipment such as fans, ductwork, motors, and control instru-




mentation.  The low values listed in the table are for minimal transportation




and simple layout and  installation of control devices.   High values are for




higher transportation cost and for difficult layout  and installation problems.




The extreme high values are for unusually complex installations on existing




process equipment.  Table 6-4 lists the major cost categories and related




conditions that establish the installation cost range from low to  high.  The




"installed cost" estimates reported in Section 6-7 are the sum of the purchase




costs and the total installation costs.




6.5.3  Maintenance and Operation




     The following sections describe the working equations for  the operation




and maintenance costs of various control devices.  Numerical values for the




variables expressed in these equations are found in Tables 6-5 and 6-6.




6.5.3.1   General




     The costs of operation and maintenance will  vary widely because of dif-




ferent policies of control equipment users.   This variance will depend on such




factors as the quality and suitability of the control equipment, the user's under-




standing of its  operation, and his vigilance  in maintaining it.  Maintenance
                                    6-15

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Table 6-3.  TOTAL INSTALLATION COST FOR VARIOUS TYPES OF CONTROL
     DEVICES EXPRESSED AS A PERCENTAGE OF PURCHASE COSTS
Equipment type
Gravitational
Dry centrifugal
Wet collector:
Low, medium energy
o
High energy
Electrostatic
precipitators
Fabric filters
Afterburners
Cost, percent
Low
33
35

50
100
40
50
10
Typical
67
50

100
200
70
75
25
High
100
100

200
400
100
100
100
Extreme high
-
400

400
500
400
400
400
 High-energy wet collectors usually require more expensive fans and motors.
                                  6-16

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Table 6-4.   CONDITIONS AFFECTING INSTALLED COST OF  CONTROL  DEVICES
      Cost category
                                            Low cost
                                                                                     High cost
  Equipment transportation
Minimum distance; simple
loading and unloading
procedures
Long distance; complex procedure for
loading and unloading
  Plant age
Hardware designed as an
integral part of new plant
Hardware installed into confines of old
plant requiring structural or process
modification or alteration
  Available space
Vacant area for location of
control system
Little vacant space requires extensive
steel support construction and site pre-
paration
  Corrosiveness of gas
Noncorrosive gas
Acidic emissions requiring high alloy
accessory equipment using special han-
dling  and construction techniques
  Complexity of startup
Simple startup, no exten-
sive adjustment required
Requires extensive adjustments; testing;
considerable down time
  Instrumentation
                                   Little required
                                    Complex instrumentation required to assure
                                    reliability of control or constant monitoring
                                    of gas stream
  Guarantee on
  performance
                                   None needed
                                    Required to assure designed control effi-
                                    ciency
  Degree of assembly
Control hardware shipped
completely assembled
Control hardware to be assembled and
erected in the field
  Degree of engineering
  design
Autonomous "package"
control system
Control system requiring extensive in-
tegration into process, insulation to
correct temperature problem, noise
abatement
  Utilities
                                   Electricity, water,
                                   waste disposal facilities
                                   readily available
                                     Electrical and waste treatment facilities
                                     must be expanded, water supply must be
                                     developed or expanded
  Collected waste material
  handling
No special treatment
facilities or handling re-
quired
Special treatment facilities and/or han-
dling required
  Labor
                                   Low wages in geographical
                                   area
                                     Overtime and/or high wages in geographical
                                     area
                                                     6-17

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            Table 6-5. ANNUAL MAINTENANCE COSTS FOR ALL
                      GENERIC TYPES OF CONTROL DEVICES
Generic type
Gravitational and dry
centrifugal collectors
Wet collectors
Electrostatic precipi-
tators:
High voltage
Low voltage
Fabric filters
Afterburners :
Direct flame
Catalytic
Dollars per acfm
Low
0.005

0.02


0.01
0.005
0.02

0.03a
0.07
Typical
0.015

0.04


0.02
0.014
0.05

0.06b
0.20
High
0.025

0.06


0.03
0.02
0.08

o.iob
0.35
 Metal liner with outside insulation.
b
 Refractory lined.
                                  6-18

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    Table 6-6.  MISCELLANEOUS COST AND ENGINEERING FACTORS
     Fan efficiency = 60 percent
            Pump efficiency = 50 percent
                      Power cost,  dollars/kw-hra
     All devices
 Low

0.005
Typical

 0.011
 High

0.020
                           Hours of operation

                          8760 hours per year

                     24 hr/day x 365 days/yr = 8760
              Power requirements vs efficiency for high-

           voltage electrostatic precipitators,  10~3 kw/acfm
                             Low
                            0.19
                 Medium
                  0.26
                  High

                  0.40
                Power requirements vs efficiency for low-

           voltage electrostatic precipitators (10   kw/acfm)
                             Low
                            0.015
                                   High
                                  0.040
      Liquor cost in 10 3 dollars per gallon per hour (for wet system)
     Wet scrubber
                             Low
 0.35
                 Typical
 0.50
 High

1.00
           Make up liquor requirements, 0.0005 gal/hr -  acfm
—
 Based on national average of large consumers.
                                 6-19

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Table 6-6 (continued).  MISCELLANEOUS COST AND ENGINEERING FACTORS
Power requirements
Low efficiency
"Scrubbing" (contact) 0.0013
power, horsepower/acfm
Medium efficiency
0.0035
Scrubber liquor data
Low
Liquor circulation rate, 0.001
gal/acfm
Minimum head require-
ments, feet water *1
Typical
0.008
30
High efficiency
0.015

High
0.020
60
Pressure drop through equipment, inches of water
Generic type
Dry centrifugal collector
Fabric filter
Afterburners
Electrostatic precipitators
and gravitational
collectors
Low
-
2-3
0.5
0.1
Typical
2-3
4-5
1.0
0.5
High
4
6-8
2
1
 * 1 psig = 2.3 ft water
                                 6-20

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and operation usually are very difficult to define and  assess, but often may




be a significant portion of the overall cost of controlling air pollutant emis-




sions.  Although the combined operating and maintenance costs may be as




low as 10 percent of the annualized total cost for a gravitational settling




chamber,  for example,  they may be as high as 90 percent of the total an-




nualized cost for a high-efficiency wet collector.




     Maintenance cost is the expenditure required to sustain the operation of




a control device at its designed efficiency with a scheduled  maintenance pro-




gram and necessary replacement of any defective parts.  On an annual basis,




maintenance cost  in the following equations is assumed proportional to the




capacity of the device in acfm.  Table 6-5 shows annual maintenance cost




factors for all types of particulate control devices.  Simple, low-efficiency




control devices have low maintenance costs; complex, high-efficiency devices




have high maintenance costs.




     Annual operating cost is the expense of operating a  control device at




its designed collection efficiency.  This cost depends on the following factors:




(1) the gas volume cleaned,  (2) the pressure drop across the system, (3) the




operating time,  (4) the consumption and cost of electricity,  (5) the mechan-




ical efficiency of the fan,  and (6) the scrubbing liquor consumption and costs




(where applicable).
                                    6-21

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6. 5. 3. 2  Gravitational and Centrifugal Mechanical Collectors


      In general, the only significant cost for operating mechanical collectors


is the electric power cost, which varies with the unit size and the pressure


drop.  Since pressure drop in gravitational collectors is low, operational costs


associated with these units are considered to be insignificant.  Maintenance


cost includes the costs of servicing the fan motor, replacing any lining worn


by abrasion, and, for multiclone collectors, flushing the clogged small dia-


meter tubes.


      Cost equation - The theoretical annual cost (G) of operation and main-


tenance for centrifugal collectors can be  expressed as follows:
0.7457 PHK
  6356E

                                                                       (1)
where:


      S = design capacity of the collector,  acfm


      P = pressure drop inches of water (see Table 6-6)


      E = fan efficiency, assumed to be 60 percent (expressed as 0. 6)

      0. 7457 = a constant (1 horsepower = 0. 7457 kilowatt)

      H = annual operating  time (assumed 8760 hours)


      K = power cost, dollars per kilowatt-hour (see Table 6-6)


      M = maintenance cost,  dollars per acfm (see Table 6-5)


For computational purposes the cost formula can be simplified as follows:

                             r            fi          i
                       G = S 195. 5 x 10    PHK + M                   (2)
                                    6-22

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fi.R.3.3 Wet Collectors - The operating costs for a wet collector power and




scrubbing liquor costs.  Power costs vary with equipment size, liquor circula-




tion rate, and pressure drop.  Liquor consumption varies with equipment size




and stack gas temperature.  Maintenance  includes servicing the fan or com-




pressor motor, servicing the pump, replacing worn linings, cleaning piping,




and any necessary chemical treatment of the liquor in the circulation system.




     Cost equation - the theoretical annual  cost (G) of operation and mainten-




ance for wet collectors can be expressed  as follows:





                                                                      (3)
where:




     S = design capacity of the wet collector, acfm




     0.7457 - a constant (1 horsepower = 0.7457 kilowatts)




     H = annual operating time (assumed 8760 hours)




     K = power costs, dollars per kilowatt-hour




     P = pressure drop across fan,  inches of water (see Table 6-6)




     Q = liquor circulation, gallons per acfm (see Table 6-6)




     g = liquor pressure at the collector, psig (see Table 6-6)




     h = physical height liquor is pumped in circulation system, feet (see




        Table 6-6)




     W = make-up liquor consumption, gallons per acfm (see  Table 6-6)
                                   6-23

-------
     L = liquor cost, dollars per gallon (see Table 6-6)




     M = maintenance cost, dollars per acfm (see Table 6-5)




     E = fan efficiency, assumed to be 60 percent (expressed as 0. 60)




     F = pump efficiency,  assumed to be 50 percent (expressed as 0. 50)




     The above equation can be simplified according to Semrau's  total "con-




tacting power" concept. 6  Semrau shows that efficiency is proportional to the




total energy input to meet fan and nozzle power requirements.  The scrubbing




(contact)  power factors in Table 6-6 were calculated from typical performance




data listed in manufacturers' brochures.  These factors are in general agreement




with data reported by Semrau.  Using Semrau's concept the equation for operating




cost can be simplified as follows:





           G=S  fo.7457HK  /Z +   Qh  \   +  WHL +  M]

                 L           (    1980 j               J

where Z = contact power (i.e. ,  total power input required for collection




          efficiency), horsepower per acfm (see Table 6-6).   It is a combi-




          nation of:



                                  /     P   \
     1.   fan horsepower per acfm = —	  , and
                                  \  6356 E /



     Oi                 ,.   I   Qg    the power to  atomize water\
     2.   pump horsepower per acfm  = .,   ^        f
                                    \  1722F  through a nozzle          /




     The pump horsepower, Qh/1980, required to provide pressure head




is not included in the contact power requirements.
                                   6-24

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fi.5.3.4.  Electrostatic Precipitators -  The only operating cost considered in




the operation of electrostatic precipitators is the power cost for ionizing




the gas and operating the fan. As the pressure drop across the equipment is




usually less than 1/2 inch of water, the cost of operating the fan is assumed




to be negligible.  The power cost varies with the efficiency and the size of the




equipment.




     Maintenance usually requires the services of an engineer or highly-




trained operator, in addition to regular maintenance personnel.  Maintenance




includes servicing fans and replacing damaged wires and rectifiers.




     Cost equation -  The theoretical annual cost (G) for operation and




maintenance of electrostatic precipitators is as follows:




                     G = S  [JHK  +  M]                    (4)




where




     S = design capacity of the electrostatic precipitator, acfm




     J = power requirements, kilowatts per acfm (see Table 6-6)




     H= annual operating time (assumed 8760 hours)




     K= power cost, dollars per kilowatt-hour (see Table 6-6)




     M= maintenance cost,  dollars per acfm (see Table 6-5)




6^5.3.5 Fabric Filters - Operating costs for fabric filters include power costs




for operating the fan  and the bag cleaning device.  These costs vary directly




with size of equipment and the pressure drop.  Maintenance costs include costs




for servicing the fan  and shaking mechanism, emptying the hoppers, and




replacing the worn bags.




                                  6-25

-------
      Cost equation - The theoretical annual cost (G) for operation and maintenance
of fabric filters is as follows:
                         G = S
                                       (5)
where:
      S = design capacity of the fabric filter, acfm
      P= pressure drop, inches of water (see Table 6-6)
      E = fan efficiency, which is assumed to be 60 percent
         (expressed as 0. 60)
      0.7457 = a constant  (1 horsepower = 0.7457 kilowatt)
      H = annual operating time  (assumed 8760 hours)
      K = power cost, dollars per kilowatt-hour (see Table 6-6)
      M= maintenance cost, dollars per acfm (see Table 6-5)
For computational purposes, the cost formula can be simplified as follows:
                        G = S
          —
195. 5 x 10   PHK + M                  (6)
6.5.3.6  Afterburners - The major operating cost item for afterburners is
fuel.  Fuel requirements are a direct function of the gas volume, the
enthalpy of the gas, and the difference between inlet and outlet gas temperatures.
For most applications,  the inlet gas temperature at the source ranges from
300°  to 400° F.  Outlet temperatures may vary from 1200° to 1500° F for
                                                                         2
direct flame afterburners and from 730° to  1200° F for catalytic afterburners.
The use of heat exchangers may bring about a 50 percent reduction in the
                       7 8
temperature  difference. '   Table 6-7 lists hourly fuel costs based on a
natural gas cost of $0. 60 per million Btu.   No credit was given for heat
of combustion of particulate or other matter.  These costs were developed
                                                                     9
from  enthalpies  (heat content) of the process gas at given temperatures.
                                   6-26

-------
Maintenance includes servicing the fan,  repairing the refractory lining,
washing and rinsing the catalyst, and rejuvenating the catalyst.
     The equation for calculating the operation and maintenance costs (G)
is as follows:
                                                                     (7)
                          I  UO
-------
                     Table 6-7.  HOURLY FUEL COSTS
Device
Direct flame (DF)
DF with heat exchanger
Catalytic afterburner (CAB)
CAB with heat exchanger
Temperature, "F
Inlet
380
1000
380
650
Outlet
1400
1400
900
900
A
Temperature,
°F
1020
400
520
250
Fuel cost, a
dollars/acfm-hr
$0.00057
0.00023
0.00028
0.00014
&These figures include the cost of heating an additional 50 percent excess air.
It is assumed there is no heat content in the material or pollutant being consumed.
Adding the recurring maintenance and operation costs to this figure gives
a total annualized cost of control.  Total annualized cost estimates are shown
in Section 6.7.
6. 5. 6  Assumptions  in Annualized Control Cost Elements
      Annualized control costs will differ from installation to installation
and from region to region, and certain simplifying assumptions have been
necessary to develop the cost figures of this section.  If more information
for a given location is  available, it is  desirable to substitute this for the
assumptions used here.
6.5.6.1  Annualized Capital Cost Assumptions
      The simplifying assumptions for computing the total annualized
capital cost are as follows:
      1.  Purchase and installation costs are depreciated over 15 years, a
         period assumed to be a feasible economic life for control devices.
                                    6-28

-------
     2.  The straight line method of depreciation (6-2/3 percent per year)
         is used because it is the most common method used in accounting
         practices.   This method has the simplicity of a constant annual
         writeoff.

     3.  Other costs called capital charges—which include interest, taxes,
         insurance, and other miscellaneous costs—are assumed to be
         equal to the amount of depreciation, or 6-2/3 percent of the
         initial capital  cost of  the control equipment installed.   Therefore,
         depreciation plus these other annual charges amount to 13-1/3
         percent of the initial capital cost of the equipment.
6,5.6.2  Operating Cost Assumptions — The following assumptions were taken

into account for computing operation and maintenance costs.
     1.  Power costs included in annual operating expense reflect electricity
         used by all systems directly associated with the  control equipment.
         Electrical power requirements are computed on a constant usage
         basis at a  specified gas volume.
     2.  For wet collectors, it is assumed that the liquor is recirculated
         in a closed system.  Liquor consumption consists  of the makeup
         liquor which must be added from time to  time.  Stack gas tempera-
         ture  influences the rate of liquor loss; this influence is partially
         accounted for  by assuming a constant  loss per cubic foot of stack
         gas volume.  This assumption is necessary because of the ex-
         tremely wide range of stack gas temperatures.
     3.  The costs for  electricity and water are computed on the marginal
         rate  classes for each size user, which assumes  that any additional
         consumption will be priced  at the lowest rate-highest volume class
         available.  Except where  specifically  indicated,  the typical values
         for the pressure drop  and cost of electricity (see Table 6-7) were
         assumed in all control cost calculations and illustrations.
     4.  The disposal cost and/or recovered value of collected effluents
         are not included in the operating cost  calculations because of
         cost differences from process to process.  Disposal cost fig-
         ures for several major industrial categories are reported in
         Section 6.8.
  331-7160-69-28

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6.5.6.3  Maintenance Cost Assumption — It is assumed that a user of control
equipment establishes a preventive (scheduled) maintenance program and
carries it out  to maintain equipment at its designed collection efficiency.
Further, it is assumed that unscheduled maintenance, such as replacement
of defective parts, is undertaken as required.  The cost incurred for equip-
ment modification or repair due to an operational accident is  not included.
6. 6  METHOD FOR ESTIMATING ANNUAL COST OF CONTROL FOR A
     SPECIFIC SOURCE
6.6.1  General
       As previously indicated, it is beyond the scope of this report to
identify and assess the cost of control for a specific source.  Such assess-
ments  can, however, be calculated by applying the steps outlined below.
6.6.2  Procedure
       The following procedure can be used to determine the  expected cost
of control for any source.
       Step 1.  Describe the source (including characteristics of the process),
the characteristics and consumption of fuel for combustion, and the total
number of hours in operation annually.   Emissions can be determined by
making stack gas tests or can be estimated by making calculations using the
emission factors.
       Step 2.  Select the applicable types of control equipment.  Figure 6-1
illustrates what must be considered in selecting the  optimum  type of control
equipment.
       StepS.  Specify pressure drops,  efficiencies, construction material,
energy and fuel requirements,  and size limitations for  the selected control
equipment, taking into account any existing equipment.
       Step 4.  Determine  the gas flow in acfm at the point of collector loca-
tion.   For wet collectors, this would be  the water saturated gas volume.  This
should be done by taking measurements at maximum operating conditions.
                                    6-30

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    Step 5.  Determine the estimated total purchase cost for the specific
selected device (curves found in Section 6. 7) at the required gas volume and
control efficiency.   For fabric filters, select the proper filter medium for
the process.
    Step 6.  Multiply the cost found in step 5 by the low, typical, and
high installation cost factors (Table 6-3), and add the result to the estimated
total purchase cost to obtain the corresponding low, typical, and high total
installed costs.  Conditions  affecting the cost of installation are listed in
Table 6-4.
    Step 7.   Calculate the  total annual capital cost as follows:
          annualized capital cost =  depreciation + capital charges
                                 =  0.133 X total investment cost*
    Step 8.   Compute the cost of electricity, maintenance, and liquor
consumption.
    Step 9.   Compute low,  medium,  and high operating and maintenance
costs from the appropriate formulas:
         Dry centrifugal collectors
         G =S  [195.5 XlO~6  PHK  + M]
        G = S   10.7457  HK(Z+-.+WHL + M
                                    /           j
Wet scrubbers
       [0
Electrostatic precipitator
G = S  [JHK + M]
Fabric filters
                   ft
G = S  [195. 5 X 10~   PHK + M]
Afterburners
                   «
G = S  [195. 5 X 10~   PHK + M + HF]
*Based on the assumptions in Section 6. 5. 6.1
                                   6-31

-------
where:
       G = theoretical value for operating and maintenance costs
       S = the design capacity of the collection device, acfm
       P = pressure drop of the gas, inches of water
       H = annual operating time
       K = power costs, dollars per kilowatt-hour
       Q = liquor circulation, gallons per acfm
       h = physical height that liquor is pumped in circulation system, feet
       Z = total power input required  for scrubbing efficiency,  horsepower
           per acfm
       M = maintenance cost, dollars per acfm
       W - liquor consumption, gallons per hour per acfm
       L = cost of liquor, dollars per gallon
       j =  power requirement, kilowatts per acfm based on efficiency
       F = fuel cost, dollars per hour per acfm
       Step 10.  Add the typical  annualized capital cost to the typical
operating and maintenance cost to yield the estimated total annualized cost
of control.
       Step 11.  Because  the above calculation is a point estimate, the range
of costs should be investigated.  For this, a variance is calculated and applied
to the total estimated annual cost.  The low cost  variance (V ) and high cost
variance (V ) of an equipment combination can be computed by using the square
root of the  sum of the squares.  The formulas for these variances are as
follows:
         V.  =     \/(C   -  C)2    +    (G   -  G)2
           1        V   m      1            ml
         V^  =    \/(C^   -  C  )2   +    (G,   -  G  )2
           h       V   h       m           h      m
                                   6-32

-------
where:
p  c   and C  are the low, typical,  and high annual capital cost estimates,
T  m       h
respectively, and G , and G , and G  are the low, typical,  and high operation
and maintenance cost estimates.  These formulas are taken  from the usual
definition of the standard error of a linear combination of statistically
independent variables.  They permit computation of the most probable, rather
than the extreme,  range of  costs.
     Step 12.  The high cost variance (V  ) is added to the total estimated annual
cost to yield the high cost limit.
     Step 13.  The low cost variance (V ) is subtracted from this total esti-
mated annual cost to yield the low cost limit.
6.6.3 Sample Calculations
     The following calculations illustrate the method used to determine the
total estimated annual cost  of control.  The  following example shows the
estimation of annualized cost for a 60, 000 cfm, 90 percent (medium efficiency)
wet collector.
     Step 1. Annual operating time = 8760 hours (H)
     Step 2.  Wet collector (given)
     Step 3.  90 percent efficiency  (given)
          Scrubbing power required -  0. 0035  horsepower per acfm (Z)
     Step 4.  Actual gas flow = 60, 000 acfm (given)
     Step 5.  Purchase cost = $17, 000 (from Section 6.7.4 for wet collectors)
     Step 6.  Installation factors from Table 6-3 are 50 percent, 100 percent,
           and 200 percent
             Installation factor           50%        100%      200%
             Installation cost          8,500      17.000     34,000
             Purchase cost           17,000      17.000     17,000
             Total capital cost       $25,500    $34,000    $51,000
    Step 7.  0.133 X Total capital cost     =     annual capital cost  (C)
                                 6-33

-------
      C = 0.133 x $25,500 = $3400

      C  = 0.133 x $34,000 = $4530
       m
      C = 0.133 x $51, 000 = $6800
       h

      Step 8.   Power cost, dollars/kw-hr (K)

           Low              Typical              High

           0.005             0.011                0.020

           Maintenance cost, dollars/acfm, (M)

           Low              Typical              High

           0.02              0.04                 0.06
                          _3
           Liquor cost, 10   dollars/gal, (L)

           Low              Typical              High

           0.35              0.50                 1.00

           Head required for circulation in system, feet, (h)

           Low              Typical              High

           1                  30                   60

           Liquor circulation,  gallons per acfm, (Q)

           Low              Typical              High

           0.001             0.008                0.020
                                _3
           Makeup liquor rate, 10   gal/hr-acfm, (W) = 0.5

      Step 9.  Using the following formula to determine annual operating cost

(G),
            G  =  S     Z  + -TTTT:-     (0.7457 HK) +  WHL  + M
           the low, typical, and high operating and maintenance costs are as

           follows:
          Gl  - $8200          G  =  $18,100          G,  -  $35,900
            1                    m                     h
                                  6-34

-------
    Step 10.  From the steps 7 and 9,
            C   = $4530          G  =  $18,100
             m                   m
          Then, the total estimated annual cost is as follows:
              C   + G  -$22,600
               m    m
    Step 11.  Using the square  root of the sum of the squares of the
differences, the high and low cost variances are as follows:
                    Vl  T(Cm -
                         /            2
                   V  =/(4530 - 3400)   + (18,100-8200)'
                   V  =  $10,000
                   V,  =  (C,  -  C  )   +  (G,  - G  )
                     h  V   h     m        h     m
                         /             2                      2
                   V  =1(6800 -  4530)   + (35,900  -  18,100)
                   V,  =  $17,900
                     h
    Step 12.  From Step 10, the total estimated annual cost = $22,600
          From Step 11, V  = $10,000
          Low cost limit = $22, 600-$10, 000 = $12, 600
    Step 13.  Total estimated annual cost = $22, 600
          From Step 11, V  = $17, 900
          High  cost limit - $22, 600 + $17, 900 = $40, 500
    Step 14.  The amount  of particulate matter emitted  may be calculated
if the inlet conditions are known.
                                 6-35

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6.6.4  Annualized Cost Variation
      The previous section illustrated the probable high and low cost limits
for a single installation, taking into account the variation in costs for installa-
tion, maintenance, and operation.  To compute the annualized cost for a given
emission reduction system, one  must take into account four variables:  (1)
collection efficiency of the system, (2) cost of installing the system,  (3) cost of
operation,  and (4) maintenance cost.  A  more  complete summary of the range
of total annualized costs is shown in Table 6-8 for a 60, 000 acfm wet collector.
This table illustrates cost figures for 81 possible  combinations of each of
the four variables, with each variable taking on three independent values-
low, typical, and high. It is constructed by the procedure outlined in Steps
1 through 10 in the previous section.  The constants for computing these
values are taken from Tables  6-5 and 6-6.  Table  6-8 shows that a  low-
efficiency 60, 000 acfm wet collector with low installation,  maintenance, and
operation costs will cost  approximately $6100 per year to operate (extreme
upper  left hand corner).   The most efficient (99 percent efficiency) wet
collector, according to the table, will cost as high as $137,400 per year
to operate.  The most likely costs for efficiencies of 75 percent,  90 percent,
and 99 percent are $11, 300; $22, 700; and $74, 500, respectively.  The type of
data shown in Table 6-8 is useful in developing cost-effectiveness relation-
ships.  Note that this table does not show the variances, V and V ;  these
should be used only when the probable cost limits are desired.
6. 7  COST CURVES BY EQUIPMENT TYPE
6.7.1  General
     For the convenience  of those who may use the cost information described
in this chapter,  the following sections contain a series of control cost curves
(see Figures 6-5 through 6-24).  For each type of  control equipment, a series
of curves  is presented: (1) purchase cost curves,  (2) installed cost curves,
and (3) annualized cost curves.
                                    6-36

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                        Table 6-8.  ILLUSTRATIVE PRESENTATION OF ANNUAL COSTS OF CONTROL
                                         FOR 60,000 acfm WET SCRUBBER (dollars)


e


o


O
m

°h





MI
Mm
Mh
MI
MHI
Mh
MX
Mm
Mh
E =75%a'b
1
j c
1
6,100
7,300
8,500
9,500
10,700
11,900
18,300
19,500
20,700
I
m
6,800
8,000
9,200
10,100
11,300
12,500
18,900
20,100
21,300
T
n
8,100
9,300
10,500
11,500
12,700
13,900
20,300
21,500
22,700
E = 90%
m
:
1
11,800
13,000
14,200
20,300
21,500
22,700
36,900
38,100
39,300
I
m
13,000
14,200
15,400
21,500
22,700
23,900
38,100
39,300
40,500
T
n
15,200
16,400
17,600
23,700
24,900
26,100
40,300
41,500
42,700
E, = 99%
ti
j
1
35,500
36,700
37,900
71,100
72,300
73,500
128,200
129,400
130,600
I
m
37,800
39,000
40,200
73,300
74,500
75,700
130,500
131,700
132,900
T
n
42,300
43,500
44,700
77,900
79,100
80,300
135,000
136,200
137,400
CO
-q
         d
 E = efficiency factor.

