STUDY OF TECHNICAL AND COST INFORMATION
FOR
GAS CLEANING EQUIPMENT
IN THE
LIME
AND
SECONDARY NON-FERROUS METALLURGICAL INDUSTRIES
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Contract No. CPA 70-150
STUDY OF TECHNICAL AND COST INFORMATION
FOR
GAS CLEANING EQUIPMENT
IN THE
LIME AND SECONDARY NON-FERROUS METALLURGICAL INDUSTRIES
FINAL REPORT
(Submitted December 31, 1970)
by
L. C. Hardison, Coordinating Engineer
H. R. Herington, Project Director
Industrial Gas Cleaning Institute, Inc.
Box 448, Rye, New York 10580
Prepared for
The National Air Pollution Control Administration
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INDUSTRIAL GAS CLEANING INSTITU1E, INC
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
150 Purchase Street
AMERICAN AIR FILTER CO., INC.
AMERICAN STANDARD, INC.
Industrial Products Div.
ARCO INDUSTRIES CORPORATION
BELCO POLLUTION CONTROL CORP.
BUELL ENGINEERING CO., INC.
BUFFALO FORGE COMPANY
THE CARBORUNDUM CO.
Pollution Control Div.
CHEMICAL CONSTRUCTION CORP.
Pollution Control Div.
DELTA PINCORPORATED
THE DUCON CO., INC.
DUSTEX DIVISION
American Precision Industries
FISHER-KLOSTERMAN, INC.
FULLER COMPANY, DRACCO PRODUCTS
GALLAGHER-KAISER CORPORATION
THE KIRK & BLUM MANUFACTURING CO.
Box 448
MEMBERS
Rye, New York 10580
KOERTROL CORPORATION
Sub. of Schutte & Koerting Co.
KOPPERS COMPANY, INC.
Metal Products Division
MIKROPUL
Div. of The Slick Corp.
NATIONAL DUST COLLECTOR CORP.
Sub. of Environeering, Inc.
'PEABODY ENGINEERING CORP.
PRECIPITAIR POLLUTION CONTROL, INC.
Sub. of Advance Ross Corp.
PRECIPITATION ASSOCIATES OF AMERICA
RESEARCH-COTTRELL, INC.
SEVERSKY ELECTRONATOM CORP.
THE TORIT CORPORATION
UOP AIR CORRECTION DIVISION
WESTERN PRECIPITATION DIVISION
Joy Manufacturing Co.
WHEELABRATOR CORPORATION
ZURN INDUSTRIES, INC.
STATEMENT OF PURPOSES
The Industrial Gas Cleaning Institute, incorporated in 1960 in the State of New York, was founded to
further the interests of manufacturers of air pollution control equipment, by
encouraging the general improvement of engineering and technical standards in the manufacture,
installation, operation, and performance of equipment
disseminating information on air pollution; the effect of industrial gas cleaning on public health; and
general economic; social, scientific, technical, and governmental matters affecting the industry, together
with the views of the members thereon; and
promoting the industry through desirable advertising and publicity.
ACKNOWLEDGEMENT
The efforts of the IGCI Engineering Standards Committee in the preparation, editing and reviewing of
this Report are gratefully acknowledged:
Harry Krockta, Chairman, The Ducon Company, Inc.
G. L. Brewer, UOP Air Correction Division
C. A. Gallaer, Buell Engineering Co., Inc.
N. D. Phillips, Fuller Co., Dracco Products
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
TABLE OF CONTENTS
IV.
Introduction
Summary of Technical Data
Technical Data
A. General Description
B. Process Descriptions and Costs
1. Rotary Lime Kilns
a. Description
b. Specifications and Costs of
Air Pollution Control Equipment
c. Discussion
2. Brass/Bronze Reverberatory Furnaces
3. Lead Cupolas
4. Lead/Aluminum Sweating Furnaces
5. Lead Reverberatory Furnaces
6. Zinc Calcination Furnaces
7. Aluminum Chlorination Stations
C. Discussion of Costs
1. Comparison of Installed Costs
2. Discussion of Operating Costs
D. Installation and Test Data
1. Rotary Lime Kilns
2. Brass/Bronze Reverberatory Furnaces
3. Lead Cupolas and Reverberatory Furnaces
4. Lead/Aluminum Sweating Furnaces
5. Zinc Calcination Furnaces
6. Aluminum Chlorination Stations
Conclusions and Recommendations
List of Figures
List of Tables
List of Appendices
Page No.
1
5
7
7
20
24
24
38
57
62
91
113
135
158
162
176
176
195
199
199
228
232
235
242
246
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
V^^^^^^^^^H^^^^^^^^^^H^^M
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
LIST OF FIGURES
Process Flow Sketch for Typical Lime Kiln
Costs of Electrostatic Precipitators for Rotary Lime Kilns
(LA-Process Weight)
Costs of Electrostatic Precipitators for Rotary Lime Kilns (High
Efficiency)
Costs of Fabric Collectors for Rotary Lime Kilns
Costs of Wet Scrubbers for Rotary Lime Kilns (LA-Process Weight)
Costs of Wet Scrubbers for Rotary Lime Kilns (High Efficiency)
Comparison of Abatement Costs for Rotary Lime Kilns
Process Flow Sketch of Brass/Bronze Reverberatory Furnaces
Cost of Fabric Collectors for Brass/Bronze Reverberatory Furnaces
Cost of Wet Scrubbers for Brass/Bronze Reverberatory Furnaces
( LA-Process Weight)
Cost of Wet Scrubbers for Brass/Bronze Reverberatory Furnaces
(High Efficiency)
Comparison of Abatement Costs for Brass/Bronze Reverberatory
Furnaces
Process Flow Sketch of Lead Blast Furnace or Cupola
Costs of Fabric Collectors for Lead Cupolas
Costs of Wet Scrubbers for Lead Cupolas
Process Flow Sketch of Typical Reverberatory Furnace Sweating
Page No.
25
44
45
51
58
59
60
64
80
87
88
89
92
105
110
Facility 115
Figure 17 Typical Fabric Collector Installation for Reverberatory Furnace
Sweating Facility 119
Figure 18 Typical Wet Scrubbing Installation for Reverberatory Furnace
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Page No.
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Figure 24
Figure 25
Figure 26
Figure 27
Figure 28
Costs of Fabric Collectors for Sweating Furnaces
Costs of Wet Scrubbers for Sweating Furnaces
Comparison of Abatement Equipment Costs for Sweating Furnaces
Process Flow Sketch for Lead Reverberatory Furnace
Process Flow Sketch for Lead Reverberatory Furnace with Wet
Scrubber
Costs of Fabric Collectors for Lead Reverberatory Furnaces
Costs of Wet Scrubbers for Lead Reverberatory Furnaces
Process Flow Sketch for Aluminum Chlorination Station
Wet Scrubber Cost Data for Aluminum Chlorination Stations
(LA-Process Weight)
Wet Scrubber Cost Data for Aluminum Chlorination Stations (High
Efficiency)
129
132
134
139
141
151
157
164
175
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Table 9
Table 10
Table 11
Table 12
Table 13
Table 14
Table 15
Table 16
Table 17
Table 18
Table 19
LIST OF TABLES
Definition of Collector Types Applicable to Various Industrial Areas
Selection of Participants in Narrative and Specification Writing
Participants in Specification Writing Seminar and Workshop
Participants in Process Narrative Writing
LA-Process Weight and Allowable Emissions
Definition of Outlet Grain Loadings for High Efficiency Level Bids
City Cost Indices
Average Hourly Labor Rates by Trade
Typical Analysis of Commercial High Calcium and Dolomitic
Limestones
Typical Exhaust Gas Production for Various Lime Kiln Sizes
Typical Chemical Analysis of Lime Kiln Emissions
Electrostatic Precipitator Process Description for Rotary Lime Kiln
Specification
Electrostatic Precipitator Operating Conditions for Rotary Lime Kiln
Specification
Electrostatic Precipitator Cost Data for Rotary Lime Kilns
Fabric Collector Process Description for Rotary Lime Kiln
Specification
Fabric Collector Operating Conditions for Rotary Lime Kiln
Specification
Fabric Collector Cost Data for Rotary Lime Kilns
Wet Scrubber Process Description for Rotary Lime Kiln Specification
Wet Scrubber Operating Conditions for Rotary Lime Kiln
Page No.
10
12
13
15
17
18
22
23
28
31
33
40
41
42
48
49
50
54
Table 20
Specification 55
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 21
Table 22
Table 23
Table 24
Table 25
Table 26
Table 27
Table 28
Table 29
Table 30
Table 31
Table 32
Table 33
Table 34
Table 35
Table 36
Table 37
Table 38
Table 39
Table 40
Table 41
Wet Scrubber Cost Data for Rotary Lime Kilns (High Efficiency)
Types of Copper-Bearing Scrap
Brass/Bronze Reverberatory Furnace Particulate Emissions — Test 1
Emission From Baghouse on Brass/Bronze Reverberatory Furnace —
Test 2
Brass/Bronze Reverberatory Furnace Particulate Emissions - Test 3
Gaseous Emissions from Brass/Bronze Reverberatory Furnace
Fabric Collector Process Description for Brass/Bronze Reverberatory
Furnace Specification
Fabric Col lector Operating Conditions for Brass/Bronze Reverberatory
Furnace Specification
Fabric Collector Cost Data for Brass/Bronze Reverberatory Furnaces
Wet Scrubber Process Description for Brass/Bronze Reverberatory
Furnace Specification
Wet Scrubber Operating Conditions for Brass/Bronze Reverberatory
Furnace Specification
Wet Scrubber Cost Data for Brass/Bronze Reverberatory Furnaces
(LA-Process Weight)
Wet Scrubber Cost Data for Brass/Bronze Reverberatory Furnaces
(High Efficiency)
Typical Composition of Lead Cupola Charge
Typical Properties of Cast Hard Lead
Calculated Concentrations of Lead and Antimony Fume
Fabric Collector Process Description for Lead Cupola Specification
Fabric Collector Operating Conditions for Lead Cupola Specification
Fabric Collector Cost Data for Lead Cupolas
Wet Scrubber Process Description for Lead Cupola Specification
Wet Scrubber Operating Conditions for Lead Cupola Specification
Page No.
57
63
69
70
71
72
76
78
81
82
84
85
86
94
95
98
102
103
104
106
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Page No.
Table 42
Table 43
Table 44
Table 45
Table 46
Table 47
Table 48
Table 49
Table 50
Table 51
Table 52
Table 53
Table 54
Table 55
Table 56
Table 57
Table 58
Table 59
Wet Scrubber Cost Data for Lead Cupolas (LA-Process Weight)
Wet Scrubber Cost Data for Lead Cupolas (High Efficiency)
Fabric Collector Process Description for Sweating Furnace
Specification
Fabric Collector Operating Conditions for Sweating Furnace
Specification
Fabric Collector Cost Data for Sweating Furnaces
Wet Scrubber Process Description for Sweating Furnace Specification
Wet Scrubber Operating Conditions for Sweating Furnace
Specification
Wet Scrubber Cost Data for Sweating Furnaces
Comparison of Total Annual Costs for Wet Scrubbers and Fabric
Collectors for Sweating Furnaces
Fabric Collector Process Description for Lead Reverberatory Furnace
Specification
Fabric Collector Operating Conditions for Lead Reverberatory
Furnace Specification
Fabric Collector Cost Data for Lead Reverberatory Furnaces
Wet Scrubber Process Description for Lead Reverberatory Furnace
Specification
Wet Scrubber Operating Conditions for Lead Reverberatory Furnace
Specification
Wet Scrubber Cost Data for Lead Reverberatory Furnaces
(LA-Process Weight)
Wet Scrubber Cost Data for Lead Reverberatory Furnaces (High
Efficiency)
Wet Scrubber Process Description for Aluminum Chlorination
Specification
Wet Scrubber Operating Conditions for Aluminum Chlorination
Specification
108
109
123
125
126
128
130
131
133
148
149
150
153
154
155
156
170
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Page No.
Table 60
Table 61
Table 62
Table 63
Table 64
Table 65
Table 66
Table 67
Table 68
Table 69
Table 70
Table 71
Table 72
Table 73
Table 74
Table 75
Table 76
Table 77
Table 78
Table 79
Table 80
Wet Scrubber Cost Data for Aluminum Chlorination Stations
(LA-Process Weight)
Wet Scrubber Cost Data for Aluminum Chlorination Stations (High
Efficiency)
Derived Cost Indices for Rotary Lime Kilns (Precipitator)
Derived Cost Indices for Rotary Lime Kilns (Fabric Collector and
Scrubber)
Cost in Dollars/SCFM for Rotary Lime Kiln Air Pollution Control
(Precipitator)
Cost in Dollars/SCFM for Rotary Lime Kiln Air Pollution Control
(Fabric Collector and Scrubber)
Derived Cost Indices for Brass/Bronze Reverberatory Furnaces
Cost in Dollars/SCFM for Brass/Bronze Reverberatory Furnaces
Derived Cost Indices for Lead Cupolas
Cost in Dollars/SCFM for Lead Cupolas
Derived Cost Indices for Sweating Furnaces
Cost in Dollars/SCFM for Sweating Furnaces
Derived Cost Indices for Lead Reverberatory Furnaces
Cost in Dollars/SCFM for Lead Reverberatory Furnaces
Derived Cost Indices for Aluminum Chlorination Stations
Cost in Dollars/SCFM for Aluminum Chlorination Stations
Sample "Summary of Installation Data" Form (Pages 1 and 2)
Number of Rotary Lime Kiln Installations by Year Placed in Service
Total Gas Volumes from Rotary Lime Kilns Treated by Year of
Installation
Efficiency Representations Available from Equipment Manufacturers
Properties of Rotary Lime Kiln Dusts from Mechanical Collector
172
173
181
182
183
184
185
186
187
188
189
190
191
192
193
194
200
202
203
204
Tests
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INDUSTRIAL GAS CLEANING INSTITUTE,
Table 81
Table 82
Table 83
Table 84
Table 85
Table 86
Table 87
Table 88
Electrical Resistivity of Dusts from 50 T/D Rotary Lime Kiln
Summary of Installation and Test Data for Rotary Lime Kilns
Summary of Installation and Test Data for Brass/Bronze
Reverberatory Furnaces
Summary of Installation Data for Lead Cupolas
Summary of Installation Data for Sweating Furnaces
Summary of Installation Data for Lead Reverberatory Furnaces
Summary of Installation Data for Zinc Calcination Furnaces
Summary of Installation Data for Aluminum Chlorination Stations
INC.
Page No.
209
210
229
230
236
239
243
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
LIST OF APPENDICES
Appendix I Program Planning and Execution
Appendix II Detailed Instructions for Preparing Specifications
Appendix III Rule 54 of the Air Pollution Control District of Lost Angeles County
Appendix IV Sample Specification for Air Pollution Abatement Equipment
Appendix V Detailed Instructions for Preparing Bid Price Proposals
Appendix VI Detailed Instructions for Listing Installations
Appendix VII List of IGCI Publications
Page No.
249
259
265
269
277
283
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
i.
INTRODUCTION
The Industrial Gas Cleaning Institute (IGCI) is an association of
manufacturers which was created primarily to serve manufacturers of industrial
gas cleaning equipment; but like any organization with a worthwhile purpose,
its efforts are beneficial to others.
Its activities to develop and improve standards help the entire gas
cleaning industry. Its work with technical committees of other associations
benefits other industries. Its cooperation with government agencies simplifies
their tasks.
Under this contract, members of the IGCI collected and formalized
information on air pollution control for processes in the lime and secondary
non-ferrous smelting industries. The specific process areas covered are:
(1) Rotary Lime Kilns (other than those in paper mills)
(2) Brass and Bronze Reverberatory Furnaces
(3) Lead Cupolas
(4) Lead and Aluminum Sweating
(5) Lead Reverberatory Furnaces
(6) Zinc Calcination
(7) Aluminum Chlorination
Three specific kinds of information are included:
(1) Narrative descriptions of the processes in question, the
associated air pollution control equipment, and the problems
special to the processes.
(2) The preparation of specifications and cost estimates for
equipment to serve each of the specified processes.
(3) A tabulation of the past installations, and all of the available
test data for each of these industries after January 1, 1960.
All of the data has been collected and summarized, and should serve as
a valuable guide to the air pollution abatement methods useful in these
industries, and to the costs of air pollution abatement.
The industrial areas covered vary from well-defined processes for which
good air pollution control systems are routinely available — for rotary lime
kilns — to relatively obscure processes for which there is no established
approach, as is true of zinc calcination in the secondary metals industry.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Good test data is available in some areas; however, for many small
furnace applications, inexpensive fabric filters are supplied on the basis of good
practical experience, and little test data has been accumulated.
Little relationship exists between the lime industry and the secondary
smelting industries. These were lumped together in this contract as a matter of
convenience in the overall NAPCA program. Lime producers use native
limestone, oyster shells, and other calcium-rich natural materials to make
quicklime. The product is sold for use in steel making, agriculture and basic
chemical manufacture. Secondary smelters process scrap metals to reclaim
valuable components which can be resold at a profit.
There is a close relationship between lime manufacture for the uses
included in this contract and lime sludge reburning for paper mills. Lime sludge
is produced in Kraft mills during the paper making process. This material is
calcined or "burned" in a kiln similar to that used for agricultural or
metallurgical lime, and requires similar air pollution control equipment. A
number of member companies initially reported paper mill applications for
inclusion in this report because of these similarities. These have been eliminated
from this study.
There were also some points of confusion in the smelting industries
because of similarities between secondary processes and similar primary
smelting applications. This was true of the aluminum chlorination application,
and particularly of zinc calcination. Most of the latter applications reported by
members turned out to be primary production of zinc oxide. Again, reports
were carefully screened to limit applications described to those actually within
the definition of the program.
The industrial areas covered comprise a very limited section of the total
air pollution control market. Of the 29 member companies, only nine were
identified as actively involved in servicing these industries. Most of these
companies had applications and experience with rotary lime kilns, while none
were actively involved in zinc calcination process air pollution control. The
limited experience of the member companies in secondary smelting (as opposed
to utility power production or ferrous smelting, for example) appears to relate
to the small size and diversity of the secondary smelting applications rather
than to the lack of need for air pollution control equipment.
The program was carried out over a six month period beginning on July
1, 1970 and terminating with the submission of this report draft on December
31, 1970. Several milestones in the progress of the program were identified
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Event
Completion of Work Plan
Completion of Progress Reports:
Progress Report No. 1
Progress Report No. 2
Progress Report No. 3
Progress Report No. 4
Final Report Draft Submission
Date
July 31, 1970
July 31, 1970
August 31, 1970
September 30, 1970
October 30, 1970
November 30, 1970
Although the time period was shorter than optimum for a program
involving coordination of the activities of a large group of companies, these
steps were completed in the allotted time. This required careful planning of the
details of the program and good cooperation of the member companies
involved. Appendix I describes the program planning and execution in some
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
II. SUMMARY OF TECHNICAL DATA
This study contains six process descriptions for the process areas
covered. These descriptions combine published material and first-hand
experience gained by the member companies in servicing the industries
involved.
Ten equipment specifications were written for air pollution control
equipment. Each of these described a typical installation and specified two
levels of performance for each of three equipment sizes. In all, 60 price
quotations were requested. In addition to the technical specifications for the
air pollution control equipment, generally acceptable terms and conditions are
specified. These specifications are based almost entirely on the experience of
the member companies. They contain several significant items of technical
interest for each application, including:
A. Gas flow vs. furnace size relationship
B.
Gas conditions and properties at the collector inlet
C. Selected minimum quality conditions for some collectors
D. Efficiency levels and grain loadings for good collection
(LA-Process Weight) and very good collection (High Efficiency).
Probably the most significant information presented is the cost figures
generated in response to the specifications. These pertain to all 60
specifications, and give figures for the collection equipment only, the total
equipment, and the complete turnkey installation. These quotations are based
entirely on the background of the IGCI members in designing, building, and
installing equipment of the types specified.
This cost data was presented in three ways for convenience in
estimating costs at sizes other than those specified:
A. Graphically, on log - log plots of cost vs. furnace size
B. Algebraically by fitting a power formula to the cost — furnace
size relationship, and
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
In addition to the first costs of equipment, the maintenance costs were
estimated for each of the cases specified, and the operating horsepower was
estimated. From these figures, the total annual cost method (or any other
sound method) can be used to compare the economics of alternative equipment
types for the general conditions of this study. Caution is recommended in using
these numbers for specific applications rather than estimates tailored to the
conditions of the installation in question.
The installations made by the IGCI member companies since January 1,
1960 were reported and are tabulated. A total of 153 installations were
reported, as follows:
Rotary Lime Kilns
Brass/Bronze Reverberatory Furnaces
Lead Cupolas
Lead/Aluminum Sweating Furnaces
Lead Reverberatory Furnaces
Zinc Calcination Furnaces
Aluminum Chlorination Stations
79
16
11
18
17
6
6
153
Of these, the distribution among equipment types was:
Electrostatic Fabric Wet Mechanical
Precipitators Collectors Scrubbers Collectors
Rotary Lime Kilns
Brass/Bronze
Lead Cupolas
Sweating Furnaces
Lead Reverb.
Zinc Calcination
Aluminum Chlor.
18
9
10
12
17
5
71
35
6
1
6
1
6
55
21
1
22
Relatively good test data was reported for the rotary lime kilns.
However, little test information was available for the other applications.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
III. TECHNICAL DATA
This section contains all of the data relative to process requirements,
typical specifications, costs, and existing installations of air pollution control
equipment. This information was generated by the members of the Industrial
Gas Cleaning Institute who have been active in supplying equipment in the lime
and secondary non-ferrous metals areas. Editing of this material was done only
to bring it together in a consistent form for ease of reference.
A.
GENERAL DESCRIPTION
The format used for presentation of the collected information was
chosen to provide a reasonably smooth progression from general descriptive
material to specific examples of equipment specification and price data for
each of the industrial segments represented in the study. For each area, the
following sequence is used in Section B.
1. Description of the process
a. Manufacturing aspects
b. Air pollution control equipment
2. Specifications and Costs
a. Electrostatic precipitators
b. Wet Scrubbers
c. Fabric Collectors
3. Summary comments
The data is presented, in turn for each of the industrial process
segments, and an overall summary is presented in Section C. Installations
completed since January 1, 1960 by the IGCI member companies are tabulated
in Section D.
Several points arose during the preparation of this material which merit
some detailed comment. These involve:
1. Selection of applicable equipment types
2. Selection of companies best qualified to write narratives,
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
3. Selection of emission levels for equipment specifications and
bids
4. Basis for preparing specifications and bid prices
These points will be covered in turn in the following
paragraphs.
/. SELECTION OF APPLICABLE EQUIPMENT TYPES
In general the processes covered by this study are equipped (or should
be equipped) with devices for the removal of particulate matter from the
effluent discharged into the air. In some cases, there is also a requirement for
removal of a noxious gas such as carbon monoxide from a lead smelting cupola.
Usually the gaseous pollutant control devices are either built into the smelting
furnace — as is the case for the cupola, or for smoke incinerators in
reverberatory furnaces - or omitted altogether. For this reason, the air
pollution control equipment considered in this study is limited to particulate
collection after the gaseous emissions have been treated.
One exception is taken to this general rule. Aluminum chlorination
stations produce a fume in which aluminum chlorides, oxides and hydroxides
are emitted in a stream containing high concentrations of chlorine gas and
hydrogen chloride gas. The gaseous constituents here are a major part of the air
pollution problem, and they are abated by the addition of air pollution control
equipment, rather than by modification of the process. In this case alone the
requirements for abatement of gaseous constituents are taken into account in
selecting applicable equipment types.
The emphasis on particulate control equipment in this study should not
be interpreted as a bias on the part of the IGCI member companies toward
particulate collection. Rather, it is an indication that the specific industrial
areas covered are far more likely to require "add-on" equipment for collection
of fumes and dusts than for control of gaseous emissions.
The members of the Industrial Gas Cleaning Institute work
independently of each other in commercial application of their specific lines of
equipment. For this reason, unanimity of opinion as to the types of equipment
applicable to each of the industrial areas presented is limited to a few
generalizations. These were formulated by the Engineering Standards
Committee, which is the group selected by the president of IGCI to pass upon
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
all public statements of position on technical matters. This group met in Rye,
New York on August 18, 1970 and agreed upon the following:
(1) Mechanical dust collectors or cyclones would not alone be
suitable collection devices for any of the specific applications covered. They are
useful as precleaners in combination with other, more efficient collectors, and
in such cases they would be considered as a part of the dust collection system.
(2) Electrostatic precipitators would ordinarily be suitable for
collection of any of the particulate matter discharged from the subject
processes if the operating conditions were chosen properly. However, the
conventional single-stage precipitator is not competitive with fabric filtration or
wet scrubbing on a small scale. For this reason, precipitators were listed as
acceptable for only the largest application in this study, the rotary lime kiln. As
development work is done on small electrostatic precipitators, the cost
difference .is likely to become less significant, and precipitators may find
acceptance in some of the areas from which they are now excluded for reasons
of high cost.
(3) For several application areas, fabric filters predominate over wet
scrubbers on the basis of both cost and factors relating to the recovery of the
particulate matter in dry form rather than wet. In these cases, the scrubbers
may not be competitive for the average application but show cost or
performance advantages in a specific circumstance. For this reason the scrubber
is included for each of the areas.
(4) In the case of the aluminum chlorination station, both
particulate collection and gas absorption are required to provide adequate air
pollution control. This can be done only by a wet scrubber if the air pollution
abatement job must be done by a single piece of equipment. Only wet
scrubbing is indicated as an adequate approach, although installations involving
combinations of equipment can be made with fabric filters or electrostatic
precipitators.
The result of this selection is shown in Table 1, which lists the
equipment types considered by the members of the Engineering Standards
Committee as acceptable in each area.
2. SELECTION OF COMPANIES TO WRITE NARRATIVES,
SPECIFICATIONS AND PREPARE BID PRICE PROPOSALS
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Table 1
DEFINITION OF COLLECTOR TYPES APPLICABLE TO
VARIOUS INDUSTRIAL AREAS
Collector
Type
Electrostatic
Precipitator
Fabric
Collector
Wet
Scrubber
1.
Lime
Kiln
Yes
Yes
Yes
2.
Brass
Reverb.
No*
Yes
Yes
3.
Lead
Cupola
No*
Yes
Yes
4.
Lead
Sweat.
No*
Yes
Yes
5. 6.
Lead Zinc
Reverb. Calcin.
No* ***
Yes
Yes
4**
Alum.
Sweat.
No*
Yes
Yes
7.
Alum.
Chlor.
No
No
Yes
2* *
Bronze
Reverb.
No*
Yes
Yes
Note that Electrostatic Precipitators are not applicable to these areas only because the sources are
too small to make precipitator application economical under ordinary circumstances.
These areas were subsequently combined with others, and eliminated from the list (Brass/Bronze and
Lead/Aluminum).
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
equipment for every segment of industry. However, it is unlikely that any one
of the companies has covered all of the possible applications. In the limited
area covered by this study, 16 Institute member companies indicated an
interest in the industries covered, while 18 of the members indicated at least
one past application at the beginning of the program*.
In order to assign the work on this project equitably among those
members who have taken an active interest in the lime kiln or secondary metals
area covered by this program, the members were surveyed for interest in
participating in regard to each industrial segment, and on the number of
applications of equipment made by each. The survey forms, etc. are included in
Appendix I of this report. The results of these two surveys were used by the
Engineering Standards Committee to select companies for participation in each
area. The companies selected in each of the categories included three
participants and two alternates wherever possible. In a few areas there were not
five companies actively involved. The five companies are listed alphabetically in
each category in Table 2.
Failure of a company to appear on this list does not necessarily indicate
lack of interest or ability on the part of a particular supplier of equipment. The
interest of each company in participating in this program was taken into
account to a significant extent in selecting the companies to be involved.
A further reduction in the number of companies actually involved in
preparation of the narratives, specifications and bid prices took place on the
basis of availability of the member's time.
The specifications were drafted at a Seminar-Workshop session held in
Detroit, Michigan on September 2 and 3, 1970. At this meeting, the basic
requirements of the program were reviewed with representatives of the
participating companies, and first draft specifications were prepared by groups
shown in Table 3. The specification drafts prepared in Detroit were reviewed
and edited by the Coordinating Engineer, and then distributed to selected
companies for preparation of bid prices.
One person was selected to prepare the process description in each case,
and a portion of the Detroit workshop was devoted to a technical interchange
*lt should be noted that the number here does not agree precisely with the
number of companies who reported on installations during the project. Some
distinctions, such as the exclusion of paper mill applications in this study,
were originally overlooked.
-------
ro
Table 2
SELECTION OF PARTICIPANTS IN NARRATIVE AND SPECIFICATION WRITING
Lime
Kiln
American
Standard
Ducon
Fuller
Brass/Bronze
Reverb.
American Air
Filter
Ducon
Fuller
Lead
Cupola
American Air
Filter
Chemico
Fuller
Lead/Alum.
Sweat.
Lead
Reverb.
American Air Ducon
Filter
Buell
Fuller
Zinc
Calcin.
Buell
Alum.
Chlor.
Fuller
Fuller Fuller MikroPul
Research-Cottrell Koppers UOP
Research-Cottrell Research-Cottrell Research-Cottrell Environeering
Western
Precip.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 3
Participants in Specification Writing
Seminar and Workshop
Herbert R. Herington — IGCI Project Director
L. C. Hardison — IGCI Coordinating Engineer
Harry Krockta, Chairman — Engineering Standards Committee
Ralph R. Calaceto - MikroPul
E. R. Gibbs- Koppers
Raymond B. Hunter — American Air Filter Company
Morris Mennell — Koppers
Robert Peden — Western Precipitation
A. R. Pike — UOP Air Correction Division
William J. Rudy — Ducon Company
J. J. Sheehan — Buell Engineering Company
Harold Treichler - Fuller Company
Robert J. Wright - Fuller Company
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
between the participants. The individuals selected to prepare the narratives are
listed in Table 4.
The narrative drafts were prepared subsequent to the Detroit Workshop
and were then edited by the Coordinating Engineer and reviewed by all the
participants in the industry group prior to the final draft.
3. SELECTION OF EMISSION LEVELS FOR EQUIPMENT
SPECIFICA TIONS AND BIDS
The degree of reduction in the amount of dust discharged into the air
has a large influence over the design and the cost of wet scrubbing and
electrostatic precipitation equipment. The cost of these increases sharply as
efficiency requirements approach 100%. Costs of fabric filters, on the other
hand, are not very sensitive to the efficiency level specified.
In order to make a reasonable comparison between the three
alternatives, it is necessary to establish the required performance level. The
local conditions surrounding a particular installation dictate the performance
requirements which should be specified, and equipment should never be
acquired without a thorough knowledge of the local requirements.
For the purposes of this project, two arbitrary levels of performance
were established, and equipment costs prepared for each:
(a) Conformance with the present Los Angeles Air Pollution
Control District process weight requirements, and
(b) Reduction to a low concentration of paniculate matter which
should show little or no visible color in the stack discharge.
It is emphasized that these are arbitrary performance levels chosen for
illustrative purposes in this study. While the first efficiency level is acceptable
throughout much of the United States, and the second level should be
acceptable almost anywhere, no specifications for air pollution control
equipment should be written without a good understanding of all of the local
requirements.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 4
Participants in Process Narrative Writing
1.
2.
3.
4.
5.
6.
7.
Rotary Lime Kilns
William J. Rudy - The Ducon Company
Brass/Bronze Reverberatory Furnaces
Raymond B. Hunter — American Air Filter Co.
Lead Cupola
L. C. Hardison — Air Resources (for Research-Cottrell)
Lead/Aluminum Sweating Furnace
Harold Treichler — Fuller Company
Lead Reverberatory Furnace
L. C. Hardison — Air Resources (for Research-Cottrell)
Zinc Calcination
Morris Mennell — Koppers
Aluminum Chlorination Station
A. R. Pike - UOP Air Correction
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
The LA-Process Weight Specification is typical of many such ordinances
throughout the country. It is based on an allowable emission of particulate
matter which increases with process feed rate. However, the allowable emission
rate in pounds per hour of particulate increases more slowly than does the feed
rate to the process. Because the emission produced in most processes is
proportional to the feed rate, the particulate collection efficiency must be
higher for large processes than for small ones. The law also specifies an absolute
maximum of 40 Ib/hr of particulate matter, regardless of process size, so that
very large process units must have very efficient collection devices. Most of the
processes covered by this study are relatively small in terms of total feed rate,
and the 40 Ib/hr maximum emission level is not usually applicable for the lime
kilns or secondary smelters.
A list of allowable emission rates under the LA-Process Weight
regulation is given in Table 5. A more detailed version of Rule 54 of the Air
Pollution Control District of Los Angeles County is given in Appendix III.
In general, this type of regulation is easy to interpret and leads to
definite, clear-cut levels of performance required for air pollution control
systems, provided the rate at which particulate matter is generated by the
process and the process feed rate (or process weight) are known. The
particulate emission rate is best obtained by direct measurement by a qualified
source test engineer or company if the process is an existing one, or obtained
from the manufacturer of the furnace or kiln if the installation is in the
planning stage. The process weight is the sum of all of the feed materials to the
process, excluding air and liquid or gaseous fuels. The process weight ordinarily
exceeds the rated product capacity of the equipment because it includes output
product, plus losses and byproducts.
The second specification included for each of the air pollution control
systems covered by this report is called the "High Efficiency" case. This is
taken as an arbitrary stack grain loading (concentration of particulate matter,
measured in grains per actual cubic foot) which should produce an effluent
with little or no visible opacity, excluding that due to water. This grain loading
is based on the best judgment of the members of the IGCI Engineering
Standards Committee. The levels specified are arbitrary, and while most
member companies will guarantee performance to the grain loading specified,
they will not ordinarily represent or guarantee freedom from visible emissions.
(Exceptions to this rule exist. A manufacturer may have an identical
installation known to produce a color-free effluent and be willing to guarantee
performance on this basis.) Table 6 lists the values assigned by the Engineering
Standards Committee to this "High Efficiency" case.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 5
LA-PROCESS WEIGHT AND ALLOWANCE EMISSION
•Process
Wt.'hr(lbs)
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
3200
3300
•See Definition
Maximum Weight 'Process
Disch/hr(lbs) Wt/hr(lbs)
.24
.46
.66
.85
1 ..03
1.20
1.35
1.50
1.63
1.77
1.89
2.01
2.12
2.24
2.34
2.43
2.53
2.62
2.72
2. 80
2.97
3.12
3.26
3.40
3.54
3.66
3.79
3.91
4.03
4. 14
4.24
4.34
4.44
4.55
4.64
4.74
4.84
4.92
5.02
5.10
5.18
5.27
5.36
3400
3500
3600
3700
3800
3900
4000
4100
4200
4300
4400
4500
4600
4700
4800
4900
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
11000
12000
13000
14000
15000
16000
17000
18000
19000
20000
30000
40000
50000
60000
or
more
i n Ru 1 e 2 ( j ) .
Maximum We i gh t
Disch /hr( 1 bs)
5.44
5.52
. 5.61
5.69
5.77
5.85
5.93
6.01
6.08
6.15
6.22
6.30
6.37
6.45
6.52
6.60
6.67
7.03
7.37
7.71
8.05
8.39
8.71
9.03
9.36
9.67
10.0
10.63
11.28
11.89
12.50
13.13
13.74
14.36
14.97
15.58
16.19
22.22
28.3
34.3
40.0
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 6
Definition of Outlet Grain Loadings For
High Efficiency Level Bids
Rotary Lime Kilns
Brass Reverberatory Furnaces
Lead Cupolas
Lead Sweating Furnaces
Lead Reverberatory Furnaces
Zinc Calcination Furnaces
Aluminum Sweating Furnaces
Aluminum Chlorination Stations
Bronze Reverberatory Furnaces
Outlet
Loading
gr/ACF
0.03
0.01
0.03
0.03
0.01
0.01
0.03
0.02
0.03
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
This table shows these loadings in gr/ACF at the stack discharge
because they correlate with the opacity of the plume better than gr/SCF. Most
frequently, measurements of particulate loading are reported in gr/SCF and the
conversion of this value to gr/ACF should not be overlooked. Also, it should be
noted that very large diameter stacks are likely to show a more visible plume at
the same grain loading than small stacks.
4. BASIS FOR PREPARING SPECIFICATIONS AND BID
PRICES
Several simplicications were made in the preparation of the
specifications which have some bearing on the results which are reported here.
These should be kept in mind when using the prices, operating costs, etc.
The form of the specification for equipment may have an influence
over the price quoted. Overly-restrictive specifications may add 5 - 10% to the
equipment price without a corresponding increase in value received by the
purchaser. In each of the cases presented in this report, prices are based on a
specification which covers most of the conditions of purchase in an equitable
way. Instead of writing each specification independently, the participants in
the Detroit workshop agreed upon the general terms and conditions to be
specified, and these conditions were made identical for each specification. The
final specification in each case was made by inserting one page of descriptive
material and one page of operating conditions pertaining to the specific
application into the standard format. To avoid unnecessary repetition, a sample
of the complete specification for one of the six applications is included as
Appendix IV to this report. Only the pages pertinent to specific applications
are contained in the body of the report.