 Subscripts 1, m,  and h indicate low,  medium, and high ranges,  respectively.
-»
"I = installation factor.

 M = maintenance factor.

 O = operating factor.

 Note:  A similar table can be generated to show the various control costs for any type of control equipment
 by specifying operating conditions and calculating each entry.  This procedure provides complete information
 to aid in the assessment of existing controls or other  control alternatives.

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      The estimated purchase cost curves show the dollar amounts charged by
manufacturers for basic control equipment, exclusive of transportation
charges to the installation site.  This basic control equipment  includes
built-in auxiliary parts of the control unit,  such as instrumentation and
solution pumps.  The installed cost curves include the purchase costs,
additional auxiliary equipment costs, and installation costs,  as  described in
Section 6. 5. 2.  The annualized  cost curves include elements discussed in
Section 6.5.3 through 6.5.6.  The assumptions, sources of data, and the
limitations used to develop this information are discussed in Sections
6.3 and 6.4.
6.7.2  Gravitational Collectors
      In computing the cost of gravity collectors,  three collection efficiencies
were considered.  These efficiencies were based on the assumption of essentially
complete removal of 87-micron, 50-micron, and  25-micron particles, and
are designated as low, medium, and high efficiencies, respectively.    The low
and medium efficiency collectors are simple expansion chambers, and the
high efficiency collector is a multiple-tray settling chamber,  commonly called
a Howard separator.
      In actual  operation,  the collection efficiency for a gravitational  collector
depends on  the particle size distribution. In cleaning the flue gas from  a
stoker-fired  coal furnace,  for example, low-, medium-,  and high-efficiency
collectors would have particle removal efficiencies of approximately 64 per-
cent,  75 percent,  and 88 percent, respectively.  In cleaning the flue gas from
a pulverized  coal furnace,  these same collectors,  because of the smaller-
sized particles emitted by the combustion unit,  would have approximate
efficiencies  of 21 percent, 34 percent, and  56 percent, respectively.
      The purchase costs of gravitational collectors are shown for three
difference efficiences in Figure 6-5.  These are approximate costs for typical
                                     6-38

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installations.  If it were necessary to include insulation or a corrosion-
resistant lining, the costs would be higher.  The total installed cost was  also
calculated for each efficiency and is shown in Figure  6-6.  The total  installed
cost is the sum of the purchase and installation costs. The installation costs
were assumed to  range from 33 percent to 100 percent of the purchase cost
(see Table 6-3), and this range results in a cost band for each efficiency, as
shown in the figure. No annualized cost curves  are presented  for these col-
lectors because operation and maintenance costs,  other than for  removal and
disposal of collected material, usually are negligible, except where corrosion
maybe a problem.   Section 6.8 provides specific information on the  disposal
of collected material.
6.7.3 Dry Centrifugal Collectors
     The costs of purchasing, installing, and operating mechanical centri-
fugal collectors are given in Figures 6-7, 6-8,  and 6-9 respectively.  The
curves in these figures show costs for collectors that operate at nominal
efficiencies of 50 percent, 70 percent, and 95 percent (see  Section 6.4).
Costs are plotted for equipment sizes ranging from 10, 000 to 1, 000, 000 acfm.
The assumptions used in calculating annual operation  and maintenance costs
for dry centrifugal collectors are as follows:
     1.   Annual operating time = 8760 hours
     2.  Collector  pressure drop = 3 inches of water
     3.  Power cost = $0. 011/kw-hr
     4.  Maintenance cost = $0.015/acfm
6.7.4 Wet Collectors
     The costs of purchasing, installing, and operating wet collectors are
given in Figures 6-10,  6-11, and 6-12, respectively,  as a function of equip-
ment size.  The curves in these figures show costs for collectors that operate
at nominal efficiencies of 75 percent,  90 percent, and 99 percent (see Section
                                   6-39

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                  100
O5


h^
o
               _S   10

               "o
               2  5.0
               o
               (J
I

-------
    100
                      Costs may vary by - 20 percent.
             i    i  i  i i  i 111      i   i  i  i i  i 11
       10            50     100           500   1000

      GAS VOLUME THROUGH COLLECTOR, 103 acfm
 Figure 6-7.  Purchase  cost  of  dry centrifugal
              collectors.
      '10             50    100           500   1000

       GAS VOLUME  THROUGH COLLECTOR, 103 acfm


Figure 6-8.  Installed  cost  of  dry  centrifugal
             collectors.
                       6-41

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             HIGH EFFICIENCY

             MEDIUM EFFICIENCY

             LOW EFFICIENCY
                                  300   500


                                I   I   I  I I  I II
     10             50     100           500   1000

     GAS VOLUME THROUGH COLLECTOR,  103 acfm


    Figure 6-9.  Annualized cost of operation of

                 dry centrifugal collectors.
  1000
   500
   100
o
u
X
(J
o:
13
Q.
    50
    10
                    Costs may vary by ~ 20 percent.

                    	LLLL
     1         5   10       50  100      500  1000


      GAS VOLUME THROUGH COLLECTOR, 103 acfm


  Figure 6-10.  Purchase cost of wet col lectors.
                       6-42

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1/1
o
u
o
UJ
1000

 500





 100


  50




  19

  5




  1
      E  I  I  I Mllll   I  |  I |  HIM   I   |  | I I Ili
      —    HIGH
      -  X
      1         5   10        50  100       500  1000

      GAS VOLUME  THROUGH COLLECTOR, 103acfm

  Figure 6-11.  Installed cost of wet col lectors.
  1000,=
      1        5    10       50   100      500 1000

      GAS VOLUME THROUGH COLLECTOR, 103 ocfm


   Figure 6-12.   Annualized cost  of operation
                 of wet collectors.

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6.4).  The basic hardware  costs for medium and high collection efficiency
equipment are reported by  manufacturers to lie  in the same  cost range and
both appear  on the same curve in  Figure 6-10.  The higher installed cost of
a high collection efficiency  system in Figure 6-11 results from the need for
larger,  more expensive auxiliary equipment (based on Table 6-3). The
assumptions used in calculating annual operating and maintenance costs for
wet collectors are as  follows:
      1.   Annual operating time = 8760 hours
      2.   Contact power requirements:
          0. 0013 horsepower/acfm for 75 percent efficiency
          0. 0035 horsepower/acfm for 90 percent efficiency
          0. 015 horsepower/acfm for 99 percent efficiency
      3.   Power cost = $0. 011/kw-hr
      4.   Maintenance cost = $0. 04/acfm
      5.   Head required for liquor circulation in collection system =
          30 feet
      6.   Liquor circulation = 0. 008 gallon/acfm
      7.   Liquor consumption =  0. 0005 gallon/hour-acfm
      8.   Liquor cost = $0. 0005/gallon
6.7.5 High-Voltage Electrostatic  Precipitators
      The costs of  purchasing, installing, and operating high-voltage electro-
static precipitators are given in  Figures 6-13, 6-14, and  6-15, respectively.
The curves  in these figures show costs for collectors that operate at nominal
efficiencies  of 90 percent,  95 percent, and 99. 5 percent.  These costs are
plotted for equipment  sizes ranging from 20, 000 to 1, 000, 000 acfm.   The
assumptions used in calculating annual operation and maintenance costs for
high-voltage electrostatic precipitators are as  follows:
      1.   Annual operating time = 8760 hours
      2.   Electrical power requirements:
                                    6-44

-------
  1000
   500
O  100
U

UJ
I
U
ct
    50
    10
                     Costs may vary by - 20 percent.
     10            50     100           500    1000


     GAS VOLUME THROUGH COLLECTOR, 1Q3 acfm



 Figure 6-13.   Purchase cost of high-voltage

                electrostatic  precipitators.
  1000
     10             50     100           500     1000


     GAS  VOLUME THROUGH COLLECTOR, 103 acfm


  Figure 6-14.   Installed cost of high-voltage

                 electrostatic precipitators.
   331-716 O - 69 - 29
                      6-45

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100
  10            50    100           500   1000
   GAS VOLUME THROUGH COLLECTOR, 103 acfm

Figure 6-15.  Annualized cost  of operation
              of  high-voltage  electrostatic
              precipitators.
                   Costs moy vary by - 20 percent
   1              5     10            50     100
   GAS VOLUME THROUGH COLLECTOR, 103 acfm

 Figure 6-16.   Purchase cost of low-voltage
               electrostatic   precipitators.
                    6-46

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             0. 00019 kw/acfm for low efficiency
             0. 00026 kw/acfm for medium efficiency
             0. 00034 kw/acfm for high efficiency
     3.   Power cost = $0. 011/kw-hr
     4.   Maintenance cost = $0. 02/acfm
 6.7.6  Low-Voltage Electrostatic Precipitators
     The curves in Figures 6-16,  6-17,  and 6-18 indicate purchase cost,
 installed cost, and operation cost of low-voltage electrostatic precipitators
 for low and high collection efficiencies based on design gas velocities of
 150 and 125 feet per minute, respectively.  Packaged modular low-voltage
 precipitators with flow rates of less than 1500 acfm are used to collect
 oil mist from machining operations.  Purchase cost of such a unit usually
 is less than $1200.  The assumptions used in calculating annual operation
 and maintenance costs for low-voltage electrostatic precipitators are as
 follows:
     1.   Annual operating time  = 8760 hours
     2.   Electrical power requirements:
             0. 000015 kw/acfm for low efficiency
             01 000040 kw/acfm for high efficiency
     3.   Power cost = $0. 011/kw-hr
     4.   Maintenance cost = $0. 02/acfm

 6.7.7 Fabric Filters
     Figures 6-19, 6-20, and  6-21 show purchase cost,  installed cost, and
annualized cost of control for three different  types of filters. Each of the
three filters is designed with about the  same efficiency—99. 9 percent.  Costs
are plotted for equipment sizes ranging from  10,000 to 1,000,000 acfm.
    The control cost curves represent the following different types of filter
installations:
                                   6-47

-------
1000
   1              5     10            50    100
   GAS VOLUME THROUGH COLLECTOR,  103 acfm

Figure 6-17.   Installed cost of low-voltage
               electrostatic   precipitators.
100
   1             5     10            50    100
   GAS VOLUME THROUGH COLLECTOR, 103 acfm
Figure 6-18.    Annualized cost of operation
               of low-voltage electrostatic
               precipitators.
                    6-48

-------
   100
o
-a
O
U
X

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    1.  Curve A represents a fabric filter  installation with high-temperature
        synthetic woven fibers (including fiberglass) and felted fibers cleaned
        continuously and automatically.
    2.  Curve B represents an installation using medium-temperature synthetic
        woven and felted fibers,  such as Orion or Dacron, cleaned contin-
        uously and automatically.
    3.  Curve C is the least expensive installation.   Woven natural fibers are
        used in a single compartment.  Filters are intermittently cleaned.
        This equipment is rarely designed for processes handling over 150,000
        acfm.
These control cost  curves do not  include data for furnace hoods, ventilation
ductwork and pre-coolers that may appear only in certain  installations.  The
assumptions for calculating operating and maintenance costs are as follows:
    I.  Annual operating time =  8760  hours
    2.  Pressure drop of the  gas through the three  types of fabric filters = 4
        inches of water
    3.  Power cost = $0. 05/acfm
    4.  Maintenance cost = $0. 05/acfm
6. 7. 8 Afterburners
    Afterburners are separated into four categories:  (1) direct flame, (2)
catalytic,  (3) direct flame with heat recovery,  and (4) catalytic with heat
recovery.  Equipment and installation  costs were  obtained from both the litera-
ture and manufacturers of afterburners.  Sufficient data was received on
catalytic afterburners to define the narrow purchase cost range shown in
Figure 6-22.   The figure  shows that purchase costs  of direct flame after-
burners have a wider range than those of catalytic afterburners.
    Figure 6-23 shows  the installation costs for afterburners.  Heat ex-
changers are considered accessory equipment and appear as part of the
installation cost. Installation costs may range from 10 percent to 100 percent
of the purchase costs, although in some  situations they may be as high as 400
percent.
                                    6-50

-------
O
U
O
LJJ
N
13
Z
    10            50     100            500   1000

    GAS VOLUME THROUGH COLLECTOR, 103 acfm


 A  HIGH-TEMPERATURE SYNTHETICS, WOVEN  AND
    FELT.  CONTINUOUS  AUTOMATIC CLEANING.
 B - MEDIUM-TEMPERATURE SYNTHETICS, WOVEN AND
    FELT.  CONTINUOUS  AUTOMATIC CLEANING.
 C-WOVEN  NATURAL  FIBERS.    INTERMITTENTLY
    CLEANED - SINGLE  COMPARTMENT.

  Figure 6-21.   Annualized cost of operation

                 of fabric filters.
   100
   50
O   10
CJ
X
(J
                      IT
               I   I I  HIM
I   I  I Ml
     1              5     10                  100

     GAS VOLUME THROUGH COLLECTOR,  103 Ocfm

  Figure 6-22.  Purchase cost of afterburners.
                       6-51

-------
                   100
OS
 I
Ol
to
O  10
u
<
h-
z
                      FI    f
                      1              5     10             50    100

                      GAS VOLUME THROUGH COLLECTOR, 103 ocfm

                   CABHE -  CATALYTIC  AFTERBURNER  WITH  HEAT
                           EXCHANGER
                   DFHE  -  DIRECT FLAME AFTERBURNER WITH HEAT
                           EXCHANGER
                   CAB   -  CATALYTIC AFTERBURNER
                   DF    -  DIRECT FLAME  AFTERBURNER

                   Figure 6-23.  Installed cost of  afterburners.
                                                                                 100
                                                                                  50
                                                                    E    f
                                                                               Q
                                                                               UJ
                                                                               Z
                                                                               Z
                                                                                  10
                                                                   1              5     10             50     100

                                                                   GAS VOLUME THROUGH COLLECTOR, 1Q3 ocfm

                                                               CABHE - CATALYTIC   AFTERBURNER   WITH   HEAT
                                                                       EXCHANGER
                                                               DFHE   -DIRECT  FLAME AFTERBURNER WITH  HEAT
                                                                       EXCHANGER
                                                               CAB   -CATALYTIC  AFTERBURNER
                                                               DF     - DIRECT FLAME AFTERBURNER

                                                                 Figure 6-24.    Annualized cost of operation
                                                                                of afterburners.

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Differences in installation costs are due to the differences in burner lo-
cations relative to the emission source,  and differences in structural sup-
ports, ductwork, and foundations.   Installation costs for the addition of
equipment to existing plant facilities will be higher than similar costs for
new plants.  Other factors  accounting for different installation fees are
the degree of instrumentation required, engineering fees  in manufacturers'
bids, startup tests and adjustments, heat exchangers, auxiliary fans, and
utilities.  The assumptions for calculating operation and maintenance costs
are as follows:
   1.   Annual operating time  = 8760 hours
   2.   Fuel cost:
           $0. 57/1000 acfm-hour for direct flame afterburner with no heat
           recovery
           $0. 23/1000 acfm-hour for direct flame afterburner with heat
           recovery
           $0. 28/1000 acfm-hour for catalytic afterburner with no heat
           recovery
           $0. 14/1000 acfm-hour for catalytic afterburner with heat
           recovery
   3.   Maintenance cost:
           $0. 06/acfm  for direct flame afterburner
           $0. 20/acfm  for catalytic afterburner
   4.   Pressure drop through all afterburner types = I inch of water
   5.   Power  cost = $0. 011/kw-hr
   Cost comparisons presented in Figure 6-24 show that  the direct flame
afterburner without a heat exchanger is the most expensive.  The lower
curve in Figure  6-24 shows that the annualized cost of a direct flame after-
burner with heat recovery is lower than the cost of a catalytic afterburner
without heat recovery.
                                  6-53

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6. 8  DISPOSAL OF COLLECTED PARTICULATE EMISSIONS
6.8.1  General
      The installation of any pollution control system designed to collect par-
ticulate matter demands a decision regarding the disposal of the collected
particulate material.  This section discusses the relevant factors and illustrates
the economic consequences of disposal of the collected material.
      In the past,  pollution control equipment often was installed  either to
reduce a severe nuisance or to  recover valuable material.   Such  equipment not
only prevented valuable material from escaping to the atmosphere but also
reduced costly cleaning of the plant grounds  and facilities.
      As industrial plants become more crowded together and  as  the public
desires a higher quality of air,  more emphasis  will be placed  on  intensive
control activities.  This emphasis will increase the demand for more effective
air pollution control.  Generally, most air pollution control systems collect
material that has little economic worth.
      Basically, the alternatives for handling collected particulate material
are as follows:
      1.   Return the material to the process.
      2.   Sell the material directly as collected.
      3.   Convert the material to a saleable product.
      4.   Discard the material in the most economical manner.
The process of selecting an alternative should take into account the following
questions:
      1.   Can the material be used within the company?
      2.   Is there a profitable market for the material?
      3.   What is the most economical method of disposal ?
      4.   Is there land available for a landfill ?
                                     6-54

-------
    5.   Is there a source of water available for:
        a.  a wet pipeline system
        b.  disposal at sea
        c.  transportation by barge

    6.   Is there space available for a settling basin or filtering system?

    7.   Is there process-related equipment presently available for trans-
        porting or treating the collected material ?

    8.   Is there access to a municipal waste treatment system?
    9.   Can technology and/or markets be developed for utilization of the
        waste material ?

6.8.2 Elements  of Disposal Systems

    After examining feasible solutions  to the disposal problem, the least

costly alternative that is most compatible with other operating factors in the
plant should be chosen.  The decision should result from consideration of
each of the four functional elements of the disposal system described below
and their relationships to the manufacturing process.
    1.   Temporary  storage, which allows gathering sufficient quantities
        of the collected material to make final disposal  more economical.
        The unit cost of disposal usually is lower for greater quantities.
        Temporary  storage may be convenient at many points  in the overall
        disposal scheme,  such as  in the hopper or  settling chamber of a
        pollution control device, or in a silo some  distance from the plant.
    2.   Transportation that moves the collected material from the particulate
        control device to some location where disposal is  relatively econom-
        ical.  In most cases, transportation displaces the material to a
        location where accumulation minimizes any potential interference
        with plant activities.  Any single disposal system  may require more
        than one method of transporting the material.  For example, a con-
        veyor system may be used at the control device, a truck  may be
        used to transport the material to a landfill  area, and a bulldozer
        may be used to push it to its final disposal  location.
    3.   Treatment that changes physical and/or chemical  characteristics
        for  easier disposal.   Such treatment may simplify operations and
        reduce costs for handling and disposal of wastes.   Frequently, for
        easier transport, particulate matter is made into  a slurry by adding
                                    6-55

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          water to it.  This permits the use of a pipeline, which is often the
          most economical method for transporting wastes over long distances.
          Slurries from wet scrubbing pollution control systems frequently
          are treated in an opposite manner:  the water is removed and the
          particulate matter is concentrated by filtration or sedimentation
          This permits the ultimate disposal of a solid waste, rather than a
          sludge or a slurry.  The method of treatment should be selected
          with a view to minimizing contamination  of the  environment.  Examples
          of such  treatment methods are the wetting of fine dust to prevent air
          pollution, the neutralization and filtration of slurries to prevent con-
          tamination of receiving waters, and the proper burial of solid
          material in a sanitary landfill.

      4.   Final disposition, which pertains to discarding the unusable material.
          Material which cannot be sold, converted, or re-used ultimately
          can be discarded in landfills;  or sometimes  it can be disposed of in
          lagoons or the sea.

      The following list shows  some examples of the four functional elements
for both wet and dry disposal systems:
      A.   Storage

          (1)  Slurry of suspended particulate matter in water
              (a)    Settling basin

              (b)    Lagoon
              (c)    Tank

          (2)  Dry collected particulates
              (a)    Mound

              (b)    Rail car
              (c)    Bin

              (d)    Silo

      B.   Transportation

          (I)  Slurry of suspended particulates in water
              (a)    Barge

              (b)    Pipeline
              (c)    Truck

              (d)    Rail
                                     6-56

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        (2)  Dry collected particulates
            (a)    Truck
            (b)    Rail
            (c)    Front-end loader
            (d)    Conveying system
            (e)    Barge
    C.  Treatment
        (1)  Slurry of suspended particulate in water
            (a)    Sedimentation
            (b)    Filtration
            (c)    Flotation
            (d)    Thickening; wet combustion
            (e)    Lagoons and drying beds
            (f)    Vacuum filtration
            (g)    Centrifugation; incineration
            (h)    Neutralization
        (2)  Dry collected material
            (a)    Compressing
            (b)    Wetting
    D.  Final  Disposition
        (1)  Landfill
            (a)    Public or private disposal sites
            (b)    Quarry
            (c)    Evacuated coal mine
        (2)  Lagoon
        (3)  Dump at sea
    The arrangement of these elements  in an overall disposal scheme is
shown in Figure 6-25.   This flow diagram shows the movement of the collected
material through various stages  toward final disposal.
                                   6-57

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en
oo
                             PROCESS
                                      H20
                                                            •H2O-
                                                 PRODUCT-
                                                    COLLECTION
                                                     EQUIPMENT
                                                      STORAGE
•H20-
                                                                 TRANSPORT
                                                                  METHOD
                                                            STORAGE
    TREATMENT
    OPERATION
 STORAGE
CONVERSION
    TO
 SALEABLE
 PRODUCT
                                                              DISPOSITION OF UNUSABLE MATERIAL
                      Figure 6-25. Flow diagram for disposal of collected participate material from air pollution control equipment.

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    Environmental factors such as space, utilities, disposal facilities,
and the desired form of collected waste material usually have an important
bearing on the selection of a disposal system compatible with a specific  type
of particulate pollution control equipment.  Therefore,  a specific type of
particulate pollution control equipment may not always  call for the same waste
disposal system.
fi. 8.3 Disposal Cost for Discarded Material
    Table 6-9 describes various  disposal systems and the related costs
within specific industries.   Each system listed is specifically designed to cope
with the disposal problem and available facilities of the individual plant shown.
Therefore,  drawing general conclusions  about the relative costs of systems
listed in the table would be erroneous.  The disposal costs  shown include
capital charges and costs for labor and material.  The  disposal cost per ton
will be higher the smaller the quantity  of material, because capital charges
for investment in facilities will remain the same regardless of quantity.
     Fly ash, a residue from the combustion of coal and residual oil, probably
is the most common material collected in emission control systems.   An
estimated 20  million tons of fly ash was produced in the United States in 1965.
                                                           12
Only 3 percent of this total was sold as a marketable product.    If the cost for
discarding the remaining 97  percent of the fly ash as unusable waste were $1. 00
per ton or more,  this would represent  a  total cost of $20 million or more.  Based
on the data in Table 6-9, a cost of $1. 00 per ton is a typical unit cost.
    In certain situations,  the disposal cost of fly ash  can be a major portion
of the total annualized cost for a complete pollution control system (including
disposal facilities).  For example, the disposal costs can be as high as 80
percent of the total annualized cost for an emission control system with  older
electrostatic precipitators which are no longer depreciated.  The disposal cost
still can be as high as 50 percent for similar systems with  newly installed
electrostatic precipitators,  which usually have high depreciation charges.
                                    6-59

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Table 6-9.  COSTS OF SPECIFIC DISPOSAL SYSTEMS
Industry
Power generation
Power generation
Power generation
Power generation
Power generation
Power generation
Power generation
for chemical plant
Power generation
for chemical plant
Chemical
Chemical
Power generation
for pulp and paper
Gray iron
foundry
Petroleum
refining
Petroleum
refining
Petroleum
refining
Petroleum
refining
Petroleum
refining
Portland
cement
Soaps and de-
tergents
Collected material
Fly ash
Fly ash
Fly ash
Fly ash
Fly ash
Fly ash
Fly ash
Fly ash
Weak acid {large
volume)
Fly ash
Cupola dust
Non-dewatered
sludge
Dewatered
sludge
Sludge, filter cake,
oily solids
Oily solids
Catalyst fines
Waste dust
Suspended solids
Treatment
Sedimentation


Form pellets
Form slurry
Wetted
Sedimentation

Slurry (100,000
gal /day)
Sedimentation
Water
clarification




Slight Wetting

Transport
Pipeline
Truck
Truck
Vacuum sys-
tem, truck,
barge
Pipeline
Pneumatic
pipeline
truck
Pipeline
Truck
Barge
Barge
Pipeline
Sediment
by truck
Contract
hauling
Contract
hauling
Truck
Barge
Contract
hauling
Conveyor,
truck
Pipeline
Storage
Settling
pond
Mound
Mound
Transfer
bins, stor-
age silo
Settling
pond
Storage
silo

Silos
Tank
Tank

Dempster
dump




Bins

Final
Disposal
Landfill
(Sediment)
Landfill
City dump
Landfill
or dump
at sea
Landfill
(Sediment)
Landfill
Lagoon
Landfill
Dump at
sea
Dump at
sea
Lagoon
Landfill
Landfill
Landfill
In-plant
landfill
Dump at
sea
Landfill
Landfill
Municipal
treatment
plant
Cost estimate,
dollars/ton
0.75
0.55
1.10
2.00
2.00
2.00
1.60
0.90
3.00
1.00
2.30
1.40
4.75
2.50
20.00
7.50
2.75
1.05
2.50
                    6-60

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    Table 6-10 shows a summary of fly ash disposal costs for material col-
lected from electrostatic precipitators and mechanical collectors installed in
electric utilities and is taken from a recent survey. 13 This survey analyzed
the costs of disposal, the sales, and the uses of fly ash collected by 54 electric
utilities and reported an average disposal cost of  $0.74 per ton.  Analysis of
the data for individual utilities revealed that disposal cost is partly a function
of geographical location.  The average disposal cost per ton in the heavily-
populated East is higher than that reported elsewhere.

      Table 6-10.  COST OF ASH DISPOSAL BY ELECTRIC UTILITIES
Type and collection method
Fly ash (mechanical collector)
Fly ash (electrostatic precipitator)
Bottom ash
Disposal costs, dollars/ton
Low
$0.15
0.12
0.15
Medium
$0.59
0.77
1.04
High
$1.67
1.74
4.76
6.8.4 Return of Collected Material to the Process
    In some process operations, collected material is sufficiently valuable to
warrant its return to the process.  In these situations, the value of the recovered
material can partially or wholly pay for the collection equipment. In many ap-
plications, however, the cost for the high efficiency control systems necessary
to achieve desired ambient air quality will be greater than the revenue returned
for recovery of the material collected.  This is illustrated by the hypothetical
example in Figure 6-26.
    The figure shows a linear relationship between collection efficiency and
value of material recovered.  It also shows a curvilinear  relationship between
collection efficiency and related equipment costs.  Up to the break-even point D
(which corresponds to an efficiency of about  97 percent), the recovery value
°f material collected is greater than the cost to achieve the recovery.
  Ml-716 0-69-30
                                    6-61

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O5
                             ASSUME: CFM, GRAIN LOADING CONSTANT
                        O
                        O
                                                                  PROFIT MAXIMUM
                                   VALUE OF MATERIAL
                                   RECOVERED
                                                                                                         BREAK  EVEN   F
                                                                                                         POINT
                                                COST OF EQUIPMENT
                                               /  /I /  /  /  /I/  /
                                                   70
75          80          85

       EFFICIENCY, %
                                                                                                   90
95
                                                                                                                          100
                                                  Figure 6-26.Theoretical effect of dust value on control cost.

-------
Equipment designed for efficiencies greater than 97 percent, according to the
curve,  would have a higher cost than the potential recovery value.
    If profit were the only control incentive, 85 percent collection efficiency
would achieve the maximum profit, as illustrated by the profit line AB.  If
however, emission standards made 97 percent collection efficiency necessary,
no profit would be achieved at the break-even point D.   For collection efficiency
greater than 97 percent,  equipment costs would  exceed recovery costs.  At
99 percent efficiency, for example,  control  equipment would cost the amount
shown by FH, and the value  recovered would be  the amount GH.  The difference
FG would represent an expense and can be considered  as the net control cost.
     The cement industry is one example where return of the collected
material to the process is commonly practiced.  A survey conducted in 1956
shows that, out of 383 kilns,  a total of 349 return collected dust to the pro-
    14
cess.   Not only does recovered dust, in such situations, have value as a
raw material, but its recovery also reduces disposal costs and decreases
other related costs for the preparation of raw materials used in the process.
6.8.5 Recovery of Material  for Sale
     Although material collected by air pollution control equipment may be
unsuitable for return to a process within the plant, it may be suitable for
another manufacturing activity.  Hence,  it may be treated  and sold to another
firm that can use the material.  Untreated pulverized fly ash, for example,
which cannot be reused in a  furnace,  can be sold as a raw  material to a
cement manufacturer.  It also can be used as a soil conditioner,  or  as  an
asphalt filler, or as landfill material.  For  such uses,  pulverized fly ash
requires no treatment and can be sold for as much as $1. 00 per ton.  Pul-
verized fly ash which is treated can yield an even more valuable  product.
A limited number of utilities,  for example,  sinter pulverized fly ash to
Produce a lightweight aggregate which can be used to manufacture bricks and
lightweight building blocks.
                                   6-63

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      At the present time, however, the sale of raw or treated collected
process material usually does not offer an opportunity to offset control costs
to a significant extent.
                                    6-64

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                      REFERENCES FOR SECTION 6

 1,  Wilson, E. L.  "Statement Presented at Hearings before the Subcommittee
    on Air and Water Pollution of the Committee on Public Works,  U.S.
    Senate, 90th Congress, First Session on S.  780, Part4."  U.S. Govern-
    ment Printing Office, Washington, B.C., 1967, p.  2632.

 2.  Danielson, John A. (ed.)  "Air Pollution Engineering Manual. "  U.S.
    Dept. of Health, Education, and Welfare, National Center for Air Pollution
    Control, Cincinnati, Ohio, PHS-Pub-999-AP-40, 1967.

 3.  "Air Pollution Manual - Part II - Control Equipment."  American Industrial
    Hygiene Association, Detroit, Michigan, 1968.

 4.  "Census of Manufacture 1963."  Volumes 1, 2, and 3, U.S. Bureau of
    Census.

 5.  Ridker, Ronald G.  "Economic Costs of Air Pollution. "  Frederick A.
    Praeger Publishers, New York, 1967.

 6.  Semrau, Konrad T.  "Dust Scrubber Design - A Critique on the State of
    the Art."  J. Air Pollution Control Assoc. ,  Vol. 13,  pp. 587-594,
    Dec. 1963.

 7.  Sandomirsky,  Alex G. , Benforado, D. M.,  Grames,  L. D., and Pauletta,
    C. E.  "Fume Control in Rubber Processing by Direct-Flame Incinera-
    tion."  J.  Air Pollution Control Assoc. , Vol.  16, pp. 673-676, Dec.  1966.

 8.  Hein, Glen M.  "Odor Control by Catalytic and High-Temperature Oxida-
    tion." Annals, New York Academy of Science, 116(2):656-662, July 1964.

 9.  "North American Combustion Handbook. " 1st edition, North American
    Manufacturing Co. ,  Cleveland, Ohio.

10.  Decker, L. D.  "Odor Control by Incineration. " (Presented at the
    Meeting of the Middle States Air Pollution Control Association Section,
    Nov. 1965.)

U.  Eckenfelder, W. Wesley.   "Industrial Water Pollution Control. "  McGraw-
    Hill, New York, 1966, p.  4.
                                  6-65

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12.  Gambs, Gerard C.  "Report on Flyash in England,  Europe, and Soviet
     Union."  Research Div. Library,  Consolidated Coal Co. ,  July 1,
     1966, p. 1.

13.  "53 Utilities Give Data on Flyash Sales and Uses. "  Electrical World,
     Vol. 168, pp.  61-63, Aug. 21, 1967.

14.  Kannewurt, A. S. and Clausen, C. F. "1956 Survey, Portland Cement
     Association."  Report MP-54, Chicago,  May 1958,  p. 37.

15.  Gale, W.  M.   "Technical Aspects of a Modern Cement Plant. "  Clean
     Air, 1(2):7-13, 1967.
                                 6-66

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    7. CURRENT RESEARCH IN CONTROL OF PARTICULATE MATTER




    A total of 501 identified projects relating to air pollution research were




active in 1966.   Of these projects, only 16 related directly to research on the




control of particulate matter.  Five of the 16 projects were financed by the




Federal Government (both as in-house and contract projects),  and the rest




were performed by control equipment manufacturers,  public utilities,  and




some of the larger basic industries.




    To provide the research and development necessary to keep pace with




the particulate pollution problem and the increasing requirements for improved




control, the National Air Pollution Control Administration (NAPCA) has under-




taken a series of pollution device development system studies.  These studies




will be conducted by industrial organizations under contract to NAPCA.  Their




purpose is to systematically identify and carry out research needed to improve




the performance and extend the application of major pollution control equip-




ment.




    These studies include research on high-temperature bag filtration directed




toward increasing bag life and determining the mechanisms that cause bags to
                                    7-1

-------
        2
rupture.   Additional studies are under way to determine performance under


various dust inlet feed modes and the effects on filtration of particle size


distribution along the filter bag.  In another study, the potential of fabric


filters for  controlling fly ash emissions from power plants burning pulverized

                     3
coal was investigated.


      Combustion research at the NAPCA includes an evaluation of emissions

                               4
from a pilot trench incinerator.   Laboratory investigations into the effects


of fuel additives, burner operation, and burner modifications on particulate

                                                   5
emissions  from oil combustion are being conducted.


      Five  basic types of wet scrubbers are being studied in an attempt to re-


late collection efficiency to cost of operation,  to improve scrubber effectiveness


in the control of incinerator emissions, and to evaluate the scrubber as a gas-


liquid contactor.   A 100-to 500-cfm test unit was constructed to carry out

                    £
these investigations.


      Contract studies currently being conducted by NAPCA pertain to systems


analysis studies covering both theory and application of the various modes of


control of particulate matter.


      A research program in the field of high-temperature electrostatic pre-


cipitation is being conducted by the U.  S. Bureau of Mines.   Data from a pilot


plant at which fly ash is collected show collection efficiencies in the 90 to 98

                                                                   7
percent range at a temperature of 1460°F and a pressure of 80 psig.
                                      7-2

-------
    Research by universities and manufacturers is under way to determine



the effects of sparking rates and gas and dust flow on collection efficiencies


                           8,9
of electrostatic precipitators.



    Wet scrubber research includes a study of the parameters affecting



particle collection in a venturi scrubber    and removal of particles by foam



in a sieve plate column.     Investigations into the performance parameters of


                                           12 13
the flooded disc  scrubber have been reported.   '


    Cloth filtration application studies by private companies are under way



enlarge oil- and coal-fired steam generators   '   and sinter plants.



    Additional research is being conducted by equipment manufacturers in an



effort to improve technology on the collection of particulate matter.



    The October 1968 issue of the Journal of the Air  Pollution Control



Association is devoted entirely to current aerosol research progress reports.
                                    7-3

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                       REFERENCES FOR SECTION 7

 1.  "Guide to Research in Air Pollution. "  U. S. Dept. of Health, Education,
     and Welfare, National Center for Air Pollution Control, Washington, D. C,
     PHS-Pub-981,  1966.

 2.  Spaite, P. W. and Harrington,  R. E.  "Endurance of Fiberglass Filter
     Fabrics." J. Air Pollution Control Assoc. ,  1/7(5):310-313,  May 1967.

 3.  Borgwardt, R. H., Harrington, R. E., and Spaite, P. W.   "Filtration
     Characteristics of Fly Ash from a Pulverized Coal Fired Power Plant."
     J. Air Pollution Control Assoc. , 1_8(6):387-390, June 1960.   (Presented
     at the 60th Annual Meeting of the Air Pollution Control Association,
     Cleveland, Ohio,  June 1967, Paper No. 67-35.)

 4.  Burckle, J. O. , Dorsey, J. A. , and Riley,  B. T.  "The Effects of the
     Operating Variables and the Refuse Types on the Emissions  from a
     Pilot Scale Trench Incinerator." In:  Proceedings of the 1968 National
     Incinerator Conference, American Society of Mechanical Engineers,
     New York, pp. 34-41.

 5.  Wasser,  J. H., Hangebrauck, R. P.,  and Schwartz, A. J.  "Effect of
     Air-Fuel Stoichiometry  on Air Pollutant Emissions from an  Oil Fired
     Test Furnace." J. Air  Pollution Control Assoc. ,  3L8(5):332-337,  May
     1968.

 6.  Private communication from Chief, Control Equipment Research Unit,
     Process Control Engineering Program, National Center for  Air Pollution
     Control,  1968.

 7.  Shale,  C. C.  "Progress in High Temperature Electrostatic Precipita-
     tion."  J. Air Pollution  Control Assoc. , 1.7(3):159-160,  March 1967.

 8.  Penney, G. W.  "Electrostatic  Precipitation Studies at Carnegie Institute
     of Technology." J. Air Pollution Control Assoc. , Vol.  17,  pp. 588-589,
     Sept. 1967.

 9.  Robinson, M.  "Electric Wind Turbulence in Electrostatic Precipitation. "
     J. Air  Pollution Control Assoc. , Vol.  17, pp. 605-606, Sept. 1967.

10.  Theodore,  L.  "A  Study of Venturi Scrubbers." J. Air Pollution Control
     Assoc., r7(9):598-599,  Sept. 1967.
                                    7-4

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11.  Taheri,  M. and Calvert, S.  "Removal of Small Particles from Air by
    Foam in a Sieve-Plate Column." J. Air Pollution Control Assoc.,  18(4):
    240-245, April 1968.

12.  Walker, A. B. and Hall, R.  M.  "Operating Experience with a Flooded
    Disc Scrubber—A New Variable Throat Orifice Contactor." J. Air
    Pollution Control Assoc. ,  JL8(5):319-323,  May 1968.

13.  Orr, C., Burson, J. H., and Keng, E. Y.  H.  "Aerosol Research in
    Chemical Engineering at Georgia Tech. "  J. Air Pollution Control
    Assoc., 1/7(9):590-592, Sept. 1967.

14.  Felgar,  D. N. and Ballard,  W. E.   "First Years Experience with Full-
    Scale Filterhouse at Alamitos Bag Filterhouse." Southern California
    Edison Company,  Los Angeles, 1965.

15.  Smith, R. I.  "Baghouse Collectors on Oil and Coal Fired Steam Genera-
    ting Plants." Public Electric and Gas Company, Newark, New Jersey.
    (Unpublished.)

16.  Smith, J.  H.  "Testing Feasibility  of Baghouse on Windbox End of
    Sinter Plant. " Kaiser Steel  Corp. ,  Fontana, California.  (Unpublished.)
                                  7-5

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                         8.  BIBLIOGRAPHY
The following bibliography contains a broad listing of articles pertaining to
particulate air pollution control.  The articles are arranged according to spe-
cific source categories.  The following arrangement of categories is intended
to aid the reader in locating articles in specific areas.
INTERNAL COMBUSTION ENGINES
    Piston Engines - Gasoline - Automotive Type            8-3
    Piston Engines - Diesel                                8-6

HEAT AND POWER SOURCES
    Coal Combustion                                       8-8
    Oil Combustion                                       8-14
    Gas Combustion                                       8-17
    Nuclear Power                                        8-18

REFUSE DISPOSAL SOURCES
    Open Burning                                         8-18
    Municipal Incinerators                                8-19
    On-Site Incinerators                                   8-21
    Other Disposal Methods                               8-24

METALLURGICAL PROCESS SOURCES
    Aluminum                                            8-26
    Copper                                               8-26
    Iron and Steel                                         8-27
    Lead                                                 8-32
    Zinc                                                 8-32

CHEMICAL PROCESS SOURCES
    Mineral Acids                                         8-33
    Pulp and Paper                                       8-35
    Oil Refineries                                         8-36
    Paint and Varnish                                     8-37
    Plastics and Resins                                   8-37
    Other Chemicals                                      8-38
                                   5-1

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                     8.  BIBLIOGRAPHY (Continued)
MINERAL PROCESS SOURCES
     Bituminous Concrete Manufacturing                   8-39
     Calcium Carbide                                    8-40
     Cement                                             8-40
     Concrete Batch Plants                                8-41
     Ceramic, Clay,  and Refractories                     8-41
     Glass and Frit                                      8-41
     Gypsum                                             8-42
     Lime                                               8-42
     Pits and Quarries                                    8-42
     Other                                               8-43

FOOD AND AGRICULTURAL SOURCES
     Coffee Roasting                                      8-44
     Cotton Ginning                                      8-44
     Feed and Grain                                      8-44
     Fish Meal Processing                                8-45
     Other                                               8-45
                                  3-2

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                   INTERNAL COMBUSTION ENGINES

PISTON ENGINES - GASOLINE - AUTOMOTIVE TYPE

Beckman, E. W. , Fagley, W.  S. ,  and Sarto, J. O.  "The  Cleaner Air Package -
Exhaust Emission Control by Chrysler. " In: Hearings before the Subcommittee
on Air and Water Pollution of the Committee on Public Works,  U.S. Senate,
90th Congress,  1st Session,  Feb. 13-14 and 20-21, 1967, pp. 411-424.

Bush, A.  F. , Glater,  R.  A. , Dyer,  J. , and Richards,  G.   "The Effects of
Engine Exhaust  on the Atmosphere When Automobiles Are Equipped with
Afterburners."  Univ. of  Calif. Report 62-63, Dept. of Engineering,  Los
Angeles,  Dec.  1962,  38 pp.

Derndinger, Hans-Otto.   "Motor Vehicle Engines."  [Kraftfahrzeugmotoren. ]
VDI (Ver. Deut.  Ingr.) Z.  (Duesseldorf), 108(19):842-845, July 1966.  (Text
in German.)

Ebersole, G.  D. and McReynolds,  L. A.  "An Evaluation of Automobile Total
Hydrocarbon Emissions." In:  Vehicle Emissions,  Part II, SAE Progress in
Technology  Series, Society of Automotive Engineers, New York, 1966, Vol. 12,
pp. 413-428.  (Presented at Mid-Year Meeting,  Society of Automotive Engineers,
Detroit, Michigan, June 6-10,  1966, Paper  66048.)

Eldib,  I.  A. "Problems in Air Pollution and Their Solutions with New Tech-
nology."  In:  Technical and Social Problems of Air Pollution, Symposium of
Metropolitan Engineers Council on Air Resources, New York, 1966, pp. 7-28.

Fiala, E. and Zeschmann, E.  G.  "The Exhaust Gas Problem of Motor Vehicles,
Parti."  [Zum Abgasproblem der Strassenfahrzeuge, Teil  1. ]  Automobiltech.
Z.  (Stuttgart),  67(9):302-308,  Sept.  1965.

Fiala, E. and Zeschmann, E.  G.  "The Exhaust Gas Problem of Motor Vehicles,
Part II. "  [Zum Abgasproblem der Strassenfahrzeuge, Teil 2.]  Automobiltech.
Z.  (Stuttgart),  67_(12):419-422, Dec.  1965.

"The Control of Automobile Emissions (Ford Crankcase  Emissions Control
System, Ford Thermactor System for Exhaust Control). "  Ford Motor Co. ,
Dearborn, Michigan,  1966, 6 pp.

Gardner,  J. W.   "Automotive Air Pollution. "  3rd Report of the Secretary of
Health, Education,  and Welfare to the U. S.  Congress Pursuant to Public Law
88-206, The Clean Air Act, 89th Congress,  2nd Session, Document No. 83,
March 25, 1966, 17 pp.
                                   3-3

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Grant, E. P. and Nissen, W.  E.   "California's Program for Motor Vehicle
Emission Control."  In:  Proceedings, International Clean Air Congress,
Parti, London,  1966,  Paper VI/19, pp.  210-212.

Heinen, C. M.   "The Development and Manufacture of Control Equipment. "
Arch. Environ.  Health, 16(1):98-104, Jan. 1968.

Hirao, O.  "Problems  of Air Pollution Due to Vehicle Emission Gases. "
J.  Japan Soc. of Mechanical Engineers (Tokyo), 69(575): 1568-1572, 1966.

Hunigen, E. , Jaskulla, N. ,  and Wettig, K.  "The Reduction of Carcinogenic
Contaminants in Exhaust Gases of  Petrol Engines through Fuel Additives and
Choice of Lubricants." In:  Proceedings, International Clean Air Congress,
Part I, London,  1966,  Paper VI/12, pp.  191-193.

Jackson, M. W.  "Effects of Some Engine Variables and Control Systems on
Composition and Reactivity of Exhaust Hydrocarbons. "  In:  Vehicle Emissions,
Part II, SAE Progress in Technology Series, Vol. 12, Society of Automotive
Engineers, New York,  1966, pp. 241-247.

Jackson, W. E.  "Air  Pollution from Automobiles in Philadelphia. " Preprint.
(Presented at the 58th Annual Meeting of the Air Pollution Control Association,
Toronto, Canada, June 20-24, 1965,  Paper 65-137.)

Jensen, D. A.  "Sources and Kinds of Contaminants from Motor Vehicles -
Informative  Report No. 4. "  J. Air Pollution Control Assoc. , _14(8):327-328,
Aug. 1964.

Jensen, D. A.  "Separating  Fact from Fiction in Auto Smog Control. " Arch.
Environ. Health, M(l):150-154, Jan. 1967.   (Presented at the American
Medical Association  Air Pollution  Medical Research Conference, Los Angeles,
March 2-4,  1966.)

Kopa, R.  D. , Tribus,  M. ,  Scope,  S. , and Treat,  R.  "Exhaust Control
Devices: An Investigation of Exhaust 'Scrubbing' Devices. "  In:  1st Report
of Air Pollution  Studies, Univ. of Calif, at Los Angeles, Dept. of Engineering,
July 1955, 22 pp.

Larsen,  R.  I.   "Motor Vehicle Emissions and Their Effects. " Public Health
Rept. , 77(ll):963-969,  Nov. 1962.

Lohner,  Kurt, Muller, Herbert, and Zender,  W.  "About the Process Tech-
nique for the Combustion of  Exhaust Gases in Gasoline Engines in Stationary
                                     8-4

-------
Operations."  [Uber die Verfahrenstechnik der Nachverbrennung der Abgase von
Ottomotoren bei stationarem Betrieb. ]  VDI  (Ver.  Deut.  Ingr.)  Z.  (Duesseldorf),
109/31): 1488,  Nov. 1967.  (Text in German.)

Ludwig, J. H.  "The Vehicle Pollution Problem." Preprint.  (Presented at the
American Public Power Association Conference,  Denver, Colo.,  May 8-11,
1967.)

Ludwig, J. H.  "Progress in Control of Vehicle Emissions."  J. Sanit. Eng.
Div., Am.  Soc. Civil Engrs. , 93(SA-4):73-79, Aug.  1967.

Meurer,  S.  "Change in the  Concept of Mixture Formation and Combustion in
Diesel Engine. "  [Der Wan del in der Vorstellung von Ablauf der Gemisch-
bildung und Verbrennung im Dieselmotor. ]  Motortech. Z. ,  27(3):131-139,
March 1966.

Morris, J. P. and Calonge, A. B.   "Contamination Generation of Internal
Combustion Engines. " Preprint.  (Presented at the 4th Annual Technical
Meeting and Exhibit, American Association for Contamination Control, Miami
Beach, Florida,  May 25-28,  1965.)

Ridgway, Stuart L.  and Lair, John C.  "Automotive Air  Pollution:  A System
Approach." J.  Air Pollution Control Assoc. , 1_0(4):336-340, Aug.  1960.

Rispler,  L. and Ross, C. R.  "Ventilation for Engine Exhaust Gases. "
Occupational Health Rev. , 17(4): 19-22, 1965.

Rose,  A. H.  "Summary Report of Vehicular Emissions and Their Control. "
Preprint.   (Presented at the Winter Annual  Meeting,  American Society of
Mechanical Engineers, Chicago, Illinois, Nov. 1965.)

Schenk, Rudolf, Flory,  Fritz, and Hofmann, Hans.  "Reduction of Harmful
Exhaust Gas Emissions in Gasoline Motors by Means of Suction-Tube Gasoline
Injection. " [Herabsetzung der schadlichen Abgasemissionen bei Ottomotoren
durch Saugrohr-Benzineinspritzung. ]  Motortech.  Z.  (Stuttgart), _28(10):399-
402, Oct.  1967.  (Text in German.)

Starkman, E.  S.   "Engine Generated Air  Pollution - A Study of Source and
Severity."  Preprint.  (Presented at Federal International Des Societes
Ingenieures Techniques de 1'Automobile,  Germany, June  15,  1966.)

Varchavski, I. L.  "Some Theoretical Problems of Providing Less Toxic
Operation of Automobile Engines. "  Proceedings of the International Clean Air
Egress, Parti, London, 1966, p.  212.   (Unpublished.)
                                    3-5

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Yamaki,  N.   "Several Problems on Control of Motor Vehicle Exhaust Pollution.
J. Japan Petroleum Inst. (Tokyo), 1(9):682-696, Sept.  1965.   (Text in Japanese.

PISTON ENGINES - DIESEL

Braubacher,  M. L.  "Reduction of Diesel Smoke in California. "  Preprint.
(Presented at the West Coast Meeting,  Society of Automotive Engineers,  Los
Angeles, California, Aug. 8-11, 1966, Paper 660548.)

Chittawadgi,  B.  S. and Dave, N. R.  "Reducing Smoke in Diesel Exhaust
Gases."  Indian Eastern Engr.  (Bombay), l£9(5):221-225, May 1967.

Fawell, H. D.  "Road Vehicle Pollution - Black Smoke - Some Causes and
Possible Method of Control. "  In:  Proceedings, Clean  Air Conference,
Harrogate, England, 1964, pp.  117-126.

Glover, I.  "The Fuel Additive Approach Towards  the Alleviation of the
Nuisance of Diesel Smoke. " J. Inst. Petrol., 52(509):  137-160, May 1966.

Golothan, D.  W.  "The Use of a Fuel Additive to Control Diesel Exhaust
Smoke: Service Performance and Marketing Experience. " Proceedings,
International  Clean Air Congress,  Parti, London, 1966, pp. 163-167,
Paper VI/13.

Grant, E. P. and Nissen, W. E.  "California's Program for Motor Vehicle
Emission Control. "  Proceedings,  International Clean Air Congress,  London,
1966, pp. 210-212, Paper VI/9.

Groebler, H.  "Exhaust Gas Washing and Noise Absorbing Device for Diesel
Motors." [Auspuffgaswasch- und Larmschluckgerat fuer Dieselmotoren. ]

Hedlund, Folke, Ekberg, Gustav, Mortstedt,  Sten-Erik,  and As lander, Alle.
"Diesel Exhaust Gases.  Investigation with  Proposals for Action. " Communica-
tions Department,  Stockholm,  Sweden, Guidance Group Concerning Develop-
ment Work in the Field of Motor Vehicle  Exhaust Gas,  Sept.  1967.

Jensen, D. A.  "Separating Fact from  Fiction in Auto Smog Control. " Arch.
Env. Health,  14(1):150-154, Jan. 1967.  (Presented at  the American Medical
Association,  Air Pollution Medical Research  Conference, Los Angeles,
March 2-4, 1966.)

Jensen, D. A.  "Sources and Kinds of Contaminants from Motor Vehicles,
Informative Report No. 4. "  J.  Air Pollution  Control Assoc. , _14(8):327-328,
Aug. 1964.

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Johnson, K. R.  "The Control of Smoke Emission from Diesel Engine Vehicles."
lv  The Implications of Air Pollution Control, Vol. 1.  National Physical
Research Laboratory,  Council for Scientific and Industrial Research, Surban,
South Africa, 1964, pp. 2-1 - 2-16.

Ludwig,  J.  H.  "Seminar on Air Pollution by Motor Vehicles. " Preprint.
U.S. Public Health Service, Cincinnati, Ohio, 1967,  54 pp.

McConnell, G.  and Howells, H.  E.  "Diesel Fuel  Properties and Exhaust Gas-
Distant Relations ?"  Preprint.  (Presented at the Automotive Engineering
Congress,  Society of Automotive Engineers,  Detroit, Michigan, Jan.  9-13,
1967, Paper 670091.)