Prices were requested in such a way as to indicate three bases:
(a) Air pollution control device. This includes only the flange-to-
flange precipitator, fabric collector, or scrubber.
(b) Air pollution control system equipment. This includes major
items such as fans, pumps, etc.
(c) Complete turnkey installation. This includes the design, all
materials and equipment and startup.
In order to maintain a consistent approach to quoting in each area, the
specifications were written around the air pollution control device. The process
description was, however, made general enough to allow the members to quote
on the auxiliary equipment, such as fans, pumps, solid handling devices, etc.,
and to quote on an approximate installation cost. A complete set of
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
instructions for preparing specifications and for quoting are given in Appendix
II and Appendix V.
Labor costs are a variable from one location to another, and it was not
possible to establish the complex pattern of variations in turnkey prices which
occurs as a function of local variations in hourly rate, productivity and
availability of construction tradesmen. In order to provide a consistent basis for
the preparation of price quotations, the cost indices given in Table 7 were used.
This was taken from "Building Construction Cost Data, 1970".* This gives a
construction cost index for 90 cities, using 100 to represent the national
average. These figures are for the building trades, but they should be
representative of field construction rates in general.
These figures do not take productivity differences into account and
may understate the variations in cost from one city to another.
The participating companies were instructed to estimate the installation
costs as though erection or installation of the system would be in Milwaukee,
Wisconsin or another city relatively convenient to the participants point of
shipment with a labor rate near 100. Readers are cautioned to take local labor
rates and productivity into account when making first estimates of air pollution
control system installed costs based on the data in this report. Table 8 shows
the tabulated hourly rates for various construction trades (based on national
averages) which may be useful for this purpose.*
B.
NARRATIVE DESCRIPTIONS AND COSTS
The following sections include all of the descriptive and cost data
developed by the participating member companies. A separate section is
devoted to each of the application areas:
1. Rotary Lime Kilns (other than paper mill)
2. Brass/Bronze Reverberatory Furnaces
3. Lead Cupolas
4. Lead/Aluminum Sweating Furnaces
"Godfrey, Robert Sturgis, "Building Construction Cost Data," Robert Snow
Means Co., Inc., Box G, Duxbury, Mass. 02332
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
5. Lead Reverberatory Furnaces
6. Zinc Calcination Furnaces
7. Aluminum Chlorination Stations
Past installation data is collected in a separate section, with a discussion
of the application pattern.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 7
CITY COST INDICES
Average 1969 Construction Cost & Labor Indexes
City
Albany, N.Y.
Albuquerque, N.M
Amarillo, Tx.
Anchorage, Ak.
Atlanta, Ga.
Baltimore, Ma1.
Baton Rouge, La.
Birmingham, Al.
Boston, Ma.
Bridgeport, Ct.
Buffalo, N.Y.
Burlington, Vt.
Charlotte, N.C.
Chattanooga, Tn.
Chicago, III.
Cincinnati, Oh.
Cleveland, Oh.
Columbus, Oh.
Dallas, Tx.
Dayton, Oh.
Denver, Co.
Des Moines, la.
Detroit, Mi.
Edmonton, Cn.
El Paso, Tx.
Erie, Pa.
Evansville, In.
Grand Rapids, Mi.
Harrisburg, Pa.
Hartford, Ct.
Honolulu, Hi.
Houston, Tx.
Indianapolis, In.
Jackson, Ms.
Jacksonville, Fl.
Kansas City, Mo.
Knoxville, Tn.
Las Vegas, Nv.
Little Rock, Ar.
Los Angeles, Ca.
Louisville, Ky.
Madison, Wi.
Manchester, N.H.
Memphis,- Tn.
Miami, Fl.
Index
Labor
98
86
87
131
88
90
83
79
106
104
104
86
70
81
107
108
121
106
86
100
94
93
117
80
77
98
93
103
90
104
99
92
97
73
78
94
82
115
78
113
92
95
89
83
98
Total
100
95
84
148
94
93
88
86
103
102
107
90
75
84
103
104
112
99
89
103
91
96
111
83
83
99
97
99
92
100
109
89
98
75
79
93
82
107
81
102
93
98
92
82
94
City
Milwaukee, Wi.
Minneapolis, Mn.
Mobile, Al.
Montreal, Cn.
Nashville, Tn.
Newark, N.J.
New Haven, Ct.
New Orleans, La.
New York, N.Y.
Norfolk, Va.
Oklahoma City, Ok.
Omaha, Nb.
Philadelphia, Pa.
Phoenix, Az.
Pittsburgh, Pa.
Portland, Me.
Portland, Or.
Providence, R.I.
Richmond, Va.
Rochester, N.Y.
Rockford, III.
Sacramento, Ca.
St. Louis, Mo.
Salt Lake City, Ut.
San Antonio, Tx.
San Diego, Ca.
San Francisco, Ca.
Savannah, Ga.
Scranton, Pa.
Seattle, Wa.
Shreveport, La.
South Bend, In.
Spokane, Wa.
Springfield, Ma.
Syracuse, N.Y.
Tampa, Fl.
Toledo, Oh.
Toronto, Cn.
Trenton, N.J.
Tulsa, Ok.
Vancouver, Cn.
Washington, D.C.
Wichita, Ks.
Winnipeg, Cn.
Youngstown, Oh.
Index
Labor
103
99
94
77
79
122
102
89
132
73
82
90
106
101
no
82
102
98
76
110
109
117
110
93
82
111
124
72
94
104
82
99
101
99
105
81
105
84
114
85
81
98
85
62
107
Total
108
98
90
89
82
109
100
95
118
77
88
93
101
97
106
87
103
97
79
107
109
110
103
95
82
107
109
77
96
99
89
97
100
97
103
84
105
93
103
89
91
94
90
82
106
Historical Average
Year
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956
1955
1954
1953
1952
1951
1950
1949
1948
1947
1946
1945
1944
1943
1942
1941
1940
1939
1938
1937
1936
1935
1934
1933
1932
1931
1930
1929
1928
1927
1926
1925
1924
Index
100
91
86
83
79
78
76
74
72
71
69
67
65
63
59
58
57
55
53
49
48
48
43
35
30
29
29
28
25
24
23
23
23
20
20
20
18
17
20
22
23
23
23
23
23
23
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 8
AVERAGE HOURLY LABOR RATES BY TRADE
Trade
Common Building Labor
Sk i 1 led Average
Helpers Average
Foremen (usually 35<£ over trade)
Bricklayers
Bricklayers Helpers
Carpenters
Cement F inishers
E lectr ic ians
G laz iers
Hoist Engineers
Lathers
Marble & Terrazzo Workers
Pa inters, Ord inary
Painters, Structural Steel
Paperhangers
P iasterers
P Iasterers He Ipers
P lumbers
Power Shovel or Crane Operator
Rodmen (Reinforcing)
Roofers, Composition
Roofers, T He & Slate
Roofers Helpers (Composition)
Steamfitters
Spr ink ler Insta 1 Iers
! Structural Steel Workers
! Tile Layers (F loor)
T ile Layers Helpers -
Truck Drivers
Welders, Structural Steel
1970
$5.00
6.85
5.15
7.20
7.15
5.20
6.95
6.75
7.50
6.25
7.05
6.60
6.45
6.20
6.50
6.30
6.60
5.30
7.75
7.20
7.30
6.30
6.35
4.75
7.70
7.70
7.45
6.50
5.25
5.15
7.15
1969
$4.55
6.05
4.65
6.40
6.40
4.70
6.15
5.90
6.45
5.50
5.90
5.95
5.60
5.45
5.80
5.60
5.95
4.85
6.90
6.20
6.35
5.55
5.60
4.45
6.90
6.90
6.45
5.60
4.80
4.60
6.35
1968
$4.10
5.50
4.20
5.85
5.85
4.30
5.40
5.30
5.95
5.10
5.40
5.45
5.25
5.05
5.30
5.15
5.50
4.45
6.15
5.65
5.80
5.05
5.10
4.00
6.10
6.10
5.90
5.20
4.35
4.30
5.80
1967
$3.85
5.15
4.00
5.50
5.55
4.05
5.10
5.05
5.60
4.75
5.10
5.20
5.05
4.75
4.95
4.75
5.15
4.15
5.75
5.35
5.45
4.75
4.85
3.75
5.70
5.70
5.55"
4.90
4.15
3.95
5.45
1966
$3.65
4.90 |
3.85
5.25 i
5.35
3.95
4.90
4.85
5.45
4.60
4.85
5.05
4.90
4.50
4.80
4.55
5.00
4.00
5.55
5.05
5.15
4.65
4.80
3.55
5.50
5.50
5.25
4.80
4.05
3.65
5.10
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
1.
AIR POLLUTION CONTROL FOR ROTARY LIME KILNS
a.
PROCESS DESCRIPTION
1)
MANUFACTURING ASPECTS
On the basis of the best estimates available, 80-90% of lime production
in the U. S. is in rotary kilns. The kiln is a furnace made of steel lined with
refractory brick, and fired by any one of three available fuels; natural gas,
pulverized coal or oil, or by a combination of these fuels.
The raw materials for lime manufacturing are essentially calcium
carbonate (limestone) or calcium magnesium carbonate (dolomite or dolomitic
limestone), with varied amounts of impurities. If the magnesium-carbonate is
less than 5%, the limestone is referred to as high calcium. If the
magnesium-carbonate content is 30-40%, it is referred to as dolomitic
limestone. Lime is produced by heating sized limestone to decompose the
carbonate releasing C02 and leaving the calcium oxide as the product. During
the heating process, moisture and volatile organic matter are driven off. Then at
higher temperatures decomposition of the carbonate begins. Rotary lime kilns
are basically heat exchangers and conveyors. The flow of stone and combustion
products is counter-current through the kiln. Figure 1 indicates the basic flow
of solids and combustion products through a kiln and the associated air
pollution control equipment.
EQUIPMENT
Rotary kilns are of two basic types; the "long rotary kiln" and the
"short rotary kiln with external pre-heater". (In this report, the specification
was based on the "long rotary kiln".) Long rotary kilns generally have exit
gases in the 1100 - 1400°F temperature range, while short rotary kilns with
pre-heaters generally run between 1700 and 2100° F. For the short rotary kilns
acceptable feed sizes are more limited than for the long rotary kilns. Space
requirements for the pre-heater systems are less.
Pre-heater equipped kilns are particularly successful when they have
contact type coolers and soaking pits. The application of pre-heater systems is
limited to feed materials which do not degrade during calcining.
Rotary kilns are available to handle capacities from 50 tons per day
(which is unusually small) up to 650 tons per day. This maximum tonnage will
probably go to a much higher rate in the future although the largest
-------
NATURAL
GAS
AND AIR
ro
01
CONTACT
COOLER
LIMESTONE
FEED
FABRIC
COLLECTOR
YY
FINES
FINES
Figure 1
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
commercial installation at this date is 650 TPD. Kilns vary in size from 6 feet
to 12 feet in diameter and up to 400 feet in length.
At the feed end of the kiln hot gases are cooled by pre-heating the
stone, while at the other end the kiln discharges the lime quite hot. For this
reason, product coolers are usually provided to pre-heat the combustion air.
Heat efficiency may sometimes be improved through the use of chain sections
and pre-heating tubes at the feed end.
As long as the feed size range is narrow and the minimum size is about
1/2", good mixing takes place in the bed and produces a very uniform lime.
However this bed motion also contributes to abrasion and dust formation and
gives rise to the need for efficient dust collection equipment.
The efficiency of dust collection required varies with the feed size and
stone quality, as well as with discharge gas concentration limits. Large systems
are generally required because gas volumes are high; tempering with air or
quenching with water may be required, and both of these contribute additional
gas volume. Two collection stages are common. Sludge kilns with fine feed sizes
have highest dust loadings in the exit gases.
Product cooling equipment used with rotary kilns is generally of two
types, either satellite coolers for finer materials or contact type coolers for
coarse lime. Satellite coolers are less effective but involve less maintenance and
operating costs than contact coolers. Contact coolers result in considerably
better fuel consumption but have higher operating costs and headroom
requirements. Rotary coolers and grate type coolers are secondary choices in
the lime industry.
Although rotary kilns have a much higher fuel consumption than shaft
kilns or other calcining systems, the majority of U. S. lime plants use the rotary
kilns. The main reasons for the selection of rotary kilns are:
1. Can handle a wider range of feed sizes
2. Can use all three major fuels singly or in combination
3. Are easily controlled and can be fully automated
4. Can handle smaller feed sizes than shaft kilns
5. Can produce a uniform product in practically any desired quality over a
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
wide range of product grades. This is because of the ease of control and
good mixing in the bed
6. Can operate at high capacity with great operating flexibility
There are some disadvantages, however:
1. Rotary kilns require more space, especially if they are not equipped
with pre-heat systems
2. The first cost is higher than most other systems
3. They have higher fuel consumption
4. They are especially uneconomical for low capacities
5. The refractory cost is higher because of the possible movement of the
refractory within the kiln shell. Stresses are imposed on the refractory
which do not exist in a stationary kiln.
FEED MATERIALS
The carbonates of calcium or magnesium are obtained from deposits of
limestone, marble, chalk, dolomite or oyster shells. Although limestone is the
usual raw material for manufacture of lime, some of the operations use oyster
shells. This is particularly true in the Gulf Coast area. Limestone deposits exist
in every State in the U. S., but only a small portion is of sufficient purity for
industrial use. For chemical usage, a rather pure limestone is preferred as a
starting material because of the high calcium lime that results. The lower grades
are generally suitable for agricultural purposes. Table 9 gives some typical feed
compositions.
More than 90% of the limestone quarried is from open pit operations
with the remainder from underground mines. The quarries are generally chosen
which furnish a rock that contains a low percentage of impurities such as silica,
clay or iron.
The limestone feed to the kilns consists of stone sizes between 1/4" and
2". In general for most applications, however, the feed is maintained in the
1/4"- 1/2" size range.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 9
TYPICAL ANALYSIS OF COMMERCIAL
HIGH CALCIUM AND DOLOMITIC LIMESTONE
Calcium Carbonate (CaC03)
Magnesium Carbonate (MgCOg)
Iron Oxide
Aluminum Oxide
Silica (Si02) + acid insolubles
Loss on ignition
High Calcium Dolomitic
Wt. %
97.40
1.25
0.11
0.35
0.95
43.40
52.34
47.04
0.04
0.20
0.26
47.67
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
PRODUCTS
Limestone and lime are employed in more industries than any other
natural substance. Lime is second only to sulfuric acid in tonnage production
among the pure chemicals. Lime is usually sold as a high calcium quick lime
containing not less than 90% of calcium oxide. Other constituents are magnesia
(0-5%) and small percentages of calcium carbonate, silica, alumina and
ferric-oxide impurities. The suitability of a lime for any particular use depends
on its composition and physical properties. These can be controlled by the
selection of the limestone and the detail of the manufacturing process.
Many chemical and metallurgical processes require high calcium lime. In
sulfite paper processing, however, a magnesia lime works better. Other uses of
lime include air and water pollution control. Lime slurries have been used for
scrubbing of stack gases to remove HCI, HF, S02, etc.
There are many municipalities which use lime softening in their water
treatment plants. The acidity of industrial waste water is effectively controlled
by the use of lime as a reagent.
PROCESS CHEMISTRY
There are three essential factors in the kinetics of limestone's
decomposition:
(a) The stone must be heated to the dissociation temperature of the
carbonates. For calcite (CaCOg) this temperature is approximately 1648°F
while dolomite (CaCO3' MgCO^) dissociates in the range of 930-1480° F.
Because MgCOg dissociates at a much lower temperature (755-895° F) than
CaCOg, the dissociation temperature for the mixture varies with the
proportions of MgCOg. The heat consumed to attain the theoretical minimum
dissociation temperature is approximately 1.5 million Btu/ton high calcium
quicklime and 1.25 million Btu/ton dolomitic quicklime produced.
(b) The dissociation temperature must be maintained until all of the carbon
dioxide is expelled. The heat requirement during this period is approximately
2.8 million Btu/ton high calcium quicklime and 2.6 million Btu/ton dolomitic
quicklime produced.
(c) The carbon dioxide gas must be removed to keep recarbonation to a
minimum because of the reversible nature of the dissociation reaction.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
NATURE OF THE AIR POLLUTANTS
The nature of air pollutants emitted from rotary lime kilns is a function
of the type of limestone charged (high calcium or dolomitic) and the type of
fuel burned (coal, oil or natural gas).
The gaseous effluent is usually between 800 and 1800° F. It is
composed of carbon dioxide, water vapor and nitrogen. Sulfur dioxide and
sulfur trioxide are also present if sulfur-containing oil or coal are used as fuels.
The composition and volume of gases discharged from rotary lime kilns
varies with the type of limestone feed, the fuel used, completeness of
combustion, quantity of excess air, etc.
An approximate relationship between gas flow and process weight is
presented in Table 10. This is influenced by the fuel composition to some
degree. Natural gas and pulverized coal represent the major fuel types used in
this application. Other fuels utilized to a minor degree in rotary lime kilns
include fuel oil, wood, sawdust and propane. However, these fuels are usually
uneconomical, unavailable or unsuitable because of poor combustion
characteristics.
A typical overall kiln exhaust gas composition is as follows:
N2 - 59.7% (by vol.)
C02
H20
^Jo
24.3%
15.3%
0.7%
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Table 10
Typical Exhaust Gas Production for Various Kiln Sizes
EXHAUST GAS, SCFM
Process Wt.
Tons Lime
Produced per Day
125
250
500
Gas
Fired
Kiln
11,000
26,600
46,900
Fuel/Lime Ratio
Coal Fired Kiln
1:3
8800
17600
35200
1:4
6900
13800
27600
1:5
5700
11400
22800
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The CC>2 content of lime kiln gases is relatively high because the
exhaust gases contain CC>2 released during the chemical reaction
(limestone-Hime) as well as the CC>2 resulting from combustion of the fuel.
Minor gaseous contaminants include SC^, SOg and oxides of nitrogen,
in concentrations which depend upon the type of fuel used. For instance,
virtually no SC>2 or SOg is present in the exhaust gases from a kiln fired with
natural gas, while concentrations of S02 in the range of 0.05 - 0.3% (by vol.)
occur with coal firing. Oxides of nitrogen (NOX) are present in combustion
gases from the burning of natural gas, coal or fuel oil in concentrations of 100
ppm to 1400 ppm.
The paniculate emissions can include raw limestone and completely
calcined lime dust, fly ash, tars and unburned carbon (if pulverized coal is used
as the fuel). The quantity of dust emitted from a rotary lime kiln can be as high
as 15% of the product lime weight.
The particulate emissions from rotary lime kilns can be in the range of
2 - 20 gr/scf with typical chemical analyses from gas fired kilns as shown in
Table 11.
The calcination or thermal decomposition of high calcium limestone
(CaCOg) or dolomitic limestone (CaCOg • MgCOg) proceeds in accordance
with the following reversible reactions:
1. CaCO3 + heat ^ CaO (quicklime) + C02 t
2. CaC03 • MgC03 + heat + CaO • MgO (dolomitic quicklime) + 2 C02
2) Air Pollution Control Equipment
The kiln exhaust gases represent the single largest source of airborne
particulate matter in the lime industry. The major contaminant is quicklime
dust caused by the abrasion of the stone in the kiln. The stone becomes friable
as it approaches the decomposition temperature and dusting occurs. The lime
dust presents a difficult control problem as it is hot, dry and not easy to wet. It
is a dust of mixed composition varying all the way from the raw limestone to
final completely calcined products. It will also be mixed with flyash, tars, and
unburned carbon if pulverized coal is the fuel. The dust control problem is
much more critical with rotary limestone kilns since recirculation of hot
exhaust gases is not practical after pre-heating the kiln feed.
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Table 11
Typical Chemical Analysis of Lime Kiln Emissions
Component
CaO
CaCO3
Ca(OH}2
MgO
CaSO4
Other
High Calcium
66.3
23.1
6.4
1.4
1.2
1.6
Dolomitic
7.2
64.3
28.2
.3
If pulverized coal is used as a fuel, the particulates would also include
flyash (consisting mostly of the oxides of silicon, aluminum and iron) and
soot and tars resulting from incomplete combustion.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
The approach that has been taken in the selection of gas cleaning
equipment on existing installations has been made strictly on the ability of the
equipment to remove the particulates.
In recent years, however, there has been an increase in the concern for
effective control of gaseous emission (S02, SOg and NOX) but this has not yet
become a major consideration in the selection of dust control equipment. The
emission of lime dust has been considered mainly a nuisance rather than one
creating a health hazard.
The total quantity of dust discharged from the kiln ranges from 5-15%
of the weight of the lime produced. Exhaust gas temperatures will range from
800° to 1800° F. It has also been established that the dust concentration will
increase as the gas volume increases under conditions when the kiln capacity is
pushed. An increase in production rate from 100 to 135 percent of design
capacity could double the quantity of dust discharged.
The gases leaving the kiln are usually first passed through a dust settling
chamber where the coarser material settles out. On many installations, a first
stage primary dry cyclone collector is used to collect a large percentage of the
coarse material. This primary collector stage, therefore, consists either of a low
efficiency dust chamber or a high efficiency dry cyclone. The removal
efficiency (by weight) at this stage can vary anywhere from 25% to 85% of the
dust being discharged from the kiln.
The lime dust collected in this primary stage is taken to a waste dump,
used as land fill or used for agricultural land treatment. The inclusion of a first
stage depends on two considerations: (1) whether or not the coarse lime has a
resale value, and (2) whether the kiln operation or the feed material (the stone)
will create higher than normal kiln outlet loadings. If the loading is estimated
to be higher than the 5-15% figure, a primary cyclone should be seriously
considered to alleviate the operating and maintenance problems that go with
high loadings. This is especially true in the case of wet scrubbers since
extremely high loadings could increase the potential material build-up in the
collector and also impose a heavy load on the slurry disposal system.
The selection of the second stage or final dust collector depends on a
variety of factors. On the basis of overall collection efficiency only, at the high
efficiency level in this study (.03 grains/ACF) any one of the three major
categories of collection equipment, (wet scrubber, fabric filter or electrostatic
precipitator) could be selected and achieve the required stack control on
particulate emission. At the lower efficiency (LA-Process Weight) a single stage
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medium pressure drop scrubber could be selected and would carry a total
installed cost figure somewhat less than what would be required for the high
efficiency scrubbers (Venturi or two stage dynamic). Depending upon
equipment size, this difference could be only marginal and it may be more
practical to select a higher efficiency system even in areas where code
requirements are not very stringent. The high efficiency wet scrubber is the
logical choice if the wet scrubber is selected.
The selection of the type of gas cleaning equipment must be based on
consideration of several factors in addition to efficiency. In order to determine
what kind of collector (wet scrubber, fabric filter, electrostatic) best suits the
particular application and the compliance with local air pollution codes, one
must evaluate capital equipment costs; codes; operating and maintenance costs;
water availability; horsepower requirements; in the case of fabric filters and
electrostatic precipitators, handling of dry collected material; in the case of
scrubbers, the required slurry handling system; water pollution and
requirements of control of gaseous pollution (S02, 803, NOX, etc.)
The size analysis of the dust being discharged from the kiln may
contain as much as 30% below 5 microns and 10% below 2 microns. It is
accepted that secondary dry cyclone collectors are unable to meet even the less
stringent code requirements. The choice must be among the other three
categories. A brief description of each follows:
Fabric Filters
Fabric filter installations for lime kilns consist of compartmented units
called "Baghouses". These contain tubes or envelopes made of glass fiber cloth
to withstand temperatures up to 550° F. As the kiln exhaust temperatures are
higher than this, cooling is required. It is achieved by (1) evaporative water
sprays, (2) indirect radiation convection heat exchange by means of U-tube
coolers, (3) ambient air dilution, or (4) a combination of these. Even though
glass fabric can withstand temperatures in the 550°F range, it is fragile due to
the loss in strength resulting from the interyarn friction produced during
flexing of the cloth. The flexing is done during the cleaning process.
In order to maintain acceptable pressure drop values (usually less than
5" wg), the collected dust cake must be removed periodically. This is
accomplished by isolating one of the compartments and collapsing or shaking
the bags lightly by reverse gas flow. (Mechanical shakers are seldom used with
glass cloth.) Each compartment is "off-line" for a nominal time of 2-5 minutes
to complete the cleaning. The dust falls to the hopper during cleaning. The
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total dust load will control the time required between repeated cleaning of each
compartment.
As one compartment is usually off-line for cleaning, the total available
filtration area is thus reduced. Filter units are specified on the basis of air to
cloth ratios (cfm of gas per square foot of cloth) for the total unit and for one
compartment off-line for cleaning. Air to cloth ratios for this service are
nominally 2.2/1 when one compartment is off-line.
If the air to cloth ratio, which is by definition superficial face velocity,
is excessively high, the pressure drop will increase, dust impaction may cause
cake breakage, and dust "bleed through" may occur. Each manufacturer knows
the optimum ratio for his type of fabric and method of cleaning for
satisfactory operation.
Insulation of the equipment may be required if condensation of
moisture can occur due to the combination of high moisture content in the gas
and extremely low ambient temperatures. Condensation can cause many
maintenance problems including (1) deterioration of the enclosure, (2)
malfunction of the dust handling equipment, and (3) most important —
blinding of the filter surface. Sometimes a partial enclosure can reduce or
eliminate excessive effects of wind and low air temperatures.
Replacement of the fabric is the largest single cost item in the
maintenance of this equipment. This is a true case in point of the adage that
"an ounce of prevention is worth a pound of cure". Regular inspections and
repair or replacement of failed bags can provide significant savings as well as
maintain a consistently high collection efficiency. A nominal two year life is
achieved for fabric in this application.
Waste handling equipment generally consists of screw conveyors to
remove the dust from the hoppers or move it to a collection point from.the
hopper valves. Sometimes air assisted gravity conveyors are used in place of
screws for dust handling.
Electrostatic Precipitators
Precipitators for lime kiln application are of the dry, horizontal flow,
plate type construction common to many other applications. They are
constructed of carbon steel, and therefore the kiln gases must be cooled to an
acceptable level.
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Cooling might be accomplished by air dilution or water evaporation.
Evaporative cooling is preferred because it results in a lower final gas flow, and
the moisture additive may improve the dust precipitability.
Multiple, independently energized electrical sections are used for better
power distribution so as to sustain high level performance.
The kiln gas enters the precipitator and flows through passages created
by parallel rows-of collecting plates. Discharge electrodes are centered in each
passage, and charge the dust particles negatively. The charged dust particles
precipitate on the collecting surface, from which they are removed by the use
of programmed rapping. The dislodged material falls by gravity into hoppers.
The efficiency of a precipitator is a function of the gas velocity and
treatment time. Thus, higher efficiencies are attained in any process by
increasing the precipitator size. Virtually any desired efficiency can be
obtained.
Wet Scrubbers
This category includes a considerable number of commercially available
units of different designs in the low to medium pressure drop operating range,
(6-8" wg) that could be applied and would meet the LA-Process Weight code.
As stated, however, savings in initial cost may not justify this selection and
make itmore advisable to consider the higher efficiency units that are available.
The wet scrubber selected to meet the more stringent code (this report, .03
gr/ACF) would be either a multi-stage dynamic scrubber or a Venturi-type
scrubber operating at a pressure drop of 14-15" wg at conditions. This study
included the multi-stage dynamic type for the high efficiency level as tabulated
in Table 19. A distinct advantage of the wet scrubber for this application is that
it can be fabricated to include a pre-humidification section as part of the
scrubber design, therefore, eliminating the need for a separate pre-cooler or gas
quenching stage.
The wet scrubber can also continue to perform under severe conditions
of operation and minimum maintenance until proper operating conditions are
restored. Wet scrubbers, however, do carry potential problems that are not
associated with dry systems. These are basically — the internal material
build-up in the scrubber if liquid rates fall or if dust loadings become unusually
high because of upset conditions; the build-up at the wet-dry zone especially on
horizontal gas inlets; the potential corrosion which must be considered if
sulphur bearing fuels are used; the fact that there will be a visible steam plume;
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the proper consideration and attention that must be given to the disposal of
slurry.
In considering the slurry disposal system, one must avoid unusually
long and horizontal runs if slurry is being led to settling ponds or basins. Some
areas also may require treatment of the very highly alkaline slurry before
disposal. Consideration should also be given to the proper location of the
primary exhaust fan if a Venturi-type scrubber is used. Placing this fan before
the scrubber is not practical at the high gas temperatures. This places the fan on
the discharge of the scrubber in the cool gas stream. In this location, the fan
may require alloy construction to avoid corrosion. Fan maintenance may be
excessive if conditions of condensation or scrubber water entrainment exist.
These cause material build-up on the fan resulting in fan imbalance. Frequently
this can be avoided by reheating the gases slightly (10-20°F) before they enter
the fan.
All three categories of collectors have been used commercially although
most of the installations are wet scrubbers.
All three types of equipment have met high performance standards
where they have been properly designed and operated. Reports regarding
operating and maintenance costs for wet scrubbers and fabric collectors vary
widely although it appears that on the average, these costs are higher for wet
scrubber and fabric filters than for electrostatic precipitators.
b. SPECIFICATIONS AND COSTS FOR ROTARY LIME KILN
APPLICATIONS
The specifications for each type of equipment were prepared in the
same form as the Sample Specification given in Appendix IV. For simplicity,
only the parts of the specification relating to the application in question are
given for each of the equipment types in this section of the report.
1)
ELECTROSTATIC PRECIPITATORS FOR LIME KILNS
Precipitators are not often utilized for rotary lime kilns. They have
been applied successfully to dusts of this type, however, and are economical for
the larger installations.
SPECIFICATIONS
The information provided the member companies for quoting these
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units is given in Tables 12 and 13. These Tables present the information
furnished as pages 3 and 4 of a specification, leaving only the general
conditions and terms to be covered in pages 1, 2, 5 and 6. Ordinarily, a good
deal more data will be supplied to the equipment manufacturer, particularly
when requesting installed costs. Drawings of the existing process equipment,
soil conditions, source test results, etc. are often appended.
COSTS
Two cases are specified for each of the precipitator sizes. The first of
these corresponds to the LA-Process Weight regulation, given in Appendix III.
The prices quoted for this case are listed in Table 14a. The higher efficiency
case involves larger and more costly precipitators, as shown in Table 14b.
Several descriptive comments by the precipitator manufacturer are
included in the following paragraphs. In each case the comments cover the
equipment items only, although the turnkey cost includes other items such as
ductwork, foundations, etc.
LA-PROCESS WEIGHT
The Small Electrostatic Precipitator quotation includes:
One (1) precipitator, containing 11 gas passages, 9" x 20'-0" x 18'-0",
(when treating 24,500 cfm at 700°F, will be 98.1% efficient). Two (2) 250 ma
rectifier sets will be used to energize the precipitator. A cooling tower capable
of removing 105,500 Btu/Min. which will cool 35,000 cfm of gas at 1200°F to
700°F, requiring 10 gal. of water per minute. A dust system consisting of a 530
cubic foot storage hopper adjacent to the precipitator, a screw conveyor and
elevator.
The Medium Electrostatic Precipitator quotation includes:
One (1) precipitator, containing 23 gas passages, 9" x 24'-0" x 18'-0",
(when treating 59,500 cfm at 700°F, will be 98.6% efficient). Two (2) 250 ma
rectifier sets will be used to energize the precipitator. A cooling tower capable
of removing 256,500 Btu/Min. will cool 85,000 cfm of gas at 1200°F to
700°F, requiring 24 gal. of water per minute. A dust system consisting of a
1230 cubic foot storage hopper adjacent to the precipitator, a screw conveyor
and elevator.
The Large Electrostatic Precipitator quotation includes:
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Table 12
ELECTROSTATIC PRECIPITATOR PROCESS DESCRIPTION
FOR ROTARY LIME KILN SPECIFICATION
The electrostatic precipitator is to handle the exhaust gas from a rotary lime kiln
fired by natural gas. The precipitator will be used to remove limestone and lime dust from
the exhaust gas. The rotary kiln is fed with 1/4" to 1/2" limestone. There is no preheater on
the kiln and the feed end of the kiln is equipped with a dust fall-out chamber. The dust
chamber is followed by a flash cooling system which reduces the gas temp from 1200°F to
550 - 500°F.
The exhaust gas will be brought from the feed end housing to a point twenty feet
outside the building and twenty feet above grade. The precipitator will be located at grade in
an area beyond the duct work and the area is free of space limitations. A fan will follow the
precipitator and then a stack 50 feet in height.
The precipitator is to operate in such a manner as to continuously reduce the outlet
loading to the specified levels. An automatic control should be supplied to give maximum
dust removal. Two or more electrical fields in direction of gas flow must be included. The
hoppers should have a minimum side and valley angle of 60 °. A screw conveyor system to
bring the dust to one point 3 feet outside the precipitator is to be included. A safety
interlock system must be included on all access openings to the inside of precipitator. The
rapping system must have a variable impact and timing cycle. From the common dust point
the dust will be elevated to a dust bin adjacent to the collector. The bin will have a fifteen
(15) foot clearance from grade. Hoppers and conveyors should be insulated.
For purposes of this quotation, the external hoppers and conveyor will be considered
auxiliary equipment.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 13
ELECTROSTATIC PRECIPITATOR OPERATING CONDITIONS
FOR ROTARY LIME KILN SPECIFICATION
Three sizes of electrostatic precipitators are to be quoted at each of two efficiency
levels as specified below:
Small
Medium
Large
Kiln capacity, ton/day
Process weight, Ib/hr
Kiln outlet gas
Flow, ACFM
Temp., °F
% moisture
Precipitator inlet
Flow, ACFM
Temp., °F
% moisture
Precipitator inlet loading, Ib/hr
Precipitator inlet loading, gr/ACF
125
18,700
35,000
1,200
12
20,000
550
16
815
4.75
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt %
Case 1 — LA Process Weight
15.4
0.090
98.1
Case 2 — High Efficiency
250
37,400
85,000
1,200
12
50,000
550
16
1,960
4.55
26.9
0.063
98.6
500
74,800
150,000
1,200
12
90,000
550
16
3,500
4.55
40
0.052
98.85
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt %
5.15
0.03
99.4
12.9
0.03
99.3
23.2
0.03
99.3
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 14a
Electrostatic Precipitator Cost Data
for Rotary Lime Kilns
(LA-Process Weight)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt. %
Controlled Emission, gr/ACF
Type of Charge
o
Inlet Gas Temperature, F
Fan (.3" WgJ
System Horsepower Precip. HVPS*
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment**
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance , $/Year
ELECTROSTATIC PRECIP.
SMALL
125
24,500
98.1
.090
Limestone
700
LL
42
50,600
50,900
12,350
113,850
65,600
72,200
20
1,500
MEDIUM
250
59,500
98.6
.063
Limestone
700
iU
60
64,600
62,900
29,500
157,000
101,100
111,200
20
1,500
M
LARGE
500
105,000
98.85
.052
Limestom
700
50
74
87,900
76,500
51,500
215,900
150,200
165,200
20
2,500
* High voltage power supply, figured as horsepower equivalent.
** This includes the gas cooling system.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 14b
Electrostatic Precipitator Cost Data
for Rotary Lime Kilns
(High Efficiency)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt . 1
Controlled Emission, gr/ACF
Type of Charge
o
Inlet Gas Temperature, F
Fan C3" wg)
System Horsepower Precip. HVPS*
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance $/Year
ELECTROSTATIC PRECIP.
SMALL
125
24,500
99.4
.03
Limestone
700
12
59
68,200
57,800
12,350
138,350
76,900
84,600
20
2,000
MEDIUM
250
59,500
99.3
.03
Limestone
700
30
105
79,400
72,600
29,500
181,500
109,100
120,000
20
2,000
LARGE
500
105,000
99.3
.05
Limestone
700
50
129
102,500
85,000
51,500
239,000
155,200
171,000
20
3,000
High .Voltage Power Supply, figured as horsepower equivalent.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 2
Costs of Electrostatic Precipitators
For Rotary Lime Kilns
(LA-Process Weight)
600 -i
rt
O
(=)
03
t/>
3
O
J^
H
300
200
100
50
25
10
TIT
rm
1
Turnkey Installation
for Grass Roots Plant
ffitt
Srft
&L
Precipitator
Auxiliary Equipment
125 250 500
Kiln Capacity, Ton/Day
±000
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 3
Costs of Electrostatic Precipitators
For Rotary Lime Kilns
(High Efficiency)
03
O
o
rt
V)
3
O
43
H
45
600
300
200
100
50
25 -
10
t
Turnkey Installation
Grass Roots Plant
I!
m
Precipitator and
Auxiliary Equipment
Precipitator
Only
3
r&
50
125 250 500
Kiln Capacity, fon/Day
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
One (1) precipitator, containing 43 gas passages, 9" x 24'-0" x 18'-0",
(when treating 105,000 cfm at 700°F, will be 98.85% efficient). Two (2) 500
ma rectifier sets will be used to energize the precipitator. A cooling tower
capable of removing 451,000 Btu/Min. will cool 150,000 cfm of gas at 1200°F
to 700°F, requiring 40 gal. of water per minute. A dust system consisting of a
2160 cubic foot storage hopper adjacent to the precipitator, a screw conveyor
and elevator.