Meyer, W. E.  "Controlling Odor and Smoke from Diesel Exhaust. " In:
Proceedings, Sanitary Engineering Conference on Air Resources Planning and
Engineering, Pittsburgh,  Pa. , 1965, pp. 41-54.

Rao, T.  V.  L.   "Diesel Smoke.  "  J.  Inst. Engrs.  , 46(1):5-19, Sept. 1965.

Reed, L. E.  arid Wallin, S. C.  "Methods of Removing Smoke from the Exhaust
Gases of Diesel Engines. " In:   Proceedings, Harrogate  Conference, National
Society for Clean Air,  London,  England, 1960, pp. 3-7.

Rispler, L. and Ross, C. R.  "Ventilation for Engine Exhaust Gases. "
Occupational Health Rev. ,  17_(4): 19-22,  1965.

Rose, A. H.  "Summary Report of Vehicular Emissions  and Their  Control. "
Preprint.  (Presented at the Winter Annual Meeting,  American Society of
Mechanical Engineers,  Chicago, 111.,  Nov.  1965.)

Springer, K.  J. , Lepisto,  P. , and Wood, C.  "Investigation of Diesel Powered
Vehicle Odor and Smoke." Southwest Research Institute, San Antonio, Texas,
Proposal 10-4336A, Nov.  19,  1965, 46pp.

Springer, K.  J. "Investigation of Diesel Powered Vehicle Odor and Smoke. "
Southwest Research Institute,  San Antonio, Texas, March 26,  1967, 16pp.
(Monthly Progress Report 2, Feb.  15-March 15,  1967.)

Springer, K.  J.  "Investigation of Diesel Powered Vehicle Odor and Smoke—
Part 2." Southwest Research Institute,  San  Antonio,  Texas, May 3, 1967,
12PP. (Monthly Progress Report 3,  March  15-April 15,  1967.)
                                    3-7

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Springer,  K.  J.  "Investigation of Diesel Powered Vehicle Odor and Smoke-
Part 2. "  Southwest Research Institute,  San Antonio, Texas,  May 26, 1967,
12 pp.   (Monthly Progress Report 4, April 15-May 15, 1967.)

Springer,  K.  J.  "Investigation of Diesel Powered Vehicle Odor and Smoke-
Part 2."  Southwest Research Institute,  San Antonio, Texas,  July 1,  1967,
102 pp.  (Monthly Progress Report 5, May 15-June 15, 1967.)

Springer,  K.  J.  "Investigation of Diesel Powered Vehicle Odor and Smoke—
Part 2."  Southwest Research Institute,  San Antonio, Texas,  Aug.  1,  1967,
17 pp.   (Monthly Progress Report 6, June 15  - July 15,  1967.)

Springer,  K.  J.  "Investigation of Diesel Powered Vehicle Odor and Smoke—
Part 2."  Southwest Research Institute,  San Antonio, Texas,  Sept. 1, 1967,
184 pp.  (Monthly Progress Report 7.)

                       HEAT AND POWER SOURCES

COAL COMBUSTION

Barker, K. and MacFarlane, W. A.  "Fuel Selection and Utilization. " World
Health Organization Monograph Ser.  46  (Air Pollution),  1961, pp. 345-363.

Bins, R. V.  "Air Pollution Control System at Bay Shore Generating Plant of
the Toledo Edison  Company." Air Eng.  , 8_(5):20-22, 24, May 1966.

Borgwardt, R. H. , Harrington, R.  E. ,  and Spaite,  P. W.  "Filtration
Characteristics of Fly Ash from a Pulverized Coal-Fired Power Plant. " J.
Air Pollution Control  Assoc. , 18(6):387-390,  June 1968.  (Presented at the
60th Annual Meeting,  Air Pollution Control Association, Cleveland, Ohio,
June 11-16, 1967,  Paper 67-35.)

Bovier,  R. F.  "Sulfur-Smoke Removal  System. "  Preprint.  (Presented at
the 26th Annual American Power Conference, Chicago, 111. , April 16,  1964.)

Bovier,  R. F. , Tigges, A. J. , Verrochi, W. A. , and Lambert, W.  H.
"Solving a Valley Air  Pollution  Problem. "  Preprint.  (Presented at the 54th
Annual Meeting,  Air Pollution Control Association,  New York,  June  15, 1961.

"Sonic Smoke Collecting—Background Information. "  Braxton Corporation,
Medfield,  Mass. , April 1965, 86 pp.

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Burke, S. A. and Collins, K. E.  "The Performance of the B. C. U. R. A.
Fully-Automatic  Smokeless Stoker for Central Heating. " J. Inst.  Heating
Ventilating Engrs.  (London),  Vol. 34,  pp.  114-128, July 1966.

Cahill, William J. ,  Jr.  "Control of Participate  Emissions on Electric
Utilities Boilers. " In:  Proceedings, Metropolitan Engineers Council on Air
Resources Symposium on New Developments in Air Pollution Control,  New
York, Oct. 23, 1967, pp. 74-84.

Chamberlin,  R. L. and Moodie, G.   "What Price Industrial Gas Cleaning?"
In: Proceedings  of International Clean Air Congress,  Parti, London,  1966,
pp. 133-135.  (Paper V/7.)

Cuffe, S. T.  and Gerstle,  R. W.  "Emissions from Coal-Fired Power Plants:
A Comprehensive Summary. " Dept. of Health, Education,  and Welfare,
National Center for Air Pollution Control,  Cincinnati, Ohio, PHS-Pub-999-
AP-35,  1967, 26 pp.

Cuffe, S. T. , Gerstle,  R. W. ,  Orning, A. A., and Schwartz, C.  H.  "Air
Pollutant Emissions from Coal-Fired Power Plants,  Report No. 1." J. Air
Pollution Control Assoc. , _14(9):353-362, Sept. 1964.

Danielson, J.  A.   "Air Pollution Engineering Manual. "  Dept. of Health,
Education, and Welfare, National Center for Air Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40, 1967, 892pp.

Debrun, G.  "The Continuous Measurement of the Dust Content of the Com-
bustion Gases, at the Exit of the Dust Collectors in the Large Central Power
Stations of Electricite de  France. "  [La mesure en continu de 1'empoussiere-
ment des gaz de combustion a la sortie des depoussiereurs des  grandes
centrales thermiques E. D. F. ]  Pollut. Atmos. (Paris), _9(34):84-90, April -
June 1967.  (Text in French.)

"Dust Control Methods. "  Coal Age, 7_2(8):56-62, Aug. 1967.

Engelbrecht, H.  L.  "Electrostatic  Precipitators in Thermal Power Stations
Using Low Grade  Coal. "  Preprint.   (Presented at  the 28th Annual Meeting,
American Power Conference, April 26-28, 1966.)

Fernandas, J.  H. , Sensenbaugh,  J.  D. ,  and Peterson, D. G.   "Boiler
Emissions and Their Control. "  Preprint.  (Presented at the  Conference on
Air Pollution Control, Mexico City,  April  28,  1966, 19 pp.)

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Flodin,  C.  R. and Haaland, H. H.  "Some  Factors Affecting Fly-Ash Collector
Performance on Large Pulverized Fuel-Fired Boilers. " Air Repair, 5>(1):27-
32, May 1955.

Fournier, M.  and Jacquinot, P.  "Fight Against Atmospheric Pollution from
Domestic Furnaces, Control Measures  in Effect in the Special Protection
Zones in Paris during Winter of 1965-1966. "  [Lutte contre la pollution atmos-
pherique due aux foyers domestiques, controle exerce dans les zones de pro-
tection speciale  a Paris hiver 1965-1966.]  Pollut. Atmos.  (Paris), j)(34):91-
99, April - June 1967.   (Text in French.)

Gartrell, F.  E.   "Control of Air Pollution  from Large Thermal Power
Stations."  Rev. Soc. Roy. Beige Ingrs. Ind. (Brussels), No. 11, pp. 471-482,
Nov. 1966.

Gartrell, F.  E.  and Barber, J.  C.   "Pollution Control Interrelationships. "
Chem. Eng. Progr. , _62 (10): 44-47,  Oct. 1966.

George, R.  E. and Chass, R. L.  "Control of Contaminant Emission from
Fossil Fuel-Fired Boilers." Am. Chem.  Soc., Div. Fuel Chem. Preprints,
K>(l):31-56, 1966.  Also:  J. Air Pollution Control Assoc. , r7(6):392-395,
June 1967.

Gerstle, R.  W. , Cuffe, S. T. , Orning,  A.  A., and Schwartz,  C.  H.  "Air
Pollutant Emissions from Coal-Fired Power  Plants, Report No.  2."  J.  Air
Pollution Control Assoc. ,  l_5(2):59-64,  Feb.  1965.

Glensy, N.  "Mechanical Handling of Coal and Ash. "  Eng. Boiler House Rev.
(London), .81(6): 170-177, June 1966.

Goldberger, W.  M.  "Collection of Fly Ash in a Self-Agglomerating Fluidized-
Bed Coal Burner. " American Society of Mechanical Engineers, Report No. 67-
WA/FU-3,  United Engineering Center,  New York, 1967, 16pp.

Gosselin, A. E. , Jr. and Lemon, L. W.  "Bag Filterhouse Pilot Installation
on a Coal-Fired Boiler, Preliminary Report  and Objectives. "  Proceedings,
American Power Conference, Vol. 28, pp.  534-545, 1966.

Griswold, S. S.   "Control of Stationary  Sources. " Technical  Progress  Report,
Vol. 1,  Los Angeles County Air Pollution Control  District,  April 1960,  179 pp.

"Guide to Air  Pollution Control Methods. "  Modern Power  Eng. ,  ^0(6):63-78,
June 1966.
                                    8-10

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Hangebrauck, R. P. ,  von Lehmden, D.  J. ,  and Meeker, J.  E.  "Sources of
polynuclear Hydrocarbons in the Atmosphere. "  Dept. of Health, Education,
andWelfare, National Center for Air Pollution Control,  Cincinnati, Ohio,
PHS-Pub-999-AP-33, 1967, 44pp.

"Informative Air Pollution Problems in  Fly Ash Sintering Plant, Informative
Report No. 6." J. Air Pollution Control Assoc. , _15(3): 123-124,  March 1965.

Katz, J.  "The Effective  Collection of Fly Ash at Pulverized Coal-Fired
Plants." J. Air Pollution Control Assoc. , Vol. 15, pp.  525-528, Nov.  1965.
(Presented at 58th Annual Meeting, Air  Pollution Control Association,  Toronto,
Canada, June 20-24, 1965, Paper 65-131.)

King, D. T.  "Dust Collection in Coal Preparation Plants. "  Mining Eng. ,
   :64-69, Aug. 1967.
Kirov, N. Y.  "Efficient Combustion - The Control of Air Pollution at the
Source."  In: Proceedings, Clean Air  Conference, Univ. of New South Wales,
Paper 22, 1962,  22 pp.

Kloepper, D. L.  , Rogers, T. F. , Wright, C. H. ,  and Bull, W.  C.  "Solvent
Processing of Coal to Produce a De-Ashed Product. " Gulf Oil Corp. ,
Spencer Chemical Div. ,  Merriam,  Kansas, Research &  Development Report
9, Feb. 27,  1965, 469 pp.

Laroche,  M.  "Special Fuels: The Parts Played by Charbonnages de France
in the Fight Against Air Pollution. "  [Combustibles speciaux la participation
des Charbonnages de France a la lutte centre la pollution atmospherique. ]  In:
Proceedings, International Clean Air Congress, Parti,  London, 1966,
pp, 64-66. (Paper 111/9.)

"Layout and Application of Overfire  Jets for Smoke Control in Coal-Fired
Furnaces."  National Coal Association, Washington,  D.  C., Dec.  1962,
18pp.

leavitt, J. M.  "Air Pollution Studies and  Control:  TVA Coal Electric
Generating Plants."  In:  Proceedings, Sanitary Water Resources Engineering
Conference,  Vanderbilt Univ. ,  Nashville,  Tennessee, 1965, pp.  200-207.

Lock, A. E.  "Reduction of Atmospheric Pollution by Efficient Combustion
Control." Plant  Engineering (London), _11(5):305-309, May 1967.

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Magnus,  M. N.  "History of Fly Ash Collection at the South Charleston Plant."
J.  Air Pollution Control Assoc. ,  15(4): 149-154, April 1965.

Martin, R.  "Generator Can Double as Anti-Pollution Weapon. "  Petro/Chem.
Engr. ,_38(9):52, 55-56, Aug.  1966.

"Modern Dust Collection for Coal-Fired Industrial Heating and Power Plants. "
A. LA. No.  34-C,  National Coal Association,  Washington, D. C. ,  Sept. 1961,
14 pp.

Moore, W. W.  "Reduction in Ambient Air Concentration of Fly-Ash—Present
and Future Prospects. "  In:  Proceedings, 3rd National Conference on Air
Pollution, Washington, D.  C. , 1966, pp.  170-178.

Plumley,  A.  L. , Whiddon, O. D. , Shutko, F.  W. , and Jonakin,  J.  "Removal
of SO2 and Dust from Stack Gases. "  Combustion, _40(1): 16-23, July 1968.
(Presented at the American Power Conference, Chicago,  Illinois, April 25-27,
1967.)

Pollock,  W. A. , Frieling, G. , and Tomany, J. P.   "Sulfur Dioxide and Fly
Ash Removal from Coal Burning Power Plants. "  Air Eng. , £(9):24-28,
Sept.  1967.

"Pollution of the Atmosphere in the Detroit River Area. " International Joint
Commission, United States and Canada, 1960,  241 pp.

Pottinger, J. F.  "The Collection of Difficult  Materials by Electrostatic
Precipitation." Australian Chem. Process. Eng.  (Sydney), 20(2): 17-23,
Feb.  1967.

Pursglove, J. , Jr.   "Fly Ash in 1980."  Coal  Age, 72(8):84-85, Aug.  1967.

Quack, R. "Dust and Gas  Emission from Thermal Power Stations. "   [Die
staub- und gasformigen Emissionen von Warmekraftwerken. ]  Brennstoff-
Warme-Kraft, j.8(10):479-486, Oct. 1966.

"Report on Smoke Performance of Vessels Plying the Detroit River During
Navigation Season 1964. "  International Joint Commission, Detroit River Area,
Technical Advisory Board on Air Pollution, March 1965,  148  pp.

"Report on Sulfur Dioxide and Fly Ash Emissions from  Electric Utility Boilers.
Public Service  Electric and Gas Co. ,  Trenton, N. J. , Jersey Central Power
and Light Co. ,  New Jersey Power & Light Co. , Morristown; and Atlantic City
Electric  Co.,  N.  J. ,  Feb. 24, 1967,  67 pp.
                                      8-12

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"Restricting Dust Emission from Forced-Draft Boiler Installations,  Capacity
10 ton/hr and Over, Hard-Coal Fired with Mechanical Grates. "  [Staubauswurf-
begrenzung Dampfkessel liber 10 t/h Leistung Steinkohlenfeuerungen  mit
Unterwind-Zonenwanderrost. ]  VDI (Verein  Deutscher Ingenieure) Kommission
Reinhaltung der Luft, Duesseldorf,  Germany, VDI No.  2091,  Nov.  1961,  22 pp.
(Translated from German.)

"Restricting Dust Emission from Forced-Draft Boiler Installations,  Capacity
30 ton/hr and Over, Hard  Coal-Dust Fired with Dry Ash Removal. "
[Staubauswurfbegrenzung Dampferzeuger liber 10 t/h Leistung Steinkohlen-
Staubfeuerungen mit trockenem Ascheabzug.J  VDI (Verein Deutscher Ingenieure)
Kommission Reinhaltung der Luft, Duesseldorf, Germany, VDI No.  2092,
Nov. 1961, 22pp.  (Translated from German.)

"Restricting Dust Emission from Forced-Draft Boiler Installations,  Capacity
30-600 ton/hr and Over, Hard  Coal-Dust Fired with Liquid Ash Removal. "
(Staubauswurfbegrenzung Dampferzeuger liber 10 t/h Leistung Steinkohlen-
Staubfeuerungen mit flussigem Ascheabzug.] VDI (Verein Deutscher  Ingenieure)
Kommission Reinhaltung der Luft, Duesseldorf, Germany, VDI No.  2039,
Nov. 1961, 22 pp.  (Translated from German.)

"Restricting Dust Emission from Natural-Draft Steam Generators, Capacity
25 ton/hr and Less, Lignite-Fired with Stationary or Mechanical Grates.  "
[Staubauswurf Dampferzeuger uber  10 t/h Leistung Braunkohlen-Rostfeuerungen
feststehende Roste oder mechanische  Roste  ohne Unterwind.]  VDI (Verein
Deutscher Ingenieure) Kommission  Reinhaltung der Luft, Duesseldorf,  Germany,
VDI No. 2098, July 1958,  17pp.  (Translated from German.)

"Restriction of Dust Emission  in Anthracite-Briquet Factories."  [Staubaus-
wurfbegrenzung Steinkohlen-Brikettfabriken. ] VDI  (Verein Deutscher Ingenieure)
Kommission Reinhaltung der Luft, Duesseldorf, Germany, VDI No.  2292,
Oct. 1961,  10 pp.  (Translated from German.)

Schueneman, J. J.  "Air Pollution from Use of Fuel - Current Status and Future
of Particulate Emissions Control." Nat. Engr. ,  69_(3):11-12, March 1965.

Schueneman, J. J.  "Some Aspects of Marine  Air Pollution Problems on  the
Great Lakes." Informative Report  No.  1, TI-1 Marine Committee,  J.  Air
Pollution Control Assoc. ,  14(9):378-384, Sept. 1964.

Schwarz, K.  "Dust Emissions from Coal-Fired Boilers in the Federal
Republic of Germany. "  [Die Staubemissionen kohlegefeuerter Dampfkessel-
grossanlagen in der Bundesrepublik Deutschland. ] In:  Parti, Proceedings
hternational Clean Air Congress, London,  1966, Paper V/8, pp. 136-141.
                                  8-13

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Smith, W. S. and Gruber,  C. W.  "Atmospheric Emissions from Coal Combus-
tion - An Inventory Guide. " U.S. Dept. of Health, Education, & Welfare, Div.
of Air Pollution, Cincinnati, Ohio,  PHS-Pub-999-AP-24, 1966, 112pp.

Spencer, J.  D.   "Bureau of Mines Research and Technological Work on Coal,
1964."  U.  S. Bureau of Mines,  Coal Research Center, Morgantown, W. Va.,
1965, 125 pp.

Strewe, W.  "Heat Production from Solid  Fuels. "  [Waermeerzeugung mit
festen Brennstoffen. ]  Gesundh.  Ingr. , §6(4):111-116,  April 1965.

"Studies on Smoke  Purification. "  [Studio  sui dupuratori  di fumo.]  Fumi
Polveri (Milan), _6(3):69-85, March 1966.

Tebbens, B. D. , Thomas, J. F. , and Mukai, M.  "Particulate Air Pollutants
Resulting from  Combustion."  In:  Symposium on Air-Pollution Measurement
Methods, American Society for Testing Materials, Spec. Techn.  Pub. 352,
1964, pp. 3-31.

Thieme, W.  "Measures for Reducing Emission from Domestic Hearths Using
Solid Fuels."  Staub (English Translation), ^5(11):10-13, Nov.  1965.

Trenck, H.  M.   "Provisions Against Atmospheric  Pollution Due to  Domestic
Heating in the Federal Republic  of Germany. "  [Provedimenti control 1'inguina-
mento atmosferico prodotto dal tis caldamento domestico nella Germainia
Federale.]   Fumi Polveri  (Milan), 6(7-8):213-216, 1966.

Van  Doornum, G. A.  W.   "Smokeless Combustion of Bituminous Coal. "  Coal,
Gold, and Base Minerals of S. Africa, _14(7):32-33, 37, Sept. 1966.

Watson, K.  S. and Belecher, K. J.  "Further Investigation of Electrostatic
Precipitators for Large Pulverized Fuel Fired Boilers. " International J. Air
Water Pollution (Oxford),  _10_(9):573-583, Sept.  1966.

Weyers, W. and Engels,  L. H.  "The Results of Technical Measures for Dust
Removal in Underground Coal Preparation and the  Associated Conveying Plant.'
Staub (English Translation), _26(l):21-24,  Jan. 1966.

OIL  COMBUSTION

Alliot,  L. , Auclair,  M. ,  Labardin, A., Mauss, F. , Four, R.  , and lehle, F.
"Emission of Solid Particles by  Combustion of Fuel Oils  (Central Hot Water
Heating). "  [Emission de particules solides par la combustion d'huiles combusti
                                    8-14

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fluides (Chauffage central a eau chaude).]  Rev. Inst.  Franc. Petrole Ann.
Combust Liquids (Paris), 20(11):1755-1792, Nov.  1965.

Alliot, L. and Auclair, M.   "Experiments on  Combustion of Domestic Fuel in
an Experimental Boiler. "  [Essais de combustion  de fuel domestique sur
chaudiere experimentale. ]  Rev. Inst.  Franc.   Petrole  (Paris), 20(11): 1757-
1771, Nov. 1965.

Axtman, W. H.  "Heavy Oil  Burners and Air Pollution. "  Fuel Oil and Oil
Heat,J6(l):61-64, Jan.  1967.

Barker,  K. and MacFarlane, W. A.   "Fuel Selection and Utilization. "  In:
World Health Organization,  Monograph Ser. 46, "Air  Pollution, " 1961,
pp. 345-363.

Belyea, H. A. and Holland, W.  J.   "Flame Temperature in Oil-Fired Fuel-
Burning Equipment and its Relationship to Carbonaceous Particulate Emis-
sions. "  J. Air Pollution Control Assoc. , _17_(5):320-323, May 1967.

Chittawadgi, B.  S. and Voinov,  A.  N.  "Mechanism of Action of Ferrocene on
Smoke Reduction in Diffusion Flames. " Indian J.  Technol. , _3(7):209-211,
July 1965.

Danielson, J.  A.  "Air Pollution Engineering Manual.  " U.S.  Dept.  of Health,
Education, and Welfare, National Center for Air Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40,  1967,  892pp.

Etoc, Pierre.  "The Use of Ammonia to Eliminate Acid Smuts from Oil-Fired
Plant."  J. Inst. Fuel,  40(317):249-251, June  1967.

Fauth, Ulrich  and Schule, Walter.   "Gaseous and  Solid Emissions from Oil-
Fired Stoves. " Staub (English translation), 27_(6):1-11, June 1967.

Finfer,  E.  Z.  "Fuel Oil Additives for Controlling Air Contaminant Emissions.'
J. Air Pollution  Control Assoc.  , r7_(l):43-45,  Jan. 1967-

Four, R. and lehle,  F.  "Emission of Solid Particles as a Function of Power in
a Domestic Heating Plant. "  [Emission de particules solides en fonction de  la
Puissance dans une installation de chauffage domestique.]  Rev. Inst. Franc.
Petrole (Paris),  20_(11):1783-1792, Nov.  1965.

Griswold, S. S.  "Control of Stationary Sources. " Los Angeles County Air
Pollution Control District, Technical Progress Report Vol.  1,  April 1960,
tf9 pp.
                                   3-15

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"Guide to Air Pollution Control Methods. " Modern Power Engr. , 60_(6):63-78,
June 1966.

Hagiwara,  I.  "Prevention of Smoke and Soot by Adding Additives to Heavy Oil. '
Heat Engr.  (Tokyo),  19(4):31-35, April 1967.  (Text in Japanese.)

Hangebrauck, R.  P. , von Lehmden, D. J. , and Meeker,  J.  E.   "Sources of
Polynuclear Hydrocarbons in the  Atmosphere. " U.S.  Dept.  of Health, Educa-
tion, and Welfare, National Center for Air Pollution Control, Cincinnati,  Ohio,
PHS-Pub-999-AP-33,  1967, 44pp.

Hattori,  I.   "Prevention of Urban Air Pollution and Regional Heating and
Cooling Systems."  Clean Air (Tokyo),  3_(6):12-19,  March 1966.

Kirov, N. Y.  "Efficient Combustion - The Control of Air Pollution at the
Source. " In:  Proceedings of the Clean Air Conference,  Univ. of New South
Wales,  1962, Paper 22.

Labardin, A. and Mauss,  F.  "Influence of Burner Function on the Emission
of Solid Particles."  [Influence du fonctionment des bruleurs sur les emissions
de particles solides.]  Rev. Inst. Franc.  Petrole (Paris), 20(11):1771-1783,
Nov. 1965.

Lock, A. E.  "Reduction of Atmospheric Pollution by Efficient Combustion
Control."  Plant Eng.  (London),  11J5): 305-309, May 1967.

Oiestad, A. and Brief,  R.  S.  "Impingement Baffle Plate  Scrubber for Flue
Gas."  J. Air Pollution Control Assoc. , 14(9):372-377, Sept. 1964.

Pesterfield,  C. H.  "Literature and Research Survey to Determine Necessity
and Feasibility of Air Pollution Research  Project on Combustion of Commer-
cially Available Fuel Oils. " J. Air Pollution Control Assoc. , 14(6):203-207,
June 1964.

"Pollution of the Atmosphere in the Detroit River Area. "  International Joint
Commission, United States and Canada, 1960,  241 pp.

"The Present Aspect of Public Nuisance Prevention Control in the Electricity
Supply Enterprise in Japan. "  Clean Air Heat Management (Tokyo), _15(3):6-8,
March 1966.

Reminiczky,  K.  "High Soot Emission by Small Oil Stoves. " [Kis olajtuzelesek
nagy Koromemisszioi. ] Energia  Atomtech (Budapest), 20(10):479-485, Oct.
1967.  (Text in Hungarian.)
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"Report on Smoke Performance of Vessels Plying the Detroit River During
Navigation Season 1964. "  International Joint Commission, Detroit River Area,
Technical Advisory Board on Air Pollution,  March  1965,  148 pp.

Schueneman, J. J.  "Air Pollution from Use of Fuel - Current Status and
Future of Particulate Emission Control."  Nat. Eng. , 69_(3):11-12, March 1965.

Schueneman, J. J.  "Some Aspects of Marine Air Pollution Problems on the
Great Lakes. "  Informative Report 1,  J. Air Pollution Control Assoc. ,
14(9):378-384,  Sept.  1964.

Smith, W. S.   "Atmospheric Emissions from Fuel Oil Combustion - An  Inven-
tory Guide."  U.S. Public Health Service,  Div. of Air Pollution, Cincinnati,
Ohio, PHS-Pub-999-AP-2,  1962, 95 pp.