HIGH EFFICIENCY CASE
The Small Electrostatic Precipitator quotation includes:
One (1) precipitator, containing 13 gas passages, 9" x 15'-0" x 27'-0"
(when treating 24,500 cfm at 700°F, will be 99.4% efficient). Three (3) 250
ma rectifier sets will be used to energize the precipitator. A cooling tower
capable of removing 105,500 Btu/Min. will cool 35,000 cfm of gas at 1200°F
to 700°F, requiring 10 gal. of water per minute. A dust system consisting of a
550 cubic foot storage hopper adjacent to the precipitator, a screw conveyor
and elevator.
The Medium Electrostatic Precipitator quotation includes:
One (1) precipitator, containing 19 gas passages, 9" x 24'-0" x 27'-0",
(when treating 59,500 cfm at 700°F, will be 99.3% efficient.) Three (3) 250
ma rectifier sets will be used to energize the precipitator. A cooling tower
capable of removing 256,500 Btu/Min. will cool 85,000 cfm of gas at 1200°F
to 700°F, requiring 24 gal. of water per minute. A dust system consisting of
1250 cubic foot storage hopper adjacent to the precipitator, a screw conveyor
and elevator.
The Large Electrostatic Precipitator quotation includes:
One (1) precipitator, containing 33 gas passages, 9" x 24'-0" x 27'-0",
(when treating 105,000 cfm at 700°F, will be 99.3% efficient.) Three (3) 500
ma rectifier sets will be used to energize the precipitator. A cooling tower
capable of removing 451,000 Btu/Min. will cool 150,000 cfm of gas at 1200°F
to 700° F, requiring 40 gal. of water per minute. A dust system consisting of a
2190 cubic foot storage hopper adjacent to the precipitator, a screw conveyor
and elevator.
It should be noted that, whereas the operating conditions specified a
temperature of 550°F after cooling, a temperature of 700° F was used for the
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
quotation. The manufacturer's judgment was that the dust resistivity would be
too high for good precipitator performance at 550°F, and that this condition
could be corrected by increasing the operating temperature. Responses by
manufacturers of air pollution control equipment often include such
exceptions to the conditions specified and the experience of the precipitator
manufacturer in treating similar problems should be utilized.
The costs reported in Tables 14a and 14b are plotted in Figures 2 and 3.
2)
FABRIC FILTERS FOR LIME KILNS
Fabric filters are specified for both efficiency levels, but with the
understanding that a fabric collector of ordinary design would have a higher
efficiency than the "high efficiency" case. The pertinent process description
and operating conditions are specified in Tables 15 and 16.
It should be noted that the operating conditions specified at the
collector inlet were exactly the same for the fabric collector as for the
electrostatic. The costs for the three filter sizes are given in Table 17. Whereas
the electrostatic precipitator design temperature was modified by the
precipitator manufacturer to 700°F, the filter manufacturer quoted equipment
to operate at the specified 550°F. The costs given in Table 17 are plotted on
log-log coordinate paper in Figure 4.
3)
WET SCRUBBERS FOR LIME KILNS
The specification information for the wet scrubber is given in Tables 18
and 19. The scrubber inlet conditions are similar to those specified for
precipitators and fabric filters, but the outlet volume (which sets the size of the
scrubber and the fan) is considerably smaller, due to cooling of the gas as it
becomes saturated.
The cost data submitted by the manufacturer is shown in Tables 20 and
21. Some descriptive information was supplied by the manufacturer which
points up differences in the basic design of the equipment offered for the two
efficiency levels.
LA-PROCESS WEIGHT
For the LA-Process Weight or Lower Efficiency requirement, the
scrubber offered is a single stage centrifugal tower type scrubber fabricated of
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 15
FABRIC COLLECTOR PROCESS DESCRIPTION
FOR ROTARY LIME KILN SPECIFICATION
The bag filter is to handle the exhaust gas from a rotary lime kiln fired by natural
gas. The filter will be used to remove limestone and lime dust from the exhaust gas. The
rotary kiln is fed with 1/4" to 1/2" limestone. There is no preheater on the kiln and the feed
end of the kiln is equipped with a dust fall-out chamber. The dust chamber is followed by a
flash cooling system which reduces the gas temp, to 550°F - 500°F.
The exhaust gas wilt be brought from the feed end housing to a point twenty feet
outside the building where a fan will be located. (The fan outlet is five (5) feet above grade).
The fabric filter will be located in an area beyond the fan and the area is free of space
limitations. The fabric filter should be of positive design.
The fabric filter is to operate in such a manner that a single compartment (with no
more than one quarter of the total collecting surface area) is isolated for cleaning. The
cleaning method is to be reverse air flow type. Each section should be capable of isolation
for maintenance and have provisions for personnel safety when the filter is in use. The
hoppers should have a minimum to side and valley angle of 60° with screw conveyors to
bring the dust to a centrally located point 3 feet outside the filter. Dust removal should be a
continuous process. The hopper valve is to be included in the quote. From this point the
dust will be elevated to a dust bin adjacent to the filter. The bin will have a 15 foot clearance
from grade. Treated glass cloth filter bags should not exceed 12" in diameter and 30 feet in
length. The cleaning cycle should be adjustable in duration of compartment cleaning and
total cycle length. No more than two bags must be removed to have access to all bags.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 16
FABRIC COLLECTOR OPERATING CONDITIONS
FOR ROTARY LIME KILN SPECIFICATIONS
3. OPERATING CONDITIONS
Three sizes of fabric collectors are to be quoted. While two levels of efficiency
are specified, it is expected that a single fabric quotation will be supplied for
each size range.
Small
Medium
Large
Kiln capacity, ton/day
Process weight, Ib/hr
Kiln outlet gas
Flow, ACFM
Temp., °F
% moisture
Filter inlet
Flow, ACFM
Temp., °F
% moisture
Filter inlet loading, Ib/hr
Filter inlet loading, gr/ACF
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt %
125 250 500
18,700 37,400 74,800
35,000 85,000 150,000
1,200 1,200 1,200
12 12 12
20,000 50,000 90,000
550 550 550
16 16 16
815 1,960 3,500
4.75 4.55 4.55
Case 1 — LA Process Weight
15.4 26.9 40
0.090 0.063 0.052
98.1 98.6 98.85
Case 2 — High Efficiency
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt %
5.15
0.03
99.4
12.9
0.03
99.3
23.2
0.03
99.3
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 17
Fabric Collector Cost Data
for Rotary Lime Kilns
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM ;
Efficiency, Wt . %
Controlled Emission, gr/ACF
Type of Charge
e
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other 1
Total
Installation Cost, $ :
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance $/year
FABRIC FILTER
SMALL
125
20,000
99 Plus
0.03
Limestone
550
Hot 60
Cold 111
53,250
10,480
3,740
18,610
6,610
94,690
75,750
20 - 25
11,000.00
MEDIUM
250
50,000
99 Plus
0.03
Limestone
550
150
300
75,620
17,910
4,675
20,680
11,890
130,775
100,695
20 - 25
18,000.00
LARGE
500
90,000
99 Plus
0.03
Limestone
550
300
600
106,515
27,840
6,440
23,250
16,405
180,450
135.,340
20 - 25
30,000.00
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 4
Costs of Fabric Collectors
For Rotary Lime Kilns
500
300
Turnkey Installation
! for Grass Roots Plant
±Hti+fH-t-ht+4-HH-H+H
f Fabric Filter S.
Auxiliary Equipment
Fabric Filter
Only
25
125 250 500
Capacity, Ton/Day
1000
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
carbon steel throughout. Operating pressure drop across the unit is 8.0" wg.
Scrubber includes lower shell extension for humidification of hot inlet gases.
Inlet connection has a 304 stainless steel insert sleeve. All doors are of the
quick acting type.
"Auxiliaries" include the required main exhaust fan of the heavy duty
radial bladed type; a TEFC motor (460 volt, 60 cycle, 3 phase); V-belt drive
and guard; a recycle pump; a recycle and bleed pump with motor and drive;
and a tank with liquid level and make-up water controls.
The installation cost item includes the ductwork from the kiln dust
chamber take-off to the scrubber inlet — ductwork from scrubber outlet to the
fan inlet and discharge stack at fan outlet. All structural supports; erection of
the total system including excavation and concrete work, liquid feed piping and
electric hook-up from adjacent power source are also included.
HIGH EFFICIENCY CASE
For the High Efficiency Level, the scrubber is a two stage dynamic
scrubber including an integral wetted fan, which in addition to being the prime
mover in the total system, is also the second stage of the scrubber. Fabrication
of the collector is of carbon steel except for the fan wheel which is type 304
stainless steel. Scrubber to include lower shell extension for humidification of
hot inlet gases. The inlet connection has a type 304 stainless steel insert sleeve.
All doors are of the quick acting type with the flushed fan as an internal part of
the scrubber.
The horsepower consumed by the fan is comparable to the horsepower
requirement of a free standing scrubber operating at 8.0" wg pressure drop.
The auxiliaries include a TEFC drive motor (460 volt, 60 cycle, 3
phase); V-belt drive and belt guard; recycle tank; recycle and bleed pump with
motor and drive; tank liquid level and make-up water controls.
Installation costs include the ductwork from the take-off of the dust
chamber to the scrubber inlet, and the stack on top of the vertical scrubber
discharge. Also included are all structural supports; erection of the total system
including excavation and concrete work, liquid feed piping and electric
hook-up from adjacent power source.
The following quantity of make-up water will be required to cover the
evaporative loss and the bleed rate to maintain a 5% recycle slurry. This applies
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
to both the low and high efficiency system:
125 TPD System 75 GPM
250 TPD System 180 GPM
500 TPD System 300 GPM
The costs given in Tables 20 and 21 are plotted on log-log coordinates
in Figures 5 and 6.
Several points should be noted when comparing the equipment quoted
for the LA-Process Weight and High Efficiency cases. The high efficiency
scrubber is a proprietary design aimed at producing good efficiency at
minimum cost for this specific application. Various proprietary designs are
available as well as conventional Venturi or orifice-type scrubbers.
The cost comparison indicates that the high efficiency can be achieved
with a lower expenditure of capital and operating cost. It is not unusual that
the first costs of high efficiency scrubbers are little higher than lower efficiency
designs; however, the power costs will ordinarily increase substantially with
increases in efficiency. That they do not in this comparison (which shows
almost identical horsepower requirements for the two efficiencies) is peculiar
to the equipment of the manufacturer preparing these quotations. The lower
efficiency design is for a Venturi scrubber, whereas the high efficiency scrubber
is a dynamic type.
c. DISCUSSION OF COSTS FOR ROTARY LIME KILN
APPLICATION
Rotary lime kiln applications are most frequently handled by wet
scrubbers. The reason for this is apparent when the costs of the turnkey
installations given for the three types of equipment are compared. Figure 7
shows these costs for the high efficiency case as a function of kiln size. The wet
scrubber satisfies all of the process requirements, yet has an initial cost of less
than 1/2 that for a precipitator or fabric filter. This holds true over the entire
range of sizes.
There is a horsepower penalty involved with the scrubber operation,
however. Rather surprisingly, this is not significant in comparison with the
fabric collector. However, it requires much more power than the electrostatic
precipitator.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 18
WET SCRUBBER PROCESS DESCRIPTION
FOR ROTARY LIME KILN SPECIFICATION
The scrubber is to handle the exhaust gas from a rotary lime kiln fired by natural gas.
The scrubber will be used to remove limestone and lime dust from the exhaust gas. The rotary
kiln is fed with 1/4" to 1/2" limestone. There is no preheater on the kiln and the feed end of
the kiln is equipped with a dust fall-out chamber. The dust chamber is followed by a wet
scrubber with pre-cooling sprays or saturation chamber as required. Such pre-cooling
equipment is to be located at the discharge from the fall-out chamber, and must cool the
ductwork to a maximum of 550°F. It will be considered as an integral part of the scrubber
for this quotation.
The exhaust gas will be brought from the precooling section to a point twenty feet
outside the building where a fan will be located. (The fan outlet is five (5) feet above grade.)
The scrubber will be located in an area beyond the fan. The area is free of space limitations.
The scrubber is to be designed to withstand the full discharge pressure developed by the fan.
The scrubber is to operate in such a manner as to continuously attain the efficiency
levels specified in the following section.
The scrubber shall have a conical bottom designed to avoid the collection of
sediment or deposits. Liquor effluent is to be piped to a recirculation tank from which the
recirculation pump takes suction. Fresh makeup water is to be added to the system at this
point. Discharge from the recirculation pump is to be partially returned to the scrubber and
part withdrawn to a slurry settling basin to be provided by the customer. The slurry
withdrawal is to be set to maintain about 10 weight percent solids when the kiln is operating
at design capacity.
The scrubber and external piping are to be constructed of carbon steel. Packing
glands are to be flushed with fresh water to prevent binding of the seals.
For purposes of this quotation, the following is to be considered auxiliary
equipment:
(1) pumps and reservoir
(2) fan
(3) external piping
(4) controls
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 19
WET SCRUBBER OPERATING CONDITIONS
FOR ROTARY LIME KILN SPECIFICATIONS
Three sizes of scrubbers are to be quoted for each of two levels of efficiency.
(B)
Medium
(C)
Large
Furnace capacity, ton
Production rate, Ib/hr
Process weight rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature, °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet gas volume, ACFM
Outlet gas temperature, °F
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt %
125
10,400
18,700
35,000
1,200
815
2.82
19,000
164
250
20,800
37,400
85,000
1,200
1,960
2.69
46,000
164
500
41,600
74,800
150,000
1,200
3,500
2.72
81,000
164
Case 1 - LA Process Weight
15.40
0.094
98.1
Case 2 — High Efficiency
26.7
0.068
98.6
40
0.058
98.9
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt %
4.89
0.03
99.4
11.85
0.03
99.4
20.8
0.03
99.4
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 20
Wet Scrubber Cost Data
for Rotary Lime Kilns
(LA-Process Weight)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.%
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance $/year
WET SCRUBBER
SMALL
125
35,000
98.1
0.094
Limestone
1,200
65
7 >200
10,850
18,050
57,900
71,500
10
4,800
MEDIUM
250
LARGE
500
85,000 1.50,000
98,6
0.068
Limestone
1,200
147
13,100
16,770
29,870
79,700
97,100
10
5,600
98.9
0.058
Limestone
1,200
268
23,600
36,960
60,560
103,900
127,170
10
6,500
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 21
Wet Scrubber Cost Data
for Rotary Lime Kilns
(High Efficiency)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.l
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Total Installation Cost, $
A. Grass-Roots
B. Add -On
Expected Life, Years
Operating and Maintenance $/year
WET SCRUBBER
SMALL
125
35,000
99.4
0.03
Limestone
1,200
60
14,300
9,250
23,550
48,900
61,400
10
4,800
MEDIUM
250
85,000
99.4
0,03
Limestone
1,200
140
25,800
12,600
38,400
66,300
83,400
10
5,600
LARGE
500
150,000
99.4
0,03
Limestone
1,200
245
44,700
16,700
61,400
86,900
110,400
10
6,500
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
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Figure 5
Costs of Wet Scrubbers
For Rotary Lime Kilns
(LA-Process Weight)
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125 250 500
Kiln Capacity, Ton/Day
1,000
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 6
Costs of Wet Scrubbers
For Rotary Lime Kilns
(High Efficiency)
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200
100
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-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 7
Comparison of Abatement Costs
for Rotary Lime Kilns
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125 250 500
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
The horsepower shown for the 500 ton kiln in Table 21 is 245. If the
operation is carried out 24 hours/day, 300 days/year, this would cost
245 x 300 x 24 x 0.746/0.85 x $.01 = $15,425
per year at M per kw-hr and 85% efficiency of the driver.
Several other factors merit some consideration in the choice of
equipment. For example, the precipitator and fabric filter life was estimated at
20 or more years, whereas the scrubber shows only 10 years expected life.
While differences in estimates made by different manufacturers have less
significance than if all were prepared by the same person, it is likely that there
is a difference due to the more difficult corrosion problems presented in wet
scrubber applications.
Precipitator maintenance is principally involved with inspection, with
only nominal cleaning and replacement of parts. Fabric filter maintenance
consists mainly of bag replacement, which is a substantial cost that increases in
proportion to the size of the collector. For the wet scrubber, more extensive
cleaning, replacement of plugged or eroded nozzles, etc. involves a maintenance
cost, which increases with the size of the scrubber.
REFERENCES FOR LIME KILN SECTION
1. Boynton, R. S., "Chemistry and Technology of Lime
& Limestone" 1966 (Interscience) Wiley
2. Lewis, C. J., Crocker, B.B., "The Lime Industry's Problem
of Airborne Dust" APCA Journal 19, 31-39 (Jan. 1969)
3. Anon., "River Rouge Plant Supplies Detroit Steelmakers",
.Rock Products (July, 1966)
4. Schwarzkopf, F., "A Comparison of Modern Calcining
System" Rock Products (July, 1970)
5. Shreve, R. Norris, "Lime Manufacture" Chemical Process
Industries, 3rd Edition, McGraw-Hill Book Co.
6. IGCI Publication EP-5 "Information for Preparation of
Bidding Specifications for Electrostatic Precipitators",
IGCI, Box 448, Rye, N.Y.
7. IGCI Publication F-2 "Fundamentals of Fabric Collectors
and Glossary of Terms", IGCI, Box 448, Rye, N.Y.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
2. AIR POLLUTION CONTROL
REVERBERATORY FURNACES
FOR BRASS/BRONZE
a.
PROCESS DESCRIPTION
Process Flow
The basic flow of the process begins with the raw material, which in the
bronze and brass industry consists primarily of copper-base alloy scrap. The
scrap contains many contaminants that must be removed. The common
contaminants would include oil, grease, insulation, rubber, anti-freeze solutions
and many other chemicals. A list of various copper bearing scrap follows in
Table 22. Methods of pre-processing scrap fall into three basic categories:
mechanical, hydrometallurgical, and pyrometallurgical. Of these separation
techniques, the pyrometallurgical method contributes the most toward air
contamination. A brief outline of these methods follows:
1) Mechanical
Hand sorting
Stripping (wire insulation)
Shredding
Magnetizing
Briquetting
(Compressing scrap)
2) Hydrometallurgical
Concentrating (gravity separation in a liquid medium)
3) Pyrometallurgical
Sweating (low melting point metals)
Burning (rubber insulation, etc.)
Drying at low temperature (to drive off volatile
impurities such as oil and grease)
Blast furnace or cupola (dense molten metal
separates from the non-metallic slag)
The pre-processed scrap is then fed into a furnace such as the open
hearth reverberatery. After the heat is begun additional charges of scrap are
usually added. A diagramatic flow sheet relating these processes to the overall
scheme is shown in Figure 8.
The next step in the process is the refining stage. Here the remaining
impurities and other elements in excess of the specifications are removed. Many
different methods are employed to achieve the desired results. Refining is
primarily a process of purification using chemicals which are commonly called
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 22
TYPES OF COPPER-BEARING SCRAP
1. No. 1 copper wire
2. No. 2 copper wire
3. No. 1 heavy copper
4. Mixed heavy copper
5. Light copper
6. Composition or red brass
7. Red brass composition turnings
8. Genuine babbitt-lined brass bushings
9. High-grade, low-lead bronze solids
10. Bronze papermill wire cloth
11. High-lead bronze solids and borings
12. Machinery or hard red brass solids
13. Unlined standard red car boxes (clean journals)
14. Lined standard red car boxes (lined journals)
15. Cocks and faucets
16. Mixed brass screens
17. Yellow brass scrap
18. Yellow brass castings
19. Old rolled brass
20. New brass clippings
21. Brass shell cases without primers
22. Brass shell cases with primers
23. Brass small arms and rifle shells, clean fired
24. Brass small arms and rifle shells, clean muffled (popped)
25. Yellow brass primer
26. Brass pipe
27. Yellow Brass rod turnings
28. Yellow brass rod ends
29. Yellow brass turnings
30. Mixed unsweated auto radiators
31. Admiralty brass condenser tubes
32. Aluminum brass condenser tubes
33. Muntz metal tubes
34. Plated rolled brass
35. Manganese bronze solids
36. New cupro-nickel clippings and solids
37. Old cupro-nickel solids
38. Soldered cupro-nickel solids
39. Cupro-nickel turnings and borings
40. Miscellaneous nickel copper and nickel-copper-iron scrap
41. New monel clippings and solids
42. Monel rods and forgings
43. Old monel sheet and solids
44. Soldered monel sheet and solids
45. Soldered monel wire, screen, and cloth
46. New monel wire, screen, and cloth
47. Monel castings
48. Monel turnings and borings
49, Mixed nickel silver clippings
50. New nickel silver clippings and solids
51. New segregated nickel silver clippings
52. Old nickel silver
53. Nickel silver castings
54. Nickel silver turnings
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o>
DOMESTIC
&
INDUSTRIAL
SCRAP
SEPARATION
PROCESS
REVERBERATORY
FURNACE
COOLING
SURFACE
GAS OR OIL
FUEL + AIR
MECHANICAL
HYDROMETALLURGICAL
PYROMETALLURGICAL
SLAG
METAL
PRODUCT
FABRIC
COLLECTOR
t
_LIL
FINES
FAN
Figure 8
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
fluxes. These may be solid, liquid, or gaseous. Compressed air is often used to
oxidize the unwanted elements of aluminum, iron, manganese, and silicon by
blowing it through the liquid pool. The less easily oxidized copper and tin
remain in the bath. Part of the zinc, however, is unavoidably lost. Sometimes
an inert gas such as nitrogen is used to carry gaseous impurities away from the
liquid metal if oxidation is to be avoided.
A slag is usually formed on the surface of a melt. A layer of 1/4" to
1/2" of slag is desirable as a cover or heat retainer. The slag may aid the flux by
degassing, densifying, fluidizing and homogenizing the alloy. It may also act as
a hardener, or become part of the alloy depending upon its composition. When
impurities can be removed by the flux as slag, no real air pollution problem will
occur. An air pollution problem will occur when a gas is blown below the
surface of a bath of metal causing impurities to be released.
Alloying the melt by adding various pure metals such as zinc or tin will
result in the metallic characteristics required. It is usually best, however, to add
slag formers while charging so that the cover will be formed early in order to
protect the zinc from excessive oxidation.
The method of pouring molten alloy into ingot molds varies: It is either
tapped directly into a moving automatic mold line or poured into a holding
ladle and transferred to the mold line.
During the pouring process, large volumes of metallic oxide fumes are
emitted as the alloy is no longer protected from the air by the slag cover.
Smooth top ingots are produced by covering the metal surface with ground
charcoal. The charcoal produces a shower of sparks which is difficult to capture
in hoods. Hooding movable equipment of this type can be a very complex
problem.
Equipment
The principal item of equipment is the reverberatory open hearth
furnace. This furnace operates by transfering heat from the burner flames, roof
and walls onto the charge. The entire roof is sloped down to form a restricted
section or throat near the back of the hearth which maximizes the amount of
reflected radiation. The furnace has a shallow, generally rectangular, refractory
hearth for holding the metal charge. This is one of the least expensive methods
of melting because the flame and products of combustion come in direct
contact with the solid and molten metal.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Nature of Air Pollutants
Air or gas usage in the process gives rise to pollution. This usage,
coupled with fumes from the furnace, causes pollutant emission. There are four
principle factors which contribute metallic oxide fumes in brass and bronze
smelting.
1) Alloy composition: the rate of loss of zinc is approximately
proportional to the zinc percentage in the alloy.
2) Furnace type: direct-fired furnaces, such as the open hearth
reverberatory, produce higher fume concentrations than
crucible or electric-type furnaces because the hot, high velocity
combustion gases come directly in contact with the metal
resulting in excessive oxidation.
3) Excessive emissions result from poor foundry practices such as:
Improper combustion
Overheating of charge
Addition of zinc at maximum furnace temperature
Flame impingement on charge
Heating charge too rapidly
Insufficient flux cover
Superheating metal
Poor control of furnace atmosphere
4} Pouring temperature: for a given percentage of zinc, an increase
in temperature of 100°F increases the rate of zinc loss about
three times. Melting points for copper alloys are generally in the
1500-1800° F range.
Careful consideration of these factors will greatly reduce air
contamination.
The gas effluent or the gas exiting from a direct-fired furnace producing
brass or bronze metal is ordinarily in the temperature range of 1700°F to
2400°F. It may contain hydrocarbon compounds as well as any impurities
from the charge which are picked up by the mixture of combustion products
and infiltrated air. The latter include solid dust particles and oxide fumes.
A general description of pollutants encountered is as follows:
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
1) In copper based foundries, metallic oxides can account for as
much as 98% of the particulate matter. Zinc oxide and lead
oxide fumes occur in the submicron size range. The size range
of these fumes produces a tremendous scattering of light which
accounts largely for the visible plume discharge.
2) Other solid emissions may include dust, carbon, and smoke
from burning charge impurities. If a sulfur containing fuel is
used, sulfur oxides will also be released. Nitrogen oxides will be
formed to some extent by the burner.
Furnace emission factors vary depending upon the type of charge, flux,
slag, fuel and air conditions. Usually emission values for reverberatory furnaces
run from 26 Ib./ton to 160 Ib./ton. Emission rates, however, frequently occur
outside this range. Gas composition is described in a series of tests which were
performed by the National Air Pollution Control Administration (NAPCA) to
analyze the gas discharge from industrial furnaces and air pollution control
systems. These tests are summarized in the following paragraphs:
Test 1
A heat of 85-5-5-5 red brass was made in a 100-ton reverberatory
furnace. A total of 105,000 pounds of metal was charged to the furnace over a
period of 6.7 hours. Oxygen was supplied to the burners for 5.3 of these hours
to increase the melting rate. During a 9.3 hour refining period there was
intermittent air blowing, and 500 pounds of fluxes were added. Pouring took
3.5 hours.
The air pollution control system serves three 100-ton reverberatory
furnaces. The gases pass through a common spray chamber and then through a
set of U-tube radiation coolers. From this point, the 450°F to 650°F gases are
mixed with bleed-in air, go through the baghouse and a 75 horsepower fan, and
pass to the stack. The 16-compartment shaker-type baghouse is fitted with
heat-set Orion bags. The total filter area is 7,360 square feet and the rated
capacity is 19,000 cfm at 220° F. The design filter ratio, with one compartment
out for cleaning, is 2.75/1.
Measured gas temperature at the baghouse inlet cycled between 200T
and 220°F. The measured gas volume averaged 15,000 SCFM (7CPF). Baghouse
pressure drop varied from 4 to 5 inches of water.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
One inlet sample was taken during each of these three furnace periods:
charging, refining, and pouring. A continuous baghouse outlet sample was
taken over the entire heat, as listed in Table 23.
Test 2
A set of two 1-hour samples was taken at the stack of the system
described in Test 1. Two reverberatory furnaces were operating during these
tests. Both furnaces were melting during the first test and both were charging
during the second test, as listed in Table 24.
Test 3
A reverberatory furnace rated at 60 tons was tested over a full cycle,
with three baghouse inlet samples (charge, refine, pour) and a single baghouse
outlet sample.
Furnace gases pass to a spray chamber and then to U-tube coolers.
Air-bleed dampers are located at the U-tubes. The baghouse, with a rated
capacity of 22,000 cfm at 180°F, has 5,940 square feet of Dacron fabric. The
design filter ratio is 3.87/1. A 75 horsepower fan is used in the system.
Measured stack gas volume was 18,000 SCFM (70°F) during this testing period.
Capture efficiency of the hooding is estimated at 80 to 85 per cent. Results are
in Table 25. Gaseous contaminants are listed in Table 26.
AIR POLLUTION CONTROL
The nature of contaminants in brass and bronze smelting requires
careful consideration of ventilation and gas cleaning equipment used.
Hooding, Ventilating and Exhaust Requirements
Reverberatory furnaces require hoods over charge doors, slag doors, tap
holes and the main stacks. Inlet velocities for these of 100 to 200 feet per
minute are usually sufficient providing good industrial hood design technique is
used. Arrangements should be provided to turn down or shut off furnace
burners during periods when the furnace is open so as to not overload the fan
exhaust capacity. The periods of concern are when the furnace is open for
lancing, charging, rabbling, slag removal, charging metal or pouring metal.
Fabric Collectors
Fabric collectors are the most frequently used equipment to control
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 23
BRASS/BRONZE REVERBERATORY FURNACE PARTICULATE EMISSIONS
Test 1
Emissions, furnaceb Baghouse outlet0
Cycle Length, hr. Ib/hr. Cycle total, Ib/hr. Total, Ib.
Ib.
Charge3 6.73
Refine 9.30
194.2
159.3
1,308
1,482
Pour
3.53
12.8
45
Total
19.56
2,835
3.32 64.8
aTotal charge: 105,000 Ib. Alloy produced: BBII Alloy No.
4A: 85-5-5-5
"Furnace emission factor: 53.7 Ib/ton
Collection efficiency: 97.7 per cent
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 24
EMISSIONS FROM BAGHOUSE ON
BRASS/BRONZE REVERBERATORY FURNACES
Test 2
Sample
D-1
Baghouse Outlet
gr/SCF
0.025
Ib/hr
5.13
D-2
0.031
6.37
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 25
BRASS/BRONZE REVERBERATORY FURNACE PARTICULATE EMISSIONS
Test 3
Cycle
Total
Length, hr.
22.1
Emissions, furnace"
Ib/hr. Cycle total,
Ib.
11,294.2
Baghouse Outlet0
Ib/hr. Total, Ib.
Charge3
Refine
Pour
8.5
10.3
3.3
500.1
681.1
8.5
4,250.8
7,015.3
28.1
2.17 47.9
aTotal charge: 144,000 Ib. Alloy produces: BBIIAIIoyNo.
5A: 81-3-7-9
"Furnace emission factor: 156.9 Ib/ton
Collection efficiency: 99.6 per cent
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 26
GASEOUS EMISSIONS FROM BRASS/BRONZE REVERBERATORY FURNACE
Results
Test 1
Test 3
1. 0,
2. C02%
3. CO ppm
4. S02 ppm
5. N02 ppm
6. h^S ppm
7. Hydrocarbons ppm
8. Total Halogens
17.9
0.89
23.2
N/A
N/A
N/A
0.03
N/A
19.0
0.57
20
< 1
<0.1
< 1
N/A
< 1
Note: 02, C02, and CH^ data are integrated samples over one cycle of the
furnace; S02, N02, H2S, and halogen data are detector tube samples.
N/A indicates data not available.
Results for Test 2 not available.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
emissions. Efficiencies of 95% to 99.6% by weight are reported. Various fabric
media are employed such as glass fibers, wool and synthetics like Orion",
DacronRand Nomex". By catching the larger particles and building up a mat
they are capable of filtering in the submicron range. Glass media was the
preferred high temperature filter but it is being replaced by Nomex. Although
glass can withstand a higher temperature, the fibers gradually break because of
the periodic flexing of the bag resulting in higher maintenance costs.
One of the critical factors in baghouse design is the filter velocity. With
a relatively small concentration of fumes a velocity of 2.5 FPM is
recommended. Larger concentrations require lower filter velocities. High
velocities require more frequent shaking which results in excessive bag wear. A
pressure drop of 2 to 6 inches of water is normal and high pressure differentials
across bags should be avoided.
The baghouse should be completely enclosed to protect the bags from
weather variations. The exhaust fan may be placed downstream from the
baghouse to protect its impeller from material impingement which causes
excessive wear.
Baghouses do have one disadvantage. The gas stream must be cooled
before passing through the bags. This is usually accomplished by means of a
water jacket type cooler which can effectively reduce a 2000 F discharge to
about 900 F. An air cooled radiation convection system can then be used to
cool the gas to a media-safe temperature.
High Energy Wet Collectors
High-energy Venturi scrubbers can be used for high efficiency cleaning.
The collector uses a Venturi-shaped construction to establish gas throat
velocities of much higher values than with other types of wet collectors. The
principal mechanisms of collection are impaction and diffusion. Particles are
accelerated to very high velocities and then impinged upon atomized water
droplets. Water is supplied to the throat of the Venturi. The resulting mixture
of gases, fume-dust agglomerates, and dirty water must be channeled through a
separation section for the elimination of the impurities. Pressure drops of 50"
to 60" of water are needed for high efficiency cleaning. Gas velocities may
range from 18,000 to 24,000 FPM in the throat. Water rates to the throat will
range from 10 to 15 GPM per 1000 ACFM of gas.
Electrostatic Precipitators
While precipitators are highly efficient devices, they are not ideally
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
suited for the brass/bronze smelting industry, mainly because of the low gas
flows used.
Comparison of Equipment Types
The relative merits of fabric filters and high-energy Venturi scrubbers in
brass and bronze smelters are as follows:
FABRIC COLLECTORS
Advantages
Disadvantages
1. Efficiency is very high.
2. Recovers dry product.
3. Pressure drop and horsepower
requirements are low.
4. No water pollution problem
exists.
1. Bag replacement cost is high.
2. Bags may be damaged by over-
heating.
3. Condensation will produce
caking and interfere with oper-
ation.
4. First cost is high
WET SCRUBBERS
2.
3.
1. Tolerates high temperatures
(for metal construction)
2. Can collect gases as well as
particulates.
3. First cost is low.
4. Maintenance cost is relatively
low.
5. There is no condensation problem 5.
if gases are cooled too much.
May create a water disposal
problem.
Product is collected wet.
Corrosion problems are more
severe than with dry system.
Steam plume opacity may be
objectionable.
Pressure drop and horsepower
requirements are high.
6. Solids build up at the wet—dry
interface may be a problem
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Equipment Design Considerations
Fabric filters require a low temperature gas stream; less than 550° F.
Orion and Dacron cannot be used above 275° F. Temperature reductions in the
gas stream can be obtained by means of a water jacket type cooler used in
series with an air cooled convection system. Caution must be used to avoid
condensation on fabric filters by over-cooling. If water condenses on the fabric,
it may cause caking and blinding of the filter. Acid attack must also be
considered if condensation occurs where C02 and sulfur oxides are present.
Venturi scrubbers require some precooling of high temperature gas to
prevent rapid evaporation of fine droplets. The precooling can be accomplished
by a direct spray quencher. Special consideration must be given to corrosion
problems in the duct work.
Efficiencies of fabric filters are usually higher than for Venturi
scrubbers. Fabric filter efficiencies are in the range of 95% to 99.6%. Venturi
scrubber efficiencies are directly related to the pressure drop across the throat
and the gas stream particle characteristics. Manufacturers usually will not
guarantee Venturi scrubber efficiencies without a background of field test
experience.
b. SPECIFICATIONS AND COSTS FOR BRASS/BRONZE
REVERBERATORY FURNACE APPLICATIONS
As in the case for the rotary lime kilns, a complete equipment
specification was prepared for both fabric filters and wet scrubbers to serve a
series of brass/bronze reverberatory furnace sizes. The electrostatic precipitator
was not considered applicable to this process, so no prices were obtained for
precipitators.
Only the parts of the specification which pertain to this application
were included in this section of the report. A complete sample specification is
given in Appendix IV.
1)
FABRIC FILTERS FOR BRASS/BRONZE FURNACES
Fabric filters are the most widely used pieces of equipment for
brass/bronze furnace air pollution abatement. A typical process description for
inclusion in a fabric filter specification is shown in Table 27. The operating
conditions for each of three sizes of furnaces are given in Table 28. Although
the specification includes a low efficiency case (89.6 to 93.2%) to meet the
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 27
FABRIC COLLECTOR PROCESS DESCRIPTION
FOR BRASS/BRONZE REVERBERATORY FURNACE SPECIFICATION
The reverberatory open-hearth is an oil fired furnace where the products of
combustion and metallic fumes are normally vented directly from the furnace through a
cooling device to a fabric collector. The furnace is a side charged, non-tilting type, fired with
low sulfur No. 2 oil. The sulfur content will not exceed 2% by weigh t.
Hooding
The hooding shall consist of vents over the side charge door, pour spout and flue for
general combustion and metallic fumes emission control.
Cooling
A "U" tube cooler (not forced draft tube bundle type cooler) shall deliver dust laden
gases to the I.D. fan. The "U" tube cooler hopper will terminate into 9" screw conveyor.
Emergency bleed in of ambient air shall be provided to Quench gas temperature to
the collector. The entering air temperature to the collector will not exceed 270°'F.