"Studies on Smoke Purification. "  [Studio sui depuratori di fumo.]  Fumi
Polveri (Milan), 6_(3):69-85, March 1966.

Wasser, J. H. , Hangebrauck,  R.  P. , and Schwartz,  A.  J.   "Effects of  Air-
Fuel Stoichiometry on Air Pollutant  Emissions from an Oil-Fired Test Furnace. "
Preprint.  (Presented at the 60th Annual Meeting, Air Pollution Control  Associ-
ation, June 11-16, 1967, Paper 67-124.)

Wentink,  G.  "Measurements of Soot Concentration  in the Combustion Gases of
Some Liquid Fuels."  Staub  (English Translation),  27_(4):8-12, April 1967.

GAS COMBUSTION

Barker, K. and MacFarlane, W. A.   "Fuel Selection and Utilization. "  In:
World Health Organization,  Monograph Ser.  46,  "Air Pollution," 1961,
pp. 345-363.

Chass, R. L. and George,  R. E.  "Contaminant Emissions from the Combustion
of Fuels."  J.  Air Pollution Control Assoc. ,  1_0(1):34-43, Feb.  1960.

Danielson, J. A.  "Air Pollution Engineering Manual." U.S. Dept.  of Health,
Education, and Welfare, National Center for Air Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40, 1967, 892pp.

Griswold,  S. S.  "Control of Stationary Sources. "  Los Angeles County Air
Pollution  Control  District,  Techn. Progr.  Report,  Vol. 1, April 1960,   179 pp.

"Guide to Air Pollution Control  Methods. "  Modern  Power Eng. , 60(6):63-78,
June 1966.
                                    3-17

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Schueneman, J.  J.  "Air Pollution from Use of Fuel - Current Status and
Future of Particulate Emission Control."  Nat. Eng., 69(3): 11-12, March 1965.

NUCLEAR POWER

Ettinger,  H.  J. ,  Moss, W.  D. ,  and Busey, H.  "Characteristics of the Aerosol
Produced from Burning Sodium and Plutonium. "  Univ. of Calif. ,  Los Alamos
Scientific Laboratory Report Nos. LA-3491 and TID-4500, Los Alamos, New
Mexico, July 1966, 51 pp.

Kitani, S.  "Aerosol in Nuclear Safety - Collecting Capability of Aerosol Filter.
Nucl. Eng. (Tokyo), 13(2):21-26, Feb.  1967.

Morgenthaler, A.  C.   "Survey of Air and Gas Cleaning Operations. "  General
Electric  Co. , Report HW-61840,  Hanford Atomic Products Operation, Richland,
Washington, Sept. 1,  1959,  22 pp.

Schwendiman, L. C.  "Radioactive Airborne Pollutant - Effective  Control in a
Nuclear Power Economy. "  Preprint.  (Presented at the Northwest Meeting,
Air Pollution Control Association, Portland, Oregon,  Nov. 5, 1964, Paper
HWSA-3683.)

Silverman, L.  "Performance of  Diffusion  Boards for Radioactive Gases and
Particulates. " Proceedings, 8th Atomic Energy Commission Air  Cleaning
Conference, Oak Ridge, Tenn. ,  1963, pp.  177-188.

"Techniques for Controlling Air Pollution from the  Operation of Nuclear
Facilities. "  In:  Report of a Panel on Techniques for Preventing Atmosphere
Pollution from the Operation of Nuclear Facilities,  Vienna, Nov. 4-8, 1963.
International Atomic Energy Agency,  Safety Series  17,  1966, 123 pp.

                         REFUSE DISPOSAL SOURCES

OPEN BURNING

Meland, B. R.  and Boubel,  R. W.  "A Study of Field Burning under Varying
Environmental Conditions."  J. Air Pollution Control Assoc. , 1_6(9): 481-484,
Sept.  1966.

"Air Pollution Problems from Refuse Disposal Operations in Philadelphia and
the Delaware Valley." Dept. of Public Health, Philadelphia, Pa.,  Div. of
Environmental Health, 1965, 8 pp.
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MUNICIPAL INCINERATORS

Bender, R. J.  "Incinerator Plant- Plus."  Power, _lll(l):62-64, Jan.  1967.

Beorse, B. , Kurtz,  P., Mizushima, J. , Chipman, R. D. ,  and Bush, A. F.
"A Study of Air Pollution Control Aspects of Refuse Incineration. "  In:  First
Report of Air Pollution Studies, Univ. of California, Report 55-27, June 30,
1955, 63 pp.

Bump, R. L-  "The Use of Electrostatic Precipitators for Incinerator Gas
Cleaning in Europe. "  In:  Proceeding of the National Incinerator Conference,
American Society Mechanical  Engineers, New York, May 1-4, 1966,  pp. 161-
Calaceto, R. R.  "Sludge Incinerator Fly Ash Controlled by Cyclonic Scrubber. "
Public Works, _94(2):113,  Feb. 1963.

Cederholm, C.  "Collection of Dust from Refuse Incinerators in Electrostatic
Precipitators Provided with Multicyclone After-Collectors."  In:  Part I,
Proceedings of International Clean Air Congress, London, 1966,  Paper V/3,
pp. 122-125.

Corey, R. C.   "Some Fundamental Considerations in the Design and Use of
Incinerators in Controlling Atmospheric Contamination. "  In: Air Pollution,
L. C. McCabe  (ed.),  McGraw-Hill, 1952, pp. 394-407.

Fernandas, J.  H.  "Incinerator Air Pollution Control Equipment. "  Economic
Study of Solid Waste Disposal  Needs and Practices, Vol. 4, Technical-
Economic Overview, Combustion Engineering, Inc. , Windsor, Connecticut,
Nov. 1,  1967.

Fife, J. A. "Control of Air Pollution from  Municipal  Incinerators."  In:
Proceedings of the 3rd National Conference  on Air Pollution,  Washington, D.C. ,
1966, pp. 317-326.

Fife, J. A. and Boyer, R. A.,  Jr.  "What Price Incineration Air Pollution
Control?" In:  Proceedings of the  National Incinerator Conference, American
Society of Mechanical Engineers,  New York, 1966, pp. 89-96.

Flood, L.  P.  "Air Pollution from Incinerators - Causes  and Cures."  Civil
    ,  Amer.  Society of Civil Engr. ,  pp. 44-48, Dec. 1965.
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Greeley, S. A., Clarke, S. M. , and Gould, R. H.  "Design and Performance
of Municipal Incinerators in Relation to Air Pollution." In: Summary of the
Conference of Incineration,  Rubbish Disposal, and Air Pollution, F. R.
Bowerman (ed.),  APF Rept.  3, Jan. 1955, pp. 25-26.

Jens, W.  and Rehm, F. R.   "Municipal Incineration and Air Pollution Control."
In:  Proceedings of the National Incinerator Conference,  1966, pp.  74-83.

Kaiser, E. R.  "Prospects for Reducing Particulate Emissions from Large
Incinerators."  J. Air Pollution Control Assoc. ,  _16(6):324, June 1966.

Kirov, N. Y.  "Emissions from Large Municipal Incinerators and Control  of
Air Pollution. " Clean Air, ^.(2):19-25,  Sept. 1967.

Kreichelt,  T.  E.   "Air Pollution Aspects of Tepee Burners Used for Disposal
of Municipal Refuse. "  U.S. Dept. of Health, Education and Welfare, Div.  of
Air Pollution, Cincinnati, Ohio, PHS-Pub-999-AP-28, 1966,  35 pp.

Lenehan,  J. W.   "Air  Pollution Control in  Municipal Incineration. "  J. Air
Pollution Control Assoc. , 1_2(9)-.414-417, 430, Sept.  1962.

Meissner,  H.  G.   "Air Pollution from Incinerators. "  Civil Engr. , 34:40-41,
Sept. 1964.

Meissner,  H.  G.   "The Effect of Furnace Design and Operation on Air Pollution
from Incinerators. "  In:  Proceedings of the National Incinerator Conference,
American Society of  Mechanical Engineers, New  York, 1964,  pp. 126-127.

O'Connor,  C.  and Swinehart, G.  "Baghouse Cures Stack Effluent. " Power
Eng. , pp.  58-59, May 1961.

Pascual, S. J.  and Pieratti,  A.  "Fly Ash  Control Equipment  for Municipal
Incinerators."  In:  Proceedings of the National Incinerator Conference,  New
York, 1964, pp. 118-125.

"Air Pollution Problems from Refuse Disposal Operations  in Philadelphia and
the Delaware Valley." Preprint.   Philadelphia,  Pa., Dept. of Public  Health,
Div. of Environmental Health, 1965, 8 pp.

Rogus,  C.  A.  "An Appraisal of Refuse Incineration in Western Europe. "  In:
Proceedings of the National Incinerator Conference, New York, May 1-4,  1966,
pp. 114-123.
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Rogus, C. A.  "Control of Air Pollution and Waste Heat Recovery from Incin-
eration."  Public Works,  97(6): 100-103, June 1966.

Stahenow, G.  "European  Practice in Refuse Burning. "  In:  Proceedings of the
National Incinerator Conference, New York, 1964, pp. 105-113.

Stenburg,  R.  L.  "Modern Incineration of Community Wastes. "  In:  Proceedings
of the National Incinerator Conference, American Society of Mechanical Engi-
neers, New York,  May 1964, pp. 114-117.

Stenburg,  R.  L. ,  Hangebrauck, R. P. ,  von Lehmden, D. J. , and Rose,  A. H. ,
Jr.  "Field Evaluation of Combustion Air Effects on Atmospheric Emissions
from Municipal Incinerators. " J. Air Pollution Control Assoc. ,  12(2):83-89,
Feb.  1962.

Stephenson,  J. W.  and Cafiero, A. S.  "Municipal Incinerator Design Practices
and Trends."  In:  Proceedings of the National Incinerator Conference, New
York,  May 1-4, 1966, pp. 1-38.

Sterling, M.  "Bush and Trunk Burning Plant in the City of Detroit. "  J.  Air
Pollution Control Assoc. , l_5(12):580-582,  Dec. 1965.

Syrovatka, Z. "New Incineration System for  Town Refuse. "  Czech. Heavy
fold., Vol. 11, pp.  15-18, 1966.

Walker, A. B.  "Electrostatic Fly Ash Precipitation for Municipal Incinerators -
A Pilot Plant Study. "  In:  Proceedings of the National Incinerator Conference,
New York, 1964, pp.  13-19.

Wegman,  L.  S.  "An Incinerator with Refractory Furnaces  and  Advanced Stack
Gas Cleaning Systems. "  In:  Proceedings of Metropolitan Engineers Council
on Air Resources,  Symposium on Incineration of Solid Wastes,  New York,  1967,
pp. 34-42.

Williamson, J.  E.  and MacKnight,  R. J. "Incineration." In: Air  Pollution
Engineering Manual,  Public Health Service, Cincinnati,  Ohio, PHS-Pub-
999-AP-40,  1967,  pp. 413-428.

ON-SITE INCINERATORS

Albinus, G.   "Reducing the Emission of Small Waste Incinerators by Structural
and Control Measures."  Staub, 25(11):17-20, Nov.  1965.
  331-7160-69-32                          "

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"How to Control Participate Emissions to Abate Air Pollution. " Heating, Piping,
and Air Conditioning, pp.  137-152,  June 1959.

"Apartment House Incinerators (Flue-Fed). " National Academy of Sciences,
Building Research Advisory Board, Washington, D. C. ,  Pub.  1280,  1965,  38pp.

Calaceto,  R.  R.  "Sludge Incinerator Fly Ash Controlled by Cyclonic Scrubber. "
Public Works, 94(2): 113, Feb.  1963.

Challis, J. A.  "Three Industrial Incineration Problems. " In:  Proceedings of
the National Incinerator Conference, American Society of Mechanical Engineers,
New York, May  1-4, 1966, pp.  208-218.

Fernandes, J. H.  "Incinerator Air Pollution Control Equipment. " In:  Econom-
ic Study of Solid Waste Disposal Needs and Practices, Vol. 4, Technical-Eco-
nomic Overview, Combustion Engineering, Inc., Windsor, Conn., Nov.  1, 1967.

Fife, J. A.  "Refuse Disposal and the Mechanical Engineer. "  (Compounding
Problems Promise a Major Role for the Mechanical Engineer.)  Heating, Piping,
Air Conditioning, 3^(11):93-100, Nov. 1966.

Flood, L. P.  "Air Pollution from Incinerators - Causes and Cures."  Civil
Eng. , pp. 44-48, Dec. 1965.

Haedike, E. W. , Zavodny, S. ,  and Mowbray, K.  D.   "Auxiliary Gas Burners
for Commercial and Industrial Incinerators."  In:  Proceedings of  the National
Incinerator Conference, American Society of Mechanical Engineers, New York,
May 1-4,  1966, pp. 235-240.

Houry,  E.  and Koin, H. W.  "Principles of Design of Smokeless, Odorless
Incinerators for Maximum  Performance. " American Gas Assoc. , Cleveland,
Ohio, Research  Bulletin 93, Dec. 1962, 41 pp.

Kaiser, E. R. and Tolciss, J.  "Control of Air Pollution from the Burning of
Insulated Copper Wire. "  J. Air Pollution Control Assoc. , J13(l):5-ll, Jan.
1963.

Kaiser, E. R. and Tolciss, J.  "Smokeless  Burning of Automobile Bodies."
J. Air Pollution Control Assoc. ,  l_2(2):64-73,  Feb.  1962.

Lieb, H.  "Dust Separation and Flue Gas Composition of the Industrial Refuse
Incineration Plant of the Base. " Mitt,  der Grosskesselbesitzer, Vol.  93,
pp. 434-437,  Dec. 1964.
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MacKnight,  R. J.,  Williamson, J. E. ,  Sableski, J. J. , Jr. , and Dealy, J. O.
"Controlling the Flue-Fed Incinerator. " J. Air Pollution Control Assoc. ,
10(2):103-109,  125, April  1960.

"Apartment House Incinerator Criteria. "  New York City Dept.  of Air Pollution
Control, March 1966.

"Criteria Used for Upgrading Existing Apartment House Incinerators in the
City of New York. "  New York City Dept.  of Air Pollution Control, Jan. 1967,
21pp.

"Criteria for Incinerator Design and Operation. " Dept. of Health,  Air Pollu-
tion Control Service,  Ontario, Canada,  May 1966, 20pp.

"Air Pollution Control Section. " In:   Domestic Incinerator  Report, Phila-
delphia,  Pa.,  Feb. 1963.

Papovich, M. , Northcraft, M. , Boabel, R. W., and Thomburgh, G.  E.
"Wood Waste Incineration." Oregon State College,  Engineering Experiment
Station, Corvallis,  1961, 8 pp.

Smith, S.  "New Way to Scrub Incinerator Gases. "  Air Eng. , _2(5):40-42,
May 1960.

Stenburg, R. L.  "Modern Incineration of Combustible Material - Industrial
and Commercial. "  Preprint.  U.S. Dept.  of Health, Education, and Welfare,
Div.  of Air Pollution.   (Presented  at the East Central Section, Air  Pollution
Control Association Meeting, Columbus, Ohio, Sept. 20,  1962.)

Stenburg, R. L.  "Modern Methods of Incineration. " Air Eng. ,  Vol.  6,
pp.  20-21, 34, March 1964.

Stenburg, R. L.  "Status of the Flue-Fed Incinerator as a Source of Air
Pollution."  Am. Ind.  Hyg. Assoc. J. ,  Vol. 24, pp. 505-516, Oct. 1963.

Sterling, M.  "Air Pollution Control  and the Gas Industry. "  J. Air Pollution
Control Assoc. , 11 (8):354-361, Aug.  1961.

Vickerson, G.  L.  "Fly Ash Control  Equipment for Industrial Incinerators. "
In: Proceedings of the  National Incinerator Conference, New York, May 1-4,
1966, pp.  241-245.
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Voelker, E. M.  "Control of Air Pollution from Industrial and Household
Incinerators."  In:  Proceedings of the 3rd National Conference on Air Pollu-
tion, Washington, D.  C.,  1966, pp. 332-338.

Voelker, E. M.  "Essentials of Good  Planning."  In:  Proceedings of the National
Incinerator Conference, New York, 1964, pp.  148-152.

Williams, R. E.  "Incineration Practice and Design Standards. "  In:  Proceed-
ings of Clean Air Conference,  Univ. of New South Wales, Vol. 2, Paper 27,
p. 26.

Williamson, J.  E. , Netzley, A.  B. ,  Sableski, J. J. , Talens, P. G. , Walters,
D. F., and Brown,  R. S.  "Incineration." In:  Air Pollution Engineering
Manual,  U.S. Dept. of Health, Education, and Welfare, Public Health Service,
Cincinnati, Ohio, PHS-Pub-999-AP-40, 1967,  pp.  428-506.

Williamson, J.  E. , MacKnight, R. J. , and Chass, R.  L.  "Multiple-Chamber
Incinerator Design Standards for Los Angeles County. " Los Angeles County
Air Pollution Control  District, Calif., Oct.  1960,  32pp.

Woodland, R. G. , Hall, M.  C. ,  and Russell, R. R.  "Process for Disposal of
Chlorinated Organic Residues."  J. Air Pollution Control Assoc. ,  15(2):56-58,
Feb. 1965.

Woodruff, P. H. and Wene,  A. W. "General Overall Approach to Industrial
Incineration. " In: Proceedings of the National Incinerator Conference,
American Society of Mechanical Engineers,  New York, May 1-4,  1966,  pp.
219-225.

OTHER DISPOSAL METHODS

Bowerman, F. R.  "Transfer Operations."  In:  Proceedings of the National
Conference on Solid Waste Research,  American Public Works Association,
Chicago, Feb. 1964, 75 pp.

Bugher,  R. D.  "Transportation Systems."  In:  Proceedings Surgeon General's
Conference on Solid Waste Management,  U.S.  Public Health Service, National
Center for Urban and  Industrial Health,  Cincinnati, Ohio,  PHS-Pub-1729, 1967,
pp. 73-86.

"Car Junkyards Try Sophistication. "  BusinessWeek,  No. 1904, pp. 108-112,
Feb. 26, 1966.
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"Compositing - Is it Economically Sound?" Refuse Removal J. ,  Summer 1965.

"Do You Need a Sanitary Landfill ?"  U. S. Dept. of Health, Education, and
Welfare,  Public Health Service, Washington,  D. C. ,  PHS-Pub-1012, 1963,
5pp.

Golueke,  C.  G.  and McGaughey,  P.  H.  "Future Alternatives to Incineration
and their Air Pollution Potential. "  In:  Proceedings of the 3rd National Con-
ference on Air Pollution, Washington, D. C. ,  Public  Health Service,
PHS-Pub-1649,  1967,  pp. 296-305.

Harding,  C.  I.  "Recycling and Utilization. "  In:  Proceedings of the Surgeon
General's Conference  on Solid Waste Management, Cincinnati,  Ohio, U.  S.
Public Health Service, PHS-Pub-1729,  1967,  pp.  105-119.

Haug, L.  "When Does Transfer Pay Off. "  Refuse Removal J. , Aug. 1966.

"How to Build a Fill. " 1963 Sanitation Industry Yearbook,  p.  20.

"Scrap and Salvage. "  1963 Sanitation Industry Yearbook, p. 24.

Seely, R. J.  "Solid Waste Report for the City of Chicago. " Chicago,  Illinois,
1966, 33  pp.

Vogely,  W. A.  "Abandoned and Scrap Automobiles. " In:  Proceedings of the
Surgeon General's  Conference on Solid Waste  Management, Cincinnati, Ohio,
PHS-Pub-1729,  1967,  pp. 51-60.

Weaver,  L.  "The  Sanitary Landfill. " Preprint.  U. S. Dept. of Health,
Education, and Welfare,  Public Health Service, March 1956.

Weston, R.  F.  "Future Alternatives to Incineration and their Air Pollution
Potential. " In:  Proceedings of the 3rd National Conference on Air Pollution,
Washington,  D.  C.  , U. S. Public Health Service,  PHS-Pub-1649, 1967,
pp. 306-308.

Wiley, J. S.  and Krochtitzky, O. W.  "Composting Developments in the United
States."  Compost  Science, _6(2):5-9, Summer 1965.
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                   METALLURGICAL PROCESS SOURCES

ALUMINUM

Barenstein, M.  "Air Pollution Control in Non-Ferrous Metallurgical Industry -
The Use of Wet Scrubbers."  Ind. Heating, 43(10): 1866-1868,  1870,  Oct.  1967.

Junker, E.  "Electrostatic Filters for Exhaust Gas  Cleaning at Pressure  Die
Casting Machines. "  [Electrofliter zur Abluftreinigung an Druckgiessmaschinen.;
Giesserei (Dusseldorf), 54(6): 152-154, March 16, 1967.

Ott, R. R. and Hatchard,  R.  E.  "Control of Fluoride Emissions at Harvey
Aluminum, Inc.  - Soderberg  Process Aluminum Reduction Mill. " J. Air
Pollution Control Assoc. , _13 (9): 437-443, Sept. 1963.

Rothman,  S.  C.  "Engineering Control of Industrial Air Pollution: State of the
Art, 1966."  Heating, Piping, Air Conditioning, pp.  141-148,  March 1966.

Schnitt, H. and Moser,  E. "Further Developments of the Fluorine Problems
in the Aluminum Industry. " [Weitere Entwicklungen zum  Fluorproblem in der
Aluminum Industrie. ]  Z.  fuer Erzbergau Metallhuettenwesen, 18(3):111-115,
March 1965.

Teller, A. J.  "Control of Gaseous Fluoride  Emissions. "  Chem. Eng.  Progr. ,
63(3):75-79, March 1967.

Wagner, K.  "Possibilities for Exhaust Air Cleaning in Pressure Die Casting
Foundries."  [Moglichkeiten fur Abluftreinigung in  Druckgiessereien. ]
Giesserei (Dusseldorf), 54(6): 150-152, March 16, 1967.

COPPER

Hausberg,  G.  and Kleeberg,  U.  "Installation for Purification of Waste  Gases
Generated during Chlorine Treatment of Light Metal Foundry Melts."
[Abgasreinigungsanlagen fur die Chlorbehandlung von  Leichtmetallschmelzen.  ]
Giesserei (Duesseldorf), 53(5):137-141, March 3, 1966.

Jackson, N. H.  "Fume Emissions from the Melting of Copper and its Alloys. "
In:  Parti, Proceedings of the Clean Air Congress, London, 1966, Paper VI/7,
pp. 177-178.
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Johnson, R. K.  "The New Hayden Smelter - Its Unique Design Features."
J.  Metals, pp.  376-381, June 1959.

"Restricting Dust Emission from Copper - Ore Smelters. "  [Staubauswurf-
begrenzung, Kupfererzhutten. ] VDI, Kommission Reinhaltung der Luft, Dussel-
dorf, VDI No.  2101, Jan.  1960,  24pp.

IRON AND STEEL

Adams, R. L.  "Application of Baghouses to Electric Furnace Fume Control."
J.  Air  Pollution Control Assoc. ,  1£(8):299-302, Aug. 1964.

Archer, A.  "Clean Air and the Iron Foundry. "  In:  Part I,  Proceedings of the
International Clean Air Congress,  London, 1966, Paper IV/8, pp.  99-102.

Basse, B.  "Gases Cleaned by the Use of Scrubbers. "  Blast Furnace Steel
Plant,  pp. 1307-1312, Nov. 1956.

Bloomfield, B.  D.  "Costs, Efficiencies,  and Unsolved Problems of Air
Pollution Control Equipment.  " J.  Air Pollution Control Assoc. , 17(l):28-32,
Jan. 1967.

Brandt, A. D.  "Current Status and Future Prospects - Steel Industry Air
Pollution Control. "  In:  Proceedings of the 3rd National Conference on Air
Pollution, Washington, D. C. , 1966, pp. 236-241.

Broman, C.  "Scrubbing for Clean Air. "  Preprint.  (Presented at the 59th
Annual Meeting, Air Pollution Control Association,  San Francisco,  Calif.  ,
June 20-24, 1966.)

Campbell, W. W. and Fullerton, R. W.  "Development of an Electric Furnace
Dust-Control  System. "  J.  Air Pollution Control Assoc. , _12(12) :574-577,  590,
Dec. 1962.

Chamberlin, R.  L.  and  Moodie,  G.  "What Price Industrial Gas Cleaning?"
In:  Part I, Proceedings of the International Clean Air  Congress, London,
Paper V/7, 1966, pp. 133-135.

Cooper, R. L. and Lee, G. W.  "Alleviation of Air Pollution in the Coking
Industry. "  In:  Part I, Proceedings of the International Clean Air Congress,
London, 1966, Paper V/l, pp. 117-119.
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Cosby, W.  T.  "The Impact of Oxygen on Gas  Cleaning in the Steel Industry. "
Iron & Steel,  36(14):632-637, Dec. 18, 1963.

Davies, E. and Cosby, W.  T.  "The Control of Fumes from Arc Furnaces. "
In:  Fume Arrestment, Spec. Report 83, William Lea and Co. , Ltd. ,  London,
1964, pp.  133-143.

Douglas, I. H.  "Direct Fume Extraction and Collection Applied to a Fifteen
Ton Arc Furnace. " In:  Fume Arrestment, Spec. Report 83, William Lea and
Co. , Ltd. , London, 1964, pp. 144-149.

Dublinskaya,  F.  E. , Zaitsev, M. M. ,  and Zhigalina, I. S.  "Purification of
Gases  Originating from  Melting Steel in Oxygen Converters when Removed
with the Combustion of the Carbon Monoxide. "  Steel (English translation),
Vol. 6, pp. 500-501, June 1966.   (From Russian.)

"Dust Out of Foundries.  "  Metal  (London), 1_(1):55, June 1966.

Elliott, A.  C.  and Lafreniere, A. J.  "Collection of Metallurgical Fumes from
Oxygen Lanced Open Hearth Furnaces. " J. Metals (Japan),  jU3(6):743-747,
June 1966.  Also:  J. Air Pollution Control Assoc. ,  1_4(10) :401-406, Oct.  1966.

Ellison, W. and Wechselblatt, P. M.  "Cupola Emission Cleaning Systems-
Utilizing High Energy Venturi Scrubbing. " Modern Casting, 50(2):76-82,
Aug. 1966.

Engelberg, F.  "Dust Generation and Removal in Shot-Blasting Chambers. "
[Staubentwicklung in Schleuderradputzraumen und Entstaubung. ] Giesserei
(Dusseldorf), 54(6): 144-148, March 16, 1967.

Engels, L. H.  "Feed Gas Cleaning in Coke Oven Larry Cars.  " (A Contribu-
tion to the Wet Separation of Dusts.) Staub (English Translation), 26(11):23-31,
Nov. 1966.

"Foundry Fume Disappears - Gas Cleaning at Ford's Leamington Plant. " Iron
and Steel (London), 40(l):8-9, Jan.  1967.

Frame, C. P. and Elson, R. J.   "The Effects of Mechanical Equipment on
Controlling Air Pollution at No.  3 Sintering Plant, Indiana Harbor Works,
Inland Steel Company. "  J.  Air Pollution  Control Assoc. ,  13^(12) :600-603,
Dec. 1963.
                                   8-28

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Fullerton, R. w.  "Impingement Baffles to Reduce Emissions from Coke
Quenching."  j.  Air Pollution Control Assoc. , 17(12) :807-809,  Dec. 1967.

"Gas Scrubber Installation Successfully Controls Foundry Cupola Emissions. "
Air Eng. , JJ(3):8, 11, March 1966.

Greaves, M.  J.  "The Effect of Modern Burdens on Blast Furnace Design. "
J. Metals (Japan), _18(3):378-384, March 1966.

Harris, E. R. and Beiser, F. R.  "Cleaning Sinter Plant Gas with Venturi
Scrubber." J. Air Pollution Control Assoc. , lj^(2) :46-49, Feb  1965.
 Hemon, W. C. L.  (ed. ) (Tech.  Committee TI-6)  "Air Pollution Problems of
 the Steel Industry. "  Informative Report TI-6, Technical Committee,  J. Air
 Pollution Control Assoc. ,  _10(3):208-218, 253, June 1960.

 Henschen, H. C.  "Wet Vs Dry Gas Cleaning in the Steel Industry. "  J. Air
 Pollution Control Assoc. ,  1_8(5) :338-342, May 1968.  (Presented at the 60th
 Annual Meeting,  Air Pollution Control Association, Cleveland,  Ohio, June 11-16,
 1967, Paper 67-149.)

 Herrick, R.  A. , Olsen, J. W. , and Ray,  F.  A.   "Oxygen- Lanced Open Hearth
 Furnace Fume Cleaning with a Glass Fabric Baghouse. "  J.  Air Pollution
 Control Assoc. ,  1.6(1): 7- 11, Jan.  1966.

 Hoff, H. and Maatsch, J.  "Converter Waste Gas Cleaning by the 'Minimum
 Gas' Method at Fried-Krupp. "  In:  Fume Arrestment, Special  Report 83,
 W. Lea and Co. , London,  1964, pp.  104-108.

 Holland, M.  andWhitwam, K. B.   "Direct Fume Extraction for Large Arc
 Furnaces. "  In:  Fume Arrestment, Special Report 83, William Lea and Co. ,
 London, 1964, pp.  150-159.

 Hoy, D.  "Dust Control in the Foundry. "  Foundry Trade J.  (London), 122
 (2631):545-548, May 11, 1967.

 Jackson, A.   "Fume Cleaning in Ajax Furnaces.  "  In:  Fume Arrestment,
 Special Report 83,  William Lea and Co. , London,  1964, pp.  61-64.

 Johnson, J. E.   "Wet Washing of Open  Hearth Gases. " Iron Steel Eng. ,
 44(2):96-98,  Feb. 1967.

 Kapitulskiil, V.  B.  and Kogan L.  A.  "A Comparison of the  Hygiene Character-
 istics of the' Smokeless and Ordinary Methods of Charging  Coke  Ovens. "  Coke
 Chem.  (USSR),  No. 8, pp.  29-31,  1966.

                                   8-29

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Krikau, F. G.  "Effective Solids Removal for Basic Oxygen Furnace Flue Dust
Pollution Control. "  (Presented at the 28th Annual Meeting, American Power
Conference, April 26-28,  1966.)

Lemke, E. E. , Hammond, W. F. , and Thomas, G.  "Air Pollution Control
Measures for Hot Dip Galvanizing Kettles. "  J.  Air Pollution Control Assoc.,
10(l):70-77, Feb. 1960.

Lloyd, H. B. and Bacon, N. P.  "Operating Experience with Oxygen-Assisted
Open-Hearth Furnaces. "  In: Fume Arrestment, Special Report 83,  William
Lea and Co. , London, 1964, pp. 65-70.

Loszek, W. "The Problem of Maintaining Clean Air in a Zone Polluted by
Waste Gases from Metallurgical Works. "  In: Part I,  Proceedings of the
International Clean Air Congress, London, 1966, Paper IV/10,  pp. 105-111.

Mitchell,  R. T.  "Dry Electrostatic Precipitators and Waagner-Biro Wet
Washing Systems. " In:  Fume Arrestment, Special Report 83, William Lea
and Co., London, 1964, pp. 80-85.

Namy, G. , Dumont-Fillon, J. , and Young, P. A.  "Gas Recovery Without
Combustion from Oxygen Converters:  The IRSID-CAFL Pressure Regulation
Process. " In:  Fume Arrestment, Special Report 83,  William Lea and Co. ,
London, 1964, pp. 98-103.

Ochs, H.  J.  "Purification of Air  in Rolling Mills. " [Umluftreinigung in Walz-
Betrieben. ] Metall.  (Germany), 1_9(4):348-351,  April  1965.

Pallinger, J.  "A New Wet Method for Separation of Very Fine Dust. " Staub
(Diisseldorf), _22(7): 270-275, 1962.

Parker, C.  M. "BOP Air Cleaning Experiences. "  J.  Air Pollution Control
Assoc., _16 (8): 446-448, Aug. 1966.

Pottinger, J. F.  "The Collection of Difficult Materials by Electrostatic
Precipitation." Australian Chem. Process Eng. (Sidney), 20(2):17-23,
Feb. 1967.

Punch, G.  "LD and Kaldo Fume Cleaning - CONSETT Developments. " Iron
and Steel (London), 3£(2):75-80, 86, Feb. 1965.

Rabel, G.  , Neuhaus, H. , and Vettebrodt, K.  "The Wetting of Dusts  and Fine
Ores for the Purpose of Reducing  Dust Formation. » Staub (English transla-
tion),  _25(6):4-8,  June 1965.
                                   8-30

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 Restricting Emission of Dust, Tar Mist and Gas when Charging Coke Oven"
[Auswurfbegrenzung fur Staub, Teernebel und Case beim Fullen von Koksofen;
Kokereien und Gaswerke. ] VDI (Verein Deutscher Ingenieure) , Kommission
Reinhaltung der Luft, Dusseldorf, VDI 2302, June 1962,  26 pp.

Sem,  M. O. and Collins, F.  C.  "Fume Problems in Electric Smelting and
Contributions to their Solution. "  J. Air Pollution Control Assoc. , 5(3):157-158,
187, Nov. 1955.

Schneider, R.  L.  "Engineering,  Operation and Maintenance of Electrostatic
Precipitators in Open Hearth Furnaces. "  J. Air Pollution Control Assoc. ,
     : 348-353, Aug.  1963.
Schueneman, J.  J. ,  High, M. D. and Bye, W.  E.  "Air Pollution Aspects of
the Iron and Steel Industry. " U. S. Dept. Health,  Education and Welfare, Div.
of Air Pollution, Cincinnati, Ohio, PHS-Pub-999-AP-l, June 1963, 129pp.

Smith, J. H.  "Air Pollution Control in Oxygen Steelmaking. " J. of Metals,
13(9): 632-634, Sept.  1961.

Smith, W.  M. and Coy, D. W.   "Fume Collection in a Steel Plant. "  Chem.
Eng.  Progr. , 62(7):119-123, July 1966.

Spenceley, G. D. and Williams, D. I.  T. "Fumeless Refining with Oxy- Fuel
Burners." Steel Times (London),  1_93(5115) :150-158, July 29, 1966.

Storch,  O.  "Experiences with the Application of Wet Collectors in the Iron and
Steel Industry. " [Erfahrungen mit der Anwendung von Nassabscheidern in Eisen
and Stahlhutten-Werken. ] In:  Part I, Proceedings of the International Clean
Air Congress, London, 1966, Paper V/2, pp. 119-122.

Storch,  O.  "A New Venturi Scrubber to  Separate Dust Particles less than
1 Micron, Especially of Brown Smoke." Staub (English translation) , _26(11) :32-34,
Nov.  1966.

Sullivan, J. L. and Murphy, R.  P.   "The Control of Fume from a Hot Blast
Cupola by High Energy Scrubbing without Appreciable Thermal Buoyancy Loss. "
In: Parti, Proceedings  of the International Clean Air Congress,  London, 1966,
Paper V/10,  pp. 144-146.

Thorn, G. W. and  Schuldt, A. F.  "The Collection of Open Hearth Dust and its
Reclamation  Using the SL/RN Process. "  Can. Mining and Met.  Bull. , 59
(654):1229-1233, Oct.  1966.
                                    8-31

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Tulcinsky, S.  and Lemaire, A.  "Cooling and Scrubbing of Smoke Emitted by
LD Steel Converters in Sidmar Ironworks." Rev. de Metallurgie (France),
63(9):659-665, Sept.  1966.

Underwood, G.  "Removal of Sub-Micron Particles from Industrial Gases,
Particularly in the Steel and Electricity Industries. " International J. of Air &
Water Pollution, Vol. 6,  pp.  229-263,  1962.

Wheeler,  D.  H.   "Fume Control in L-D Plant. "  Preprint.  (Presented at the
60th Annual Meeting, Air Pollution Control Association,  Cleveland, Ohio,
June 11-16, 1967, Paper 67-96.)

Wheeler,  D.  H.  and Pearse,  D.  J.  "Fume Control Instrumentation in Steel-
making Processes. " Blast Furnace Steel Plant, .53(12) :1125-1130,  Dec. 1965.

Willett, H. P.  "Cutting Air Pollution Control Costs."  Chem. Eng.  Progr. ,
£3(3):80-83, March 1967.

Yokomiyo, K. "Air Pollution Prevention Equipment Installed in Muroran Steel
and Iron Works,  Ltd. " Clean Air Heat Management (Tokyo), 1.5(7-8): 19-28,
Aug. 1966.

LEAD

Danielson, J.  A. (ed.) "Air  Pollution Engineering Manual. " U. S. Dept. of
Health,  Education, and Welfare, National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40, 1967,  892 pp.

Snowball, A.  F.   "Development of an Air Pollution Control Program at
Cominco's Kimberley Operation. "  J.  Air Pollution Control  Assoc. , 16(2):59-62,
Feb. 1966.

"Restricting Dust and Sulfur-Dioxide Emission from Lead Smelters. "
[Auswurfbegrenzung Bleihutten. ]  VDI (Verein Deutscher Ingenieure),
Kommission Reinhaltung der  Luft, Duesseldorf,  (English translation),  VDI
2285, Sept. 1961.

ZINC

Allen, G.  L. , Viets, F.  H. ,  and McCabe,  L.  C. "Control  of Metallurgical and
Mineral Dusts and Fumes in Los Angeles County, Calif. " Bureau of Mines,
Washington, D.  C. , Information Circular 7527,  April 1952,  79 pp.
                                    8-32

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Damelson, j.  A. (ed.)  "Air Pollution Engineering Manual. "  U. S. Dept.  of
Health,  Education,  and Welfare,  National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40,  1967,  892 pp.

"Restricting Emission of Dust and Sulfur-Dioxide  in Zinc Smelters. "
[Auswurfbegrenzung Zinkhutten. ]  VDI (Verein Deutscher Ingenieure), Kommis-
sion Reinhaltung der Luft,  Duesseldorf,  VDI 2284, Sept.  1961,  27 pp.

                       CHEMICAL PROCESS SOURCES

MINERAL ACIDS

Nitric Acid

"Atmospheric  Emission from Nitric Acid Manufacturing Processes. "  U. S.
Dept.  of Health, Education, and Welfare, Div.  of  Air Pollution,  Cincinnati,
Ohio,  PHS-Pub-999-AP-27, 1966,  89 pp.

"Nitric Acid Manufacture - Informative Report No. 5. "  J.  Air  Pollution Con-
trol Assoc. , ^4(3):91-93,  March  1964.

Toyama, T.  "Air Pollution and Health Impediment. "  Japan J.  Ind. Health
(Tokyo), _8(3):45-48, March 1966.

Zanon,  D. and Sordelli, D.  "Practical Solutions of Air Pollution Problems
from Chemical Processes. "  [Realizzazioni nel campo della prevenzione
dell'inquinamento atmosferico di  origine industriale. ]  Chim.  Ind.  (Milan),
(English translation), 48(2):251-261, March 1966.

Phosphoric Acid

Brink, J.  A. ,  Jr. ,  Burggrabe, W. F. , and Greenwell, L.  E..   "Mist Removal
from Compressed Gases. "  Chem.  Eng.  Prog. , 6^(4)-.60-65, April 1966.

Danielson, J.  A. (ed.)  "Air Pollution Engineering Manual."  U. S. Dept.  of
Health,  Education and Welfare, National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40,  1967,  892 pp.

Sulfuric Acid

Arkhipov,  A. S. and Boystsov, A.  N.  "Toxic Air Pollution from Sulfuric Acid
Production."  Gigiena Sanit.   (English translation),  Vol. 31, pp. 12-17
Sept. 1962.
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"Atmospheric Emissions from Sulfuric Acid Manufacturing Processes. " U. S.
Dept. of Health, Education,  and Welfare, Div. of Air Pollution,  Cincinnati, Ohio
PHS-Pub-999-AP-13, 1965, 127 pp.

"Blocks Air Pollution.  Snares  1700 Ib.  of H2SO4 per Day. "  Chemical Proc.,
Feb. 1962.

Brink, J. A. , Jr. ,  Burggrabe, W. F. ,  and Rauscher, J. A.  "Fiber Mist
Eliminators for Higher Velocities. "  Chem. Eng. Prog. , j30(ll):68-73,
Nov. 1964.

Brink, J. A., Jr.   "Air Pollution Control with Fibre Mist Eliminators. "
Canadian J. of Chem. Eng., Vol.  41, pp. 134-138,  June 1963.

Brink, J. A. , Jr. ,  Burggrabe, W. F. ,  and Greenwell,  L. E.  "Mist Removal
from Compressed Gases." Chem. Eng. Prog. ,  6£(4):60-65,  April 1966.

Danielson, J. A.  (ed.)  "Air Pollution Engineering Manual."  U. S.  Dept.  of
Health, Education,  and Welfare, National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40, 1967,  892 pp.

Meinhold, T.  F.  "Three-Way Payout for H SO  Gas Cleaner. "  Chem.  Proc.,
_29(3):63-64,  March 1966.

Stastny,  E.  P. "Electrostatic Precipitation. " Chem. Prog. , £2(4) :47-50,
April 1966.

Stopperka, K.  "Electroprecipitation of Sulfuric Acid Mists from the Waste
Gas  of a Sulfuric Acid Production  Plant. "  Staub  (English translation), 25(11):
70-74, Nov.  1965.

"Teflon Monofilament Cleans Up Acid Stack Gases. " Chem. Eng. , 72(22): 112-
114, Oct. 25, 1965.

Toyama, T.  "Air Pollution and Health Impediment. "  Japan J. Ind. Health
(Tokyo), _8(3):45-48, March 1966.

Willett, H. P.  "Cutting Air Pollution Control Costs. " Chem. Eng. Prog.,
_63(3):80-83,  March 1967.

Zanon, D. and Sordelli, D.  "Practical Solutions of Air  Pollution Problems
from Chemical Processes. " [Realizzazioni nel campo della prevenzione dell'
inquinamento atmosferico  di origine industriale. ] Chim. Ind. (Milan)
(English translation), 48(2):251-261,  March 1966.
                                   8-34

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PULP AND PAPER

Blosser, R. Q. and Cooper H.  B. H.  "Particulate Matter Reduction Trends in
the Kraft Industry. " National Council for Stream Improvement, Atmospheric
Pollution Technical Bulletin 32, New York,  April 4, 1967, 26 pp.

Boyer, R. Q.  "The Western Precipitation Recovery System. " Tappi,
43(8):688-698, Aug. 1960.

Collins, T. T. , Jr.  "The  Venturi Scrubber on Lime Kiln Stack Gases. "
Tappi, 42(1):9-13, Jan. 1959.

Cooper, S. R. and Haskell, C. F.  "Cutting Chemical Ash Losses in a Kraft
Recovery System. " Paper Trade J. , _L51_(13):5S, March 27,  1967.

Gehm, H. W.  Statement Presented at the Hearings before Subcommittee on
Air and Water Pollution of the Committee on Public Works, U. S. Senate,
90th Congress, 1st session on S.  780, May  15-18,  1967,  Part IV, pp. 2361-
2382.

Harding, C. I.  and Landry, J.  E.  "Future  Trends in  Air Pollution  Control in
the Kraft Pulping Industry."  Tappi, 49(8):61A-67A, Aug. 1966.

Landry, J. E. and Longwell, D.  H.   "Advances in  Air Pollution  Control in the
Pulp and Paper Industry. "  Tappi, 48_(6):66A-70A,  June 1965.

Owens,  V.  P.  "Considerations for Future Recovery Units in Mexican and Latin
American Alkaline Pulping Mills."  Combustion, 38_(5):38-44, Nov.  1966.

Saha, I. S.  "New Flue-Gas Scrubbing System Reduces Air Pollution. " Chem.
Eng. , _24(7):84-86, March 27, 1967.

Stuart, H. H.  and Bailey, R. E.  "Performance Study of  Lime Kiln  and
Scrubber Installation. " Tappi, 48(5): 104A-108A, May 1965.

Walker, A. B.  "Enhanced Scrubbing of Black Liquor Boiler Fume by
Electrostatic Pre-agglomeration:  A Pilot Plant Study. "   J.  Air Pollution
Control Assoc. , l^(12):622-627,  1963.
                                    8-35

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OIL REFINERIES

"Atmospheric Emissions from Petroleum Refineries - A Guide for Measurement
and Control. " U. S. Public Health Service, Div. of Air Pollution, Cincinnati,
Ohio, 1960, 64 pp.

Danielson, J.  A.  (ed.)  "Air Pollution Engineering Manual. " U.  S. Dept. of
Health,  Education,  and Welfare, National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40,  1967, 892 pp.

Gammelgard,  P.  N.  "Current Status and Future Prospects - Refinery Air
Pollution  Control. "  Proc.  of the National Conference on Air Pollution,
Washington, D. C. , Dec.  13,  1966,  pp.  260-263.

Harrison, A.  F. , Louden,  W. L. , and Jones, G.  "The Disposal of Chemical
Effluents from Refineries Utilizing Acid  Treatment Processes. "  [Die
Aufbereitung von Raffinerieabwassern aus der Saure-Raffination. ]  Erdol Kohle
(Hamburg), _19(8): 587-591,  Aug.  1966.

Hess, K.  and Stickel, R.  "Soot-Free Combustion of Petrochemical Waste
Gases."  [Zur russfreien Verbrennung petrochemischer Abgase, ]  Chem.  Ing.
Tech. (Weinheim),  _39(5-6):334-340,  March 20,  1967.

Kropp,  E. P.  and Simonsen, R.  N.  "Scrubbing Devices for Air Pollution
Control."  Paint Oil Chem.  Rev.,  _115(14):11,  12, 16,  July 3, 1952.

London, D.  E. "Requirements for Safe Discharge of  Hydrocarbons to Atmo-
sphere.  "  In:  Proceedings of Midyear  Meeting,  American Petroleum Institute,
Div.  of  Refining,  Philadelphia, Pa., May 15,  1963, Section III.  43, 1963, pp.
418,  433.

Miller,  P. D. , Jr.  , Hibshman,  H. J. , and Connel, J.  R.  "The Design of
Smokeless Nonluminous Flares. "  In:  Proceedings of the  23rd Midyear Meeting,
American Petroleum Institute, Div.  of Refining,Los Angeles, Calif. ,
May  14, 1958, Section III, pp. 276-281.

"The Petroleum Refining Industry - Air Pollution Problems and Control
Methods,  Informative Report No. 1.  "  J. Air Pollution Control Assoc. ,
14(l):30-33, Jan.  1964.

Rose, A.  H. ,  Jr. ,  Black, H. H. ,  and Wanta,  R. C.  "Air and Water Pollution
Studies  Related to Proposed Petroleum Refinery for Sand  Island - Oahu,
Territory of Hawaii (Report to Board of Health,  Territory of Hawaii). "  Public
Health Service, Div. of Air  Pollution,  Cincinnati, Ohio, Dec. 1965, 60pp.
                                   B-36

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Termeulen, M.  A.   "Air Pollution Control by Oil Refineries. "  In:  Parti,
Proceedings of international Clean Air  Congress, London, 1966, Paper IV/5,
pp.  92-95.

Wilson, J. G. and Miller, D. W.   "The Removal of Particulate Matter from
Fluid Bed Catalytic Cracking Unit Stack Gases. "  J. Air Pollution Control
Assoc.,  r7(10):6S2-6S5, Oct. 1967.

PAINT AND A^ARNISH

Boulde, M. J. ,  Severs,  R.  K. ,  and Brewer,  G.  L.  "Test Procedures  for
Evaluation of Industrial Fume Converters (Sampling and Analytical Techniques
Reviewed for)." Air Eng. ,  8_(2)-.20-23, Feb.  1966.

Danielson, J.  A. "Air Pollution Engineering Manual. "  U. S. Dept. of Health,
Education, and Welfare, National Center for Air Pollution Control,  Cincinnati,
Ohio, PHS-Pub-999-AP-40,  1967,  892pp.

Morash, N. , Krouse,  M. , and Vosseller,  W. P.   "Removing Solid  and Mist
Particles from Exhaust Gases. "  Chem. Eng. Progr.  , 63(3):70-74,
March 1967.

Stenburg, R. L.  "Control of Atmospheric Emissions  from Paint and Varnish
Manufacturing Operations. "  Public Health Service, Div.  of Air Pollution,
Cincinnati, Ohio, Technical Report A58-4, June  1958, 30 pp.

PLASTICS AND RESINS

Danielson, J.  A. "Air Pollution Engineering Manual. "  U. S. Dept. of  Health,
Education, and Welfare, PHS-Pub-999-AP-40, 1967,  892pp.

First, M. W.   "Control of Haze and Odours from Curing of Plastics. "   In:
Parti,  Proceedings of International Clean Air Congress, London, 1966,
Paper VI/11, pp. 188-191.

Kenagy,  J. A.  "Designing a 'Clean Room'for Plastic Processing." Mod.
Plastics,  44(3):98-99, Nov.  1966.

Parker,  C. H.   "Plastics and Air Pollution. " Soc. Plastics Engrs. J.  ,
23_(12):26-30, Dec.  1967.
   331-716 0-69-33

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OTHER CHEMICALS

Ammonia

Kaylor, F. B.  "Air Pollution Abatement  Program of a Chemical Processing
Industry." J. Air Pollution Control Assoc. ,  15(2):65-67, Feb.  1965.

Fertilizer

Grant, H. O.  "Pollution Control in a Phosphoric Acid Plant. "  Chem.  Engr.
Prog. ,  60_(l):53-55,  1964.

Sachsel, G.  F. , Yocum, J. E. , and Retzke,  R. A.  "Fume Control in a
Fertilizer Plant - A Case History. " J. Air Pollution Control Assoc. ,
_6(4):214-218,  Feb.  1957.

Sauchelli, V.  "Chemistry and Technology of Fertilizers. "  ACS Monograph
148, Reinhold, 1960.

Miscellaneous Chemicals

"Air Pollution Control in Connection with  DDT Production - Informative
Report No. 6. "  J.  Air Pollution Control Assoc. ,  14(3):94-95, March 1964.

Boldue, M.  J. ,  Severes,  R. K. , and Brewer, G.  L.  "Test Procedures for
Evaluation of Industrial Fume  Converters  (Sampling and Analytical Techniques
Reviewed For). " Air Eng. , _8(2):20-23, Feb.  1966.

Kaylor, F. B.  "Air Pollution Abatement  Program of a Chemical Processing
Industry. " J. Air Pollution Control Assoc. ,  _15(2):65-67, Feb.  1965.

Massiello, F.  "Air Pollution  Control at Drew Chemical Corporation."
In:  Proceedings of Technical  Conference, Mid-Atlantic States Section, Air
Pollution  Control Association, Newark, N. J. , 1962,  pp.  8-12.

Sandomirsky, A. G. , Benforado, D. M. ,  Grames, L. D. ,  and  Pauletta,  C. E
"Fume Control in Rubber  Processing by Direct-Flame Incineration. "  J.  Air
Pollution  Control Assoc.,  l_6(12):673-676, Dec.  1966.

Storch, H. C.  "Product Losses Cut with  a Centrifugal  Gas Scrubber. "  Chem.
Engr.  Prog. , 62_(4):51-54, 1966.

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                       MINERAL PROCESS SOURCES

BITUMINOUS CONCRETE MANUFACTURING

Danielson,  J. A.  (ed.)  "Air Pollution Engineering Manual. "  U. S.  Dept.  of
Health, Education, and Welfare,  National Center for Air Pollution Control,
Cincinnati,  Ohio, PHS-Pub-999-AP-iO,  1967,  892 pp.

Gallaer,  C. A.   "Fine Aggregate Recovery and Dust Collection. " Roads and
Streets, pp. 112-117, Oct. 1956.

Hankin, M. , Jr.  "Is  Dust the Stone  Industry's Next Major  Problem?"  Rock
Prod., 70(4):80-84, 110, April 1967.

Hayes, S. C. , McGrane,  N.  M. , and Perils, D.  B.  "Visual Clarity in Kiln
Discharge Gases. "  J. Air Pollution Control Assoc. , _5(3):171-172,  186,
Nov. 1955.  (Presented at the Annual Meeting of the Air Pollution Control
Association, Detroit,  Mich.,  May 22-26, 1955, Paper 55-33.)

"Low Dust Despite Heavy  Fines,  High  Production. "  Roads  and Streets,
Aug. 1960.

Lundberg, G. R.  "Summary of Dust Collection Systems in  Asphalt  Plants. "
(Presented at the 10th Annual  Convention of the National Bituminous Concrete
Association, Miami Beach,  Fla. ,  Feb. 3,  1965,  14pp.)

McKin, W.  A.  "Dust Control Check on an Urban Asphalt Plant. " Roads and
Streets, pp. 173-175, Aug.  1959.

Mitchell, R. D.   "Primary Dust Collectors. "  (Presented at the 10th Annual
Convention of the National Bituminous  Concrete Association, Miami Beach,
Fla. , Feb.  1965, 8 pp.)