As corrosion may occur if fluxes contain compounds of a hygroscopic nature,
provision for standby heat is required. The heater is to be direct fired thermostatically
controlled.
Physical Layout — Equipment
The furnace is located on an outside wall of the melt building. Duct work will be
required to tie into stack that is presently in existence (in case of new installation hooding
on the vents over the side charge door, pour spout must tie into stack or flue from main
furnace). The stack shall be capped with a hand operated damper for emergency by-pass.
Take-off from the stack shall be at the 40' above ground level. Duct work will enter the "U"
tube cooler. Duct work will be mtld steel 1/4"plate construction into the "U" tube cooler.
The "U" tube cooler will be a minimum of 10 ga with hoppers no less than 3/16"plate. The
collector will be provided adequate space in an area 200' x 50" immediately outside the melt
building.
Filter Baghouse - Shaker Type
The fabric filter shall be a continuous, automatic-, compartment/zed tubular cloth
filter designed for uninterrupted service. The collector is to be arranged in separate
compartments which are periodically isolated by individual automatic dampers. There shall
be at least four individual compartments. The air to cloth ratio (net) with one compartment
off for cleaning shall not exceed 2.3:1.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 27
(continued)
The housing shall not be less than 14 ga. Auxiliaries shall include ladders, platforms,
outside shaker motors and drives, and catwalk access to outside shakers.
The housing shall be capable of withstanding a maximum of 20" wg negative
pressure.
Hopper discharge equipment shall consist of trough type hoppers employing a 9"
screw conveyor (heavy duty) terminating in a discharge spout. A rotary lock shall be
provided for discharge from screw conveyor.
The control panel shall consist of but not be limited to the following:
(1) "U" tube manometer or Magnehelic * gages to indicate pressure drop across
each compartment.
(2) High temp warning system (alarm).
(3) Sequencing timer for shaker drives.
The fan provided shall be a paddle wheel or radial blade heavy duty industrial
exhauster capable of continuous operation at design conditions.
The exhauster shall include flanged inlet and outlet clean-out door, heat radiation
shield on shaft, and drain. Outlet multi-blade manual control damper shall also be provided.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 28
OPERATING CONDITIONS FOR
BRASS/BRONZE REVERBERATORY FURNACE SPECIFICATION
Three sizes of fabric collectors are to be quoted in accord with the following operating
conditions. Two efficiency levels are specified, but it is expected that a single fabric filter
will be quoted for each size.
Furnace capacity, ton
Melting rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature, °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Small
20
5,000
2,200
270
64
3.4
Medium
50
12,500
5,500
270
160
3.4
Large
75
20,000
8,250
270
240
3.4
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 1 - LA Process Weight
6.67 11.58 16.19
0.35 0.24 0.23
89.6 92.1 93.2
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 2 — High Efficiency
0.19 0.47 0.71
0.01 0.01 0.01
99.7 99.7 99.7
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
LA-Process Weight requirements, it would not ordinarily be possible to operate
at low efficiency because of the dense plume which would be discharged. For
practical purposes, a fabric filter will perform in accord with the "High
Efficiency" case, and will not produce a highly visible plume.
The cost data returned by the manufacturer is shown in Table 29.
These costs are plotted using log-log coordinates in Figure 9.
2) WET SCRUBBERS FOR BRASS/BRONZE
REVERBERATORY FURNACES
While wet scrubbers are capable of providing satisfactory air pollution
abatement for this application, they do not automatically produce the high
efficiency levels achieved by the fabric filter. It is necessary to consider the
efficiency level required when specifying a scrubber. In particular, caution is
necessary when the scrubber is selected to meet a process weight limitation
such as the LA-Process Weight regulation, because serious plume opacity
problems may be encountered at this efficiency level.
Tables 30 and 31 contain all of the specification material pertinent to
the wet scrubber application. In Table 31 both low and high efficiency cases
are specified, although only the high efficiency case is likely to produce an
acceptable stack appearance.
The costs produced in response to the two specified efficiency levels are
listed in Tables 32 and 33 for the low and high efficiency cases respectively.
These figures are plotted in Figures 10 and 11 for ease of interpolation.
Note that the manufacturer has responded to the request for a
quotation, but has indicated that the specified high efficiency level cannot be
guaranteed without field testing.
c) DISCUSSION OF COSTS FOR BRASS/BRONZE
REVERBERATORY FURNACES APPLICATIONS
Whereas more rotary lime kilns are equipped with wet scrubbers than
other types of collectors, the brass and bronze reverberatory furnaces most
often have fabric collectors. The reasons for this are apparent from the costs
given in Tables 29 and 33 and plotted in Figure 12. The basic wet scrubber is
less expensive than the fabric collector, but the higher cost of auxiliaries and
installation makes the scrubber more costly than the fabric collector. In
addition, the horsepower requirement is substantially higher for the scrubber.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 29
Fabric Collector Cost Data for
Brass/Bronze Reverberatory Furnaces
INrUKMAl ION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt . %
Controlled Emission, Gr/ACF
Type of Charge
i
o
Inlet Gas Temperature, F
System Horsepower !
Equipment Cost, $ i
A. Collector i
B. Auxiliaries ;
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Total Installation Cost, $
A. Grass-Roots
B. Add-On ;
Expected Life, Years
Operating and Maintenance
Requirements $/year
FABRIC FILTER
SMALL
20
2,200
99.7
.01
Scrap §
Dross
270
21
10,800
1,332
11,570
450
24,152
21,800
15
1,368
MEDIUM
50
5,500
99.7
.01
Scrap §
Dross
270
48
15,470
2,206
15,890
450
34,016
30,800
15
1,512
LARGE
80
8,250
99.7
.01
Scrap §
Dross
270
84
19,630
3 122
22,'400
525
45,677
36,500
15
2,232
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 9
Costs of Fabric Collectors for
Brass/Bronze Reverberatory Furnaces
rt
O
Q
in
-O
o
H
i
O
u
200
100
70
50
30
20
10
H-
ffi:
Turnkey Installation
For Grass Roots
P;Ur
Fabric Filter §
Auxiliary Equipment
Fabric Filter i:
Only
20 50 80
Process Capacity, Ton/Day
200
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 30
WET SCRUBBER PROCESS DESCRIPTION FOR
BRASS/BRONZE REVERBERATORY FURNACE SPECIFICATION
The reverberatory open-hearth is an oil fired furnace where the products of
combustion and metallic fumes are normally vented directly from the furnace to the
scrubber. The furnace is side charged, non-tilting type, fired with low sulfur No. 2 oil. The
sulfur content will not exceed 2% by weight.
Hooding
The hooding shall consist of vents over the side charge door, pour spout and flue for
general combustion and metallic fumes emission control.
Physical Layout — Equipment
The furnace is located on an outside wall of the melt building. Duct work will be
required to tie into stack that is presently in existence (in case of new installation hooding
on the vents over the side charge door, pour spout must tie into stack or flue from main
furnace). The stack shall be capped with a hand operated damper for emergency by-pass.
Take-off from the stack shall be at the 40' above ground level. Duct work will be mild steel
1/4" plate where unwetted by scrubbing liquor and 304 ss. or equivalent where wetted. The
scrubber will be provided adequate space in an area 200' x 50' immediately outside the melt
building.
Wet Collector Spec.
The wet collector shall be a Venturi-type scrubber capable of developing the
necessary pressure drop to scrub gases of contaminants to meet outlet emissions specified in
the operating conditions.
The Venturi scrubber shall consist of the converging and diverging section. The
converging section causes the inlet gas to be accelerated to high velocity where water
introduced to the throat is atomized and the contaminant particles are trapped. The gas
stream is decelerated in the diverging section. The water droplets are removed from the gas
stream in the mist separator.
The Venturi scrubber and cyclonic separator are to be constructed of 304 ss.
wherever wetted by the scrubbing liquor. The mist eliminator shall be a cone-bottom center
drained vessel to avoid settling or clogging.
Pumps shall be rubber lined carbon steel or equivalent.
Fan shall be capable of developing the necessary static pressure to perform in
accordance with the operating conditions. The ductwork static pressure is 8" wg.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 30
(continued)
The pressure drop shall be no less than 50" wg to meet the LA County costs and
no less than 60" wg to meet the higher efficiency requirement.
Auxiliaries
For purposes of this quotation, the following are to be considered as auxiliary
equipment:
(1) fan and drive
(2) pumps and drives
(3) external piping
(4) dampers
(5) controls
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 31
WET SCRUBBER OPERATING CONDITIONS FOR
BRASS/BRONZE REVERBERATORY FURNACE SPECIFICATION
Three sizes of scrubbers are to be quoted in accord with the following operating conditions.
Two efficiency levels are to be quoted for each size.
Small
Medium
Furnace capacity, ton
Melting rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet gas volume, ACFM
Outlet gas temp., °F
Large
20
5,000
7,520
2,000
64
1.01
3,320
172
50
12,500
18,600
2,000
160
1.01
8,150
172
75
20,000
27,800
2,000
240
1.01
12,200
172
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 1 — LA Process Weight
6.67 11.58 16.19
0.23 0.17 0.15
89.6 92.7 93.2
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 2 — High Efficiency
0.28 0.70 1.04
0.01 0.01 0.01
99.6 99.6 99.6
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 32
Wet Scrubber Cost Data for
Brass/Bronze Reverberation Furnace
(LA-Process Weight)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt . \
Controlled Emission, gr /ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower BHP at start up
Equipment Cost, $
A. Collector § Quencher
B. 3'04 S.S. Exhauster
C. Pipe
D. 304 S.S. Pump $ Motor
E. Fan § Pump Motor Starter
Total
Installation Cost,, $ , , •, •
A. Grass-Roots (not including
B. Add-On equip.) .
Expected Life, Years
Operating and Maintenance
$/year
WET
SMALL
20
3,320
89.6*
0.23
Scrap
2,000
57
32
5,025
14,500
550
646
347
21,068
47,200
55,200
10
600
SCRUBBER
MEDIUM
50
8,150
92.7*
0.17
Scrap
2,000
140
77
9,890
20,000
670
926
728
32,214
72,300
94,300
10
600
LARGE
75
12,200
93.2*
0.15
Scrap
2,000
207
114
13,795
21,400
800
1,252
2,006
39,253
88,000
104,000
10
600
* This efficiency will be exceeded at the horsepower specified.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 33
Wet Scrubber Cost Data for
Brass/Bronze Reverberatory Furnace
(High Efficiency)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.%
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
Syste* Horsepower Jg ^r^?ati
Equipment Cost, $
A. Collector § Quencher
B. 304 S.S. Exhauster
C. Pipe
D. 304 S.S. Pump § Motor
E. F'an §' Pump Motor Starter
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance
$/year
WET
SMALL
20
3,320
99.6*
0.01
Scrap
2,000
66
>n 36
5,180
21,050
550
646
347
27,773
62,300
70,300
10
600
SCRUBBER
MEDIUM
50
8,150
99.6*
0.01
Scrap
2,000
163
90
9,980
23,000
670
926
728
35,304
79,300
91,300
10
600
LARGE
75
12,200
99.6*
0.01
Scrap
2,000
240
132
13,900
32,050
800
1,252
2^006
50,008
112,500
128,500
10
600
* This efficiency guarantee contingent upon field sampling.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 10
Costs of Wet Scrubbers for
Brass/Bronze Reverberatory Furnaces
(LA—Process Weight)
f-l
rt
o
Q
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O
o
H
i
200 _
100
70
50
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li
Wet Scrubber §
Auxiliary Equipment
i
1:1
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Ttttr
m
Wet Scrubber
Only
20 50 80
Process Capacity, Ton/Day
200
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 11
Costs of Wet Scrubbers for
Brass/Bronze Reverberatory Furnaces
(High Efficiency)
L- U \J
100 -
* 70 -
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o
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st - Thousands of
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 12
Comparison of Abatement Costs
for Brass/Bronze Reverberatory Furnaces
(Based on Turnkey Installation)
300 "I 1 1 |[[|l||||^m^4^l|||l|l||[|||[[|l[M|
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Fabric Collector pmiml
Grass Roots Plant -.----.-.-.--i-.:
20
50 80 100
Process Capacity, Ton/Day
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
While these circumstances indicate a fabric collector most economical
for the conditions specified in this study, some circumstances favor scrubbers.
For example, if acidic materials from burnout or sweating operations are
included in the gas stream discharged into the collector, it may be necessary to
use a scrubber to control the gas emission, or to eliminate the possibility of
deterioration of the bags. In particular, if sulfur dioxide emissions from a lead
smelting operation are to be included in a common air pollution control
system, the scrubber may be required for SC>2 control in the future. In this case
the scrubber cost would be higher than shown because of the need for special
materials of construction.
REFERENCES FOR BRASS/BRONZE REVERBERATORY SECTION
1. Brass and Bronze Ingot Institute and National Air Pollution
Control Administration, "Air Pollution Aspects of Brass
and Bronze Smelting and Refining Industry" (U.S. Dept.
of H.E.W., Public Health Service, August, 1969, p. 9
2. J. A. Danielson, "Air Pollution Engineering Manual"
(U.S. Dept. of H.E.W., Public Health Service, Publication
No. 999-AP-40, 1967), p. 235
3. American Conference of Governmental and Industrial Hygienists,
"Industrial Ventilation" (Library of Congress Catalog Card
Number: 62-12929, 11th Edition, 1970), p. 10-11
4. IGCI Publication F2, "Fundamentals of Fabric Collectors
and Glossary of Terms", IGCI, Box 448, Rye, N.Y.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
3.
AIR POLLUTION CONTROL FOR LEAD CUPOLAS
a.
PROCESS DESCRIPTION
The lead blast furnace or cupola is a vertical production furnace similar
to the iron cupolas used in ferrous smelting practice. Unlike the reverberatory
furnace, the cupola serves a very specific function. The cupola is used to reduce
oxidized metal. Frequently, metal scrap is charged to the cupola in
combination with lead dross or other forms of oxide. However, because the
blast furnace is less efficient in retaining the metal, and cannot be used for
purification of the molten metal, it is more common to charge scrap for
melting and purification to a reverberatory furnace.
1)
MANUFACTURING ASPECTS
Figure 13 is a process flow sketch for a typical lead cupola. Charge
stock is fed at the top of the furnace through the charging doors. The lower
section of the furnace is water cooled, and the upper section consists entirely
of refractory. The furnace is charged with a mixture of lead oxide dross and
slag, limestone, coke, and some scrap cast iron. Air is injected through tuyeres
in the bottom of the furnace and combustion of the coke serves as the source
of heat for the melting and reduction process. Additional limestone, dross and
coke are added through the charging door toward the top of the cupola and
molten metal is tapped off at the bottom. The limestone and iron form a slag
that reduces the oxidation of the molten lead. The slag is tapped periodically,
and it is customary to maintain a continuous flow of lead from the bottom of
the cupola. The process is "semi-continuous" in that charge is added over a
period of one or two days and product is withdrawn nearly continuously
during this period.
CHARGE STOCK AND PRODUCTS
Cupola charge stock consists of the lead oxide to be reduced, plus coke,
limestone, scrap iron and rerun slag. The principal sources of the lead oxide are
a) Reverberatory furnace dross
b) Melt furnace dross
c) Reverberatory furnace slag
The drosses may contain substantial amounts of lead entrained
mechanically in the lead oxide. Also, there may be a variety of metal oxides
from melting operations in which lead is alloyed with other materials. One
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CD
Ni
NATURAL GAS
AFTERBURNER -
TORCH
COOLING
WATER
SPRAY
FLUE GAS
XING
kTER ^
UT
AIR
BLAST
JLING »
FER IN
/
* * * *
« A . ,
,>' ?',
&• * * *
v • • •
xfr
y t • ^4
^%
s
~on
•»«,
**
1
CHARG
MATERIl
5^ LEAD
^ PRODUCT
1 1
SCRUBBER
VENTURI MIST
SEPARATOR
FAN
WATER SLURRY
TO SETTLING
POND
MAKE-UP
WATER
Figure 13
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
common source is the lead oxide drosses produced in letter press printing using
lead-tin-antimony typemetal.
The composition of a typical cupola charge is shown in Table 34. This
table also gives a rough measure of the feed rates for a 25T/D cupola.
The principal product of the lead cupola is antimonial or "hard lead".
Antimony-containing lead alloys have better physical properties at low
temperatures — up to the boiling point of water — and antimony is included in
many, alloys where the physical strength is important. Lead-antimony alloys
have many uses such as in piping, stereotype plate production in printing, etc.
These alloys are frequently unsuitable for very corrosive services, and must be
refined in a reverberatory or pot furnace to produce a high purity or "chemical
lead". The inclusion of antimony lowers the melting point of the alloy, which
makes it more suitable for lead stereotype plates and less suitable for high
temperature structural uses. The composition of hard lead, and some of the
physical properties are given in Table 35.
High purity lead alloys are usually specified for construction of
chemical equipment resistant to acids. These alloys are described as "chemical
lead", "acid lead", etc. These alloys, which cannot be produced directly from
the cupola, are described in more detail in the section on lead reverberatory
furnaces.
About three-fourths of the charge is withdrawn as product with the
remaining material tapped off intermittently as slag or lost with the flue gas.
Some of the slag is retained for recharging to the furnace and the remainder
discarded. The hard lead may be sold directly as a product, or charged to either
reverberatory or crucible type furnaces for further refining to remove the
metallic impurities by oxidation.
EQUIPMENT
The cupola is an extremely simple apparatus from a mechanical design
standpoint. It consists of a vertical shaft into which the charge materials are
dumped. The cupolas used in ferrous smelting are lined with refractory over the
entire length to withstand the high temperatures required to melt cast iron. For
lead applications the cupola operates at much lower temperatures and the
lower section can be of refractory-lined or water-cooled steel construction.
A molten metal level is maintained at the bottom, above which a mixed
mass of charge solids is contacted with air to burn the fuel, reduce the lead
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 34
Typical Composition of Lead Cupola Charge
Component
Dross
(15%) Metallic Lead
Pb
Sb
Sm
(85%) Metal Oxides
PbO
SbO
SnO
Rerun Slag
Scrap Iron
Limestone
Coke
Wt. %
of Total
82.5
Lb/Hr
Average
2200
4.5
4.5
3.0
5.5
120
120
80
150
100.0
2670
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 35
Typical Properties of Cast Hard Lead
Composition
Lead
Antimony
Arsenic
Tin
Copper
Nickel
Tensile Strength, Ib/in2
Brinnel Hardness
Density, Ib/in3
Specific Gravity
Melting Point, °F
Wt. %
92.5
6.0
0.4
1.0
0.1
0.01
100.0
6800
12
0.393
10.9
554
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
oxide, and melt the product. Relatively high temperatures are reached locally
in this section, but the gases cool as they pass upward through the fresh charge
added to the top of the mass.
The fuel for heating and melting is the coke added with the charge, or
in alternate loads, at the charging door. This is oxidized with blast air furnished
by an air compressor to the tuyeres at the bottom of the furnace. If infiltration
of air at the charge door level were not a factor, the flue gas would consist of
the combustion products of the blast air and coke, with some additional gas
released by the decomposition of the metal oxides and the limestone. However
the gas flow is usually far in excess of the blast air flow.
The charge doors are usually designed to accommodate addition of
charge materials by a bucket which is swung into the cupola and dumped.
Other methods of charging include conveyors or chute feeders. In the case of
bucket feed, the charge doors must be large and are frequently left open or
removed altogether. This allows a very high rate of air infiltration into the
cupola. When air pollution control equipment is installed, it is necessary to
limit infiltration at this point to minimize the size requirement and the
operating cost.
Torches or gas burners are frequently installed in the cupola directly
above the charging door to burn carbon monoxide and to abate smoke and
odor nuisances to some extent. The afterburner section must have some air
infiltration to provide for burning the CO, but will be costly to operate without
good sealing at the charge doors.
NATURE OF AIR POLLUTION PROBLEM
The chemical reactions taking place in the lead blast furnace are:
(a) oxidation of coke for heat production according to the reaction
C+ 1/2 O2 -" CO, or
C + 02 + CO2
(b) Reaction of carbon with lead dross according to
Pb 0 + C + Pb + CO
The principal air contaminants produced by the. process are carbon
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
monoxide from partial oxidation of the coke fuel, and particulate matter
entrained by the highly agitated gases passing through the vertical shaft. The
particulate contaminant consists mainly of lead oxide, but also has iron oxide,
and oxides of the metals which are constituents in the hard lead. Other charge
constituents may also be mechanically entrained. In addition there will be some
sulfur dioxide and carbonaceous material.
In addition to the particulate matter entrained by the turbulent flow of
gases upward through the charge materials, there will be some vaporization of
lead, antimony, and other metals, which condense as metal fumes at the lower
temperature in the exhaust system. The vapor pressure of these metals is a
measure of the tendency to form vapors in the furnace. Table 36 illustrates the
concentration of lead and antimony in equilibrium with the flue gas from the
cupola as a function of temperature. Vapor pressures are usually given in
millimeters of mercury or atmospheres; however, in this case they are
calculated in terms of the grain loading they will produce at atmospheric
pressure.
2)
AIR POLLUTION CONTROL EQUIPMENT
In order to reduce the emission of smoke and carbon monoxide, the
cupola should be equipped with an afterburning section directly above the
charging door. This section should be sufficiently tall to allow for a residence
time of approximately 0.5 seconds or so for the gases leaving the smelting
section of the cupola. It should be equipped with gas burners to boost the gas
temperature to the 1200°F level during start up, and provide an ignition source
at other times as required. It is apparent that excessive leakage inward at the
charging door will increase the fuel requirements for the afterburning section
significantly, and should therefore be avoided. For cupolas without air
pollution control equipment, the natural draft produced by the high gas
temperature provides adequate ventilation at the charge door when it is open.
However, when air pollution control equipment is added after the afterburner,
it is necessary to set the gas flow through this section by the accurate sizing of
the fan and air pollution control device. The selection of a gas flow rate
through the air pollution control device is one of the critical steps in the design
of the air pollution control system. It must satisfy the requirements for inward
ventilation at the charging door when it is open, but not establish an
uneconomically high rate of ventilation.
GAS FLOW RATE
The gas flow rate leaving the cupola when ventilation at the charge door
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 36
Calculated Concentrations of
Lead and Antimony Fume
Temp.,°F
Lead
Metal
Fume
PPM
Grain
Loading
gr/SCF
Antimony
Metal
Fume
PPM
Grain
Loading
ar/SCF
1150
1175
1200
1225
1250
1275
1300
1325
23.69
28.04
33.01
38.68
45.11
52.38
60.56
69.74
.0895
.1059
.1247
.1461
.1704
.1979
.2288
.2634
78.25
92.65
109.13
127.93
149.27
173.39
200.57
231.05
.1737
.2056
.2422
.2840
.3313
.3849
.4452
.5128
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
is adequate but not excessive should be carefully measured using accepted
source testing techniques before equipment is selected for air pollution control.
For budgetary purposes, the approximate size may be established on the
assumption that about 1 SCF will be required per pound of charge to the
cupola. This gas will leave the cupola at the charge door level on the order of
1200 - 1500°F. Afterburning in an incineration section above the charge door
may increase the temperature to as high as 2000° F. The gas flow leaving the
cupola is somewhat less for each pound of charge than would be the case for a
reverberatory furnace, because of the ability of the cupola to transfer heat to
the charge material before it reaches melting temperature. Also, in the cupola
the fuel is burned with less than the theoretical amount of air in order to
produce a reducing atmosphere. Both of these factors tend to limit the rate of
generation of flue gas for a given charging rate.
PARTICULATE LOADING
The fume loading leaving the afterburning section is likely to be
extremely high for the cupola. As much as 10% of the material charged to the
furnace may be entrained in the flue gas and carried into the air pollution
control equipment. A good average figure is 7% of the total charge. The gases
leaving the cupola are ordinarily cooled by infiltration of ambient air rather
than by heat exchange or quenching with water if a fabric filter is to be
installed as the air pollution control device. In this case, some dilution air can
be withdrawn from a hood over the charging door and additional dilution air
taken in immediately at the beginning of the duct to the fabric filter. This
reduces the temperature for which the duct as well as the filter must be
designed. Special care must be taken in designing the system to avoid the
possibility of ignition of the filter bags in the event that the ventilating fan
stops, or when the exit temperature becomes excessive during "burn down" at
the end of a run.
Where a wet scrubber is to be installed to collect the paniculate matter,
it is possible to limit the size of the scrubbing equipment by using water for
quenching rather than by using infiltration air. The point of introduction of the
quench water may be immediately after the afterburning section of the cupola
in which case the duct can be sized for a relatively low gas volume but must be
made of corrosion-resistant material such as a refractory-lined carbon steel or
stainless steel. The ducting to the scrubber may be made to withstand the
maximum temperature expected at the top of the cupola, and the water supply
introduced immediately ahead of the scrubber, or in the scrubber throat itself.
For a wet scrubber, the grain loading will be considerably higher than
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
for the fabric filter with introduction of quench air.
SPECIAL PROBLEMS
Several problems associate themselves specifically with cupola
operation in a secondary smelting plant. These are discussed in some detail in
the following paragraphs.
The geometry of the cupola makes the estimation of the proper gas
flow rate for the air pollution control equipment one of the most difficult
problems. This is because the ventilation rate measured at the top of the charge
door for the untreated cupola may be many times the minimum requirement
for correct ventilation. Prior to the installation of air pollution control
equipment, there is no reason to limit the gas flow at this point. However, the
addition of an afterburning section has a fuel requirement associated with it if
too much infiltration air is allowed at the charge door level. Even more costly is
the design of particulate collection equipment to handle several times the
minimum gas flow required. For this reason, it is not always possible to select a
proper gas flow for the air pollution abatement system by performing a source
test on the untreated cupola. In addition, it is necessary to make a careful
estimate of the minimum ventilating rate which will be acceptable at the charge
door prior to the selection of abatement equipment.
Another problem peculiar to the cupola involves the use of solid fuel.
Whereas reverberatory furnaces and crucibles are frequently gas fired and
subject to nearly instantaneous control of the fuel and air rates used for
combustion, the cupola is fired by the addition of coke in batches at the
charging door. After a load of coke has been dumped into the cupola, it is
difficult to control the combustion if an emergency situation arises. For
example, if the ventilating fan power fails it is not possible to have the
combustion cut back instantaneously without producing a very serious
operating problem. For this reason, the provisions for operating in high
temperature emergency situations without damage to the air pollution control
equipment should be considered in the initial design.
When fabric filters are used for collection of the oxide particulate
materials, the disposal problem is minimized because the oxides can be
recharged to the cupola. However, when wet scrubbing systems are utilized, the
oxides are recovered in a dilute slurry which may be difficult to recycle. The
simplest mechanism for handling the recovered material is shown in the flow
scheme in Figure 13, where the slurry is simply conducted to a settling pond
where it is allowed to stand for a minimum of several days. The particulate
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
matter settles to the bottom and may be dredged out, and air dried for recycle
to the cupola. The other alternatives involve using an intermediate settler and
filter, or a filter alone for separation of the oxides from the scrubbing medium.
Ordinarily, it is not possible to return the water to the sewage system or to a
natural body of water with the substantial concentration of lead compounds.
b.
SPECIFICATIONS AND COSTS
The lead blast furnace is frequently treated in combination with other
furnaces in a secondary lead plant. When this is done, it is possible to use a
single air pollution control system to service several applications. The
specifications written for IGCI member companies to use in quoting equipment
prices were based on the system serving the cupola alone, but could be
modified to handle a reverberatory furnace or a sweating furnace without much
additional cost.
The cupola effluent can be treated satisfactorily by either a fabric filter
or a scrubber of adequate design. The fabric filter will provide positive control
of particulate emissions to a low level, but has some disadvantages relating to
the unstable operating conditions of the cupola furnace. Condensation during
shutdown and possible temperature surges are examples.
The specifications for the fabric filter quote are given in Table 37. This
indicates that all of the cooling must be done by air contact and dilution,
rather than water quenching, to protect the filter from plugging with wet cake
if temperature drops suddenly. The operating conditions are given in Table 38.
As in the previous sections of this report, the complete specification consisted
of these two pages plus the general conditions in Appendix IV.
The equipment and installation costs submitted by the member
companies are given in Table 39. Only a single response was made for both the
LA - Process Weight and the High Efficiency cases, as was true of all the fabric
applications. The costs are plotted as a function of size in Figure 14.
The process description and the operating conditions were modified for
the wet scrubber because of the use of a spray quench in this case. The
description and operating conditions are given in Tables 40 and 41, and the
member company response in Tables 42 and 43. These costs are plotted in
Figure 15.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 37
FABRIC COLLECTOR PROCESS DESCRIPTION
FOR LEAD CUPOLA SPECIFICATION
The fabric filter is to serve a lead cupola or blast furnace charging the following
materials:
rerun slag
scrap cast iron
limestone
coke
dross and slag
4.5%
4.5%
3.0%
5.5%
82.5%
100.0%
The flue gas exiting the cupola is passed through an afterburning section in which
torches ignite the carbon monoxide and other combustibles produced in the cupola. This
section is immediately above the charging door and utilizes air infiltration at the charge door
to provide sufficient oxygen for combustion.
Immediately following the afterburner section, additional air is drawn into the
system to decrease the temperature level to the specified temperature for the fabric filter.
The cooled gases are then passed through carbon steel ducts through the wall of the building
to a fabric filter located outside. The filter is to be located at ground level, adjacent to the
building with sufficient elevation to provide 8' of clearance beneath the dust hopper valve
for truck access. The fan following the filter will be located on a shed roof 28' above grade
and will discharge into a new 70' stack.
The fabric filter is to operate in such a manner that a single compartment (with no
more than one quarter of the total collecting surface area) can be isolated for shaking. The
hopper is to have sufficient capacity to hold the dust collected over a 24 hour period
without interfering with normal operation of the collector. The hopper valve is to be
included in the filter quotation.
Dacron tubular bags shall be used with a gas/cloth ratio of 1.0 FPM/FT* or less at
operating conditions.
For purposes of this quotation, the following shall be considered to be auxiliary
equipment:
(1) Fan and Drive
(2) Dampers
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 38
FABRIC COLLECTOR OPERATING CONDITIONS
FOR LEAD CUPOLA SPECIFICATION
Three sizes of fabric collectors are to be quoted. While two levels of efficiency are
specified, it is assumed that a single fabric collector quotation will be supplied for each size.
Furnace Capacity, ton/day
Process weight (charge), Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature, °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Small
12
1,300
5,000
270
115
2.68
Medium
25
2,670
10,000
270
230
2.68
Large
50
5,340
20,000
270
460
2.68
Case 1 - LA Process Weight
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
3.26
0.076
96.9
4.80
0.056
97.9
6.92
0.040
98.5
Case 2 — High Efficiency
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
1.29
0.03
98.9
2.57
0.03
98.9
5.15
0.03
98.9
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 39
Fabric Collector Cost Data
for Lead Cupola
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt. %
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment ;
D. Waste Equipment
E. Other :
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance $/year
FABRIC FILTER
SMALL
12
5,000
98.9
.03
D£?i§ *
270
22
12' ,'254
1,195
3,100
450
16,999
13,428
10
1,556
MEDIUM
25
10,000
98.9
.03
Dross §
SI aa
270
33.5
16,813
2,283
4,000
450
23,536
19,022
10
2,232
LARGE
50
20,000
98.9
.03
Dross $
Slaa
270
65.5
25,429
3,347
4,500
525
33,801
27,265
10
3,836
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 14
Cost of Fabric Collectors
for Lead Cupola
200
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Q
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in
rt
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00
70
30
20
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1
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'urnkey Installatio
'or Grass Roots Pla
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Auxiliary Equipment
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LUX J.C rxxucr --•
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10
12 25 50 -100
Process Capacity, Ton/Day
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 40
WET SCRUBBER PROCESS DESCRIPTION
FOR LEAD CUPOLA SPECIFICATION
The scrubber is to serve a lead cupola charging the following materials:
rerun slag
scrap cast iron
limestone
coke
dross and slag
4.5%
4.5%
3.0%
5.5%
82.5%
100.0%
The flue gas exiting the cupola is passed through an afterburning section in which
torches ignite the carbon monoxide and other combustibles produced in the cupola. This
section is immediately above the charging door and utilizes air infiltration at the door to
provide sufficient oxygen for combustion.
Immediately following the afterburner, a spray quench is provided to reduce the gas
temperature to the 500°F level. The cooled gases are passed through carbon steel ducts
through the wall of the building at an elevation of 20' above grade and into the scrubber.
The scrubber is to be located in a clear area adjacent to the building. The fan will be located
after the scrubber on an adjacent shed roof approximately 20' above grade and will discharge
into a new 70' stack.
The ductwork after the quench section is to be 304 stainless steel or have equivalent
corrosion resistant properties. The scrubber is to be constructed of 304 L or equivalent
stainless steel wherever wetted by the scrubbing liquor.
The external piping and pumps will be rubber-lined carbon steel or equivalent. The
pump is to be equipped with fresh water flushed glands to prevent damage to the packing.
The liquor containing the collected paniculate matter is to be discharged into a settling pond
within 100' of the scrubber. The scrubber pressure drop shall be no less than 50" we (or
equivalent energy input) for the LA-Process weight specification, and no less than 60" we
(or equivalent energy input) for the high efficiency case.
For purposes of this quotation, auxiliaries shall include:
(1) Fan
(2) Pump or pumps
(3) External piping
(4) Controls
(5) Dampers
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 41
WET SCRUBBER OPERATING CONDITIONS
FOR LEAD CUPOLA SPECIFICATION
Three sizes of scrubbers are to be quoted for each of two levels of efficiency.
Furnace Capacity, ton
Production rate, Ib/hr
Process weight rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature, °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet gas volume, ACFM
Outlet gas temperature, °F
Small
12
1,000
1,300
3,675
500
115
3.65
3,550
190
Medium
25
2,000
2,670
7,350
500
230
3.65
7,100
190
Large
50
4,000
5,340
14,700
500
460
3.65
14,200
190
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 1 - LA Process Weight
3.26 4.80 6.92
0.11 0.079 0.057
96.9 97.9 98.5
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 2 — High Efficiency
0.91 1.89 3.56
0.03 0.03 0.03
99.2 99.2 99.2
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 42
Wet Scrubber Cost Data
for Lead Cupola
(LA-Process Weight)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.%
Controlled Emission, gr/ACF
Type of Charge
Inlet: Gas Temperature, °F
System Horsepower *™ f ?tart UP ,.
' ^ BHP during operati
Equipment Cost, $
A. Collector § Separator
B. 304 S.S. Exhauster
C. Pipe
D. 304 S.S. Pump S Motor
E. Fan- § Pump Motor Starter
Total
Installation Cost, $
A. Grass-Roots
B. Add -On
Expected Life, Years
Operating and Maintenance
Hrs /Month
WET SCRUBBER
SMALL
12
3,675
96.9*
0.11
Dross §
Slag
500
67
on 40
2,900
16,500
935
750
560
19,645
44,200
48,200
10
600
MEDIUM
25
7,350
97.9*
0.079
Dross §
Slag
500
135
81
4,020
16,900
1,000
840
1,080
23,840
53,500
59,500
10
600
LARGE
50
14,700
98.5*
0.057
Dross §
Slag
500
270
161
7,940
22,500
1,060
930
2,542
34,972
•78,500
86^500
10
600
Will probably produce higher efficiency at the
specified pressure drop.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 43
Wet Scrubber Cost Data
for Lead Cupola
(High Efficiency)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.%
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower ^ f ?tart UP «. .
7 v BHP during operati
Equipment Cost, $
A. Collector § Separator
B. 304 :S.S. Exhauster **
C. Pipe
D. 304 S.S.. Pump $ Motor
E. Fan § Motor Pump Starter
Ttftal
Installation Cost, $
A. Grass-Roots
B. Add -On
Expected Life, Years
Operating and Maintenance $/year
WET
SMALL
12
3,675
99.2*
0.03
Dross $
Slag
500
85
>n 49
3,050
21,500
935
750
560
26,795
.60,400
64,400
10
600
SCRUBBER
MEDIUM
25
7,350
99.2*
0.03
Dross $
Slag
500
169
98
4,220
23,000
1,000
840
1,080
29,140
66,600
72,600
10
600
LARGE
50
14,700
99.2*
0.03
Dross $
Slag
500
338
196
8,350
29,400
1,060
930
2,542
42,282
95.200
103,200
. 10
600
* Guarantee contingent upon field testing,
**
316 L S.S. recommended by manufacturer.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 15
JH
ri
o
Q
M-l
O
rt
W)
3
O
H
tn
o
u
300
200
100
70
50
30
20
10
Costs of Wet Scrubbers
for Lead Cupola
(High Efficiency)
Turnkey Installation
for Grass Roots Plant
(LA-Process Weight Case)
Wet Scrubber and
Auxiliary Equipment
Wet Scrubber Only
110
12 25 50 100
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
c.