Mundy, L.  W.  "Multiple  Tube Dust  Collectors as Applied to Asphalt Plant
Operation. " (Presented at the 10th Annual Convention of the National
Bituminous Concrete Association, Miami Beach,  Fla., Feb. 1965, 4pp.)

Von Lehmden, D. J. , Hangebrauck,  R. P.,  and Meeker, J. E.  "Polynuclear
Hydrocarbon Emissions from  Selected Industrial  Processes. "  J. Air Pollution
Control Assoc. , 15(7):306-312,  July 1965.
                                    8-39

-------
Walter, E.  "The Dust Situation at Mixing Plants Used in Bituminous Road
Construction in Western Germany. " Staub (English translation), 26(11):34-40,
Nov. 1966.

Weatherly, D.  "Controlling Dust from Road Building Material Plants. "  In:
Proceedings of the Technical Conference, Mid-Atlantic States Section,  Air
Pollution Control Association, Newark, N. J. , 1962, pp. 13-18.

Wiemer.  "Dust Removal from the Waste Gases of Preparation Plants for
Bituminous Road-Building Materials. "  Staub (English translation),  27_(7):9-22,
July 1967.

CALCIUM CARBIDE

Sem, M. O. and Collins, F.  C.  "Fume  Problems in Electric Smelting and
Contributions to Their Solution. " J. Air Pollution Control Assoc. ,
5(3)-.157-158, 187, Nov. 1955.

CEMENT

Aleksynowa, K.  "Chemical Characteristics  of Waste Cement Dust on Their
Value for Agriculture. "  [Charakterystyka chemicza cemetowych pytow
odotowuch i ich wastose dla solnict. ]  Cement,  Wopno, Gips, 11/20(3):62-64,
1955.

Kreichelt,  T. E. , Kemnitz, D. A.,  and Cuffe, S. T.  "Atmospheric Emission
from the Manufacture of Portland Cement. "  U. S. Dept.  of Health, Education,
and Welfare, National Center for Air Pollution Control,  Cincinnati, Ohio,
PHS-Pub-999-AP-17,  1967, 47 pp.

Chamberlin, R. L. and Moodie, G.  "What Price Industrial Gas Cleaning?"
In:  Part I,  Proceedings of the International Clean Air Congress, London,
1966, Paper No. V/7, pp.  133-135.

"Control at  Santee Cement."  Southern Eng. , pp. 50-51,March 1967.

Danielson, J. A.   "Air Pollution Engineering Manual. "  U.  S. Dept.  of Health,
Education, and Welfare, National Center for Air Pollution Control,  Cincinnati,
Ohio, PHS-Pub-999-AP-40, 1967, 892pp.

Doherty, R. E.  "Current Status and Future  Prospects -  Cement Mill Air
Pollution Control. "  In: Proceedings of 3rd National Conference on Air
Pollution, Washington,  D.  C. ,  1966, pp. 242-249.
                                    5-40

-------
       revention - Cement Industry. " [Staubauswurfbegrenzung Zement-
       e-J VDI (Verein Deutscher Ingenieure) Kommission Reinhaltung der
Luft, Duesseldorf,  VDI 2094,  June 1961,  51 pp.

Kohler, W.  "Method for the Abatement of Air Pollution Caused by Cement
Plants.   [Verfahren zur Verminderung der durch die  Zementindustrie
verursachten Luftverunreinigungen. ]  In:  Part I, Proceedings of the Inter-
national Clean Air Congress,  London,  1966,  Paper IV/12, pp.  114-116.

Rayher, W. and Middleton, J. T.  "The Case for Clean Air. "  (Federal
Government Plans for Nationwide  Control.)  Mill Factory, 80(4):41-56,
April 1967.

Tomaider,  M.  "Dust Collection in the Cement Industry. " In:  Part I,  Pro-
ceedings of the Clean Air Congress, London,  1966, Paper V/4,  pp. 125-128.

CONCRETE BATCH PLANTS

Danielson,  J.  A.  (ed.)  "Air Pollution Engineering Manual. "  U. S. Dept.  of
Health, Education,  and Welfare, National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40, 1967,  892pp.

Hankin, M. , Jr.  "Is Dust the Stone Industry's Next Major Problem?"  Rock
Prod., 7_0(4):80-84,  110, April 1967.

CERAMIC, CLAY,  AND REFRACTORIES

Aizenshtadt, B. M.  "Extensive Introduction of Advanced Experience with Dust
Extraction in the Refractories Industry. "  Refractories, No. 10, pp.  425-426,
Oct. 1965.

Luxon, S.  G.   "Atmospheric Fluoride  Contamination in the Pottery Industry. "
Ann. Occupational Hyg.  (London),  _6(3): 127-130, July 1963.

Mori, H.  "Hanshin Wet Type  Dust Collectors."  Clean Air and  Heat Manage-
ment (Tokyo), _15(5):5-11, May 1966.

Rutman, Z. M.  "Purification of Waste Gases from Heat Units in Refractory
Factories." Refractories, No.  10, pp. 429-432, Oct. 1966.

GLASS AND FRIT

Danielson,  J.  A.  "Air  Pollution Engineering Manual. "  U.  S. Dept. of Health,
Education,'  and Welfare, National  Center for Air Pollution Control, Cincinnati,
Ohio,  PHS-Pub-999-AP-40, 1967, 892 pp.

-------
Elliott,  J.  H.,  Kayne, N. , and LeDuc,  M. F   "Experimental Program for the
Control of Organic Emissions from Protective Coating Operations. "  Los
Angeles County Air Pollution Control District, Calif., Interim Report 7, Jan.
1961, 23 pp.
GYPSUM
Hankin, M.,  Jr.  "Is Dust the Stone Industry's Next Major Problem?"  Rock
Prod., ^70(4):80-84,  110,  April 1967.

LIME

Kaylor, F. B.  "Air Pollution Abatement Program of a Chemical Processing
Industry." J. Air Pollution Control Assoc. ,  15_(2):65-67, Feb.  1965.

Pottinger, J. F.  "The  Collection of Difficult Materials by Electrostatic
Precipitation."  Australian Chem. Process Eng.  (Sidney), _20(2): 17-23,
Feb.  1967.

PITS AND QUARRIES

Danielson, J. A.  "Air  Pollution Engineering Manual. " U.  S. Dept of Health,
Education, and Welfare, National Center for Air  Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40, 1967, 892 pp.

Davydov,  S.  A. , Aksel'rod, M.  B. , Mar'Yash, L. R. , and Klimenko,  E.  I.
"Contamination of the Atmospheric  Air with the Waste of Ore-Concentrating
Works. "  [Zagryaznenie atmosfernogo vozdukha vybrosami gornoobogatitel'nykh
kombinatov.] Hyg. and Sanit. , 2_9(2): 115-118,  Feb. 1965.

Hankin, M. ,  Jr.  "Is Dust the Stone Industry's Next Major Problem?"  Rock
Prod. , 7_0(4):80-84,  110,  April 1967.

Renninger, F. A.  "A Monitoring System for the  Detection and Control  of
Airborne  Dust."  Dust Topics  Mag., _3(4):6-8,  Oct.  1966.

Schrauf,  R.  E.   "Dust Suppression  at St.  Mary's Quarry. "  Mining Minerals
Eng.  (London),  _3(l):32-33, Jan. 1967.

Walter, E.  "Dust Control in Quarrying and Rock Processing by Means of
Suction Devices. "  Staub (English translation),  25(6):l-4,  June 1965.
                                   8-42

-------
OTHER

Gabmova, Zh.  L. ,  Vasil'eva, A. A. , Sklyarskaya, N.  Kh. ,  and Manita,  M. D.
Gigiena i Sanit.  (English translation), _28(6):65-69, June 19G3.

Mori, H.  "Hanshin Wet Type Dust Collectors. "  Clean Air and Heat Management
(Tokyo), ^5(5):5-11, May 1966.

AGRICULTURAL OPERATIONS

"Wastes in Relation to Agriculture and Forestry. "  U. S. Dept. of Agriculture,
Miscellaneous Rib. 1065, March 196S,  112 pp.

Pathark, V.  K. and Pady, S. M.   "Numbers and Viability of Certain Airborne
Fungus Spores. "  Mycologia, Vol. 57, pp. 301-310, March-April 1965.

Hewson,  E.  W.  "Air Pollution by Ragweed Pollen, 1.  Ragweed Pollen as Air
Pollution."  J.  Air Pollution Control Assoc. , JLTJIO): 651-652,  Oct.  1967.

Went, F. W. "Formation of Aerosol Particulates Derived from Natural
Occurring Hydrocarbons Produced by Plants. "  J. Air  Pollution Control Assoc. ,
p. 579,  1967.

Went, F. W. "Blue Hazes."  Nature,  187_(4738):641-G43, 1960.

"Soil Erosion by Wind,  and Measures for its Control on Agricultural Lands. "
Food and Agriculture  Organization, 1960.

"Shelterbelt Influence on Great Plains Fields, Environment,  and Crops."  U.  S.
Forest Service,  Production  Research Report 62, Oct.  1962.

"How to Control Soil Blowing. "  U.  S.  Dept. of Agriculture,  Farmers Bulletin
2169,  1961.

"Soil Conditions Influence Wind Erosion. "  U. S. Dept.  of Agriculture, Technical
Bulletin 1185,  June 1958.

"Suggested Guide for Use of Insecticides to  Control Insects Affecting Crops,
Livestock, Households,  Stored Products, Forests,  and Forest Products."
Agriculture Handbook 331,  1968.
                                   8-43

-------
COFFEE ROASTING

Danielson, J.  A.  "Air Pollution Engineering Manual. "  U. S. Dept. of Health,
Education, and Welfare, National Center for Air Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40,  1967, 892 pp.

Partee, F.  "Air Pollution in the Coffee Roasting Industry. "  U. S. Dept. of
Health, Education,  and Welfare,  Div. of Air Pollution, Cincinnati, Ohio,
PHS-Pub-999-AP-9,  1964, 15 pp.

Sullivan, J. L. , Kafka, F. L., and Ferrari,  L.  M.  "An Evaluation of Catalytic
and Direct Fired Afterburners for Coffee and Chicory Roasting Odors. "  J.  Air
Pollution Control Assoc. , _15(12):5S3-586,  Dec.  1965.

COTTON GINNING

"Airborne  Particulate Emissions from Cotton Ginning Operations."  U. S.  Dept.
of Health,  Education, and Welfare, Div. of Air  Pollution,  Cincinnati, Ohio,
Technical Report A60-5, 1960, 20pp.

"Control and Disposal of Cotton Ginning Wastes. " U.  S. Dept.  of Health,
Education, and Welfare, National Center for Air Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40,  1967, 103 pp.

Paganini,  O.  "Control of Cotton Gin Waste in Texas. " Preprint.  (Presented
at the 57th Annual Meeting of the  Air Pollution Control Association, Houston,
Tex. ,  June 24,  1964, Paper  64-94.)

"What We Know About Air  Pollution  Control. " Texas  Cotton Ginners1 Association
(Dallas), Special Bulletin 1,  March 1965, 43 pp.

FEED AND GRAIN

Barfield,  S.  "Harbor Bulk-Loading Grain Terminals. "  J. Environ.  Health,
_2S(2);151-155,  Sept.-Oct.  1965.

Danielson, J.  A. (ed.)  "Air Pollution Engineering Manual. "  U. S. Dept. of
Health, Education,  and Welfare,  National Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40,  1967, 892 pp.

"Proceedings of the National Symposium on Air  Pollution. "  Grain and Feed
Dealers National Association, Jan. 11-12, 1967, 103pp.
                                    3-44

-------
McLouth, M. E.  and Paulus,  H.  J.  "Air Pollution from the Grain Industry. "
J.  Air Pollution Control Assoc. , 11(7):313-317,  July 1961.

FISH MEAL PROCESSING

Danielson, J. A.  (ed.)  "Air Pollution Engineering Manual. " U. S. Dept. of
Health,  Education,  and Welfare,  National  Center for Air Pollution Control,
Cincinnati, Ohio, PHS-Pub-999-AP-40,  1967, 892pp.

Mandell, L. C.  "Air Pollution Control for the Fish Dehydration Industry."
(Presented at the 54th Annual Meeting of the Air Pollution Control Association,
New York, June 11-15, 1961.)

OTHER

Danielson, J. A.  "Air Pollution Engineering Manual. " U.  S. Dept. of Health,
Education, and Welfare, National Center for Air Pollution Control, Cincinnati,
Ohio, PHS-Pub-999-AP-40,  1967,  892pp.

Storch, H. L.  "Product Losses  Cut with a Centrifugal Gas  Scrubber."  Chem.
Eng.  Prog., _62(4):51-54, April 1966.
                                     8-45

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                              AUTHOR INDEX
Ackley, c.                           4_113
Adams, R. L.                        4-149, 4-150, 4-151, 4-153, 4-171,
                                     4-177, 8-27
Adrian, R. C.                        4-190, 4-196, 4-217
Aizenshtadt, B.  M                    8-41
Aksel'rod, M. B.                     8-42
Albinus,  G.                          8-21
Aleksynowa, K.                       8-40
Allen,  G.  L.                          8-32
Alliot, L.                            8-15
Alpiser,  F. M.                       3-71
Archbold, M.  J.                      4-101
Archer, A.                           8-27
Arkhipov, A. S.                       8-33
Arnold, O. M.                        4-61
Aslander, A.                         8-6
Auclair,  M.                          8-15
Axtman,  W. H.                       8-15
Bacon, N.  P.                         4-111, 8-30
Bailey, J.  M.                        4-217
Bailey, R. E.                        8-35
Ballard,  W. E.                       7-3
Banner, A. P.                        4-217
Barber, J. C.                        8~w
Barenstein, M.                       8~26
Barfield,  S.                          8~44
Barker, K.                           8'8' 8~15' 8~17
                                    A-l

-------
Barr, J.                            4-204
Basse, B.                           8-27
Baxter, W. A.                       4-109
Beckman, E. W.                     8-3
Beiser, F. R.                       8-29
Belyea, H. A.                       8-15
Bender, R. J.                       8-19
Benforado, D. M.                    4-196, 4-200, 4-217, 8-38
Bennett, K.  W.                      3-72
Beorse, B.                          8-19
Berly, E.                           4-66
Betz, L. D.                         4-86
Betz, W. H.                         4-86
Bigelow, C. G.                      4-61
Billings, C.                         4-31
Bins, R. V.                         8-8
Black, H. H.                        8-36
Black, R. J.                         3-61, 3-63, 3-64, 3-65,  3-66, 3-74,
                                    3-76, 3-83, 3-84, 3-86
Blasewitz,  A.  G.                     4-69
Blecher, K. J.                       8-14
Bloomfield,  B.  D.                    8-27
Blosser, R. O.                      4-74, 8-35
Boabel, R. W.                       8-19, 8-23
Bogue, M.  D.                        3-85
Boldue, M. J.                       8-37, 8-38
Borgwardt, R. H.                    4-135, 7-2, 8-8
Bovier, R.  F.                       8-8
Bowerman, F. R.                    8-24
                                   A-2

-------
Boyer, R. H  > Jr_                    3_85)  g_19
Boyer, R. Q-                         8_35
Boystsov, A.  N                       8-33
Brandt,  A. D.                        3-34,  3-35, 3-48, 4-111, 8-27
Braubacher, M.  L.                    8-6
Bremser, L. W.                      3-65
Brewer,  G. L.                        8-37,  8-38
Brief, R.  S.                          8-16
Brink, J.  A. , Jr.                     4-69,  8-33, 8-34
Brogan, T. R.                        3-27
Broman, C.                          8-27
Brooke, M.                           4-86
Brooks, A. F.                        4-59
Brooks, R. M.                       4-86
Brown,  R. S.                         8-24
Browning, J. A.                      4-190, 4-196
Bugher,  R. D.                        8-24
Bull, W.  C.                          8-11
Bump, R. L.                         8-19
Burckle,  J. O.                       3-76, 7-2
 Burggrabe, W. F.                    4-69, 8-33, 8-34
 Burke,  S. A.                         8-9
 Burson,  J. H.                        7-3
 Burst, J. F.                         4-211, 4-213
 Busch,  A. W.                        4-85
 Busey,  H.                           8-18
 Bush, A.  F.                          8-3, 8-19
 Bye  w  E                           3-32, 3-33, 3-34, 3-35, 3-37, 8-31
                                   A-3

-------
Cafiero,  A.  S.                        8-21
Cahill, W. J. , Jr.                    8-9
Calaceto, R.  R.                       8-19,  8-22
Calcote,  H.  F.                        4-190, 4-196
Calonge,  A.  B.                       8-5
Calvert,  S.                           7-3
Campbell, W.  W.                     4-140, 4-141,  8-27
Caplan, K.  J.                         4-170, 4-181,  4-202, 4-203, 4-217
Cederholm,  C.                        8-19
Challis,  J.  A.                        8-22
Chamberlin, R.  L.                    8-9, 8-27, 8-40
Chase, F. R.                         4-174
Chass, R. L.                         3-78,  8-10,  8-17, 8-24
Chilton,  C. H.                        4-23,  4-76,  4-198, 4-200, 4-213, 4-217
Chipman, R.  D.                       8-19
Chittawadgi, B.  S.                    8-6, 8-15
Clarke, S. M.                        8-20
Clement, R. L.                       4-140, 4-142,  4-143, 4-144, 4-145,
                                     4-183
Collins,  F. C.                        8-31,  8-40
Collins, K. E.                        8-9
Collins,  T. T. ,  Jr.                   8-35
Connel, J. R.                         8-36
Conners, E.                          4-31
Conway,  R.  A.                        4-83
Cooper,  G.                           4-217
Cooper,  H. B. H.                     8-35
Cooper,  H. B. H. , Jr.                4-74
Cooper, R. L.                        8-27
                                   A-4

-------
Cooper, S. R.                        8_35

Copp, W.  R.                          3_61

Corey, R. C.                         8-19

Cosby, W. T.                         8-28

Cote,  W. A.                          3-78, 4-179

Coy, D. W.                           4-111, 8-31

Cuffe, S. T.                          3-32, 4-111, 4-175, 4-176,  8-9,  8-10,
                                     8-40

Culhane, F.  R.                       4-150, 4-151, 4-153, 4-155, 4-156,
                                     4-157, 4-165, 4-166, 4-167, 4-169,
                                     4-170, 4-174, 4-181

Danielson, J. A.                      3-43, 4-16, 4-19,  4-23, 4-114, 4-122,
                                     4-189, 4-195, 4-202, 4-204, 4-207,
                                     4-217, 6-4, 6-26,  8-9, 8-15, 8-17,
                                     8-32, 8-33, 8-34,  8-36, 8-37, 8-39,
                                     8-40, 8-41, 8-42,  8-44, 8-45

Dave, N. R.                          8-6

Davies,  E.                           8-28

Davis, A.  L.                          3-4

Davydov, S.  A.                       8-42
Dealy, J.  O.                          8-23

Debrun, G.                           8-9
Decker, L. D.                        4-188, 4-217, 6-26

DeHaas, G. G.                        4-202, 4-203

Dennis,  R.                            4-31, 4-49

Derndinger,  H. O.                     8-3

Dickerson, B.  W.                     4-86
Doherty, R.  E.                       3-41, 3-42, 8-40

Dorsey, J.  A.                         3-76, 7-2

Douglas, I. H.                        8-28

Doyle, H.                             4~59
                                  A-5

-------
Dragoumis,  P.                        3-27
Drake, R. M. ,  Jr.                    4-189, 4-193
Drinker, P.                           4-31
Drogin, I.                            3-33, 3-53,  4-179
Dubinskaya,  F. E.                    8-28
Duffy,  R.                             4-188
Dumont-Fillon, J.                    8-30
Dunn, C. W.                         4-111
Duprey, R.  L.                        3-4, 3-83, 4-5, 5-3, 5-4, 5-5, 5-6.
                                     5-7, 5-8, 5-9, 5-10
Durham, J.  F.                        4-135
Dyer, J.                             8-3
Ebersole, G. D.                      8-3
Eckenfelder, W. W.                   6-57
Eckert, E. R.  G.                     4-189, 4-193
Eckert, J. S.                         4-55, 4-78,  4-81
Edwards,  V. H.                      4-83
Ekberg, G.                           8-6
Eldib,  I. A.                           8-3
Elliott,  A. C.                         4-111, 8-28
Elliott,  J. H.                         8-42
Ellison, W.                           8-28
Elson,  R. J.                         8-28
Engelberg, F.                         8-28
Engelbrecht, H. L.                    8-9
Engels, L. H.                         8-14, 8-28
Etoc, P.                             8-15
Ettinger, H. J.                        8-18
                                   A-6

-------
Fagley, W.  S.                         8-3
Fauth, U.                             8-15
Fawell, H. D.                         8-6
Felgar, D. N.                         7-3
Fenforado, D. M.                      6-26
Fernandas,  J. H.                      8-9, 8-19, 8-22
Ferrari, L. M.                        4-227, 4-253, 8-44
Feuss, J. V.                          3-82
Fiala, E.                             8-3
Field, M. A.                          4-191, 4-192, 4-196
Fife,  J.  A.                            3-85, 8-19, 8-22
Finfer, E.  Z.                         8-15
First, M. W.                          4-31, 4-66, 8-37
Fischer, G. I.                         4-31
Flodin, C.  R.                         8-10
Flood, L. P.                          8-19, 8-22
Flory, F.                             8-5
Flower,  F.  B.                         3-82
Foote, E. H.                          4-78, 4-81
Four,  R.                              8-14, 8-15
Fournier, M.                          8-10
Frame, C. P.                         4-111, 8-28
Frederick, E. R.                      4-132, 4-159
French,  R.  C.                         4-158, 4-160, 4-171, 4-172
Friedlander, S.  K.                     4-31
Friedrick,  H. E.                      4-127, 4-158, 4-171, 4-172, 4-180
Frieling, G.                           3-17, 3-18, 8-12
Fullerton, R. W.                      4-73, 4-140, 4-141, 8-27, 8-29
                                    A-7
   331-716 O - 69 - 34

-------
Gabinova, Zh. L.                     8-43
Gallaer,  C. A.                        8-39
Gamble,  B. L.                        4-196, 4-217
Gambs, G. C.                        6-59
Gamxnelgard, P. N.                   8-36
Gardner, J.  W.                       8-3
Gartrell, F.  E.                       8-10
Gehm, H. W.                         8-35
George, R. E.                        8-10, 8-17
Gerstle,  R. W.                       8-9, 8-10
Gilbert, N.                           4-32, 4-33
Gill, D. W.                           4-191, 4-192, 4-196
Glasgow, J.  A.                       4-111
Glater, R. A.                        8-3
Glensy, N.                           8-10
Glover, I.                            8-6
Godsave, G.  A.  E.                    4-190, 4-195, 4-196
Goldberger,  W.  M.                    8-10
Golothan,  D.  W.                      8-6
Golueke,  C.  G.                       3-69, 8-25
Goodel, P. H.                        4-200, 4-202
Gosselin,  A.  E. , Jr.                  8-10
Gould, R. H.                          8-20
Gourdine, M. C.                      3-27
Grames,  L.  D.                       4-196, 4-217, 6-26, 8-38
Grant, E. P                          8-4, 8-6
Grant, H. O.                          8-38
Greaves, M.  J.                       8-29
                                  A-J

-------
Greco, J.                             3_19>  4_109
Greeley, S.  A.                        8-20
Greenburg,  L.                         4-134, 4-135,  4-136
Greenwell, L. E.                      8-33
Gregory, C. A., Jr.                   4-190, 4-196
Griffiths,  J. C.                        4-188, 4-191,  4-204, 4-211
Griswold, S. S.                        8-10,  8-15, 8-17
Groebler, H.                          8-6
Gruber, C.  W.                        8-14
Gudmundsen, A.                       4-190, 4-196
Gusman, I.  J.                         4-161
Haaland, H.  H.                        8-10
Haedike, E.  W.                        8-22
Hagan, J. E.                          4-163, 4-164
Hagiwara, I.                          8-16
Hales, J.  M.                          3-33,  4-112
Halitsky, J.                           3-66
Hall, M. C.                            8-24
Hall, R.  M.                            4-46,  7-3
Hamming, W.  J.                       4-31
Hammond, W. F.                      4-196, 8-30
 Hangebrauck,  R. P.                    7-2, 8-11, 8-16, 8-17, 8-21, 8-39
Hankin, M. , Jr.                       8-39,  8-41, 8-42
Hansen, G.  A.                         4-202, 4-203
Hanson, V.  W.                        4-61
Harding, C.  I.                         3-4, 8-25, 8-35
Harrington,  R. E.                      4-135, 7-2, 8-8
Harris, E. R.                         8~29
                                    A-9

-------
Harris, L. S.                         4-49
Harrison, A. F.                      8-36
Harrison, B. P., Jr.                 4-175
Haskell,  C.  F.                        8-35
Hatch, T.                            4-134,  4-135, 4-136
Hatchard, R. E.                      8-26
Hattori, I.                           8-16
Haug,  L.                             8-25
Hausberg, G.                         8-26
Hawksley, P G. W.                   4-191,  4-192, 4-196
Hayes, S. C.                         8-39
Hazzard,  N. D.                       4-196,  4-200
Hedlund,  F.                           8-6
Hein, G. M.                          6-26
Heinen, C. M.                        8-4
Hem on, W.  C. L.                     8-29
Henderson,  J.  J.                      3-4
Henschen, H. C.                      8-29
Herrick, R.  A.                        4-137,  4-177, 4-178, 8-29
Hersey, H.  J. ,  Jr.                    4-149
Hess, K.                             8-36
Hewson,  E.  W.                        8-43
Hibshman, H. J.                      8-36
Hickman,  H. L.                       3-67, 3-68, 3-85
Hickman,  H. L. , Jr.                  3-61, 3-63, 3-64, 3-65, 3-66,  3-74,
                                     3-76, 3-83, 3-84, 3-86
High, M. D.                           3-32, 3-33, 3-34, 3-35, 3-37,  8-31
Hirao, O.                             8-4
Hoff,  H.                              8-29
                                   A-10