DISCUSSION OF COSTS
Both fabric filters and wet scrubbers are used for lead cupola air
pollution abatement. The fabric filter is more costly than the basic scrubber for
these applications, but is simpler to install. On the basis of equipment plus
auxiliaries, the fabric collector is less expensive, and an even larger difference in
favor of the filter appears in the "turnkey" figures.
The scrubber has a significant process advantage in that it can be used
to remove S02 from the flue gas as well as particulate matter. This may
become an important advantage in the future as S02 emission regulations
become more restrictive. It is most likely to be an important factor when lead
cupola effluents are combined with those from reverberatory furnaces, or other
sources which are likely to contain high concentrations of S02.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
REFERENCES FOR LEAD CUPOLA SECTION
1. Danielson, John A., "Air Pollution Engineering Manual",
NAPCA, U.S. Govt. Printing Office, Public Health Service
Publication No. 999-AP-40
2- Norton, Frederick Harwood, "Refractories", McGraw-Hill,
New York, 4th edition, (1968)
3. Perry, John H., "Chemical Engineers Handbook",
4th edition, McGraw-Hill, New York (1963)
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
4. AIR POLLUTION CONTROL FOR LEAD/ALUMINUM SWEATING
FURNACES
a. PROCESS DESCRIPTIONS
1) MANUFACTURING ASPECTS
The metal recovery process generally referred to as sweating is distinct
from purely metallurgical processes which involve alloying, fluxing, and the
like, and is best described as a metal separation process. The sweating process is
quite literally the sweating, or slow melting, of the low melting constituent
from a metallic scrap containing a variety of both metallic and non-metallic
impurities. Aluminum is the most common metal recovered by the sweating
process; however, tin, lead, zinc, copper, and even iron are reclaimed in this
manner, but on a considerably smaller scale.
FURNACE EQUIPMENT AND OPERATION
The type of furnace equipment employed in a sweating operation
depends largely upon the size of operation. Open hearth-type reverberatory
furnaces are used in many large aluminum recovery plants. Smaller rotary or
tube type reverberatory furnaces are used in small aluminum operations and in
operations recovering other metals such as lead and tin. This is not always the
rule, however. Many times, perhaps due to simplicity of design and operation, a
small sweating operation will employ a crude open hearth type reverberatory
furnace even though it is a less efficient operation. In the open hearth type
reverberatory furnace, the hearth is constructed with a slight incline to the rear
of the*furnace, which allows the continuous tapping of molten metal as the
sweated component melts and separates from the solid charge. The rotary
furnaces are tapped periodically from ports which are normally sealed during
rotation and firing. The furnaces are generally refractory lined, however, in the
case of tin and lead sweating, cast iron construction is possible due to the
relatively low melting points of these metals. Most of the furnaces are used to
recover alternatively a variety of metals, and consequently, refractory
construction is essential. This is especially true in the smaller metal recovery
operations; The reverberatory furnaces can be either gas or oil fired. The choice
of fuel depends on availability and price.
A typical sweating heat involves charging scrap to the furnace hearth
and gradually heating the scrap to a temperature slightly above the melting
point of the metal to be separated. As the metal is sweated from the scrap it is
tapped into ingots. Fresh charge is continuously added until either the available
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
scrap is depleted or the heat is terminated according to a planned schedule. As
the unmelted residual scrap accumulates, it must be periodically raked from the
hearth for further processing, sale, or disposal. In a typical small metals
recovery plant the sweating operation is a batch-type process, where
accumulations of scrap are sweated periodically, according to inventory
demands.
The majority of these sweating operations are completely devoid of
pollution control facilities. Again, this is especially true of the smaller plants.
Sometimes an afterburner is included either as a separate entity or, more
commonly, incorporated in the furnace itself.
A typical open hearth type reverberatory sweating furnace facility is shown in
Figure 16. It should be noted that this system has no fan, and depends solely
on the natural draft produced in the stack for ventilation of the furnace.
The foregoing discussion is valid for most reverberatory sweating
furnaces. The pollution problems and their solutions, however, are specific to a
given sweating process; the exact solution must be determined by the specific
metal being separated and the nature of the scrap charge.
ALUMINUM SWEATING
The aluminum sweating process takes place at a temperature slightly in
excess of 1220°F (the melting point of aluminum). There is very little fuming
or oxidation of the aluminum metal itself; however, the contaminants in a
typical scrap charge produce large amounts of both gaseous and particulate
emissions. The scrap charged to an aluminum sweating furnace may include any
one or combination of the following: drosses; skims; aircraft engines, seats, and
wreckage; painted aluminum sheet metal; insulated wire; automotive parts; etc.
Smoke is evolved from the incomplete combustion of organic
compounds in these charge materials, and fumes are produced from the
oxidation of zinc and magnesium contaminants. The sweating of aluminum
drosses and skims is particularly troublesome because they contain halide salts
which hydrolize to form very corrosive solutions of hydrochloric acid. Along
with the gaseous pollutants evolved including oxides of sulfur and carbon,
aluminum, chloride gas, and others, a considerable amount of particulates are
evolved in the aluminum sweating process.
Published emission rates from uncontrolled aluminum sweating furnaces
indicate an average rate of 33 pounds particulate per ton processed aluminum
-------
AFTERBURNER
AFTERBURNER
COMBUSTION
AIR
AFTERBURNER
FUEL
FURNACE FUEL
( NAT. GAS OR OIL)
MAIN BURNER
AIR *
1500°F
REVERBERATORY
FURNACE
650° F-1300 °F
FURNACE CHARGE (AS HIGH AS 40 WT. %
NON-ALUMINUM AND/OR NON- LEAD FURNACE
CHARGE ) PRODUCT
1200°F
FURNACE
STACK
Figure 16
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
metal. Assuming a typical 60 weight percent recoverable aluminum in the
scrap, one pound of particulates will be evolved for each 100 pounds of charge
material. An average furnace with a capacity of 1000 pounds of processed
aluminum per hour will produce 10 pounds of particulates per hour, a large
percentage of which is of sub-micron particle size.
LEAD SWEATING
The lead sweating process is inherently more troublesome than
aluminum sweating from a pollution standpoint. Although it is carried out at a
considerably lower temperature (approximately 650°F) and therefore produces
less metallic fumes, the nonmetallic contaminants in a typical scrap charge
produce large amounts of pollutants. One of the primary constituents of most
lead scrap charges, the junk automobile storage battery, is responsible for a
large portion of these emissions. In addition to lead storage batteries, lead
drosses and skims, lead sheathed cable and wire, aircraft ballast weights, and
other materials are charged to the sweating furnace. Large amounts of sulfur
oxides, as well as other sulfur compounds, are released from the incineration of
the lead storage batteries. The sulfuric acid produced by the hydrolysis of
sulfur trioxide gas is particularly corrosive to both furnace and pollution
control equipment. The asphaltic battery cases, grease, oil, and other organic
contaminants are only partially incinerated in the sweating furnace and
produce large amounts of smoke and soot.
It is common practice to employ a single furnace for a variety of
sweating processes, and the 1000 pound per hour aluminum sweating furnace
cited earlier could be employed for lead sweating also. However, due to the
large difference in heat required to melt lead and aluminum, this same furnace
could sweat 10,000 pounds of lead per hour, at an equivalent fuel rate.
Published data indicate that approximately 150 pounds of particulates are
evolved per ton of scrap metal charge. Assuming 60 weight percent recoverable
metallics in the charge, the 10,000 pound per hour lead sweating furnace would
emit 1250 pounds of particulates per hour, or 250 pounds of particulates per
ton of processed lead. This particulate matter is very fine, generally in the
submicron range, with some particles as small as 0.001 micron.
2)
AIR POLLUTION CONTROL EQUIPMENT
The control of aluminum and lead sweating furnace emissions is a
difficult abatement problem, and the requirements should not be
underestimated. However, good control is wholly within the capabilities of our
present technology. It is essential, however, that the individual nature of each
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
source be appreciated and the potential pitfalls considered.
The maximum allowable particulate emission levels are generally
specified as a function of process weight (as in the Los Angeles County Air
Pollution Control District) or by the opacity of the effluent gas stream. When
the allowable emission levels are expressed in terms of collection efficiency, the
opacity basis indicates efficiency requirements which are independent of
process size; whereas, the process weight efficiency requirements increase with
process size. The most stringent opacity requirement is, of course, a "clear"
stack, which for an aluminum or lead sweating process is approximately 0.03
grains per actual cubic foot. Several collection efficiency requirements have
been calculated for both aluminum and lead sweating operations over a range
of process sizes; these values are included in the specifications (Air Pollution
Control Equipment Specifications for Lead/Aluminum Reverberatory Sweating
Furnace). The required collection efficiencies range from 77.3 weight percent
to 99.7 weight percent.
In addition to venting the products of combustion from the sweating
furnace, an air pollution control system should also include hooding facilities
to provide ventilation during furnace charging and tapping. Properly designed
canopy hoods should suffice for the open hearth type reverberatory furnaces;
however, more complicated hooding may be necessary for the rotary, or tube
type reverberatory furnaces.
Of the common high-efficiency type collection equipment presently
available, only the fabric filters and wet scrubbers can provide a satisfactory
solution to the pollution problems of the lead/aluminum sweating furnace.
Although the electrostatic precipitator has the necessary performance
potential, the required auxiliary equipment and additional electrical power
supply services render the electrostatic precipitator economically impractical
for the relatively small gas volumes handled in sweating facilities.
The oily and combustible nature of the sweating furnace effluent
presents an explosion hazard and many other operational problems. An
afterburner is essential to any pollution control equipment. The afterburner
must be designed to provide adequate mixing and sufficient retention time for
complete combustion at firing temperatures. This is true whether it is an
integral part of the sweating furnace or a separate piece of equipment. A
luminous flame afterburner operating at between 1200°F and 1500°F is
generally recommended.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
FABRIC FILTERS
The installation of a fabric collector is perhaps the most common
approach to the sweating furnace abatement problem. However, due to the
temperature limitations on filter fabrics, the afterburner effluent gases must
first be cooled to an acceptable temperature level, usually around 250 F.
Evaporative cooling with a water spray, and mixing with ambient air are used,
but the most successful method uses radiant/convection U-tube heat
exchangers. Both evaporative cooling and cooling by ambient air dilution have
caused condensation of water and acid vapors in some cases. Relatively heavy,
woven Dacron bags, applied at superficial velocities of approximately two feet
per minute are commonly used in this application. Orion has also been
employed successfully in some instances.
If the baghouse temperature is allowed to drop below the water or acid
vapor dew point, hydrolysis of halide salts may take place. Direct condensation
of hydrochloric, sulfuric, or hydrofluoric acid will occur, with devastating
effects on both the baghouse shell and the fabric bags themselves. For this
reason strict temperature control must be maintained on any fabric filter
installation. Ideally a baghouse should be both fully insulated and equipped
with standby heating facilities to insure the minimum of condensation, even
during periods when the furnace is not being fired. As an added precaution
most baghouses are epoxy coated to prevent corrosion. To protect against
uncontrolled temperature surges or cooler failure an emergency dilution, or
bypass damper may be installed upstream of the baghouse, shown in Figure 17.
WET SCRUBBERS
High-energy wet scrubber systems have been successfully applied to
aluminum/lead sweating facilities and afford an excellent solution to the
pollution control problem. However, the high operating costs, the potential
water pollution problems, and the relative complexity of the equipment have
limited the appeal of scrubbers. Considerably less space is required for the
installation of a scrubber system than an equivalent baghouse. This is because
scrubbers do not require cooling of the inlet gas, and because they are,
ordinarily, smaller than the equivalent baghouse. Perhaps the most important
advantage of a scrubber system is the ability to remove corrosive gases and
mists from the furnace effluent gases as well as extremely fine particulate
matter.
An aluminum/lead sweating facility will require a high-energy Venturi
-------
CHARGE
HOOD
FURNACE
CHARGE"
CO
AFTERBURNER
1500 °F
100'F
REVERBERATORY
FURNACE
FURNACE
PRODUCT
RADIANT /CONVECTION
COOLING TUBES
1200°F
REFRACTORY
LINED DUCT
100 *F
250-F
TAP HOOD
BAGHOUSE
{SHAKER TYPE)
THERMOCOUPLE
CONTROLLED
EMERGENCY
DILUTION DAMPER
' DUST
CONVEYING
SYSTEM
Figure 17
Typical Fabric Collector Installation
for Reverberatory Furnace Sweating Facility
EFFLUENT
STACK
\/\/\/v
to
y u
FAN, MOTOR
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
scrubber possibly requiring as much as 40 or 50 inches wg differential pressure
across the transfer zone, or an equivalent scrubber, to provide the necessary
paniculate collection efficiency. The portion of the scrubber system exposed
to high temperatures and/or abrasion must be refractory lined. The remainder
of the downstream system should be fabricated of corrosion resistant materials.
With caustic addition using a pH controller and possibly clarification, the
effluent slurry will be acceptable to most municipal sewage treatment plants,
without costly inplant water treatment facilities. To avoid damage to the
scrubber during start up either a by-pass damper or an electrically interlocked
fan/pump system is recommended, as in Figure 18.
In rare cases, where the scrap charge evolves unusually large quantities
of corrosive or noxious gases and a scrubber alone cannot reduce the
particulate pollutants to an acceptable level, a combination pollution control
system may be necessary. The sweating of PVC coated wire, which evolves
hydrochloric acid and organic vapors, and Teflon" coated wire, which evolves
hydrofluoric acid, are particularly troublesome in this context. To overcome
this problem of excessive gaseous emissions, a packed absorption tower, in
addition to a scrubber or baghouse, may be necessary.
b.
SPECIFICATIONS AND COSTS
The sweating furnace effluent can be treated adequately by either a
fabric collector or a wet scrubber. The variability of the sweating operation
makes it difficult to generalize as to the size and performance requirements for
air pollution control equipment to fit a given furnace.
Careful measurement of the actual gas flows, particulate contaminant
loadings and gas contaminants over the normal range of operations carried out
in the furnace to be treated provides an effective, although costly, basis for
design.
Another alternative is to minimize the effect of the variable flow from
the sweating furnace by combining the effluent with that of the cupola or
other smelting equipment.
For purposes of this study, the process description and operating
conditions are specified for a furnace which may alternately handle aluminum
sweating and lead sweating, but which is treated apart from any other
equipment in the smelting plant.
The process description used for the fabric collector case is given in
-------
CHARGE
HOOD
FURNACE
CHARGE
AFTERBURNER
1500'F
100'F
REVERSE RATORY
FURNACE
FURNACE
PRODUCT
REFRACTORY LINED
STAINLESS STEEL
SCRUBBER
1200 "F
REFRACTORY
DUCT
100°F
TAP
HOOD
RECIRCULATION
PUMP
SLURRY
DRAIN
/ CAUSTIC
/ADDITION
CORROSION
RESISTANT
DUCT FOR
SATURATED
GAS
CORROSION
RESISTANT
EFFLUENT STACK
. CORROSION
RESISTANT
FAN, MOTOR
& DRIVE
Figure 18
Typical Wet Scrubbing Installation
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 44, and the operating conditions in Table 45. The quoted costs are
summarized in Table 46, and plotted in Figure 19.
The wet scrubber specifications are detailed in Tables 47 and 48, and
the prices received in response in Table 49. These are plotted in Figure 20. As
was the case for the fabric collector, the scrubber manufacturer did not
distinguish between the low and high efficiency cases.
c. DISCUSSION OF COSTS FOR LEAD/ALUMINUM
SWEATING FURNACES
The cost of treating a furnace to be used for sweating operations may
vary over a wide range depending upon the charge stock and desired products.
Sweating either lead or aluminum from "clean" scrap with little organic or fine
particulate material can probably be carried out without air pollution control
equipment.
For the more general case in which nearly any lead or aluminum
containing material may be included in the charge, both afterburning and
particulate collection are required. The afterburning function is most
frequently carried out in the furnace proper. Particulate collection by fabric
filtration is more expensive in terms of first cost, but has a lower operating cost
and longer life.
These factors tend to reduce the apparent cost difference, and if the
operation is run on a nearly continuous basis the fabric collector may be less
expensive. This is illustrated in Table 50, which compares the "Total Annual
Cost" for the two collector types at several levels of usage. In this example, the
fabric collector is more costly than the scrubber for 2000 hours of operation
per year, but more economical at 4000 or more hours/year. Figure 21 is a plot
of operating cost versus annual hours of operation.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 44
FABRIC COLLECTOR PROCESS DESCRIPTION
FOR SWEA TING FURNACE SPECIFICA TION
The fabric filter is to serve one aluminum reverberatory or tube furnace used for
sweating lead and aluminum alternatively. The capacity of the furnace is given in terms of
the rate of product production, which varies between the two operations. For example,
WOO Ib/hr aluminum and 10,000 Ib/hr lead are alternative designations for the same
furnace.
The charge materials will include, but will not be limited to, the items checked
below:
LEAD
Auto batteries (Complete)
Lead sheathed cable & wire
Tooling dies
Dross and skimmings
Rubber insulation
Plastic insulation
Other
ALUMINUM
Magnesium stampings
Scrap aluminum sheet
Pots and pans
Aircraft engines
Airframe scrap
Insulated wire
Other
The furnace will be used to melt lead and aluminum (the above materials) selectively,
and to burn the extraneous materials. The molten metal products are tapped into ingot
molds through a spout requiring ventilation in addition to the furnace flue gas.
The furnace is hand charged through doors at the front of the furnace. The burners
are fired at 2,200,000 BTU/hr with natural gas. There is an afterburner with a maximum
heat input of 2200,000 BTU/hr which produces a maximum exit temperature of 1500°F at
100% excess air. During the burnout phase of the operation, as much as 40% of the charge
by weight may comprise insulation with a fuel value of 10,000 to 18,000 BTU/lb.
Operating conditions will vary widely during the day as the charge materials and
products vary.
POL LUTION A BA TEMENT EQUIPMENT
The baghouse will be installed downstream of the afterburner. A radiant convection
tube cooler will bring the gas temperature down from 1500°F to 250°F. A further safety
provision shall be made by the installation of a thermocouple controlled air dilution inlet
damper. Water cooling of gas by evaporation is not acceptable.
The bag filter shall be an automatic, continuous orlon cloth filter at an aircloth ratio
of not over 2:1. The bag filter shell and hopper shall be constructed of mild steel.
Installation of baghouse will be adjacent to furnace building and be located outside
subject to ambient conditions.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 44
(continued)
Auxiliary equipment for bag filter shall include:
(1) Fan, motor, drive and damper
(2) Screw conveyor under bag filter
(3) Thermocouple controlled air dilution inlet damper
(4) Gas cooling system
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 45
OPERATING CONDITIONS FOR SWEATING FURNACE
FABRIC COLLECTOR SPECIFICATION
(Data for aluminum sweating/data for lead sweating)
Small
(1 Furnace)
Medium
(2 Furnaces)
Large
(3 Furnaces)
Furnace Capacity, ton
Melting rate, Ib/hr
Process Wt., Ib/hr
Inlet gas volume, ACFM"
Inlet gas Temp., °F*
Inlet Loading, Ib/hr*
Inlet loading, gr/ACF*
1000/10,000 2000/20,000 3000/30,000
1600/16,000 3200/32,000 4800/48,000
15,400 30,800 46,200
250 250 250
17/1230 88/2460 50/3670
0.129/9.32 0.129/9.32 0.129/9.32
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Eff., Wt. %
Case 1 — LA Process Weight
3.66/13.74
0.028/0.104
78.5/98.9
5.27/23.44
0.020/0.089
84.0/99.0
6.52/33.1
0.0165/0.084
87.0/99.1
Case 2 — High Efficiency
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Eff., Wt. %
3.86
0.03
77.3/99.7
7.72
0.03
77.3/99.7
11.6
0.03
77.3/99.7
*A fter air dilution
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 46
Fabric Collector Cost Data
for Sweating Furnaces
INFORMATION
Process Capacity, Ton/Day :
Inlet Gas Volume, ACFM
Efficiency, Wt. %
Controlled Emission, gr/ACF
Type of Charge
o
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other :
Total :
Installation Cost, $
A. Grass-Roots
B. Add-On *
Expected Life, Years
Operating and Maintenance $/year ]
FABRIC COLLECTOR
SMALL
19.2
15,400
99.5
<.01
Lead/
250
50
15,677
6,557
60,125
$83,359 !
$61,770 !
25
$4,536
MEDIUM
38.4
30,800
99.5
<.01
'Al/Mg/droi
250
100
27,841
11,320
117,250
156,411
117,310
25
$7,776
LARGE
57.6
46,200
99.5
< .01
s
250
150
41,762
- 17,158
174,375
$233,295
$174,975
25
$11,664
* No substantial difference from grass roots
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
rt
o
Q
o
in
o
H
i
t/)
O
Figure 19
Cost of Fabric Collectors
for Sweating Furnaces
600
500
400
300
200
100
70
50
30
20
10
~ — ' Turnkey Installai
— for Grass Roots .
.f i ...
— 1~ - ; - - 1 *
' 4
f
t * ,
-i = = = = = = = = EE = EE-E:E:::ji!!;; Fal
•=ppi|;:::|;:;;;;i!;; ::'"; Au3
===========!!=!=ric Collector § ;
ciliary Equipment :
::::::::::::;il!' : ::::::::::::::
,i -t
fiiiiiiiiiiiiiiiiHiiiiiiiiiiiiiiyiitb
Fabric Collector -•
Only :
-
10
20 40 60
Process Capacity, Ton/Day
100
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 47
WET SCRUBBER PROCESS DESCRIPTION
FOR SWEA TING FURNACE SPECIF 1C A TION
The scrubber is to serve one aluminum reverberatory or tube furnace used for
sweating lead and aluminum alternatively. The capacity of the furnace is given in terms of
the rate of product production, which varies between the two .operations. For example,
1000 Ib/hr aluminum and 10,000 Ib/hr lead are alternative designations for the same
furnace.
The charge materials will include, but will not be limited to, the items checked
below:
/
/
/
/
/
LEAD
Auto Batteries (Complete)
Lead sheathed cable & wire
Tooling dies
Dross and skimmings
Rubber insulation
Plastic insulation
Other
ALUMINUM
Magnesium stampings v
Scrap aluminum sheet /
Pots and pans *
Aircraft engines v
Airframe scrap *
Insulated wire /
Other
The furnace will be used to melt lead and aluminum, the above materials, selectively
and to burn the extraneous materials. The molten metal products are tapped into ingot
molds through a spout requiring ventilation in addition to the furnace flue gas.
;
/
The furnace is hand charged through doors at the front of the furnace. The burners
are fired at 2,200,000 BTU/hr with natural gas. There is an afterburner with a maximum
heat input of 2,200,000 BTU/hr which produces a maximum exit temperature of 1500 F at
100% excess air. During the burnout phase of the operation, as much as 40% of the charge
by weight may comprise insulation with a fuel value of 10,000 to 18,000 BTU/lb.
Operating conditions will vary widely during the day as the charge materials and
products vary.
The scrubber system will be installed downstream of an afterburner. The scrubber
shall be installed following a run of refractory-lined duct to suit the location of the scrubber.
The scrubber material shall be type 316 ELC stainless steel, refractory-lined in areas subject
to high temperature and/or abrasion. The draft loss across the scrubber shall be not less than
40" wg or the equivalent in energy input.
Installation of scrubber shall be adjacent to furnace- building and located outside
subject to ambient conditions.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 47
(continued)
Auxiliary equipment for scrubbers shall include:
(1) Fan, motor, drive and damper
(2) Slurry handling system (not including interconnecting pipe)
(3) Pumps
(4) Water conditioning system
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 48
OPERATING CONDITIONS FOR SWEATING FURNACE
WET SCRUBBER SPECIFICATION
(Data for aluminum sweating/data for lead sweating)
Small Medium Large
(1 Furnace) (2 Furnaces) (3 Furnaces)
Melting Rate, Ib/hr
Process Wt., Ib/hr
Inlet gas vol., ACFM
Inlet gas temp., °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet Gas Volume, ACFM
Outlet Temp., °F
1000/10,000
1600/16,000
42,500
1,500
17/1230
0.046/3.38
15,000
180
2000/20,000
3200/32,000
85,000
1,500
33/2460
0.046/3.38
30,000
180
3000/30,000
4800/48,000
127,500
1,500
50,3690
0.046/3.38
45,000
180
Case 1 - LA Process Weight
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Eff., Wt. %
3.66/13.74
0.028/0.108
78.5/98.9
5.27/23.44
0.020/0.091
84.0/99.0
6.52/33.1
0.017/0.086
87.0/99.1
Case 2 — High Efficiency
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Eff., Wt. %
3.86
0.03
77.3/99:7
7.72
0.03
77.3/99.7
11.6
0.03
77.3/99.7
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 49
Wet Scrubber Cost Data
for Sweating Furnaces
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt . \
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, °F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. Grass-Roots
B. Add-On*
Expected Life, Years
Operating and Maintenance $/year
WET SCRUBBER
SMALL
19.2
42,500
< .03
Per
1,500
250
18,850
27,950
11,050
6,800
64,650
25,000
10
2,800
MEDIUM
38.4
85,000
<.03
Specif ical
1,500
450
24,210
76,440
15,265
11,200
127,115
45,000
10
3,300 ,
LARGE
57.6
127,500
<.03
ion
1,500
675
33,140
80,760
19,177
17,200
150,277
65,000
10
3,800
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
V)
(H
OJ
O
Q
Figure 20
Cost of Wet Scrubbers
for Sweating Furnaces
(Hq* Efficiency)
300
200
100
trt
13
ti
ri
V)
3
O
H
i
tf)
O
u
70
50
30
20
10
Turnkey Installati<
for Grass Roots PI,
— ., , j ]
- - •/••••• ;.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 50
Comparison of Total Costs for
Wet Scrubbers and Fabric Collectors
For Sweating Furnaces
Basis: 38.4 Ton/Day Furnace (Lead)
10% Yearly Cost of Capital
0.01 $/kw-hr Cost of Power
25 Year Life for Fabric; 10 Year for Scrubber
Operating Hours/Year
Fabric Collector
First Cost
Annual Capital
Parts & Labor
Horsepower
Total
Wet Scrubber
First Cost
Annual Capital
Parts & Labor
Horsepower
Total
500
32,719
7,776
440
40,935
30,700
3,230
1,975
35,905
1,000
C
32,719
7,776
880
41,375
30,700
3,230
3,950
37,880
2,000
73,420)
32,719
7,776
1,760
42,215
59,115)
30,700
3,230
7,900
41,830
4,000
32,719
7,776
3,520
44,015
30,700
3,230
13,825
47,755
6,000
32,719
7,776
5,280
45,775
\
30,700
3,230
19,750
53,680
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 21
Comparison of Abatement Equipment Costs
For Sweating Furnaces
Fabric
, Collector
30
134
1,000
2,000 4,000
Incurs/Year
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
5. AIR POLLUTION CONTROL FOR LEAD REVERBERATORY
FURNACES
a. PROCESS DESCRIPTION
1) MANUFACTURING ASPECTS
Reverberatory furnaces are used in a number of ways in the processing
of lead scrap metal for reclaim. The furnace is merely a device for heating the
contents by direct contact with the products of combustion of oil or gas
burners, and by radiation from the hot walls to the contents of the furnace.
Whether there is any significant potential air contamination produced depends
to a large extent upon the use to which the furnace is put. Several of the uses
of reverberatory furnaces in a secondary lead processing plant are:
a) burnout
b) sweating
c) melting
d) purification.
BURNOUT
The burnout operation is not strictly a smelting process, but rather
involves the incineration of materials which may be present in scrap metal such
as plastics, rubber insulation, wood, paper and other combustible materials.
When a reverberatory furnace is used for burnout operations, the air pollution
control equipment requirements are similar to those for any other incineration
device. That is, the furnace must be provided with sufficient time at
temperature to burn any combustible vapors released during the incineration
process. If not, a smoke will be produced. The smoke may exceed the visible
opacity regulations in force in the area, or may produce grain loadings in excess
of the allowable emission limit. If this is the case, it will be necessary to install
a thermal afterburner to oxidize the combustible material. This subject falls
more strictly in the category of treatment of incineration equipment than
smelting equipment, however. Burnout operations may also involve the
decomposition of halogen-containing plastic materials. Polyvinyl chloride wire
insulation and Teflon are examples of combustible materials which release
halogen acids when they are burned. These materials are toxic and are
objectionable on the basis of odor when emitted into the atmosphere in
significant quantities. Burnout operations which involve substantial quantities
of halogen-containing plastics should be equipped with an afterburner-scrubber
combination in which the scrubber is used to absorb the halogen acids into a
water stream.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
SWEATING
Lead sweating operations, in which lead is separated from a mixture of
materials, many of which have higher melting points than lead, is covered in
detail in another section of this report. The air pollution problems related to
lead sweating are mainly associated with the incidental burnout of combustible
materials during sweating, with the entrainment of dusty materials in the flue
gas, and with SOX produced from batteries.
MELTING
Reverberatory furnaces may be used to melt lead pigs or ingots for
casting. This process is more commonly carried out in indirect heated furnaces
such as electrical or gas fired crucibles. The melting of lead does not, in itself,
involve any significant air pollution problem. The melting point of lead alloys
is relatively low, and the vapor pressure of metallic lead over the melt is not
high enough to make any substantial contribution of vaporized lead to the flue
gas leaving the furnace. However, in any melting operation there is the
possibility of inclusion of materials which will produce organic or
halogen-containing emissions when the furnace temperature is raised to the
melting point of lead. The inclusion of any material other than metallic lead in
the melting furnace should be considered carefully from the standpoint of the
potential air pollutants.
PURIFICATION
The principal use to which reverberatory furnaces are put in secondary
lead processing involves the melting and purification of lead by removal of
extraneous ingredients. This is the principal process which can be described as
"smelting" in the reverberatory furnace. It is to this process the remainder of
this discussion will be directed.
RAW MATERIALS AND PRODUCTS
The reverberatory furnace may be used for the purification of molten
lead by oxidation of impurities such as iron, arsenic, antimony, and tin. The
furnace may also be used for reduction of lead oxide drosses, etc. In the case of
primary smelting, only the oxidation process is carried out in the reverberatory
furnace with the reduction generally done in a lead blast furnace. Many
secondary smelters do not operate a blast furnace, and may carry out both
operations in the same reverberatory furnace. The charge stock for such
smelting operations may be molten lead from a blast furnace in which lead
oxide has been reduced by reaction with carbon or coke, or it may be lead
ingots cast during a sweating operation conducted in a separate reverberatory
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
sweating furnace. It is not uncommon that burnout, sweating, and smelting
operations are carried out sequentially in the same reverberatory furnace. Some
raw scrap material may be of sufficient high purity to charge directly to the
reverberatory furnace for purification.
Throughout the remainder of this discussion, it will be presumed that
the principal purpose of the reverberatory furnace smelting operation is the
removal of oxidizable impurities as drosses. The many alternative problems
with respect to air pollution, which arise when materials such as plastics, oils,
etc. are charged incidentally, must be treated separately.
The reverberatory furnace may be charged with molten lead from
the cupola on a continuous basis. In this case, air blowing to oxidize metal
impurities is done either intermittently or continuously. The metal dross is
removed by slagging intermittently. The molten metal product is removed from
the furnace by tapping it into molds on an intermittent basis.
Solid lead scrap may be charged continuously to the reverberatory
furnace. Items of scrap lead such as battery plates, lead pipe, cable sheathing,
etc. can be hand fed through charging doors, or fed continuously on conveyors.
Here again, the air blowing and dressing can be either intermittent or
continuous. Casting of the product is ordinarily intermittent.
In the case where solid lead scrap is charged directly to the furnace, it is
customary to start the charge by piling a small amount of solid charge material
on the hearth and gradually raising the furnace temperature until the material
becomes partially melted. As a molten bath is formed on the hearth, additional
scrap is added and product is removed when the melt level is sufficiently high.
Lead product is ordinarily classified as hard, semi-soft or soft according
to the amount of impurities it contains. Soft lead ordinarily requires fluxing in
a crucible furnace and cannot be produced economically in the reverberatory
furnace. Semi-soft lead containing between 0.3 and 0.4% antimony and up to
0.05% copper is commonly produced by the reverberatory furnace.
Although the melting point of pure lead is on the order of 625°F,
temperatures exceeding 2000°F are used for the purification of lead in the
reverberatory furnace. These higher temperatures are required principally to
bring about the reaction between the metallic impurities and the oxygen
sparged into the metal bath. If lead oxide drosses are charged to the
reverberatory furnace, it is necessary to add a reducing agent such as granular
carbon to the bath to reduce the lead oxide to metallic lead.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
FURNACE EQUIPMENT
The lead reverberatory furnace is constructed of fire brick and
refractory materials. The materials of construction need not be particularly
resistant to temperature, but the chemical reactivity of the metal drosses is
high, and the refractory linings must withstand the continual contact with
drosses and slag.
Ordinarily, the furnace is kept as tight as possible to limit the
infiltration of air through charging doors, slagging openings and inspection
ports. This minimizes the amount of fuel required to heat the leakage. Ideally,
only the flue gases produced by the burner system and air blown through the
melt to remove impurities would be vented from the furnace through a dust
collection system. In cases where substantial quantities of organic material are
present in the charge, it is necessary to allow for infiltration of air to burn the
organic vapors generated in the furnace and prevent smoking.
Leakage of air into the furnace is generally avoided by operating with
the pressure inside the furnace nearly equal to atmospheric pressure. This
balanced draft situation results in a minimum of infiltration, but may cause the
furnace to "spill" combustion products out through open doors or inspection
ports. In order to prevent serious discharge of contaminants into the foundry,
hoods are usually provided over these openings. As the hoods capture the
fumes which leave the furnace when the doors are opened, the ventilating air
from the hoods must be treated in the air pollution control device also. There is
generally no requirement for hooding the metal pouring spout through which
the molten product is tapped into molds.
A flow diagram of the reverberatory furnace with a typical gas cooling
system is shown in Figure 22. This furnace is designed in such a way that
combustible vapors generated in the furnace are incinerated before leaving the
furnace. For this reason, no separate incineration device is shown. In the case
of the fabric filter installation sketched in Figure 22, the combustion products
are cooled to a limited extent by mixing with ambient air drawn through the
ventilating hoods. Further cooling is necessary to protect the fabric filter from
damage due to high gas temperature. This cooling is provided partly by a
section of duct work arranged in a serpentine configuration which exposes a
great deal of outside surface area to the atmosphere. This serves to drop the gas
temperature to the level of about 1000-500°F. In some cases, sufficient cooling
surface is provided to bring the gas temperature all the way down to the range
acceptable for Dacron bags (around 270°F). In larger installations, it is less
expensive to provide some dilution air to do the final cooling.
-------
REVERBERATORY
FURNACE
GAS OR
OIL FU€L
COMBUSTION
AIR
LEAD
SCRAP
CHARGE
FLUX
AIR
LANCE
LEAD
PRODUCT
SETTLER -
COOLERS
Y T
T
LEAD OXIDE TO
BLAST FURNACE
STACK
DISCHARGE
FABRIC
COLLECTOR
FAN
t
^
Y
Y
t t
FINES TO
BLAST
FURNACE
co
co
Figure 22
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
In the arrangement shown in Figure 22, sufficient dilution air is added
to bring the gas temperature to 270°F, and also to provide an emergency
quench arrangement to drop the temperature even lower in the event that the
furnace temperature control does not limit the temperature properly.
In many installations, the U-tube cooler arrangement is replaced by a
large diameter cyclone which functions in exactly the same way with regard to
cooling the flue gas, but also serves as a "knock-out" chamber in which large
particulate materials settle. The large cyclone has the advantage that any heavy
materials carried over from the reverberatory furnace can settle out before
reaching the fabric filter, and any burning carbon or metal particles can be
dropped from the gas stream before reaching the filter. This is important in
protecting the combustible filter fabric from ignition.
An alternative arrangement of air pollution control equipment is shown
in Figure 23. Here, the gas leaving the reverberatory furnace and the ventilating
hoods is carried to a quench chamber where water is used to drop the
temperature to a reasonable level so that carbon steel duct work can be used
between the quench chamber and the scrubber. Quench chambers are generally
unsatisfactory as pretreating devices for fabric filters because of the possibility
that the water supply will cool the gas stream excessively and saturate it with
water. Saturated gas will very likely wet the filter cake collected on a fabric
filter and cause a "blinding" condition which will prevent the proper
ventilation of the furnace. With wet scrubbers there is no equivalent situation.
A tank for caustic addition is provided for SO2 scrubbing in Figure 23.
When either a fabric filter or a scrubber is provided for collection of the
particulate emission from a reverberatory furnace, it is necessary to furnish a
fan with sufficient horsepower to pump the gas through the air pollution device
at a high enough volume to ventilate the furnace properly. For a fabric filter
the necessary pressure is only a few inches of water column. Wet scrubbers,
however, require fans with relatively high pressure drops on the order of 50-60
inches water column in order to collect the very fine particulate material
generated by oxidizing impurities in the molten lead. When fans are installed
that have the capability of moving large quantities of air, it is usually necessary
to provide some sort of draft control at the furnace to prevent over-ventilating,
as well as to insure that adequate ventilation will be obtained. In the simplest
case, this consists of a barometric damper located after the cooling surface for a
fabric filter installation, and between the reverberatory furnace and the quench
chamber for a wet scrubbing system.