-------
Hofmann, H.                           8-5
Holden, F. R.                          4-113
Holland,  M.                            8-29
Holland,  W. J.                         8-15
Horton, R. C.                          4-161
Hottel, H.  C.                           4-187, 4-190,  4-196
Houghton, H. G.                        4-74
Houry, E.                              8-22
Howell, G. A.                          4-111
Howells, H. E.                         8-7
Hoy, D.                                8-29
Hughson,  R.  V.                         4-23
Hunigen, E.                            8-4
Huntington, R.  L.                      4-78, 4-81
lehle,  F.                              8-14, 8-15
Ilgenfritz, E.  M.                       4-217
Ingels, R.  M.                          3-43, 4-190, 4-202,  4-211,  4-217
Innes,  W.  B.                           4-188
Intelmann, W.                          4-16, 4-22
Jackson, A.                            8-29
Jackson, J.                            4-76
Jackson, M. W.                        8-4
Jackson, N. H.                         8-26
Jackson, R.                            4-14, 4-86
Jackson, W.  E.                         8-4
Jacobs, H. L.                          4"86
Jacobs, M.  B.                          3~66
Jacquinot,  P.                           8~10
                                    A-ll
    331-716 O - 69 - 35

-------
Jamison, R. M.                       4-61
Jares, J.                             4-217
Jaskulla, N.                          8-4
Jens, W.                             8-20
Jensen, D. A.                        8-4,  8-6
Johnson, G. A.                       4-31
Johnson, J. E.                       8-29
Johnson, K. R.                       8-7
Johnson, R. K.                       8-27
Jonakin, J.                           8-12
Jones, A. H.                         4-175
Jones, G.                            8-36
Judson, B. F.                        4-69
Junker, E.                           8-26
Kafka, F. L.                         8-44
Kaiser, E. R.                        3-66, 3-75, 8-20, 8-22
Kapitulskii, V. B.                    8-29
Katz, J.                             3-19, 8-11
Kaylor, F. B.                        8-38, 8-42
Kayne,  N.                            8-42
Keller, J.  D.                         4-189, 4-207
Kemnitz,  D.  A.                       3-32, 4-111,  4-175,  4-176, 8-40
Kenagy, J. A.                        8-37
Keng, E.  Y.  H.                       7-3
Kenline, P. A.                       3-33, 4-112
King, D.  T.                          8-11
Kirkpatrick,  S.  D.                    4-23, 4-76, 4-198, 4-200, 4-213, 4-217
                                  A-12

-------
Kirov, N. Y.                          8_n> 8_16>  8_20
Kirsh, J. B.                          3_68
Kitani, S.                             8_18
Klee, A. J.                            3-61, 3-63,  3-64, 3-65, 3-66, 3-74,
                                      3-76, 3-83,  3-84, 3-86
Kleeberg, U.                          8-26
Klimenko, E. I.                        8-42
Kloepper, D. L.                       8-11
Knudson, J.  C.                        3-78
Kobayashi, K.                         4-187, 4-190, 4-196
Kogan, L. A.                          8-29
Kohler, W.                            8-41
Koin, H. W.                           8-22
Kopa, R. D.                           8-4
Kowalczyk, J. F.                      3-78
Kran, W. G.                           4-190, 4-196
Kreichelt, T. E.                       3-32, 3-77,  4-111, 4-175, 4-176,
                                      8-20, 8-40
Krenz, W. B.                          4-190, 4-217
Krikau, F. G.                         8-30
Kristal, E.                            4-49
Krochtitzky, O. W.                     8-25
Kropp, E. P.                          8-36
Krouse, M.                            4-66, 8-37
Kunii, D.                              4-190, 4-196
Kurtz,  P.                             8-19
Labardin, A.                           g-16
Lafreniere, A. J.                      4-111, 8-28
Lair, J.  C.                            8~5
                                  A-13

-------
Lambert, W.  H.                      8-8
Landry, J.  E.                       8-35
Lapple, C.  E.                       4-10, 4-11, 4-14, 4-15
Laroche, M.                         8-11
Larsen, R. I.                        8-4
Larson, G. P.                       4-31
Lawson, S. O.                       3-7
Leavitt, J.  M.                       8-11
LeDuc, M.  F.                       8-42
Lee, G. W.                          8-27
Lemaire, A.                         8-32
Lemke, E.  E.                       8-30
Lemon, L.  W.                       8-10
Lenehan, J. W.                      8-20
Lepisto, P.                          8-7
Licht, W.                            4-130, 4-160, 4-173, 4-181, 4-183
                                    4-184
Lieb, H.                             8-22
Lieberman, C.                       3-71
Lloyd, H.  B.                         4-111, 8-30
Lock, A. E.                         8-11, 8-16
Lohner, K.                          8-4
London, D. E.                       8-36
Longwell,  D.  H.                      8-35
Loquercio,  P. A.                     3-66
Loszek, W.                          8-30
Louden, W. L.                       8-36
Ludwig, J.  H.                       8-5, 8-7
Lundberg, G.  R.                     8-39
Luxon, S.  G.                         8-41
                                 A-14

-------
Maatsch, J.                          8-29
MacFarlaue, W. A.                   8-8, 8-15,  8-17
MacKnight, R. J.                     3-78, 8-21, 8-23,  8-24
Magill, P.  L.                         4-113
Magnus, M. N.                       8-12
Mandell, L. C.                       8-45
Manito,  M. D.                        8-43
Martin,  R.                           8-12
Mar'Yash,  L.  R.                      8-42
Masciello,  F.                         8-38
Massey, O. D.                       4-76
Mauss,  F.                            8-14, 8-16
Mawhinney, M. H.                    4-196, 4-207,  4-211, 4-213
Mayer,  M.                           3-66, 3-73, 3-78
McCabe, L. C.                       3-66, 8-32
McConnell, G.                       8-7
McGannon, H. E.                     3-35
McGaughey, P. H.                    3-69, 8-25
McGrane, N. M.                      8-39
 McKee, H. E.                        3-5
 McKenzie, D.                         4-217
 McKim, W. A.                       8-39
 McLouth,  M.  E.                      8-45
 McMahon,  W.  A. , Jr.                 3-5
 McReynolds, L. A.                   8-3
 Meeker, J. E.                       8-11, 8-16, 8-39
 Meinhold,  T.  F.                      8-34
                                     o  o r\
 Meissner,  H.  G.                      8~^u
                                     Q  1 Q
 Meland, B. R.                       8~ib
                                   A-15

-------
Meurer,  S.                           8-5
Meyer, W. E.                        8-7
Meyers,  F.  D.                       4-196, 4-217
Middleton, J.  T.                      8-41
Miller, D. W.                        8-37
Miller, M. R.                        4-190
Miller, P. D. , Jr.                    8-36
Mills, J.  L.                          4-196
Mitchell,  R.  D.                       8-39
Mitchell,  R.  T.                       4-111, 8-30
Mizushima, J.                       8-19
Monroe,  E.  S. , Jr.                   3-76
Montross, C.  F.                      4-43
Moodie, G.                           8-9, 8-27, 8-40
Moody, R. A.                        4-217
Moore, J. F.                         3-7
Moore, W. W.                       3-14, 3-17, 8-12
Morash,  N.                           4-66, 8-37
Morgan,  B.  B.                       4-191, 4-192, 4-196
Morgenthaler, A. C.                  8-18
Mori, H.                             8-41, 8-43
Morris, J. P.                        8-5
Mortstedt, S.  E.                      8-6
Moschella, R.                        4-31, 4-66
Moser, E.                           8-26
Moss, W. D.                         8-18
Mowbray, K.  D.                      8-22
Muhich, A.  T.                       3-61, 3-63, 3-64, 3-65, 3-66, 3-74,
                                     3-76, 3-83, 3-84, 3-86
                                  A-16

-------
Mukai, M.                            g  4
Mukhlenov, I. p.                      4_76
Muller, H.                            g_4
Mundy, L. W.                         8_39
Murphy, R. P.                         8_31
Namy, G.                              8_30
Netzley, A. B.                         8-24
Neuhaus, H.                           8-30
Nishiwaki, N.                          4-187, 4-190, 4-196
Nissen, W. E.                         8-4, 8-6
Noland, R.                            4-180
Norman,  G.  R.                         3_8
Northcraft, M.                         8-23
Ochs, H.  J.                            8-30
O'Conner, C.                          3.75, 8-20
Oiestad, A.                            8-16
Olsen, J. W.                           4-178, 8-29
O'Mara, R. F.                         4-111
Orning, A. A.                         4-187, 4-196, 8-9,  8-10
Orr, C.                               7-3
Ott, R. R.                             8-26
Owens, V. P.                          8-35
Ozolins, G.                            3-4
Pady, S. M.                            8-43
Paganini, O.                           8-44
Pallinger, J.                           4-49, 8-30
Papovich,  M.                           8-23
Parker, A. S.                         4-190, 4-196
                                  A-17

-------
Parker, C. H.                        8-37
Parker, C. M.                        8-30
Partee, F.                           8-44
Pascual, S.  J.                        8-20
Pathak, V. K.                        8-43
Pauletta,  C. E.                       4-196,  4-200, 4-217, 6-26, 8-38
Paulus, H. J.                         8-45
Pearse, D. J.                        8-32
Penney, G. W.                        7-3
Perils, D. B.                         8-39
Perry, J.  H.                         4-32
Perry, R. H.                         4-23, 4-76, 4-198, 4-200, 4-213,
                                     4-217
Pesterfield, C. H.                    8-16
Peterson, D. G.                      8-9
Pieratti, A.                          8-20
Plumley,  A. L.                       8-12
Pollock, W. A.                       3-17, 3-18, 8-12
Poppele, E. W.                       4-73
Pottinger, J. F.                      8-12, 8-30, 8-42
Powers, E.  D.                        4-76
Pozin, M. E.                         4-76
Prindle, R. A.                        3-61
Pring, R.  T.                          4-173
Punch, G.                            4-111,  8-30
Pursglove, J. ,  Jr.                    8-12
Quack, R.                            8-12
                                 A-18

-------
Rabel, G.                             8_30
Radford, W.  H.                       4-74
Radier, H. H.                         4-203
Rammler, E.                          4-16, 4-22
Ramsdell, R.  G. ,  Jr.                  4-101
Rao, T. V. L.                         8-7
Rather, J. B. , Jr.                     3-7
Rauscher, J. A.                       4-69, 8-34
Ray, F. A.                            4-178,  8-29
Rayher, W.                            8-41
Reed, L. E.                           8-7
Reed, R. J.                            4-217
Reese, J. T.                          3-19, 4-109
Rehm, F. R.                          8-20
Reichenbach, G. S. , Jr.               4-31
Reminiczky, K.                        8-16
Renninger, F. A.                      8-42
Retzke, R. A.                         8-38
Rice, O. R.                            4-61
Richards, G.                          8-3
Rickles, R. N.                         4-85
Ridgway, S.  L.                        8-5
Ridker,  R. G.                         6-5
Riley, B. T.                           3-76, 7-2
Rispler, L.                            8-5,  8-7
Robinson,  M.                          7-3
Rodebush, W.  H.                       4-13°
Rogers, T. F.                         8~1:L
Rogus, C. A.                          8-21
                                  A-19

-------
Rose, A. H.                          8-5, 8-7
Rose, A. H. , Jr.                     4-129, 4-176, 4-178, 8-21,  8-36
Rosin, P.                            4-16, 4-22
Ross, C. R.                          8-5, 8-7
Rossano, A. T.                       4-31
Rothman, S. C.                       8-26
Ruff,  R.  J.                           4-202, 4-203
Russell,  R.  R.                        8-24
Rutman,  Z.  M.                       8-41
Sableski, J. J.                        3-78
Sableski, J. J.,  Jr.                   8-23, 8-24
Sachsel,  G.  F.                        8-38
Sana, I.  S.                           8-35
Sandomirsky, A. G.                   4-196, 4-217, 6-27,  8-38
Sarto, J. O.                          8-3
Sauchelli, V.                         8-38
Scheldhammer, A.                    4-77
Schenk, R.                           8-5
Schneider,  R.  L.                      8-31
Schnitt, H.                           8-26
Schrauf,  R.  E.                        8-42
Schueller, H. M.                      3-62
Schueneman, J. J.                    3-32, 3-33,  3-34, 3-35, 3-37, 8-13
                                     8-17, 8-18,  8-31
Schuldt, A.  F.                        8-31
Schule, W.                           8-15
Schwartz, A. J.                       7-2, 8-17
Schwartz, C. H.                       8-9, 8-10
Schwarz, K.                          8-13
                                  A-20

-------
Schwendinian, L.  C.
Scope, S.
Sedeler, C. G.
Seely, R. J.
Sem, M. O.
Semrau, K. T.
Senecal, J. E.
Sensenbaugh, J.  D.
Severs, R. K.
Shaffer,  N. R.
Shale, C. C.
Sheehy, J.  P.
Sheppard, S.  V.
Sherman, R.  A.
Shutko, F.  W.
Sibel,  J. T.
Silverman, L.

Simon, H.

Simonsen, R.  N.
Simpson, H.  C.
Sklyarskaya,  N.  K.
Smith, D. F.
Smith, J. H.
Smith, R. I.
Smith, S.
Smith, W. M.
Smith, W. S.
 8-18
 8-4
 4-202
 3-66, 8-25
 8-31, 8-40
 4-34, 4-35, 6-24
 4-78, 4-80
 8-9
 8-37, 8-38
 3-43
 7-2
 3-4
 4-54
 4-189
 8-12
 3-69
 4-31, 4-49, 4-66,  4-127,  4-132,
 4-133, 8-18
 4-131, 4-134, 4-138, 4-150,  4-153,
 4-162, 4-163, 4-165, 4-170,  4-180, 4-181,
 4-182, 4-183
 8-36
 4-187, 4-190, 4-196
 8-43
 4-190, 4-196
 7-3,  8-31
 7-3
4-
23
111, 8-31
14, 8-17
                                  A-21

-------
Snowball, A. F.
Sommerlad, R. E.
Sordelli, D.
Sorg, T. J.
Spaite,  P.  W.

Spaulding,  D.  B.
Spenceley, G. D.
Spencer, J. D.
Spieckerman,  J. A.
Springer, K. J.
Stahenow, G.
Stairmand, C. J.
Starkman,  E.  S.
Stastny,  E.  P.
Stenburg, R. L.
Stephan, D. G.

Stephens on, J. W.
Sterling, M.
Stern, A. C.
Stickel,  R.
Stoker,  R.  L.
Stopperka,  K.
Storch,  H.  L.
Storch,  O.
Strauss, W.
Strewe,  W.
Stuart, H. H.
8-32
3-17, 4-171, 4-172
8-33, 8-34
3-67, 3-68
4-129, 4-135, 4-163, 4-164, 4-176;
4-178, 7-2, 8-8
4-187, 4-190, 4-196
8-31
8-14
4-211, 4-213
8-7, 8-8
8-21
4-4, 4-5, 4-39,  4-40, 4-43,  4-44
8-5
8-34
8-21, 8-23, 8-37
4-3, 4-129, 4-135,  4-137,  4-160,
4-163, 4-165, 4-176, 4-178
8-21
3-38, 8-21
4-29, 4-30
8-36
4-28
8-34
4-76, 8-38, 8-45
8-31
4-10, 4-15, 4-37, 4-134
8-14
8-35
                                   A-22

-------
Sullivan, J.  L.                       4-217,  8-31, 8-44
Swinehart, G.                         3_75> 8-20
Syrovatka, Z.                         8-21
Taheri, M.                           7_3
Talens, P. G.                         8-24
Tarat, E.  Y.                         4-76
Tate, R. W.                           4-78
Tebbens, B.  D.                       8-14
Teller,  A. J.                         4-36, 4-37, 4-54, 8-26
Termeulen,  M. A.                    8-37
Theodore,  L.                         7-3
Thieme, W.                           8-14
Thorn, G.  W.                         8-31
Thomas, G.                           8-30
Thomas, J.  F.                       8-14
Thomas, N.  J.                       4-185
Thomburgh,  G. E.                    8-23
Thompson, C.  W.                     4-188, 4-191
Thring, M. W.                       4-189, 4-196, 4-207, 4-217
Tigges, A. J.                         8-8
Todd, W. F.                          4-163, 4-164
Tolciss, J.                           8-22
Tomaides, M.                         8-41
Tomany, J. P.                        3-17, 3-18, 8-12
Topper, L.                           4-189
Toyama, T.                           8-33, 8-34
Treat,  R.                             8-4
Trenck, H. M.                       8-14
                                 A-23

-------
Tribus, M.                          8-4
Trinks, W.                          4-189, 4-196, 4-207, 4-211,  4-213
Truitt, S. M.                        4-217
Tulcinsky,  S.                        8-32
Tyler, T. L.                        4-190, 4-196
Underwood, G.                       8-32
Vandaveer, F. E.                    4-202
Van Doornum, G. A. W.              8-14
Varchavski, I. L.                    8-5
Vasil'eva, A. A.                     8-43
Vasseller,  W. P.                    4-66
Vaughn, R. D.                       3-61, 3-63, 3-64,  3-65, 3-66, 3-74,
                                    3-76, 3-83, 3-84,  3-86
Venezia, R.                         3-4
Verrochi, W. A.                     8-8
Vettebrodt, K.                       8-30
Vickerson, G. L.                    8-23
Viets, F.  H.                         8-32
Voelker, E. M.                      3-79, 8-24
Vogely, W. A.                       8-25
Voinov, A. N.                       8-15
Vollheim, G.                        4-190, 4-195, 4-217
VonBergen, J. M.                    3-32
VonLehmden, D. J.                  8-11, 8-16, 8-21,  8-39
Vosseller,  W. P.                    8-37
Wagner, K.                          8-26
Waitkus, J.                          4-196, 4-217
Walker, A. B.                       4-46, 7-3, 8-21, 8-35
                                  A-24

-------
Wallach,  A.                           4_217
Wallin, S. c.                         8_7
Walsh, G. W.                         4_135>  4_137
Walter, E.                            8_40> g_42
Walters,  D.  F.                        8_24
Wanta, R. C.                         8_36
Waple, E. R.                         4_86
Warner, D. L.                        4_86
Wasser, J. H.                        7_2, 8-17
Watson, K. S.                         8-14
Weatherley,  D.                        8-40
Weaver, L.                           8-25
Weber, E. J.                         4-188, 4-191
Weber, E. V.                         4-204, 4-211
Wechselblatt, P.  M.                   8-28
Wegman,  L.  S.                        8-21
Weil,  S. A.                          4-203, 4-204
Wene, A.  W.                          8-24
Went,  F.  W.                          8-43
Wentink, G.                          8-17
Weston, R. F.                        3-66, 8-25
Wettig, K.                           8-4
Weyers, W.                          8-14
Wheeler, D. H.                       8-32
Whiddon, O. D.                       8-12
White,  H.  J.                          4-90, 4-101, 4-102
Whitwam,  K.  B.                       8-29
Wiemer, P.                           8-40
Wiley,  J. S.                          8~25
                                  A-25

-------
Wilhoyte, H.  J.                       4-190
Willett, H. P.                        8-32, 8-34
Williams, C. E.                      4-134, 4-135,  4-136
Williams, D. I.  T.                    8-31
Williams, G. C.                      4-187, 4-190,  4-196
Williams, R. E.                      8-24
Williamson, J.  E.                    8-21, 8-23, 8-24
Williamson, J.  T.                    3-78
Wilson, E. L.                        4-1, 4-6, 4-7, 4-8, 4-9, 4-35,  4-112,
                                     6-4
Wilson, J. G.                        8-37
Wood,  C.                            8-7
Woodland, R. G.                      8-24
Woodruff, P. H.                      8-24
Wright, C. H.                        8-11
Yagi, S.                              4-190,  4-196
Yamaki,  N.                           8-6
Yocum, J.  E.                        8-38
Yokomiyo, K.                        8-32
York, O. H.                          4-73
Young, P. A.                         4-111,  8-30
Zaitsev,  M. M.                       8-28
Zanon, D.                            8-33, 8-34
Zavodny, S.                          8-22
Zender, W.                           8-4
Zeschmann, E.  G.                    8-3
Zhevnovatyi,  A.  N.                    4-85
Zhigalina, I.  S.                       8-28
                                 A-26

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      CONTROL TECHNOLOGY FOR PARTICULATE AIR POLLUTANTS
                             SUBJECT INDEX
                                     A
Acid manufacturing (see specific acid)
Aerosol
    definition of                         2-1
Afterburners
    discussion of                        4-184—4-213
    typical applications of                4-213, 4-217
Aircraft
    particulate emission sources          2-4—2-5
Apartment house incinerators
    general discussion of                3-81—3-83
Asphalt batch plants
    emissions from                      3-43—3-44
    control device used in                3-43—3-44
Automobile disposal                     3-70—3-72
Automobiles
    emission sources                    2-4, 3-3—3-7
Automotive emission control systems     3-3—3-7

                                     B
Baffles (impingement)                    4-73—4-74
Baghouse filters (see Fabric filtration)
Blast furnaces
    control devices used in              3-34—3-35
                                   A-27

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Carbon black manufacturing
    emissions from                      3-53
    control devices used in              3-53
Cement manufacturing
    emissions from                      3-41—3-42, 4-175
    control devices used in              3-41-3-42, 4-111, 4-175-4-176
Centrifugal collectors (dry)
    discussion of                        3-16—3-18, 4-15—4-29
    applications of                      4-29
Cleaning of fabric filters                 4-164—4-170
Coffee processing
    emissions from                      3-54—3-56
    control devices used in              3-55—3-56
Coke manufacturing
    emissions from                      3-45—3-48
    control devices used in              3-46—3-48
Collection efficiency of control equipment  4-10, 4-19—4-24,  4-34—4-35,
                                        4-107—4-109, 6-4
Combustion sources                      2-3—2-4
Commercial and industrial incinerators
    description of                        3-77—3-80
Composting
    description of                        3-69—3-70
Contaminant (see Pollutant)
Costs of control  equipment
    general                             6-1—6-64
    maintenance and operating            6-15, 6-18, 6-19
    gravitational collectors              6-22
                                  A-28

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    centrifugal collectors (dry)           6-22
    wet collectors                        6-23
    electrostatic precipitators            6-25
    filtration                            6-25—6-26
    afterburners                         6-26—6-27
Cotton ginning
    emissions from                      3-56
    control methods in                   3-56
Cyclone collectors  (see Centrifugal
    collectors)

                                      D
Demolition of masonry
    emissions from                      3-58
Design of combustion systems            3-3—3-9
Diesel-powered vehicles
    emissions of                         3-7—3-9
Disposal of collected particulate
    material                             6-54—6-64
Domestic incinerators                    3-77
Dust
    definition of                          2-1

                                      E
Electrostatic precipitators
    (high voltage)
    discussion of                         3-19, 4-87-4-112
    applications of                        4-7-4-9, 4-109
Electrostatic precipitators (low voltage)
    discussion of                         3-19> 4-113-4-126
    applications of                        ^^ 4~123
                                   A-29

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Emission factors
    general                             5-1—5-11
    coal combustion                     5-2
    process industries                   5-11
Energy conservation                     3-25, 3-27
Energy source fuels                     3-11
Energy substitution                      3-20—3-25
Fabric filtration
    discussion of                        3-19, 4-127—4-184
    application of                       4-127—4-128, 4-175—4-180
Fabrics (filter)                          4-146—4-148, 4-158—4-164
Federal assistance for solid waste
    programs                           3-86—3-87
Filters (irrigated wet)                   4-66
Flue fed incinerators  (see Apartment
    house incinerators)
Fly ash
    definition of                         2-2
Fog
    definition of                         2-2
Foundries (gray iron)
    emissions from                      3-37—3-38, 4-176
    control devices used in               3-38, 4-176
Fume
    definition of                         2-2
                                  A-30

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                                      G
Gas cleaning devices                     3-16—3-19, 4-1—4-3
Gasoline-fueled vehicles
    emissions  of                        2-4  3-3	3-7
Glass manufacturing
    emissions  from                     3_51_3_53
    process description of               3_si_3_53
Gypsum processing
    emissions  from                     3-53—3-54
    control devices used in              3-53—3-54

                                      I
Incineration of  solid wastes              3-73—3-85
Incinerator control equipment
    efficiency  of                        3-73—3-85
Incinerators  (see specific type)
Industrial sources of particulates         2-4
Iron and steel mills
    emissions  from                     3-34—3-37
    control devices used in              3-34—3-37

                                      K
Kraft pulp mills
    emissions  from                     3-42—3-43
    control devices used in              3-42—3-43, 4-112
Landfills
    general description of                3-65—3-67
                                   A-31

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                                     •M
Mist
    definition of                         2-2
Mist eliminators                         4-66—4-76
Motor vehicles
    emission sources                    2-4, 3-3—3-7
Municipal incinerators
    general discussion of                 3-83—3-85
    control devices for                   3-83—3-85

                                     O
Open  burning                             3-58, 3-74
Open  top incinerators                     3-76
Particle
    definition of                         2-2
Particulate matter
    definition of                         2-1
Petroleum refineries
    emissions from                      3-39—3-40
    control devices used in               3-39—3-40
Phosphoric acid manufacturing
    emissions from                      3-45
    control device used in                3-45
Pollutant
    definition of                         2-1
                                     R
Research  (current) in control methods     7-1—7-3
Road dust
    control of                            3-59

                                    A-32

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 Road grading
     dust generation from                 3-59
 Sandblasting
     control of particulates from          3-59—3-60
 Scrubbers
     centrifugal spray                    4-40—4-43
     disintegrator                        4-61
     impingement plate                   4-43—4-45
     in-line wet                          4-63,  4-65
     mechanically induced spray          4_59_4_60,  4-62
     packed bed                          4-51,4-53—4-56
     performance of                      3-18—3-19,  4-32—4-65
     self-induced spray                   4-59,  4-60
    venturi                              4-44,  4-46—4-51
Settling chambers
     discussion of                        3-16,  4-10—4-14
     applications of                      4-13—4-14
Shutdown of emission sources             3-30
Sintering plants
     control devices used in               3-34
Smelters
     emissions from                      3-32,  3-49—3-50
Smoke
    definition of                         2-2
Soap and detergent manufacturing
    emissions from                      3-50  3-51
    control devices used in               3-50—3-51
                                   A-33

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Solid waste
    definition of                          3-62—3-63
    quantity produced                    3-63—3-65
Soot
    definition of                          2-2
Source relocation                         3-20
Sources of particulate matter             2-3
Spray chambers                          4-35—4-38
Spray nozzles
    types of                              4-78—4-81, 4-83
Sprays
    definitions of                         2-2
Spray towers                             4-39—4-41
Stationary combustion sources             3-10—3-15
Steel furnaces
    control devices used in               3-35—3-36
    emissions from                      3-35—3-36
Sulfuric acid manufacturing
    emissions from                      3-44
    control devices used in               3-44,  4-112

                                     W
Wet collectors
    discussion of                         4-32—4-86
Wood waste incinerators
    emissions from                      3-76—3-77
                                   A-34
                         U. S. GOVERNMENT PRINTING OFFICE : 1869 O - 331-716

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