-------
FLUE GAS
WATER
QUENCH
COMBUSTION AIR
— FUEL GAS OR OIL
AIR
DROSS
LEAD
PRODUCT
WATER
VENTURI
CONTACTOR
GAS
ABSORPTION
TOWER
MIST ELIMINATOR
SURGE
TANK
CAUSTIC
TANK
Figure 23
Process Flow Sketch for Lead Reverberatory Furnace
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
2)
CONTROL EQUIPMENT
The principal problem associated with the operation of reverberatory
furnaces for lead smelting is the emission of inorganic particulate matter. This
consists of the oxides of metal impurities such as iron, antimony, etc. and lead
oxide itself. The former are oxidized in the molten bath and rise to the surface
as drosses. They are mechanically entrained in the flue gas stream either by the
action of the sparge gas or by contact with the flue gas itself. The lead is
ordinarily vaporized from the surface of the melt into the flue gas, and reacts
there with the residual oxygen to produce lead oxide. In addition to these
metallic oxides, there may be oxides of sulfur introduced as lead sulfate or
sulfuric acid with used lead storage batteries, organic materials from the
vaporization and partial combustion of plastics, oils, etc., and halogen acids
produced by the decomposition of PVC plastics and Teflon.
In order to provide a system that will be satisfactory in all respects, it is
necessary to establish the total gas flow rate, the composition of the gas stream,
and the nature and level of the contaminants. Each of these will be considered
in some detail in the following paragraphs.
The most important single variable in sizing air pollution control
equipment is the flowing volume of the gas stream which must be
accommodated. Because of the many factors which contribute to the volume
of gas required for adequate ventilation and cooling of the effluent from
reverberatory furnaces, it is imperative that a measurement of the gas flow
using accepted flow measuring technique (such as contained in the Industrial
Gas Cleaning Institute publication WS-1) be used to measure the gas volume.
For preliminary estimate of the gas flow - such as might be used for sizing
equipment for budgetary estimates — the volume of the flue gas and ventilating
air for hoods may be approximated. Four or five ACFM at 270°F per pound of
metal melted per hour is a good first approximation. However, it should be
borne in mind that poorly sealed furnaces, or furnaces with unusually large
hooded areas may use several times as much air to provide adequate ventilation.
A first estimate of the grain loading can be made by using the "emission
factor" quoted by the National Air Pollution Control Administration for lead
reverberatory furnaces. This is given as 154 pounds of metal per ton of charge.
The rates of emission of organic materials and other contaminants such as SOo,
HCI and HF can only be estimated from the rates at which the precursor
materials can be charged to the furnace. It is not recommended that equipment
specifications be based on such estimates, but rather on a source test performed
by accepted methods.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
AIR POLLUTION CONTROL EQUIPMENT TYPES
Strictly speaking, the air pollution control equipment for a
reverberatory furnace should consist of an afterburner if any organic material is
put into the furnace, and a particulate collection device if the furnace is used
for refining of lead by oxidizing other metallic impurities. However, the
afterburning is most frequently accomplished in the reverberatory furnace
proper. This is accomplished by preventing excessive leakage of air into the
furnace, and introducing controlled amounts of oxygen either as excess air to
the gas or oil burners, or in a separate series of vent ports.
Particulate collection equipment is generally divided into four
classifications:
1. Mechanical dust collectors
2. Electrostatic precipitators
3. Fabric filters
4. Wet scrubbers
The mechanical dust collectors do not have good efficiency on the
submicron particulate matter emitted in lead smelting, and they cannot be used
alone to solve the particular air pollution problem. However, they are
sometimes used in series with one of the other collection devices where the
cyclone does a crude separation of the largest particulate matter, and the
cyclone walls serve to cool the gas stream by transferring some of the heat to
ambient air.
ELECTROSTATIC PRECIPITATORS
Electrostatic precipitators can be used for the collection of lead fume
from reverberatory furnaces, but two circumstances make the precipitator an
unlikely choice. The first of these involves the high minimum cost of
electrostatic precipitators. The minimum cost of a small precipitator is likely to
be considerably higher than the cost of either a fabric filter or wet scrubber for
a lead reverberatory furnace of nominal size. In some large installations, the gas
flow rate may be high enough to make a precipitator installation economical.
However, the optimum performance of electrostatic precipitators requires that
the electrical resistivity of the dust be within a narrow range of values. The lead
oxide dust does not fall within this range without the addition of a chemical
conditioning agent to the gas stream. For these reasons, electrostatic
precipitators are not likely to find wide use on reverberatory furnaces.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
FABRIC FILTERS
Fabric filtration has been the principal mechanism for participate
control from reverberatory furnaces. This is due to a combination of
circumstances. The fabric filter is inherently a very high efficiency device. Even
when filtering submicron particulate materials where the dust particle size is
much smaller than the opening in the fabric weave, the fabric collects particles
by electrostatic attraction to build a filter cake of very small pore size and then
collects the submicron material nearly perfectly. In addition, the fabric filter is
a dry collection device, and the lead oxide collected is in suitable form for
return to a blast furnace or reverberatory furnace for reduction to elemental
lead.
The important variables in selection of fabric filters are (1) gas to cloth
ratio, (2) fabric material and (3) bag arrangement. In general, the cost of a
fabric filter increases nearly in proportion to the amount of bag surface it
contains. For this reason, the smallest possible surface area is the lowest in first
costs. This indicates that the highest ratio of gas to cloth should be the most
economical in first costs. While this is true, the performance of fabric filters
with respect to fabric life, freedom from plugging problems, etc., is best when
the velocity of gas passing through the filter medium is very low. In general, the
installation will be more economical in the long run if a relatively low gas to
cloth ratio is used. Installations with one square foot of cloth for every two
ACFM of gas (2/1 gas/cloth ratio) have proven satisfactory. For best long term
performance, a filter ratio of 1 CFM per square foot of fabric is recommended.
Several fabrics can perform satisfactorily in the atmosphere generated
by a reverberatory furnace if the temperature is low enough. In most existing
installations, Dacron bags have been found to provide the best compromise
between cost, temperature resistance, and good life characteristics. The Dacron
bags may be operated at temperatures up to 300°F. However, deterioration is
very rapid if the bag temperature limit is exceeded. For this reason, it is wise to
design the gas conditioning system to reduce the temperature to a considerably
lower level during normal operating conditions. Temperatures of 200-250°F
are recommended, and design temperatures up to 270°F should be acceptable.
In addition to the normal cooling by dilution with cold air, dilution with cold
air plus direct heat exchange, or through heat exchange alone, an emergency
quench system should be provided to bleed cold air into the system in large
quantities if the temperature control mechanism fails.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
WET SCRUBBERS
Wet scrubbers are capable of providing the high efficiency required on
the submicron fraction of the reverberatory furnace fume but in order to
achieve very high collection efficiency, high levels of energy input are required.
In most cases this is done by taking a high pressure drop across a Venturi throat
or orifice through which the water used for scrubbing is passed concurrently
with the gas. Pressure differences on the order of 30-100 inches of water
column are required in order to provide good clean-up for the smelting
operation. In addition to the large energy input (which may require two 50-500
horsepower motors), the use of water for scrubbing introduces some corrosion
problems. SC^ in the gas stream is absorbed in water to form dilute sulfurous
acid ^2803), which makes any water that is recycled to the scrubber very
acidic. Without chemical treatment, the pH of the recirculated scrubbing water
is likely to reach a level of about 2.0. This will attack most ordinary steel
construction, so it is necessary to add lime, caustic soda or some similar
chemical conditioner to the water to minimize corrosion and prevent discharge
of very acidic water to the sewer system or to a natural body of water.
The caustic chemicals might cost several hundred dollars per day. For
example, if the SC^ content of the gases from a large furnace is 5000 ppm and
the flow rate averages 14,200 SCFM (20,000 ACFM @ 270°F), the SO2
discharge rate is 71 SCFM. Neutralization of this much SC^ with caustic
requires about 15 pounds of caustic addition per minute. At a cost of 4c/lb,
this amounts to $288 per eight hour day.
With neutralization, the corrosive action of the sulfurous acid is
reduced but it is ordinarily not desirable to use carbon steel because of the
possibility that the chemical addition will be interrupted for short periods
during which serious corrosion would take place.
The dust collected by the wet scrubber will usually be in the form of a
relatively dilute slurry. Concentrations over 10 wt % solid are not ordinarily
produced by scrubbers. If the lead oxide recovered by a wet scrubber is to be
recycled, some form of settling must be provided to separate the solid from the
water. This is usually done in a settling pond, but mechanical settlers and
drum-type filters can be used.
Although scrubbers have disadvantages as compared with fabric filters
for this application, there is one circumstance in which the scrubber may be the
only piece of equipment capable of providing adequate treatment of the gas
stream. If the sulfur content of the charge is relatively high, the SC
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
concentration in the vent gas from the reverberatory furnace may exceed local
emission standards, or it may produce a nuisance. In this case, a scrubber
designed solely for absorption of SC>2 in an alkaline scrubbing medium can be
used to abate the sulfur oxide emission. Here, it is likely that the scrubber
would be placed after an existing fabric filter which serves to remove the
particulate matter. Caustic soda, soda ash, and other soluble alkaline materials
can be used to remove the sulfur oxides from the effluent gas stream in the
form of soluble sulfites. With proper neutralization these may be suitable for
discharge into the sewage system serving the plant.
It is likely that the local regulations, or good water treating practice,
will require some oxidation of the sulfites to sulfates by aeration before the
spent scrubbing liquor is discharged into a water course or sewer. Systems for
the removal of sulfur oxides are uncommon, and good practice has not yet
been established in the secondary smelting industry.
SPECIFIC PROBLEMS
Several problems are associated with lead smelting in reverberatory
furnaces that are not common to the secondary smelting industry in general.
These are:
(1) emission of lead fumes
(2) sulfur oxide emissions
Metallic fumes generally produce dense, opaque visible plumes which
are objectionable because they are unsightly and because they contribute to the
level of particulate matter suspended in urban atmosphere. Lead fumes are
particularly objectionable because of the toxicity of lead. For this reason, the
particulate emission standards in most localities are enforced with more than
average diligence when lead oxide is suspected as a principal ingredient in the
emission. While lead oxide emissions are not subject to special regulation apart
from process weight limitations for particulate matter in general, or opacity
regulations, it is likely that lead will be singled out for special regulation as air
pollution standards become more severe. For this reason, it is reasonable to
install particulate abatement equipment capable of meeting the highest possible
standards of performance. Fabric filters generally are conceded to produce
collection efficiency greater than 99.5% for submicron fumes of this sort. It is
reasonable to install a fabric filter, even if present regulations would permit the
use of a wet scrubber at a lower efficiency level.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
A second problem peculiar to lead reclaiming is the emission of sulfur
oxides. The sulfur compounds are quite common in primary smelting because
many metals occur naturally as sulfides. For example, copper and zinc are most
commonly mined as the corresponding sulfide, and oxidized in a roasting
furnace which produces large quantities of sulfur dioxide. However, metal
reclamation processes do not ordinarily involve the sulfide ore. Lead smelting is
an exception, in that much of the lead usage in the U.S. is for the production
of lead storage batteries. These batteries contain substantial quantities of lead
sulfate when they are discarded. In addition to the lead sulfate, there may still
be some sulfuric acid present in the battery when the plates are put in to the
reverberatory furnace. If the batteries are in mixed scrap which is sweated to
produce lead, the sulfate may be released in the sweating process. If the plates
are charged directly to the reverberatory furnace, the sulfur oxides will be
released there.
The concentration of sulfur oxides may be well within local air
pollution abatement standards if the concentration of battery scrap in the
charge is low. However, concentrations of 2000-5000 ppm may be attained if
the charge consists principally of battery plates. In this circumstance, a wet
scrubber may be required for the removal of S02 from the gas stream leaving
the fabric filter. Most local ordinances will prohibit the discharge of very acidic
water into sewers or natural bodies of water, and some method of neutralizing
the scrubber water will be required.
In this circumstance, a single wet scrubbing system may serve both the
particulate collection and sulfur oxide scrubbing functions. Figure 23 illustrates
a combination of scrubbing system with neutralization of the waste water.
b. SPECIFICATIONS AND COSTS
As in previous sections, the costs compiled for lead reverberatory
furnaces were based on a standard specification plus two pages written
especially for the lead furnace and the particulate collector specified.
FABRIC FILTER
The process description used in the specification is given in Table 51.
Operating conditions for the usual three furnace sizes and two efficiency levels
are listed in Table 52. The prices quoted are summarized in Table 53.
As is usually the case, a single fabric filter quotation was presented in
response to both efficiency levels, on the basis that the fabric filter will
ordinarily produce a very high efficiency. The prices are plotted in Figure 24
for ease of interpolation.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 51
FABRIC COLLECTOR PROCESS DESCRIPTION
FOR LEAD REVERBERATORY FURNACE SPECIFICATIONS
The fabric filter is to serve a reverberatory furnace used to recover lead from lead
oxide, lead scrap, and dross materials. The charge to the furnace will consist of lead scrap,
battery plates, and lead dross. The furnace is fired with natural gas.
The air pollution control system is to capture fumes from the furnace flue arid from
a fume collection hood. These are brought into a single insulated duct. This duct passes
horizontally through the building wall at an elevation of 20' above grade. A high surf ace area
"U-tube" cooling section without insulation is provided outside the building, followed by a
dilution air damper to reduce the final temperature from 1000°F to 270°F. The filter is to
be located on grade adjacent to the building. The fan following the filter will be located on a
shed roof 28' above grade, and will discharge into a new 70' stack.
The fabric filter is to operate in such a manner that a single compartment (with no
more than one quarter of the total collecting surface area) can be isolated for shaking. The
hopper is to have sufficient capacity to hold the dust collected over a 24 hour period
without interfering with normal operation of the collector. The dust outlet should be a
minimum of 8'0" above grade in order to provide for truck access. The hopper valve is to be
included in the quotation.
Dacron tubular bags shall be used with a gas/cloth ratio of 1.0 CFM/FT^ or less at
operating conditions.
Auxiliaries are defined, for purposes of this specification, as:
ID
12)
Fan and drive
Dampers
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 52
FABRIC FILTER OPERATING CONDITIONS
FOR LEAD REVERBERATORY FURNACE
Three sizes of fabric collectors are to be quoted. While two levels of efficiency are
specified, it is expected that a single fabric quotation will be supplied for each size range.
Furnace Capacity, ton
Melting Rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature, °F
Inlet loading, Ib/hr
Small
10
1,000
5,000
270
57
Medium
25
2,500
10,000
270
130
Large
50
5,000
20,000
270
260
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 1 - LA Process Weight
2.80 4.64 6.67
0.065 0.054 0.039
94.6 96.4 97.4
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 2 — High Efficiency
0.43 0.86 1.72
0.01 0.01 0.01
99.2 99.34 99.34
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 53
Fabric Collector Cost Data
for Lead Reverberatory Furnaces
INFORMATION
Process Capacity, ton/day
Inlet Gas Volume, ACFM
Efficiency, Wt.l
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. Grass-Roots
B. Add -On*
Expected Life, Years
Operating and Maintenance $/year
FABRIC FILTER
SMALL
10
5,000
99.5
<0.01
«— lead scr
270
15
7,240.00
4,015.00
14,500.00
25,755.00
19,320.00
25
$2,592.00
MEDIUM
25
10,000
99.5
<0.01
ip and dro
270
30
13,020.00
5,802.00
29,798.00
48,620.00
36,475.00
LARGE
50
20,000
99.5
<0.01
c c . . ..v
270
60
26,040.00
11,392.00
58,396.00
95,828.00
71,875.00
25 1 25
$4,536.0(J $9,072.00
* Installation costs would be same as grass roots
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 24
Cost of Fabric Collectors for
Lead Reverberatory Furnaces
rt
o
Q
o
en
T3
a
rt
o
O
u
300
200
100
70
50
30
20
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= = = = = =|ErE:f||:EE:Ei:Ei!iiE II : EEE
r Turnkey Installat
E for Grass Roots P
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- Fabric Collector
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SiiisisBSSiisBliiil^H
10
20 30 60 100
Process Capacity, Ton/Dav
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
so-
WET SCRUBBERS
The wet scrubber specifications were written without any reference to
removal, as this is the most representative of current practice. The
specification material is given in Tables 54 and 55. The prices quoted are
summarized in Tables 56 and 57 for the LA-Process Weight and High Efficiency
cases. Figure 25 is a log - log plot of the cost data for the High Efficiency case.
c. DISCUSSION OF COSTS
There is a first cost advantage in favor of the fabric collector in the
smaller size range, which disappears as the gas volume increases. This is because
the filter cost increases more nearly in proportion to the gas flow than does the
scrubber cost. It is also apparent that the cost of pre-cooling the gas stream for
the filter becomes very high for the larger sizes. A more economical design
might have resulted if air dilution were used to a greater extent for the larger
filter. The horsepower cost associated with the wet scrubber is a significant
factor for the larger sizes.
Many of the comments made for the lead cupola apply to the
reverberatory furnace, because of the advantages of combining the effluents
from these two operations into a single stream to be processed through a fabric
filter or scrubber. In particular, the possibility of 862 emission control coupled
with stringent regulation of lead particulate emissions suggests that
combinations of scrubbers and fabric filters may become necessary.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 54
WET SCRUBBER PROCESS DESCRIPTION
FOR LEAD REVERBERATORY FURNACE SPECIFICATION
The scrubber is to serve a reverberatory furnace used to recover lead from lead oxide,
lead scrap, and dross materials. The furnace is fired with natural gas.
The air pollution control system is to capture fumes from the furnace flue and from
a fume collection hood, which are brought into a single insulated duct. This duct passes
through the building wall at an elevation 20' above grade. The scrubber is to be located at
grade outside the building. The fan will be located after the scrubber on adjacent shed roof
approximately 20' above grade, and will discharge into a new 70' stack. The ductwork ahead
of the scrubber is to be refractory-lined carbon steel, while the outlet ductwork is to be
rubber-lined carbon steel. The scrubber is to be constructed of 304 L stainless steel wherever
wetted by the scrubbing liquor.
The external piping and pumps will be of rubber-lined carbon steel or equivalent.
The liquor containing the paniculate matter is to be discharged into a settling pond within
WO' of the scrubber. The scrubber pressure drop shall be no less than 50" wg equivalent
energy input for the LA-Process Weight specification and no less than 60" wg pressure drop
equivalent energy input for the high efficiency case.
For purposes of this quotation, auxiliaries shall include:
(1)
(2)
(3)
(4)
(5)
Fan
Pump or pumps
External piping
Controls
Dampers
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 55
WET SCRUBBER OPERATING CONDITIONS
FOR LEAD REVERBERATORY FURNACE SPECIFICATION
Three sizes of scrubbers are to be quoted for each of two levels of collection efficiency.
Furnace Capacity, ton
Melting rate, Ib/hr
Inlet gas volume ACFM
Inlet temperature, °^
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet gas volume, ACFM
Outlet gas temperature, °F
(A)
Small
10
1,000
5,000
500
52
2.5
3,500
140
(B)
Medium
25
2,500
11,800
500
130
2.5
8,260
140
50
5,000
23,600
500
260
2.5
16,520
140
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 1 - LA Process Weight
2.80 4.64 6.67
0.09 0.066 0.047
94.6 96.4 97.4
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 2 — High Efficiency
0.30 0.71 1.42
0.01 0.01 0.01
99.4 99.4 99.4
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 56
Wet Scrubber Cost Data for
Lead Reverberatory Furnace
(LA-Process Weight)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.l
Controlled Emission, gr /ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. brass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance
$/Year
WET SCRUBBER
SMALL
10
5,000
94.6
.09
Proc
500
55
14,200
44,700
58,900
25,800
28,000
10
1,000
MEDIUM
25
11,800
96.4
.066
;ss Descri
500
125
14,200
41,600
55,800
25,800
28,000
10
1,000
LARGE
50
23,600
97.4
.047
ption
500
250
17,200
49,600
66,900
27,000
30,000
10
1,000
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 57
Wet Scrubber Cost Data for
Lead Reverberatory Furnace
(High Efficiency)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.%
Controlled Emission, gr/ACF
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment
D. Waste Equipment
E. Other
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance
$/year
WET SCRUBBER
SMALL
10
5,000
99.4
.01
Proc
500
65
14,200
48,500
62,700
26,400
29,000
10
1,000
MEDIUM
25
11,800
9-9.4
.01
ess Descri
500
150
14,200
49,600
63,800
26,400
29,000
10
1,000
LARGE
50
23,600
99.4
.01
ption
500
300
17,200
56,400
73,600
29,000
32,000
10
1,000
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Figure 25
Costs of Wet Scrubbers for
Lead Reverberatory Furnaces
(High Efficiency Case)
300 -
rt 200
o
Q
rt
t/i
3
o
X
H
O
u
100
70
50
30
20
10
Turnkey Installation
for Grass Roots Plant
10
(LA Process Weight)
Wet Scrubber $
Auxiliary Equipment
Wet Scrubber Only
25
50
100
Process Capacity, Ton/Day
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
6.
AIR POLLUTION CONTROL FOR ZINC CALCINATION
FURNACES
Prior to this program and through the initial stages of the program, the
member companies approached this industrial category on the basis of
experience with primary smelting furnaces. As the program proceeded, it
became apparent that the calcination operation was quite limited in secondary
smelting.
As a result, it was not possible to assemble meaningful information on
past installations, costs, and performance for secondary zinc calcining
operations. The following discussion is limited to the way "calcination" fits
into the secondary zinc smelting business, and the problems which may be
encountered in this area. A more complete description of the other processes
carried out by secondary zinc smelters is included in the "Air Pollution
Engineering Manual" published by NAPCA. These processes include:
1. Zinc Sweating
2. Zinc Melting in
a. Crucibles
b. Pot furnaces
c. Kettles
d. Reverberatory furnaces
e. Electric induction furnaces
3. Zinc retorting for
a. Reduction of zinc oxide
b. Purification of zinc
4. Burning to produce zinc oxide
a. PROCESS DESCRIPTION
Zinc calcining is the process of heating zinc carbonate ores or secondary
zinc materials to drive* off gaseous dissociation products which may be
detrimental to subsequent treatment or to product use. The process was
originally developed to remove water of hydration and carbon dioxide from
zinc carbonate ores prior to processing in horizontal retort furnaces.
Mines which once produced zinc carbonate ores are now depleted and
alternate methods of treating oxidized ores have been developed. Therefore,
calcination practices in the secondary zinc industry are now limited to a few
applications in which chlorine, fluorine, carbon and other unwanted
contaminants are removed from zinc oxide.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
The calcination of carbonate ores is similar to a drying operation with
temperatures ranging from 750 °C for zinc minerals to 1470°C for gangue
minerals. Up to 30 percent of the ore's original weight is given off as carbon
dioxide and water as described by the following chemical equation:
ZnC03 • x(H20)
PAST PRACTICE
The process was originally carried out in circular brick kilns about 10
feet in diameter and 20 feet high which were capable of treating approximately
40 tons of ore per day using 2 to 4 tons of fuel. Ore and fuel were charged in
alternate layers and combustion air was admitted through tuyeres around the
base. The shaft furnace, in which the charge was heated from external
fireboxes, was also used because it resulted in a product free from fuel ash.
Circular brick kilns and shaft furnaces were superseded by rotary kilns.
These rotary kilns consisted of a horizontally inclined steel cylinder sloped 2 to
4 percent of its length. The kilns were supported on rollers and rotated via a
pinion drive and large wheel attached to the shell of the kiln. Crude zinc oxide
was passed countercurrently to the heating gases. Fume and dust were pulled
through the kiln to a dust collection system using an induced draft fan. The
collection systems consisted of a mechanical collector/cooler and a baghouse or
an electrostatic precipitator.
Present Uses of Calcination
The few companies that continue to utilize calcination methods on zinc
materials have established that the multiple-hearth rabbling furnace is the most
satisfactory device for zinc calcination since dust carry-over is low, fuel
consumption is not excessive and maintenance costs are minimal. Refractory
lined rotary kilns are currently used to treat zinc oxide from fuming operations
where de-leading is practiced at temperatures above the generally accepted
figure for calcination.
One of the few remaining applications of calcination in the secondary
zinc industry is the treatment of zinc oxides from fuming operations. Zinc
galvanizing skimmings are melted down to remelt zinc and the fines emanating
from the remelt pot are collected and calcined to recover zinc oxide from the
zinc ammonium chloride used as a galvanizing flux. The product is used as an
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INDUSTRIAL GAS CLEANING INSTITUTE/INC.
additive in fertilizers and cattle feeds and as a raw material for chemical or
metallic zinc production.
Very little information has been published recently on zinc calcination
processes. C. H. Mathewson describes two foreign applications; one at the
Baelen plant of the Societe des Mines et Fonderies de Zinc de la Vieille
Montagne and the second at the Flin Flon, Manitoba plant of the Hudson Bay
Mining and Smelting Company. At the Baelen plant, 20 tons per day of zinc
oxides from slag reduction furnaces are treated in a six-hearth wedge furnace to
remove carbon and to complete the oxidation of the constituent elements. The
dust carry-over is less than 2 percent, practically all of which is recovered in a
standard baghouse. The Flin Flon plant treats 130 tons per day of zinc oxide
fume from the slag-fuming plant in two seven-hearth wedge furnaces to remove
chlorine, fluorine and sulfur dioxide. The calcined product is used to produce
zinc by the electrolytic process.
Air Pollution Control Equipment
Member companies of the Industrial Gas Cleaning Institute have no
record of recent gas cleaning installations in the secondary zinc calcining
industry. Because so few zinc calcining plants remain in operation in the United
States today, it is difficult to obtain data on air pollutants emitted from the
process. A detailed discussion of equipment for the recovery of particulates and
fume would not be relevant. Zinc oxide particulate emissions are characterized
by extremely small particle size. Gaseous emissions will depend on the type
of contaminants calcined from the zinc oxide. Operating conditions and
material of construction of zinc calcining gas cleaning equipment must be
selected with great care in order to minimize corrosion and chemical deterior-
ation inherent with many of these gaseous emissions.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
REFERENCES
1. Danielson, John A., "Air Pollution Engineering Manual",
NAPCA, Public Health Service Publication No. 999-AP-40
2. Mathewson, C. H., "Zinc — The Metal, Its Alloys and Compounds",
Reinhold, N.Y., 1959
3. Pomeroy, J. N. and Crowley, J. E., "Sources and Recovery of Scrap Zinc",
Metallurgical Extraction, Circulation 1959
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
7. AIR POLLUTION CONTROL FOR ALUMINUM CHLORINATION
STATIONS
a.
PROCESS DESCRIPTION
The secondary smelting of aluminum involves the removal of a variety
of impurities, both solid and gaseous. These are removed by the introduction of
a flux which reacts chemically with the impurities producing a phase which
separates from the hot melt. This discussion is concerned with the use of
chlorine as the fluxing agent.
The impurities in the aluminum may consist of "dirt" or solid
refractory oxides, gases (typically dissolved hydrogen) or metallic components,
such as magnesium which are present as alloying ingredients. The introduction
of chlorine by bubbling it through the melt, serves to agitate the bath, and at
the same time, combine with the impurities to produce a free vapor or an
insoluble dross which will float to the top.
During the fluxing process some of the aluminum reacts with the
chlorine to form AlClg which is readily sublimed from the melt. This is vented
from the furnace as a gas or rapidly hydrolized with the atmospheric moisture
present to form solid alumina, A^Og, and hydrogen chloride. The amount of
the AlClg production depends to a large extent on the amount of magnesium in
the melt which competes for the available chlorine producing a MgC^ dross.
The nearly complete elimination of fumes vented from the furnace
which include AICI-;
AI203,
HCI, and unreacted chlorine can be attained in
wet scrubbing equipment capable of both high energy impingement of the
submicron particulate and absorption of the gaseous components.
1)
MANUFACTURING ASPECTS
Furnaces generally used for fluxing are of 20,000 to 200,000 Ib.
capacity, completely enclosed, but having charging doors, side access doors,
and a roof vent used for natural draft ventilation of combustion products and
fumes. Gas or oil fired burners are used to melt the charge and maintain
temperature, but are normally turned off during chlorination. (Separate
reverberatory furnaces may be used for the melting and fluxing steps
permitting a semi-continuous operation.) The melting point of the aluminum
alloy is approximately 1220°F; however, the melt may be heated to 2000°F
and maintained in the molten state during chlorination due to the heat capacity
of the refractory lining and molten metal.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
The charge material may consist of foundry rejects or mill ends,
miscellaneous scrap, or pig aluminum. When the charge contains significant
amounts of oil, grease, or paint the problem of the production of a
carbonaceous smoke is present which can be treated by controlled oxidation.
This problem is not discussed here. Chlorine is normally introduced with
carbon lances extending through side ports in the furnace wall. Liquid chlorine
is metered into the lance which is submerged beneath the surface of the melt.
The bubbling action, produced mechanically, floats the solid impurities to the
surface where they are later skimmed as a dross. The chlorine combines with
dissolved hydrogen producing HCI which is vented through breeching to the
stack. Where separate melting and holding hearths are used, an initial
chlorination may take place in the melting hearth to remove the gross
impurities prior to transferring the melt to the holding hearth. For this
operation, a "wand" consisting of metal tube connected to the chlorine supply
is manually extended through one of the doors. The amount of chlorine
introduced at this time is normally a small fraction of the total used. Following
the chlorination, alloying material may be added to attain the desired metal
product.
The amount of chlorine used varies greatly, and is generally dependent
on the final magnesium content desired. Removing the last several tenths of a
percent of magnesium is a slow process, and large excesses of chlorine are used
to speed up the reaction. Chlorine rates may be equivalent to a total chlorine
consumption of from 5-40 Ibs. per 1000 Ibs. of metal over a period of from 20
minutes to several hours. Thus for example, it is possible to add as much as
1000 Ibs/hr of chlorine to a 100,000 Ib. melt for a period of 4 hours.
Following chlorination, the melt is removed from the furnace through a
trough and is cast into pigs, billets or a variety of miscellaneous shapes at a site
adjacent to the furnace. The time required for the entire sequence from
charging to casting is typically 24 hours. However, it may range from several
hours to several days depending on the nature of the overall operation. An
overall process flow scheme is sketched in Figure 26.
Nature of Air Pollutants
The introduction of chlorine into an aluminum bath presents some very
difficult air handling and fume elimination problems. The vent gases are at
temperatures from 500-2000°F, and contain both free chlorine and hydrogen
chloride gases. The gases must be quenched prior to scrubbing. This creates
metallurgical problems at the hot-cold and gas-liquid interface. The fume
generated is composed of sub-micron AlClg and A^Og. Hydrogen chloride is
-------
FLUE GAS
WATER
QUENCH
•COMBUSTION AIR
FUEL GAS OR OIL
CHLORINE
GAS
VENTURI
CONTACTOR
GAS
ABSORPTION
TOWER
MIST ELIMINATOR
ALUMINUM
PRODUCT
SURGE
TANK
CAUSTIC
TANK
Figure 26
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
produced in the furnace and in the quench chamber. This gas along with free
unreacted chlorine are in such quantities that a significant amount of gas
contaminant must be handled.
2)
AIR POLLUTION CONTROL
Submicron AlClg and A^Og produced in the chlorinating furnace
requires high pressure drop impaction in a wet scrubbing system. Significant
quantities of hydrogen chloride and chlorine require gas absorption using a
basic scrubbing liquor, normally NaOH. Therefore a system for storage, mixing,
control and disposal of the liquid stream is needed. This equipment is auxiliary
to the basic air handling equipment.
A fume control system for the elimination of both paniculate and
gaseous components can be designed and sized with knowledge of a few basic
furnace operating parameters.
Furnace Ventilation Requirements
Furnace vents and stacks are sized to remove the hot combustion gases
produced during maximum burner firing. During chlorination, the burners are
off and therefore the gas volumes and temperatures are much lower.
Calculations based on standard industrial ventilation techniques could be
performed where the exact condition of the furnace as regards doors, cracks,
temperatures, etc. are known. The best possible method of determining actual
ventilation requirement is on-site volumetric measurements taken downstream
of a damper which can regulate the flow. This damper should be adjusted to a
point where the desired furnace draft is obtained or where the furnace draft is
just sufficient to prevent chlorine from escaping through the doors into the
room during a period of maximum chlorine usage. The volume measured at this
time will be the minimum required. Of course, the temperature should be
determined concurrently.
Experience has provided some approximate volume flow rates for
various furnace sizes which may be used for estimation or where calculation or
measurement is difficult.
Holding Capacity, Ibs.
50,000
100,000
150,000
200,000
Ventilation
Volume, ACFM @ 1000°F
5,600
7,500
9,500
11,000
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
The above values may be considered reasonable for a "tight" furnace
i.e. with doors closed and with minimum leakage.
Contaminant Identity and Concentration
The major air control problem for chlorine fluxing furnaces is
collection of the submicron fume emitted during periods of high chlorine usage
and low magnesium content. The particulate entering the vent system may be
either AlClg or A^Og (or even some other aluminum compounds). On passing
through the cooling chamber the chloride is hydrolized, and it is reasonable to
consider all the aluminum entering the scrubber to be the oxide. Therefore,
differentiation between various aluminum compounds is an academic question.
According to the stoichiometry, a maximum of 47.9 Ibs. of A^Og are
produced for each 100 Ibs. of chlorine charged. Using this as a basis along with
the approximate ventilation requirement given above, it can be shown that the
maximum grain loading will be between 1 and 3 gr/SCF/100 Ib/hr chlorine
usage.
A similar analysis using stoichiometry may be used to calculate
maximum HCI emissions.
On-site testing during periods of chlorination will, of course, yield the
most reliable loading data. The test procedure of the IGCI with an impinger
followed by a fine porosity filter are recommended. The intent is to analyze for
total aluminum content through such methods as atomic absorption
spectroscopy, and present the results as AI203 (rather than attempting to
differentiate between various aluminum compounds which is a difficult and
unrewarding exercise). Quantities of HCI and C^ can also be determined by
suitable liquid absorption techniques using wet impingers.
The question of size distribution is again one that becomes academic,
and such determinations are always subject to doubt due to procedural
difficulties in obtaining the sample. This is true for most submicron material,
but is particularly true for A^Og - AlClg mixture since the AlClg has a
significant vapor pressure even at temperatures below its sublimation point.
Therefore, some of the gaseous AlClg will be condensing in any collection
device defying its size characterization. One of the most useful methods of
indicating size is to relate the difficulty of collection by the intended
mechanism (in this case impaction wet scrubbing) to a theoretical size. Thus if
a 40 inch pressure drop across a Venturi scrubber were required to collect 95%
of the Al+++ present, this could be related to a fictitious size which may be
defined theoretically.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
A miniature Venturi contactor has been used for on-site testing, and has been
successful in predicting the "apparent" mean size of the submicron particulate
present in aluminum fluxing furnace emissions.
The Abatement System
The items of process equipment shown in Figure 26 are discussed
below:
a) Cooling Chamber — Prior to entering the scrubber, the hot gases
must be cooled and saturated to reduce the volume and protect
the remainder of the system. Gas temperatures are between 500
- 1500°F, and are rapidly quenched to approximately the
adiabatic saturation temperature. Corrosion is severe in the
chlorine-free chloride, hot-cold, gas-liquid area of the quench
chamber. Typical construction may be of two general types:
one is a nickel alloy construction (Ni200, Incoloy 825, or
Hastelloy) which resists corrosion, is light in weight, and
requires a relatively small space requirement; the second is a
refractory acid brick construction which may be reinforced
structurally with a rubber lined steel shell.
b) Venturi Contactor — The cooled and saturated gases enter the
Venturi contactor where the particulate impinges on the
atomized water droplets. The Venturi may be constructed of
acid and chloride resistant materials, such as nickel alloys or
plastic materials. Plastic or rubber coatings must be able to
resist flaking, chipping or peeling in the high velocity throat
section and are generally not recommended. An atmospheric
damper is generally provided at the entrance to the venturi
section to permit draft control of the furnace.
c) Gas Absorption Tower — Adequate gas-liquid contact must be
provided to eliminate HCI and Cl 2- A caustic liquor is generally
required to absorb the C^ and also eliminate handling and
disposal of acid liquors. The small amounts of particulate
passing the Venturi and/or recirculating in the slurry
necessitates the tower be of a non-plugging type, either a spray
tower or mobile packed bed. The tower construction may be of
plastic or rubber lined construction.
d) Mist Eliminator — Normally this is integral with the scrubbing
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
tower for the elimination of liquid carryover. Again, it should
be of a non-plugging type such as a centrifugal collector.
e) Fans and Motors — The possibility of small amounts of
carryover and condensation necessitate the use of corrosion
resistant materials on all internal parts of the fans. Plastic or
rubber coatings on housings are common, and where tip speeds
are relatively low can also be used to coat the fan wheel. It is
often difficult to specify such low rpm, and stainless steel
wheels are necessary for medium ranges up to their top speed
limit. (Hastelloy wheels can be used at the higher speeds).
General practice is to limit the rpm to, say less than 2000, and
connect a number of fans in series to develop the necessary
static pressure. An inlet damper and fan drains should be
specified.
f) Stack — As the existing stack must be used to ventilate the hot
combustion product, it is generally unsuitable for the cold and
moist scrubber discharge. Plastic or plastic-coated steel is
generally used with heights normally just sufficient to rise above
roof lines.
g) Surge Tank — A tank having 2-3 minutes hold-up time at the
existing recirculation rate is desirable. It is, of course, important
to maintain enough caustic value in the recirculating system to
handle a complete chlorination cycle, and this may be the
overriding consideration for sizing the surge tank. Continuous,
controlled addition of caustic may eliminate this requirement.
Generally the slurry concentration accumulated over a
chlorination period is not a factor in tank sizing, but should be
investigated.
h) Recirculation Pump — Must be of suitable material to handle
alkaline and chloride containing liquor.
i) Caustic Storage Tank — A 50% sodium hydroxide solution is
available from suppliers and this eliminates the necessity of
handling and mixing solid material. The solution must be kept
above 75°F to prevent freezing, and therefore, provision should
be made for external heating of the tank and piping.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
j) Controls - In addition to the major items of equipment listed
above, the system must be ducted and piped to connect the
components. A variety of control schemes can be used to insure sufficient
addition of caustic to prevent failure due to presence of acidic liquor. pH
indication followed by manual or automatic, batch or continuous control is
required. Safety electrical interlocks are, of course, necessary to prevent
temperature excursions which could damage equipment. In all cases, an
emergency bypass to the combustion stack should be provided.
b. SPECIFICATIONS AND COSTS
The aluminum chlorination application is the only application for
which only one type of air pollution control equipment was considered
suitable. The high concentration of gaseous hydrogen chloride and chlorine
require the use of wet scrubbing to conform to good air pollution control
practice.
Although it is possible to provide good control by using a scrubber in
combination with a fabric filter or electrostatic precipitator, such combinations
are likely to be less economical. The specifications furnished the equipment
manufacturers to serve as a basis for their bid prices are written around a
scrubber alone.
The process description submitted as a part of the specification for the
scrubber installation is shown in Table 58. The operating conditions for
purposes of this quotation are summarized in Table 59. As in each of the
previous cases, the complete specification can be reproduced by inserting the
material in these two tables in the Sample Specification given in Appendix IV.
The equipment and installation costs submitted in response to these
specifications are summarized in Table 60 and Table 61. The former covers a
particulate emission regulation equivalent to the LA-Process Weight regulation,
while the latter produces a high particulate collection efficiency. There is likely
to be a noticeable particulate residual plume after the water plume has
dispersed in the lower efficiency case, whereas there should be little visible
emission other than water in the high efficiency case.
Both of the specifications are based on removal of particulate matter.
This is because the control of the submicron fume produced by the chlorine
fluxing operation is much more difficult than the absorption of HCI and C^ in
the alkaline liquor. Ordinarily either scrubber will produce good gas absorption
(over 99% efficiency) for the gaseous contaminants, and this need not be
specified separately.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 58
WET SCRUBBER PROCESS DESCRIPTION FOR
ALUMINUM CHLORINATION STATION SPECIFICATION
The aluminum chlorine fluxing furnace is used to produce a variety of alloy castings.
Charging stock is clean (non-oily) scrap consisting of mill ends, shavings, and miscellaneous
scrap extrusions of varying magnesium content. End product will have a magnesium content
of from 0.1 - 0.5 wt. % magnesium. Past experience has indicated that maximum chlorine
consumption is 20 Ib. per 1000 Ibs. of melt in a 2 hour period.
The furnace operation is such that a normal cycle lasts 24 hours — from charging to
casting. On an average 5 drops are made per week. Chlorination is performed in the holding
hearth with carbon lances inserted through ports located on the sides of the furnace.
Chlorination is not performed during furnace firing.
The furnace is vented through a port located at the middle of one side through a 30
ft. run of horizontal breeching to an 85' stack located outside of the building. At the stack
area is a 40' x 40' area available for new equipment installation, for which road access for
truck-size deliveries is available. A concrete slab designed for loads of 500 psi covers the
entire area. Electric power, steam, gas, and an abundant fresh water supply are available to
the area. Sanitary sewage will accept process water in the range of pH 4-10 providing that
solids content is less than 1% by weight.
Wet scrubbing equipment is required to reduce particulate and gaseous emissions to a
level according to local regulations and the attached table of operation. All materials of
construction to be consistent with the materials handled i.e., hot, wet, chlorine and chloride,
caustic, slurry, etc. Bids should include the following equipment:
(1) Quench chamber for cooling hot gases
(2) Wet scrubber including a venturi type contactor, a non-plugging gas
absorption tower, and mist eliminator
(3) Fans and motors to develop necessary static pressure. Fans shall be selected
which will operate at less than 2000 rpm and will be arranged in series.
(4) 85' self-supporting stack
(5) Recirculating tank
(6) 50% caustic storage tank
(7) Interconnecting ductwork and piping for all equipment furnished. Ductwork
shall begin at furnace-stack breeching
(8) Appropriate control: dampers, valves, motors, controllers, pH, safety
interlocks, etc.
With the exception of the scrubber proper, the above items are to be treated as
auxiliaries for quotation purposes.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 59
WET SCRUBBER OPERATING CONDITIONS FOR
ALUMINUM CHLORINATION STATION SPECIFICATION
Separate quotations are to be made for the following three conditions, and for each
efficiency level specified.
Small
Medium
Large
Furnace capacity, Ib.
Melting rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temp., °F
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet gas volume, ACFM
Outlet temperature, F
30,000
1,250
4,800
1,000
150
3.65
2,560
150
60,000
2,500
6,000
1,000
300
5.84
3,200
150
200,000
8,333
11,200
1,000
1,000
10.4
6,000
150
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 1 - LA Process Weight
3.19 4.64 8.93
0.15 0.17 0.19
97.9 98.5 99.0
Outlet loading, Ib/hr
Outlet loading, gr/ACF
Efficiency, wt. %
Case 2 — High Efficiency
0.44 0.55 1.03
0.02 0.02 0.02
99.7 99.8 99.9
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 60
Wet Scrubber Cost Data for
Aluminum Chlorination Station
(LA-Process Weight)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.% (For Particulates) *
Controlled Emission, gr /ACF (Part .) **
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment *
D. Waste Equipment
E. Other
Total
Installation Cost, $.
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance, $/year
Caustic
Labor
Part'1
WET SCRUBBER
SMALL
15
4,800
* 97.9
0.15
Misc. Sc:
1,000
40
14,000
40,000
3,900
6,100
64,000
58,000
78,000
10
•^ '?nQ
MEDIUM
30
6,000
98.5
0.17
•ap Al (no
1,000
60
15,800
47,500
4,300
8,100
75,700
66,000
88,000
10
ii\m
^ ann
LARGE
100
11,200
99.0
0.19
n-oily)
1,000
120
21,600
69,000
6,100
12,000
108,700
90,000
120,000
10
s!soo
* Spray Cooler
** HC1 and Cl£ Efficiencies are expected to be
99+% with 5% caustic liquor.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 61
Wet Scrubber Cost Data for
Aluminum Chlorination Station
(High Efficiency)
INFORMATION
Process Capacity, Ton/Day
Inlet Gas Volume, ACFM
Efficiency, Wt.% (For Particulates) *
Controlled Emission, gr/ACF (Part.)*
Type of Charge
Inlet Gas Temperature, F
System Horsepower
Equipment Cost, $
A. Collector
B. Auxiliaries
C. Gas Conditioning Equipment *
D. Waste Equipment
E. Other 50% Caustic tank § pump
Total
Installation Cost, $
A. Grass-Roots
B. Add-On
Expected Life, Years
Operating and Maintenance, $/year
1 Caustic
Labor
Part c
WET
SMALL
15
4,800
fe 99.7
* 0.02
Misc. £
1,000
70
14,000
49,300
3,900
6,100
73,300
60,000
80,000
10
5,000
6 000
3_ifi&5 .
SCRUBBER
MEDIUM
30
6,000
99.8
0.02
crap Al (i
1,000
100
15,800
58,500
4,300
8,100
86,700
68,500
90,500
10
4 '335
LARGE
100
11,200
99.9
0.02
ion-oily)
1,000
210
21,600
85,000
6,100
12,000
124,700
93,000
123,000
10
34,000
6 000
6.235 ,.
Spray Cooler
** Note: HC1 and Cl2 Efficiencies are expected to
be 99+% with 5 wt.% caustic liquor.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
c.
SUMMARY COMMENTS
The prices quoted for each of the two cases are plotted in Figures 27
and 28. It is apparent that the cost of the equipment and installation does not
increase sharply as the efficiency level increases. The power cost does go up
with increasing efficiency because the pressure drop is increased significantly.
It is interesting to note that the horsepower requirement is high, as is
the usual case for high energy scrubbers, but that the contribution this makes
to the overall operating cost is nominal because it only operates for about 20
hours per week. The annual cost may be estimated for the high efficiency 100
ton unit on the basis of 1c/kw-hr and 85% motor efficiency as follows:
210 HP x .746 x 20 x 52 x $.01 = $1628.00/year
Both the chemical and replacement parts costs exceed this figure by a
substantial margin.
In particular, the chemical cost is high. The consumption of caustic is in
direct proportion to the chlorine gas excess over the amount required to react
magnesium and other metals out of the solution. It is apparent that any action
which reduces the chlorine usage will also reduce the caustic consumption.
The ratio of system cost to scrubber cost is usually high for chemical
scrubbing systems. For the high efficiency, 100 ton installation, the system
equipment cost is five times the bare scrubber cost. On an installed basis, the
system cost is nearly ten times the cost of the scrubber.
Another significant item in the turnkey cost figures is the difference in
installation cost estimated for an add-on system as opposed to a new, or "grass
roots" smelter. There isn't enough room for convenient installation of a
scrubbing system in most secondary smelting plants. The additional cost
involved in locating fans, scrubbers, tanks, etc. far away from the furnace, or
on rooftop is indicated by the roughly $20,000 additional cost to install the
system in an existing plant.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
400
300
200
rt
o
o
o
tfl
rt
O
fi
H
•P
10
8
100
70
50
30
20
Figure 27
Wet Scrubber Cost Data for
Aluminum Chlorination Stations
(LA-Process Weight)
10
•H-H-H
iiffit
I
Turnkey Installation
for Grass Roots Plant
£:
Wet Scrubber
Auxiliary Equipment
Wet Scrubber
Only
15 30 100
«
Process Capacity, Ton/Day
200
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Figure 28
Wet Scrubber Cost Data for
Aluminum Chlorination Stations
(High Efficiency)
rt
O
a
•n
£
rt
t/>
3
O
O
u
400
300
200 -~
100
70
50
30
20
10
Turnkey Installation
for Grass Roots Plant
Wet Scrubber f,
Auxiliary Equipment
Wet Scrubber i
Only
10 15 30 100
Process Capacity, Ton/Day
200
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
c.
DISCUSSION OF COSTS
For each of the areas covered, with the exception of zinc calcination,
the cost estimates presented by the IGCI member companies form a reasonably
complete and consistent pattern.
1.
COMPARISON OF INSTALLED COSTS
The first costs may be generalized in two ways. The ventilation rate
specified in this study can be taken as a good estimate of the "proper" rate for
furnaces of various sizes. The cost of air pollution control equipment can be
read from the appropriate data plot as a function of furnace capacity. Or, the
costs may be generalized in terms of the cost per CFM of gas treated. This
provides the best basis for estimating costs but requires knowledge of the flue
gas rate for a particular furnace.
Both bases have been used to generalize capital costs collected in this
study. The two cautions suggested in previous sections must be repeated:
(1) Only very rough estimates of capital cost should be based on
the "cost — furnace size" relationships given here, for the ventilation
requirement may vary greatly from one furnace to another, even though both
have the same rated capacity.
(2) Capital costs based on actual gas flows are approximate at best.
Quotations from reputable manufacturers of equipment or competent air
pollution engineering specialists should be used in estimating the cost of a
particular installation.
COST VS. FURNACE SIZE
The "cost — furnace" size relationship is illustrated in the log—log plots
included in Section B. This relationship may be written mathematically as:
COST = k (SIZE) x
where:
COST = cost of installation in dollars
k = constant
SIZE = furnace size (usually in ton/day)
x = exponent
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
The costs obtained in Section B have been generalized to fit this
equation by assuming that a straight line (on log - log paper) between the
"small" furnace and the "large" one is an adequate representation of the
conditions in between. For most of the equipment types, this is a good
approximation.
The calculations were made for the constant and exponent in the cost
equation for three cases in each application area:
(1) Collector Only
(2) Total Equipment
(3) Total Installed Cost (new plant basis)
The "collector only" case represents the bare piece of control
equipment; a wet scrubber, fabric filter or precipitator, with no auxiliaries
whatever. It is usually impossible to use such a piece of equipment without the
installation of auxiliaries such as fans, pumps, dust handling conveyor, etc.
The cost of the "total equipment" includes the collector and those
items specified as auxiliaries in the descriptions written in Section B. It does
not include such things as foundations, ductwork, etc.
The "total installed cost" or turnkey cost represents the price a
contractor would ordinarily charge for a complete installation, with all
incidentals such as start up supervision included. For this study, the
"grass—roots" cost was used. This represents the cost which is associated with
installation of equipment without the space limitations and possible
interferences with installation that are characteristic of back-fit of equipment
into an existing plant.
This is not because the back-fit problems are less important than the air
pollution problems in existing plants. The choice was made only because of the
difficulty in setting meaningful ground rules as to how difficult a situation
should be assumed in the back-fit or "add-on" quotes. Some of the
manufacturers quoted no difference between the grass roots and add-on
installations. Others assumed a significant problem with "shoe horning"
equipment into an existing plant.
In general, the cost of add-on installations will exceed those for the
same equipment in a new plant. Differences of 20% additional for add-on
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
installations over the grass roots case are typical.
The calculated values for use in the cost equation are given in the
following tables:
Table 62
Table 63
Table 66
Table 68
Table 70
Table 72
Table 74
Rotary Lime Kilns
Brass/Bronze Reverberatory Furnaces
Lead Cupolas
Sweating Furnaces
Lead Reverberatory Furnaces
Aluminum Chlorination Stations
The rate of increase of cost with size is lower than generally assumed
for capital equipment. That is, while most installations are assumed to increase
in cost with the 0.6 power of size, the equipment covered here usually followed
a lower "power rule". This was particularly true for the electrostatic
precipitators. These are applied to lime kilns at the lower end of their
economical size range. Reducing the size of a very small precipitator does not
appear to reduce the cost much.
The exception to the generalization about low exponents are the wet
scrubbers. These are simple when built on a very small scale, and become more
complex as they get larger. These have an exponent of about 0.8 for the rotary
lime kiln scrubber. However, the total installed costs fit the generalization well.
One index often used in making budgetary estimates is the ratio of total
equipment cost to collector cost, or of turnkey cost to collector cost. These
ratios are helpful because of the ease with which "collector only" costs can be
estimated, and the difficulty in obtaining good estimates of the turnkey cost.
For each of the tables listed, these ratios have been calculated and tabulated.
COSTS PER CFM
Costs of equipment and installation are often quoted as a number of
dollars per CFM. For electrical precipitators and fabric filters, it is customary
for the manufacturers to use the ACFM at the collector inlet as the basis for
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
this index, while wet scrubber manufacturers use the saturated ACFM at the
scrubber outlet.
In order to put this figure into a consistent form for comparison of the
costs, the cost/SCFM has been used in this section. The ratios quoted can be
converted to an ACFM basis by multiplying $/ACFM = ($/SCFM) (530/T +
460) where T is the gas temperature in degrees F at the collector inlet.
Scrubber manufacturers should be given the gas conditions (including moisture
content) at the scrubber inlet when they are asked for price information. They
will calculate the wet gas volume at the scrubber outlet to use in sizing the
scrubber.
The cost/SCFM ratios for the application areas covered in this report
are given in the following tables:
Table 64
Table 65
Table 67
Table 69
Table 71
Table 73
Table 75
Rotary Lime Kilns
Brass/Bronze Reverberatory Furnaces
Lead Cupolas
Sweating Furnaces
Lead Reverberatory Furnaces
Aluminum Chlorination Stations
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 62
Derived Cost Indicies for Rotary Lime Kilns
(Precipitator)
COLLECTOR TYPE
ELECTROSTATIC PRECIP.
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 24500 ACFM)
MEDIUMC 59500 ACFM)
LARGE C 105000 ACFM)
ELECTROSTATIC PRECI.P
LA-PROCESS WEIGHT
COLLECTOR ONLYCA)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL ( 24500 ACFM)
MEDIUMC 59500 ACFM)
LARGE (105000 ACFM)
K"
16501
20577
26138
-
7393
12257
14978
-
X"
.29*1
.395
.437
-
.398
.462
.514
-
P. /A **
-
2.028
2.286
2.332
-
2.250
2.430
2.456
C/A**
-
3.155
3.660
3.846
_
3.5^6
3.995
4.165
C/[i**
-
1.556
1.601
1.649
.
1.576
1.644
1.696
* For use in equation COST = K • (SIZE, ton/day)*
** B/A == Cost of total equipment/cost of collector only
C/A = Turnkey cost/Cost of collector only
C/B = Turnkey cost/Cost of total equipment
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 63
Derived Cost Indicies for Rotary Lime Kilns
(Fabric Collector and Scrubber)
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL ( 20000 ACFM)
MEDIUMC 50000 ACFM)
LARGE ( 90000 ACFM)
WET SCRUBBER
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 35000 ACFM)
MEDIUMC 85000 ACFM)
LARGE (150000 ACFM)
WET SCRUBBER
LA-PROCESS WEIGHT
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEYCO
SMALL C 35000 ACFM)
MEDIUMC 85000 ACFM)
LARGE (150000 ACFM)
K"
4760
10131
20016
-
270
837
• 5977
-
115
267
5158
-
X-"
.500
.463
.444
-
.022
.691
.517
-
.856
.872
.557
-
B/A ""
-
1.7«3
1.738
1.695
-
1.647
1.488
1.374
-
2.507
2.280
2.564
C/A""
-
3.206
3.062
2.966
-
5.066
4.058
3.318
-
10.549
8.364
6.966
/* i p •• «•
L/ ()•»«»
-
1.798
1.762
1.750
-
3.076
2.727
2.415
-
4.208
3.668
2.717
For use in equation COST = K • (SIZE, ton/day)*
B/A = Cost of total equipment/Cost of collector only
C/A = Turnkey cost/Cost of collector only
C/B = Turnkey cost/Cost of total equipment
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 64
Cost per SCFM* for Rotary Lime Kilns
COLLECTOR TYPE
ELECTROSTATIC PRECIP.
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY""
ELECTROSTATIC PRECIP
LA-PROCESS V.'EIGHT
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY «»
SMALL
11194
6.09
12.35
19.22
11191*
^1. 52
10.17
16.03
MEDIUM
27185
2.92
6.68
10.69
27185
2.38
5.78
9.49
LARGE
47974
2.14
4.98
8.22
47974
1.83
4.50
7.63
;BASED ON SCFM CAT YOF, INCLUDING M20) AT COLLECTOR INLET
:FOR GRASS ROOTS INSTALLATION
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 65
Cost per SCFM* for Rotary Lime Kilns
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY s»!
WET SCRU3BER
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY !CX
WET SCRUBBER
LA-PROCESS WEIGHT
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY'"!
SMALL
10495
5.07
9.05
16.27
11175
1.28
2.11
6.48
11175
.64
1.62
6.80
MEDIUM
26238
2.87
4.98
8.78
27139
.95
1.41
3.86
27139
.48
1.10
4.04
LARGE
47228
2.26
3.82
6.69
47892
.93
1. 28
3.10
47892
.49
1.26
3.43
:BASED ON SCFM (AT 70F, INCLUDING H20) AT COLLECTOR INLET
:FOR GRASS ROOTS INSTALLATION
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 66
Derived Cost Indicies for Brass/Bronze Reverberatory Furnaces
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 2200 ACFM)
MEDIUMC 5500 ACFM)
LARGE C «250 ACFM)
WET SCRUBBER
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 3320 ACFM)
MEDIUMC 0150 ACFM)
LARGE C 12200 ACFM)
WET SCRUBBER
LA-PROCESS WEIGHT
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 3320 ACFM)
MEDIUMC H150 ACFM)
LARGE C 12200 ACFM)
K»
2969
6094
130«5
_
-
614
7792
25164
_
-
567
5491
50475
-
-
"
X-
, .431
.460
.419
_
-
.712
.424
.426
_
-
.728
.449
.101
-
- •
"
3/A""
-
-
—
2.236
2.199
-2.327
- .
-
—
5.362
3.537
3.598
-
-
-
4.193
3.257
2.845
C/A::::
-.
-
—
4.255
4.190
4.186
-
: -
—
17.389
11.403
11.691
-
-
-
13.5«6
10.568
5.691
C/B"5
-
-
—
1.903
1.905
1.799
-
1 -
i
3.243
3.246
,3.250
i
1 -
-
—
i
3.240
3.244
2.000
For use in equation COST = K - (SIZE, ton/day)x
B/A = Cost of total equipment/Cost of collector only
C/A = Turnkey cost/Cost of collector only
C/B = Turnkey cost/Cost of total equipment
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 67
Cost per SCFM* for Brass/Bronze Reverberatory Furnaces
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY""
WET SCRUBBER
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY^"
WET SCRUBBER
LA-PROCESS WEIGHT
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY •""
SMALL
1597
6.76
15.12
28.77
715
7.24
33.83
125.93
715
7.03
29.45
95.44
MEDIUM
3993
3.87
8.52
16.23
1756
20 ill
65.27
1756
5.63
18.35
59.52
LARGE
5990
3.28
7.63
13.72
2628
5.29
19.03
61.83
2628
5.25
14.93
29.87
'BASED ON SCFM (AT 70F, INCLUDING H20) AT COLLECTOR INLET
!FOR GRASS ROOTS INSTALLATION
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 68
Derived Cost Indicies for Lead Cupolas
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENTCB)
TURNKEY(C)
SMALL C 5000 ACFM)
MEDIUMC 10000 ACFM)
LARGE ( 20000 ACFM)
WET SCRUBBER
HIGH EFFECIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C) .
SMALL C 3675 ACFM)
MEDIUMC 7350 ACFM)
LARGE ( 14700 ACFM)
WET SCRUBBER
LA-PROCESS WEIGHT
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
lURNKEY(C)
SMALL C 3675 ACFM)
MEDIUMC 7350 ACFM)
LARGE C 14700 ACFM)
K"
3437
5136
. 9046
-
52«
12109
39460
-
502
7197
23455
-
X-
.512
.4«2 .
• .'1Kb
-
.70h
.320
.319
-
.706
.404
.403
-
R/A"X
-
1.387
1.400
1.329
-
B.7B5
6.905
5.064
- -
6.774
5.930
4.405
C/A""
-
2.4S3
2.531
2.401
-
2«.b«y
22.607
16.46^
-
22.U16
19.239
14.291
. «» \f
' C/B""
I
: 1.790
l.«0tt
1.B07
-
, 3.25^4
3.286
^.252
-
3.250
3.244
3.245
For use in equation COST = K • (SIZE, ton/day)x
B/A = Cost of total equipment/Cost of collector only
C/A = Turnkey cost/Cost of collector only
C/B = Turnkey cost/Cost of total equipment
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 69
Cost per SCFM* for Lead Cupolas
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY "'!
WET SCRUBBER
HIGH EFFECIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY"'"
WET SCRUBBER
LA-PROCESS WEIGHT
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY'S "
SMALL
3630
3.38
4.68
8.38
2029
1.50
13.21
42.98
2029
1.43
9.68
31.47
MEDIUM
7260
2.32
3.24
5.86
4058
1.04
7.18
23.59
4058
.99
5.88
19.06
LARGE
14521
1.75
2.33
4.21
8116
1.03
5.21
16.94
8116
.98
4.31
13.98
CBASED ON SCFM. CAT 70F, INCLUDING H20) AT COLLECTOR INLET
!FOR GRASS ROOTS INSTALLATION
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 70
Derived Cost Indicies for Sweating Furnaces
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY .
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL ( 15400 ACFM)
MEDIUMC 30800 ACFM)
LARGE ( '16200 ACFM)
wET SCRUBBER
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL ( 42500 ACFM)
MEDIUMC 85000 ACFM)
LARGE (127500 ACFM)
K«
1124
5006
. 9760
_
-
-
4133
6688
8497
«.
-
^
X"
.892
.948
.948
_
'-
-
.514
.768
.797
_
-
™ *
** **
B/A'"
-
-
-
5.253
ij.bia
5.586
-
-
-
3.^30
'4.819
4.535
** «»
C/A""
-
-
-
9.194
9.8^2
9.776
-
-
-
4.756
6.678
6.496
C/ffc"
-
-
-
1.750
l.YljU
1.7bu
i
-
-
-
,1.387
1.386
1.433
For use in equation COST = K • (SIZE, ton/day)x
B/A = Cost of total equipment/Cost of collector only
C/A = Turnkey cost/Cost of collector only
C/B = Turnkey cost/Cost of total equipment
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 71
Cost per SCFM* for Sweating Furnaces
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY-"
WET SCRUBBER
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY*::
SMALL
X1196
1.36
7.16
12.5^
11492
1.64
5.63
7.80
MEDIUM
22992
1.21
6.80
11.91
22985
1.05
5.08
7.03
LARGE
34487
1.21
6.76
11.84
34477
.96
4.36
6.24
"BASED ON SCFM (AT 70F, INCLUDING H20) AT
"FOR GRASS ROOTS INSTALLATION
COLLECTOR INLET
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 72
Derived Cost Indicies for Lead Reverberatory Furnaces
COLLECTOR TYPE
FABRIC COLLECTOR
HIGH EFFICIENCY
COLLECTOR ONLYCA)
TOTAL EQUIPMENT(B)
TURNKEYCC)
SMALL C 5000 ACFM)
MEDIUMC 10000 ACFM)
LARGE ( 20000 ACFM)
WET SCRUBBER
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 5000 ACFM)
MEDIUMC 11BOO ACFM)
LARGE C 23600 ACFM)
WET SCRUBBER
LA-PROCESS WEIGHT
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEY(C)
SMALL C 5000 ACFM)
MEDIUMC 11800 ACFM)
LARGE C 23600 ACFM)
K"
1160
3931
. 6880
-
10794
49851
72815
-
7528
34273
66078
-
X"
.795
.816
.816
-
.119
.100
.088
-
.269
.330
.305
-
B/A!{"
-
3.557
3.734
3.680
-
4.415
4.493
4.279
-
5.236
5.487
5.773
C/A"-
-
6.226
6.536
6.440
-
5.275
6.352
5.965
-'
9.521
9.823
10.079
C/B::"
-
1.750
1.750
1.750
-
1.421
1.414
1.394
-
1.819
1.790
1.746
For use in equation COST = K • (SIZE, ton/day)x
B/A = Cost of total equipment/Cost of collector only
C/A = Turnkey cost/Cost of collector only
C/B -Turnkey cost/Cost of total equipment
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 73
Cost per SCFM* for Lead Reverberatory Furnaces
COLLECTOR TYPE
FABRIC COLLECTOR.
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY55"
WET SCRUBBER
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY "•'
WET SCRUBBER
LA-PROCESS WEIGHT
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY'"*
SMALL
3630
1.99
7.09
12.42
2760
5.14
22.71
32.28
2760
5.07
26.55
48.29
MEDIUM
7260
1.79
6.70
11.72
6515
2.18
9.79
13.85
6515
2.43
13.31
23.82
LARGE
14521
1.79
6.60
11.55
13029
1.32
5.65
7.87
13029
1.66
9.57
16.71
-BASED ON SCFM CAT 70F, INCLUDING H20) AT COLLECTOR INLET
"FOR GRASS ROOTS INSTALLATION
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 74
Derived Cost Indicies for Aluminum Chlorination Stations
COLLECTOR TYPE
V/ET SCRUBBER
HIGH EFFICIENCY
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEYCO
SMALL ( 4800 ACFM)
MEDIUMC 6000 ACFM)
LARGE ( 11200 ACFM)
WET SCRUBBER
LA-PROCESS WEIGHT
COLLECTOR ONLY(A)
TOTAL EQUIPMENT(B)
TURNKEYCO
SMALL C 4800 ACFM)
MEDIUMC 6000 ACFM)
LARGE C 11200 ACFM)
K"
7539
34332
66182
_
-
— *
7539
30047
60809
_
-
™
X"
.229
.280
.259
«
-
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 75
Cost per SCFM* for Aluminum Chlorination
COLLECTOR TYPE
WET SCRUBBER
HIGH EFFICIENCY
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY'?::
WET SCRUBBER
LA-PROCESS WEIGHT
GAS FLOW, SCFM
COLLECTOR ONLY
TOTAL EQUIPMENT
TURNKEY5'"
SMALL
1742
8.03
42.07
76.50
.
1742
8.03
36.73
70.02
MEDIUM
2178
7.25
39.81
71.26
2178
7.25
34.76
65.06
LARGE
4066
5.31
30.67
53.54
4066
5.31
26.74
48.87
:BASED ON SCFM (AT 70F, INCLUDING H20) AT COLLECTOR INLET
:FOR GRASS ROOTS INSTALLATION
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
2.
DISCUSSION OF OPERATING COSTS
Several examples of cost calculations were made in Section B using the
total annual cost of an air pollution control installation as the total of:
(a) Capital Charges (including depreciation, taxes and insurance)
(b) Utilities
(c) Maintenance Materials
(d) Maintenance Labor
The first cost of equipment is often considered to the exclusion of the
long term cost of owning and operating a system. In order to make a good
estimate of the total annual cost, each of the items listed must be considered.
(a) Capital Charges may be figured according to the normal practice
of the user of the equipment. One method, used in Section B, is as follows. The
total annual capital charge is the sum of
(1) the current interest rate on borrowed money, i.e. (say
10% per year)
(2) the sinking fund depreciation charge, S
s = E/D
S = sinking fund depreciation
charge, $/year
P = initial cost, $
i = interest rate (fraction)
n = number of years life
(3) an allowance for taxes and insurance (say 3% per year)
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
For precipitators and fabric collectors which are free of corrosion
problems, the most often quoted life for the equipment was 25 years.
Scrubbers, on the other hand, were usually quoted at ten years expected life.
(b) Utilities Costs consist mainly of the costs of running the fans
that overcome the pressure loss through the collector, plus minor costs for
pump drives, solids handling equipment, and precipitator power supply.
In the case of fabric filters and scrubbers the utilities cost may be
estimated on the basis of quoted system horsepower as illustrated in Section B
for the rotary lime kilns and lead/aluminum sweating furnaces.
Fan horsepower is set by the gas flow rate through the fan and the
pressure loss. It may be approximated by:
BMP =
Fx AP (62.4
33,000 x E V 12
where:
BMP = Brake horsepower
F - Flow, ACFM
AP = Pressure loss, in wg
E = Fan Efficiency
The horsepower requirement was quoted by the manufacturers of the
equipment in Section B. Average figures are listed for each application for the
high efficiency case below:
Rotary Lime Kiln
Brass/Bronze Reverb.
Lead Cupola
Sweating Furnace
Lead Reverb.
Zinc Calcination Furnace
Aluminum Chlor.
ESP
40.5
Fabric
Filter
150
48
34
100
30
Wet
Scrubber
140
90
98
450
150
100
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
These may be scaled up or down in direct ratio to the size of the
installation for estimating purposes.
(c) Maintenance Materials are relatively minor for electrical
precipitators and are nominal for scrubbers. The principal item in this category
is the cost of replacement bags for fabric collectors. This item is large in
comparison to all other maintenance charges against the collectors. It is
frequently quoted as the total maintenance charge for fabric filters.
The maintenance charges for bag replacement are a linear function of
the size of the installation, while maintenance charges for other parts — fan
wheels, for example — should be more nearly proportional to the square root
of the size.
The aluminum chlorination station alone among the applications
covered here has a chemical consumption cost. This should vary with the
amount of unreacted chlorine vented rather than with the furnace capacity.
For a rough estimate of chemical costs, all of the chlorine injected may be
assumed to leave the furnace as HCI and react with caustic in the scrubber
according to:
HCI + NaOH -> NaCI + H20
This reaction requires almost exactly one pound of caustic per pound
of chlorine.
(d) Maintenance Labor is nominal for most air pollution control
equipment. Routine cleaning and inspection are necessary for good
performance of any type of equipment, and should not be overlooked for air
pollution control systems. Scrubbers, in particular, require frequent inspection
to determine that the nozzles are open and that no plugging or clogging of mist
eliminators has taken place. Fan wheels on fans located downstream of
scrubbers require especially frequent attention.
Fabric collectors require attention to insure that the bags are intact and
shaker or back blow mechanisms functioning properly. While the manhour
figure is not broken out in most of the estimates, 80 to 160 hours per year
should be sufficient. An allowance of 1/2 hour per bag replacement is
adequate.
Wet scrubbers vary in time requirements from nearly "maintenance
free" in a lime kiln application to "requiring frequent inspection and cleaning"
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
in aluminum chlorination. Maintenance involves frequently washing out the
fans and connecting ductwork, washing out and inspecting the entrainment
separator and body of the scrubber and inspecting piping, pumps and tanks for
chloride corrosion. Requirements might run as high as 200-400 hours per year
for the worst circumstances.
Total of maintenance parts and labor was accumulated below by taking
labor cost at $6.00/hr. where labor was broken out separately.
Cost in Dollars per Year
Rotary Lime Kiln
Brass/Bronze Reverb.
Lead Cupola
Lead Alum. Sweat
Lead Reverb.
Aluminum Chlorination
ESP
480
Fabric
Filter
18000
7776
4563
Wet
Scrubber
5600
600
600
1728
6000
The costs given here may be used as first approximations for planned
equipment installations. The costs can vary greatly from one plant to another,
and final equipment selection decisions should be based on estimated operating
costs furnished by a competent manufacturer or engineer.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
D.
INSTALLATION AND TEST DATA
All of the IGCI member companies were asked to participate in this
program by summarizing their past installation data (since January 1, 1960).
Also, any performance test information relating actual operation to design
conditions was requested. The forms used for this solicitation are shown in
Table 76. Detailed instructions for completing them are given in Appendix VI.
Twelve of the member companies actually had installations to report.
Of the companies reporting installations, seven were most active in the rotary
lime kiln area. The remainder of the application areas were reported by only
two or three companies in most cases.
The returns proved quite limited in another respect. For some of the
application areas, relatively small, inexpensive fabric filters have been found
acceptable. These devices generally perform at a high efficiency level (>99.5%)
and produce a clear effluent. For this reason they are often installed without an
efficiency guarantee, and accepted without performance tests. In this
circumstance, little performance data is obtained. However, the compilation of
the installation and test data does provide some interesting insights into the
pattern of application, the sizes of the units installed, etc.
In each of the following sections, the data on the forms returned by the
member companies is abstracted and discussed. The complete data contained
on the forms is given in a table at the end of each section.
1.
ROTARY LIME KILNS
More applications were reported for rotary lime kilns than for all the
other application areas combined. Table 77 lists the distribution of these
applications by year and collector type. Table 78 gives the capacity of the
installations in terms of the ACFM at the collector inlet. It was not possible to
list these by kiln capacity (in ton/day lime production) because in most of the
cases the kiln size was not known by the supplier of the air pollution control
equipment. All of the installations and the test data reported are listed in Table
82.
For most of the applications, no test data was secured. There was
usually a guaranteed or represented efficiency reported however, and the few
test results given indicate performance at, or slightly better than, the
represented efficiency. In many cases there was no performance representation,
or a relatively conservative one in terms of the known capability of the
-------
N)
s
Table 76
Sample
SUMMARY OF INSTALLATION DATA
SOURCE:
Page 1
(1)
TEST
NO.
(2)
CAP.
OF
UNIT
(3)
TYPE OF RAW 1
MATERIAL OR
CHARGE
(4)
FUEL2
USED
(5)
TYPE3
COLLECTOR
(Sa)
YEAR
PLACED
IN
SERVICE
(6)
GAS
VOLUME
ACFM
(7)
INLET
TEMP.
°F
(8a) (8b)
MEASURED
DUST LOADING
GR/ACF
INLET
OUTLET
(9)
DESIGN
EFF.
WT. %
(10)
IS4
PLUME
VISIBLE
1. The composition of the raw material or charge should be presented on a wt.% basis.
2. The type of fuel used in firing should be presented. Report sulfur and ash content of coal.
3. Describe the type of collector. Examples: Venturi-30" w. c.;Fabric Filter, Orion BagsjESP, Area.
4. Is the plume visible after collection? Answer yes or no here. If yes, an explanation as to time
-------
Table 76
Sample
SUMMARY OF INSTALLATION DATA
SOURCE:
Page 2
(1)
TEST
NO.
§
(11)
PARTICLE
SIZE
M.
<
>
WT.%
IN
RANGE
METHOD
OF
ANALYSIS
(12)
RESISTIVITY
OHM -CM
RESIST.
TEMP . F
METHOD.
OF
ANALYSIS
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
WT.%
(14)
CHEMICAL
COMP. OF
GAS
COMP .
VOL.%
(15)
REMARKS
NOTE
5
5. Remarks which might serve to clarify or enhance the value of the reported data should be
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 77
Number of Rotary Lime Kiln Installations
By Year Placed in Service
Year
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
Total
Fabric
Filters
—
—
3
1
4
1
4
2
t
—
3
18
Wet
Scrubbers
2
—
1
2
1
9
5
4
2
2
7
35
ESP
—
—
—
—
—
—
2
2
—
1
5
Mechanical
3
1
—
2
2
3
2
5
2
1
—
21
Total
5
1
4
5
7
13
13
11
6
3
11
79*
*IMOTE: Table 82 lists 78 installations. Twin precipitators were counted
as two installations here, but show as a single entry in Table 82.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 78
Total Gas Volume from Rotary Lime Kilns
by Year of Installation
(thousands of AC FM)
Year
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
Total
Fabric
Filters
—
—
171
83
200
115
560
190
—
—
379
1698
Wet
Scrubbers
101
—
65
96
37
389
265
213
155
296
416
2033
ESP
—
—
—
—
—
—
294
—
237
—
50
581
Mechanical
Collectors
160
91
—
35
56
103
72
289
73
36
—
915
Total
261
91
236
214
293
607
1191
692
465
332
845
5227
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 79
Efficiency Representations Available From
Equipment Manufacturers for
Rotary Lime Kilns
Year
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
Fabric
Filters
—
—
99+
99+
99.5
—
—
99+
—
—
99.5
Wet
Scrubbers
—
—
95
99
99
99
99
99.3
99-99.9
99.6
99-99.6
ESP
—
—
—
—
—
—
—
—
99.7
—
99.8
Mech-
anicals
—
88
—
—
—
—
96
96
—
—
—
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
equipment type. For this reason, neither the average efficiency levels
represented or the average performance test results are tabulated. However, a
meaningful pattern becomes apparent when the highest efficiency levels for
which equipment was being designed are considered. Table 79 lists these
efficiencies for each type of equipment for each year covered by this study.
There has been little change in the level of efficiency quoted for fabric
collectors since 1960. They are most frequently quoted as "99 plus" percent
efficient, with the tacit understanding that the efficiency should be close to
100% if the bags are intact. Occasionally the representation is changed to
99.5%, but this does not represent a change in design or expected performance.
No tests were run to substantiate the high efficiency of fabric collectors in lime
kiln service, but whenever observations of the effluent were made, it was
reported to be clear. This indicates an effluent grain loading less than 0.03
gr/ACF or 0.05 gr/SCF.
There has been a relatively flat trend in usage of fabric collectors for
lime kilns over the 10 year period.
Wet scrubbers have accounted for more installations than any other
type of collector, and nearly as many as all the others combined. The number
of installations has increased steadily from year to year with the exception of
1968 and 1969. During these years, little equipment of any kind was installed.
A pattern of efficiency representations apparently started to form in
1960 or 1961. This resulted in scrubber installations with a nominal guaranteed
efficiency of 95% in 1962. The efficiency representation increased to 99% in
1963 and 1964, and has risen to about 99.6% for recent installations. Test data
substantiates the high efficiencies represented. Frequently the scrubber outlet
grain loading is represented rather than an efficiency. An outlet loading "less
than 0.05 gr/SCF" is typical. This is a more meaningful representation than the
collection efficiency but requires a knowledge of the dust loadings and
properties of the dust which may not be available to the manufacturer.
Frequently such representations are based on pilot unit operation or experience
with similar installations.
Several additional comments are in order with respect to reported
scrubber efficiency. Scrubbers, like mechanical collectors, are inherently
size-selective. They capture large particles more easily than small ones. For this
reason, the inclusion of a mechanical separator, such as a cyclone or settling
chamber, in the process ahead of the scrubber will reduce the "efficiency" of
the scrubber even though the performance of the system may be improved.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Some of the scrubbers reported in this study had mechanical separation devices
ahead of them to reduce the particulate loading, so efficiencies reported are not
directly comparable.
Another qualification peculiar to the scrubber performance reported
involves the formation of a steam plume. The gases enter the scrubber at a
relatively high temperature. They leave at the saturation temperature which is
typically between 140 and 170°F, with a high concentration of water vapor.
This condenses upon mixing with ambient air to form a steam plume. The
steam plume is opaque and may mask a particulate load which would otherwise
be visible. The masking effect persists for a short distance as the plume is
dispersed into the atmosphere, and hidden particulate matter may become
visible as the water plume dissipates. The companies reporting scrubber
applications described the plume as "visible" if there was an appearance of
particulate solid after dissipation of the steam plume. For most of the scrubber
installations there was no visible particulate solid but there was a dense steam
plume.
Electrostatic precipitators have been applied to lime kilns to a limited
extent. Only four applications are listed for this period. There is no real pattern
of efficiency representations, but it appears that the precipitators have been
offered for either 99.7% efficiency or less than 0.05 gr/ACF. The average
precipitator handled almost twice as much gas as the average scrubber or filter,
even though the kiln sizes were comparable.
Mechanical collectors were not considered to be satisfactory devices for
lime kilns except in combination with other units. However, 21 installations of
mechanical collectors were reported over the 10 year period. These were
generally used for smaller gas flows than any of the other equipment types, and
they were generally operated at a higher temperature.
Most frequently the mechanical collectors were sold on the basis of an
"efficiency curve" which related expected efficiency to the particle size range
for the dust. No explicit efficiency was represented. For a few cases the
efficiency was established in absolute terms, with 96% as the highest
represented.
The application of mechanical collectors apparently reached a peak
around 1967 and declined subsequently.
Several tests were run to substantiate performance of the mechanical
collectors. From this data, the gas composition and dust properties are listed in
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
Table 80. One complete precipitator test furnished the dust resistivity listed in
Table 81.
Table 82 contains a complete listing of the rotary lime kiln installation
data.
-------
Table 80
Properties of Rotary Lime Kiln Dusts
From Mechanical Collector Tests
(All Analyses for Particle Size by Bahco)
Test No.
Grains/ACF
Particle Size
> 40 y
< 40 > 30
< 30 > 20
< 20 > 10
< 10 > 5
< 5
Temp., °F
ACFM
Gas Comp,
Mol %
o2
09
c62
H20
Specific
Gravity
Fuel Used
Collection
Efficiency
AP in wg
26
7.60
40.0
5.9
7.6
17.5
14.0
15.0
827
90843
2.77
NA
88
5.0
6
5.34
47.0
6.0
7.0
15.0
9.0
16.0
831
91718
67.1
7.5
18.6
6.8
2.74
NA
82
5.0
22
0.94
89.4
1.4
1.9
2.3
1.6
3.4
650
25000
58.3
5.1
14.4
22.2
NA
NA
97.0
5.3
33
0.64
89.4
1.4
1.9
2.3
1.6
3.4
650
25000
58.5
5.1
14.4
22.0
2.9
CO
Gas
97.5
2.6
35
2.17
19.5
8.5
14.0
23.8
16.2
18.0
440
52800
72.9
14.8
7.9
4.4
3.02-3.08
CO
Gas
92.23
13
35
2.40
23.2
8.8
13.0
19.0
15.0
21.0
440
52800
—
3.02-3.08
CO
Gas
93.87
13
41
0.646
16.5
5.5
11.5
29.5
22.0
15.0
395
69600
59.0
10.2
9.4
21.4
2.72
Nat.
Gas
96.86
—
63
—
63.5
5.5
7.0
9.0
6.0
9.0
722
42511
65.4
11.9
12.3
10.4
2.73
NA
95
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Table 81
Electrical Resistivity of Dust
From 50 T/D Rotary Lime Kiln
Inlet Conditions
Temp.,°F
Flow, ACFM
Loading gr/ACF
Fuel
Particle Size Distribution by Bahco,
< 40
< 20
< 10
< 5
20
10
5
3
y
y
y
y
Resistivity, ohm - cm
at 15% Moisture
in Gas
160
230
270
380
450
R
2.4 x 10 7
7 x 108
3.4 x 10 9
2.3 x 10 11
4.6 x 10 11
530
235,000
% 3.0
Natl. Gas
23
24
17
7
at 25% Moisture
in Gas
140
220
270
300
370
420
450
R
5.8 x 10 7
5.6 x 10 9
3.7 x 10 10
6 x1010
1.9x 10"
2.2x1011
1.0x 1011
-------
NO
O
Table 82
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
I
2
3
4
5
6
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
200
148
768
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Limestone and
Dolomite
Limestone
Limestone
Limestone
Dolomite
(4)
FUEL
USED
NA**
Coal
and
Oil
NA
NA
NA
NA
(5)
TYPE
COLLECTOR
Cyclone
2.3"wg
Cyclone
L.7-3.3"wg
Cyclone
2.2-3.1"w
Dynamic **
Scrubber
Dynamic
Scrubber
Cyclone
(5a)
YEAR
PLACED
IN
SERVICE
1960
1960
1960
g
* 1960
1960
1961
(6)
GAS
VOLUME
ACFM
20,200
120,000
20,000
50,700
(NA)*
50,700
(NA)
90.843
91.718
(7)
INLET
TEMP.
°F
750
600
750
400
900
(NA)*
900
(NA)
827
831
(8a) (8b)
MEASURED
DUST LOADING
gr /ACF
INLET
NA
5.0
NA
2.81-
2.89
2.37-
2.84
7.60
5.34
OUTLET
NA
NA
NA
0.071-
0.08
0.052-
0.058
1.00
1.04
(9)
DESIGN
EFF.
WT. %
F.E.
Curve
F.E.
Curve
F.E.
Curve
0.2
gr/ACF
0.2
gr/ACF
ACT.
88
82
(10)
IS
PLUME
VISIBLE
NA
NA
NA
NO
NO
YES
*For wet scrubbers, the second flow and temperature at saturation conditions.
**NA — Is used where data is either "not available" or "not applicable".
-------
Table 82 - continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
7
8
9
10
11
12
(2)
CAP.
OF
UNIT
T/D
NA
225
NA
NA
500
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Limestone
Limestone
Limestone
Limestone
Limestone
(4)
FUEL
USED
Nat'l
Gas
Gas
NA
NA
Coal
Nat'l.
Gas
(5)
TYPE
COLLECTOR
Dynamic
Scrubber
Fabric
Filter
Fabric
Filter
Fabric
Filter
Fabric
Filter
Dynamic
Scrubber
(5a)
YEAR
PLACED
IN
SERVICE
1962
1962
1962
1962
1963
1963
(6)
GAS
VOLUME
ACFM
65,000
(37,000
21,300
75,000
75,000
83,200
66,000
(32,500]
(7)
INLET
TEMP.
°F
1,300
(170)
495
550
550
550
1,440
-(171)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
10.0
NA
1.45
4-8
4.0
(Custo-
mer)
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
95
99+
99+
99+
99+
0.1
gr/ACF
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NA
NA
-------
ro
10
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
13
14
15
16
17
18
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
125
125
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Limestone
NA
NA
Limestone
Limestone
(4)
FUEL
USED
NA
NA
Gas
NA
Gas
Gas
(5)
TYPE
COLLECTOR
Cyclone
Scrubber
8"wg
Cyclone
Scrubber
8"wg
Fabric
Filter
Fabric
Filter
(5a)
YEAR
PLACED
IN
SERVICE
1963
1963
1963
1964
1964
1964
(6)
GAS
VOLUME
ACFM
20,000
30,000
(NA)
15,000
37,000
(NA)
16,000
16,000
(7)
INLET
TEMP.
°F
600
400
(NA)
NA
500
(NA)
550
550
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
8
NA
3
3.8 .
3.8
OUTLET
NA
0.036
NA
0.15
NA
NA
(9)
DESIGN
EFF.
WT. %
F.E.
Curve
99
NA
99
99+
99+
(10)
IS
PLUME
VISIBLE
NA
NA
YES
NA
NA
-------
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
19
20
21
22
23
24
(2)
CAP.
OF
UNIT
T/D
600
NA
NA
240
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Limestone
Limestone
Limestone
NA
NA
(4)
FUEL
USED
NA
Coal
NA
NA
NA
NA
(5)
TYPE
COLLECTOR
Fabric -
Fiberglas
Reverse
Air
Fabric
Filter
Cyclone
Cyclone
2.6 -
2.7"wg
Scrubber
Jcrubber
(5a)
YEAR
PLACED
IN
SERVICE
s, 1964
1964
1964
1964
1965
1965
(6)
GAS
VOLUME
ACFM
140,000
28,000
25,000
30,600
30,750
40,000
(NA)
100,000
(NA)
(7)
INLET
TEMP.
°F
550
550
900
650
640
500
(NA)
600
(NA)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
0.8
NA
0.94
0.64
NA
NA
OUTLET
NA
NA
NA
0.032
0.018
0.39
0.05
(9)
DESIGN
EFF.
WT. %
NA
99.5
F.E.
Curve
(ACT)
97.0
97.5
NA
NA
(10)
IS
PLUME
VISIBLE
NO
NA
NA
YES
NA
NA
-------
to
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
25
26
27
28
29
30
(2)
CAP.
OF
UNIT
T/D
NA
500
NA
NA
NA
100
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
Limestone"
NA
NA
NA
Limestone
(4)
FUEL
USED
NA
Coal
NA
NA
NA
Nat'l.
Gas
(5)
TYPE
COLLECTOR
Scrubber
8"wg
Fabric-
;iberglass
Reverse
Air
Scrubber
8" wg
Scrubber
Scrubber
15" wg
Dynamic
Scrubber
(5a)
YEAR
PLACED
IN
SERVICE
1965
1965
1965
1965
1965
1965
(6)
GAS
VOLUME
ACFM
35,000
(NA)
115,000
52,000
(NA)
46,000
(NA)
29,400
(NA)
52,000
(30,000
(7)
INLET
TEMP.
°F
650
(NA)
550
400
(NA)
600
(NA)
450
(NA)
1,050
(150)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
7.6
NA
2.4
20
NA
OUTLET
0.05
gr/SCF
NA
NA
0.05
0.2
NA
(9)
DESIGN
EFF.
WT. %
99
NA
98.2
NA
99
NA
(10)
IS
PLUME
VISIBLE
NA
NO
NA
NA
NA
-------
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
31
32
33
34
35
36
(2)
CAP.
OF
UNIT
T/D
140
NA
200
200
200
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
NA
Limestone
Limestone
Limestone
NA
(4)
FUEL
USED
NA
Gas
CO
Gas
CO
Gas
CO
Gas
Nat'l.
Gas
(5)
TYPE
COLLECTOR
Dynamic
Scrubber
Dynamic
Scrubber
Cyclone
2.3-6.0"wg
Cyclone
Cyclone
13'Vg
Scrubber
15'Wg
(5a)
YEAR
PLACED
IN
SERVICE
1965
1965
1965
1965
1965
1966
(6)
GAS
VOLUME
ACFM
31,000
(22,300;
4,000
25,000
Nor .
40,000
Max.
25,000
Nor.
40,000
Max.
52,800
73,300
(NA)
(7)
INLET
TEMP.
°F
1.050
NA
650
650
440
450
(NA)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
10
NA
1.5
1.5
2.17
2.40
20
OUTLET
0.045
NA
NA
NA
0.148
0.148
NA
(9)
DESIGN
EFF.
WT. 1
NA
NA
F.E.
Curve
F.E.
Curve
(ACT)
93.23
93.87
99.7
(10)
IS
PLUME
VISIBLE
NO
YES
NA
NA
YES
NA
to
-------
IS)
Table 82 - continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
37
38
39
40
41
42
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
35
300
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
NA
NA
NA
Oyster Shells
Limestone
(4)
FUEL
USED
Nat'l.
Gas
Oil
Oil
Nat'l.
Gas
Methane
NA
(5)
TYPE
COLLECTOR
Scrubber
Scrubber
i •?"
i j Wg
Scrubber
15"wg
Scrubber
15" wg
ESP
ESP
(5a)
YEAR
PLACED
IN
SERVICE
1966
1966
1966
1966
1966
1966
(6)
GAS
VOLUME
ACFM
40,000
(NA)
62,000
(NA)
48,000
(NA)
42,900
(NA)
69,600
225,000
(7)
INLET
TEMP.
°f
500
(NA)
550
(NA)
550
(NA)
500
(NA)
395
500
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
15
20
20
20
0.646
0.8
OUTLET
0.3
0.1
0.08
0.1
0.0207
NA
(9)
DESIGN
EFF.
WT. %
NA
99.5
99.7
99.5
(ACT)
96.98
99.0
(10)
IS
PLUME
VISIBLE
NA
NA
NA
NA
YES
-------
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
43
44
45
46
47
48
(2)
CAP.
OF
UNIT
T/D
NA
NA
600
600
600
600
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Sludge Lime
Limestone
Limestone
Limestone
Limestone
(4)
FUEL
USED
NA
NA
Coal
NA
NA
NA
(5)
TYPE
COLLECTOR
Cyclone
Cyclone
Fabric -
Fiberglass
Reverse
Air
Fabric -
Fiberglass
Reverse
Air
Fabric -
Fiberglass
Reverse
Air
Fabric -
Fiberglass
Reverse
Air
(5a)
YEAR
PLACED
IN
SERVICE
1966
1966
1966
9
, 1966
, 1966
, 1966
(6)
GAS
VOLUME
ACFM
36,000
37,000
36,400
140,000
140,000
140,000
140,000
(7)
INLET
TEMP.
°F
700
450
300
550
550
550
550
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
1,280
#/Min.
NA
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
Curve
96
NA
NA
NA
NA
(10)
IS
PLUME
VISIBLE
NA
NA
NO
NO
NO
-------
M
00
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
49
50
51
52
53
54
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
Limestone
Limestone
Limestone
Limestone
Limestone
(4)
FUEL
USED
Oil
NA
NA
NA
NA
NA
(5)
TYPE
COLLECTOR
Scrubber
10" wg
Cyclone
2.8"wg
Cyclone
2.2"wg
Cyclone
9.6"wg
Cyclone
2.5"wg
Cyclone
5.5"wg
(5a)
YEAR
PLACED
IN
SERVICE
1967
1967
1967
1967
1967
1967
(6)
GAS
VOLUME
ACFM
25,000
86,500
100,000
35,500
47,000
20,000
(7)
INLET
TEMP.
°F
450
600
700
300
600
600
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
5.3
5-12
NA
1,495
#/Min
NA
NA
OUTLET
0.05
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99
F.E.
Curve
F.E.
Curve
96.0
F.E.
Curve
F.E.
Curve
(10)
IS
PLUME
VISIBLE
NA
NA
NA
NA
NA
NA
-------
Table 82 - continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
55
56
57
58
59
60
(2)
CAP.
OF
UNIT
T/D
245
600
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Dolomite
Limestone
Limestone
Limestone
Limestone
Limestone
(4)
FUEL
USED
Gas
NA
Coal
High
S
Coal
High
S
Coal
High
S
Nat'l.
Gas
(5)
TYPE
COLLECTOR
Fabric
Filter
Fabric
Filter -
Glass;
Rev. Air
Dynamic
Scrubber
Dynamic
Scrubber
Dynamic
Scrubber
Dynamic
Scrubber
(5a)
YEAR
PLACED
IN
SERVICE
1967
1967
1967
1967
1967
1968
(6)
GAS
VOLUME
ACFM
50,000
140,000
62,500
(40,300
62,500
(40,300
62,500
(40,300;;
111,000
(54,100
(7)
INLET
TEMP.
°F
500
550
700
(154)
700
(154)
700
(154)
1,400
(165)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
2.00
NA
4.24
2.83
2.22
NA
NA
10-20
OUTLET
NA
NA
0.0306
0.0319
0.0318
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99+
NA
99.0
NA
NA
99.0
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NO
NO
NO
NJ
-------
N)
NJ
O
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
61
62
63
64
65
66
(2)
CAP.
OF
UNIT
T/D
NA
100*
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
Limestone
Limestone
NA
Limestone
NA
(4)
FUEL
USED
Oil
Nat ' 1 .
Gas
+
Coal
NA
Gas
NA
Gas
(5)
TYPE
COLLECTOR
Scrubber
20" Wg
ESP
(two units
Cyclone
3.0" Wg
Cyclone
Cyclone
Scrubber
50" Wg
(5a)
YEAR
PLACED
IN
SERVICE
1968
1968
1968
1968
1969
1969
(6)
GAS
VOLUME
ACFM
44,000
(NA)
**
236,920
42,511
30,000
35.850
110,000
(7)
INLET
TEMP.
°F
450
(NA)
530
722
NA
740
600
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
20
**
3.00
1.29
NA
NA
4.4
OUTLET
NA
**
0.0077
0.066
NA
NA
0.02
(9)
DESIGN
EFF.
WT. %
99.9
99.7
**
99.717
ACT
ACT
95.0
NA
F.E.
Curve
99.6
(10)
IS
PLUME
VISIBLE
NA
NO
YES
YES
NA
NA
-------
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
67
68
69
70
71
72
(2)
CAP.
OF
UNIT
T/D
650
NA
NA
NA
NA
220
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Limestone
Limestone
Limestone
Limestone
Limestone
(4)
FUEL
USED
Coal,
Low
S
Coal
Low
S
Coal
Low
S
Nat'l.
Gas
Coal
Low
S
Nat'l.
Gas
(5)
TYPE
COLLECTOR
Dynamic
Scrubber
Dynamic
Scrubber
Dynamic
Scrubber
Venturi
Scrubber
15-20 wg
Venturi
Scrubber
15-20" wg
Dynamic
Scrubber
(5a)
YEAR
PLACED
IN
SERVICE
1969
1970
1970
1970
1970
1970
(6)
GAS
VOLUME
ACFM
186,000
(98,500
63,800
(36,000
42,500
(24,600
16,500
(14,250
NA
45,000
(31,200
(7)
INLET
TEMP.
°F
1,100
(160)
950
(152)
950
(152)
430
(132)
NA
550
(136)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
NA
NA
NA
OUTLET
NA
NA
NA
0.023
0.0286
gr/SCF
NA
NA
(9)
DESIGN
EFF.
WT. %
15 gr/A(
in
0.05 gr/
out
0.05
gr/SCF
0.05
gr/SCF
99
on
2^ +
NA
NA
(10)
IS
PLUME
VISIBLE
F
NO
ACF
NO
NO
NO
NO
NO
NJ
-------
B
ro
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
73
74
75
76
77
78
(2)
CAP.
OF
UNIT
T/D
600
NA
250
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Limestone
Limestone
- Limestone
Dolomite
Limestone
NA
(4)
FUEL
USED
30%
Coal
70%
Gas
Coal
Gas
Coal
NA
Gas
(5)
TYPE
COLLECTOR
Dynamic
Scrubber
Fabric
Filter
ESP
Fabric
Filter
Fabric
Filter
Scrubber
(Sa)
YEAR
PLACED
IN
SERVICE
1970
1970
1970
1970
1970
1970
(&)
GAS
VOLUME
ACFM
186,000
(97,000
110,000
50,000
255,000
44,000
62,40
(NA)
(7)
INLET
TEMP.
°F
1,150
(162)
570
550
600
550
525
(NA)
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
1.83
12.0
2.85
0.52
NA
OUTLET
NA
NA
0.02
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99.6
99+
99.84
99.5
99.5
NA
(10)
IS
PLUME
VISIBLE
NO
NA
NO
NO
NA
-------
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
6
-
(11)
PARTICLE
SIZE
M_
<
45
40
35
30
25
20
15
10
5
>
45
40
35
30
25
20
15
10 :
5 :
WT.%
IN
RANGE
37.5-44
2.5-2.8
2.0-3.0
3.9-3.C
3.1-3.0
4.5-4.C
6.6-5.S
0.9-9.1
4.0-9.0
5.0-16.
METHOD
OF
ANALYSIS
.2
BAHCO
0
(12)
RESISTIVITY
OHM -CM
RESIST.
NA
TEMP . F
NA
-
METHOD
OF
ANALYSIS
NA
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
2.775 i
2.745 i
WT. %
NA
(14)
CHEMICAL
COMP. OF
GAS
COMP .
02
C02
N2
H20
VOL.%
7.5
18.6
67.1
6.8
(15)
REMARKS
Draft
Loss
5" wg
NJ
ro
-------
to
Table 82 - continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
35
41
(11)
PARTICLE
SIZE
M_
<
45
40
35
30
25
20
15
10
5
45
40
35
30
25
20
15
10
5
>
45
40
35
30
25
20
15 :
in
5 :
45
40
35
30
25
20
15
10
5
WT.%
IN
RANGE
16.5-20
3.0-3.2
4.2-3.4
4.3-5.4
6.0-5.0
8.0-8.0
0.0-8.9
3.8-10.
6.2-15.
8.0-21.
14.5
2.0
2.5
3.0
4.8
6.7
10.5
19.0
22.0
15.0
METHOD
OF
ANALYSIS
.0
BAHCO
1
0
0
BAHCO
•
(12)
RESISTIVITY
OHM -CM
RESIST.
NA
NA
TEMP . F
NA
NA
METHOD
OF
ANALYSIS
NA
NA
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
3.02-
3.08 sg
2.72sg
WT.%
(14)
CHEMICAL
COMP. OF
GAS
COMP .
02
C02
N2
H20
02
C02
N?
H20
VOL.%
14.8
7.9
72.9
4.4
10.2
9.4
59.0
21.4
(15)
REMARKS
-------
Table 82 — continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
22
33
(11)
PARTICLE
SIZE
*L
<
45
40
IS
30
25
20
15
10
5
45
40
35
30
25
20
15
10
5
>
45
40
35
30
25
20
15
10
5
45
40
35
30
25
20
15
10
5
WT.%
IN
RANGE
88.5
0.9
0.6
0.8
0.7
1.2
1.1
1.2
1.6
3.4
88.5
0.9
0.6
0.8
0.7
1.2
1.1
1.2
1.6
3.4
METHOD
OF
ANALYSIS
BAHCO
BAH CO
(12)
RESISTIVITY
OHM -CM
RESIST.
NA
NA
TEMP . F
NA
NA
METHOD
OF
ANALYSIS
NA
NA
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
2.9 sg
WT.%
(14)
CHEMICAL
COMP. OF
GAS
COMP .
02
C02
No
H2°
02
C02
N2
H20
VOL.1
5.1
14.4
58.3
22.2
5.1
14.4
58.5
22.0
(15)
REMARKS
N)
N)
-------
ro
Table 82 - continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
57
60
62
(11)
PARTICLE
SIZE
M.
<
NA
20
11
40
20
10
5
>
NA
11
0
20
10
5
3
WT.%
IN
RANGE
NA
50
50
23
24
17
7
METHOD
OF
ANALYSIS
NA
By
Customer
Standard
Screens
Composite
9 Tests <
(12)
RESISTIVITY
OHM -CM
RESIST.
NA
NA
.4xl07
7 x 10*
.4xl09
.3x1011
TEMP . F
NA
NA
160
230
270
380
.6xlO-M 450
.8x107"
.6x109
.7xlQl(
fi vi n1 (
.9x1011
.2x1011
.OxlflU
150
220
270
Tfin
370
420
450
METHOD
OF
ANALYSIS
NA
NA
15%
Moisture
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
CaCOs
CaO
NA
WT.%
NA
50
50
NA
(14)
CHEMICAL
COMP. OF
GAS
COMP .
02
C02
N2
H20
NA
VOL.1
0.7
24.3
59.7
15.3
NA
(15)
REMARKS
-------
Table 82 - continued
Summary of Installation and Test Data for Rotary Lime Kilns
(1)
TEST
NO.
63
73
(ID
PARTICLE
SIZE
M.
<
45
40
35
30
25
20
15
10
5
25
10
4
1
-
>
45
40
35
30
25
20
15
10
5
7^
10
4
1
WT.%
IN
RANGE
61.0
2.5
2.5
3.0
3.1
3.9
4.0
5.0
6.0
9.0
an. 2
10.8
4.3
2.9
1.8
METHOD
OF
ANALYSIS
BAHCO
Customer
Analysis
-
(12)
RESISTIVITY
OHM- CM
RESIST.
NA
TEMP . F
NA
METHOD
OF
ANALYSIS
NA
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
2.73sg
WT.%
(14)
CHEMICAL
COMP. OF
GAS
COMP .
°2
C02
N?
H20
VOL.%
11.9
12.3
65.4
(15)
REMARKS
10
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
2. Brass/Bronze Reverberatory Furnaces
A total of 16 applications of equipment was reported in this area. Of
these, all but seven were fabric collectors. These were ordinarily not sold for
specified efficiency level, although several were represented to be 99.9 percent
efficient. These ordinarily functioned well enough to provide a clear effluent
and no efficiency tests were run. Orion or Dacron bags were used in all of the
installations except one which had a 550°F operating temperature and used
glass bags.
Two Venturi type scrubbers were installed. One was designed for 28"
wg and had a reported efficiency of 99.32% on a furnace charging dross
containing lead, zinc and soldering alloys. The other operated at 35" wg and
showed only 92.5% collection efficiency. The discrepancy here lies in the
loadings at the scrubber inlet, which was almost 10 times as high on the furnace
for which the 99+% efficiency was obtained. This is apparently due to the
mechanical entrainment of large quantities of the dross which carried over into
the scrubber. The two produced effluents of nearly equal grain loading (0.045
and 0.039 gr/ACF) with the higher pressure drop producing the lower outlet
grain loading. These values may be compared with the grain loading specified
for the "high efficiency" case in Section B, which called for 0.01 gr/ACF on
brass/bronze reverberatory furnaces for good stack appearance. Both scrubbers
were reported to operate with no visible plume other than the steam plume,
however.
Three dynamic scrubbers and one dynamic mechanical collector were
also installed. No performance specifications were reported for any of these,
nor were any tests run to establish performance. One of the four was reported
to produce a clear stack. The other three were all reported to leave a visible
paniculate plume in addition to any plume due to water condensation.
Two of the fabric collectors were reported to have visible plumes. One
of these was due to failure of the cooling system which caused bag damage. The
other fabric collector installations were all reported to produce a clear effluent.
All of the collected installation data are summarized in Table 83.
-------
Table 83
Summary of Installation and Test Data for Brass/Bronze Reverberatory Furnaces
(1)
TEST
NO.
1
2
3
4
5
6
(2)
CAP.
OF
UNIT
T/n
20
30
10
20 T/D
(total
2 furn
72 T/I
Charge
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Brass/Bronze
Scrap
Brass/Bronze
Scrap
Brass/Bronze
Scrap
Copper Scrap
) Copper Scrap
Copper Scrap
(4)
FUEL
USED
Oil
Gas
Oil
#5
Oil
NA
NA
(5)
TYPE
COLLECTOR
Dynamic
Scrubber
Dynamic
Scrubber
Dynamic
Scrubber
Fabric
Filter -
Orion,
Shaker
Fabric
Filter -
Dacron
Shaker
Fabric-
Glass,
Sonic §
Reverse Ai
(5a)
YEAR
PLACED
IN
SERVICE
1960
1960
1963
1965
1965
1965
r
(6)
GAS
VOLUME
ACFM
36,000
30,000
12,000
18,000
30,000
31,500
(7)
INLET
TEMP.
°F
NA
NA
NA
250
275
550
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
NA
NA
NA
NA
NA
NA
(10)
IS
PLUME
VISIBLE
YES
NO
YES
YES*
NO
NO
ro
N>
-------
NJ
CO
O
Table 83 - continued
Summary of Installation and Test Data for Brass/Bronze Reverberatory Furnaces
(1)
TEST
NO.
7
8
9
10
11
12
(2)
CAP.
OF
UNIT
T/D
NA
50
5
75 to
100
T/D
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
Brass/Bronze
Scrap
Brass/Bronze
Scrap
Scrap Radiators
NA
Zinc and Copper
(4)
FUEL
USED
NA
Gas
Oil
#5
Oil
or
Gas
NA
Oil
(5)
TYPE
COLLECTOR
Fabric -
Orion
Shaker
Type
Venturi
Scrubber
Dynamic
Mechanical
Fabric -
Acrylic,
Shaker
Fabric -
Dacron,
Shaker
Fabric -
Acrylic,
Shaker
(5a)
YEAR
PLACED
IN
SERVICE
1967
1967
1967
1968
1968
1968
(6)
GAS
VOLUME
ACFM
38,000
4,000
2,500
81,000
24,000
41,000
(7)
INLET
TEMP.
°F
250
306
NA
260
250
250
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
NA
NA
0.01
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
NA
99.6
NA
99,9+
99.9+
99.9+
(10)
IS
PLUME
VISIBLE
YES
NO
YES
NO
NO
NO
-------
Table 83 — continued
Summary of Installation and Test Data for Brass/Bronze Reverberatory Furnaces
(1)
TEST
NO.
13
14
15
16
(2)
CAP.
OF
UNIT
T/D
NA
100
NA
10
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Dross
Containing
Lead, Zinc +
Soldering Alloy
Brass/Bronze
Scrap
NA
Brass Scrap
-
(4)
FUEL
USED
Gas
Gas
Oil g
Gas
Nat'l.
Gas
(5)
TYPE
COLLECTOR
Venturi
Scrubber
28"wg
Fabric
Filter
Fabric-
Orion
Shaker
Venturi
Scrubber
35"wg
(5a)
YEAR
PLACED
IN
SERVICE
1968
1969
1970
1970
-
(6)
GAS
VOLUME
ACFM
50,000
(30,000
10,000
53,000
15,000
(12,000
(7)
INLET
TEMP.
°F
340
(120)
250
250
1,200
)(160)
(8a) (8b)
MEASURED
DUST LOADING
/ACF
INLET
4
NA
NA
0.418
OUTLET
0.045
NA
NA
0.039
(9)
DESIGN
EFF.
WT. %
NA
99.9
99.9
ACT
92.5
(10)
IS
PLUME
VISIBLE
NO
NO
NA
NO
to
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
3.
Lead Cupolas
Four manufacturers reported a total of 11 installations in this area, as
indicated in Table 84. All but one were fabric collectors. These were
represented to be 99.85% efficient, 99.9+% efficient, or no representation was
made at all. No tests were run, but the effluent was reported to have no visible
plume in eight of the 10 cases, and the stack appearance was not available in
the other two. The single wet scrubber was of the "wet dynamic" type and was
reported to have an efficiency of 87.5%. This stack was reported to have a
visible plume.
Four of the installations were reported to serve gas flows far in excess
of that generated by a single cupola, and probably represent a single collector
installed to handle a variety of furnaces ventilated through a common stack.
Lead Reverberatory Furnaces
Three companies reported a total of 17 installations over the 10 year
period from 1960 to 1970. The complete tabulation is given in Table 86. These
were all fabric collectors, most of which used Orion bags. Temperatures were
all below 275°F, with only one below 230°F. The average size was 18,000
ACFM, but some of the installations were sized to include a blast furnace,
sweating furnace, or other equipment in addition to the reverberatory furnace.
Efficiencies were represented to be 99.85 or 99.9+ wherever a
representation was made. All the stacks were reported to be clear where there
was a record of a stack observation.
-------
Table 84
Summary of Installation Data for Lead Cupolas
(1)
TEST
NO.
1
2
3
4
5
6
(2)
CAP.
OF
UNIT
T/D
NA
28.3
NA
NA
NA
5
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
NA
NA
NA
NA
Lead Dross
Battery Plates
Coke § Slag
(4)
FUEL
USED
NA
NA
NA
NA
NA
Soft
Coal
(5)
TYPE
COLLECTOR
Fabric
Shaker
Orion
Fabric
Shaker
Acrylic
Automatic
Shaker
Orion
Intermit-
:ent Shake]
Type
Orion
Fabric
Shaker
Fiberglas
Dynamic
Scrubber
(5a)
YEAR
PLACED
IN
SERVICE
1961
1964
1964
• 1964
1965
>
1965
(6)
GAS
VOLUME
ACFM
350,000
14,680
40,000
3,800
100,000
8,000
(7)
INLET
TEMP.
°F
200
250
250
250
350
700
(8a) (8b)
MEASURED
DUST LOADING
GR/ACF
INLET
NA
NA
NA
NA
NA
4.3
OUTLET
NA
NA
NA
NA
NA
0.54
(9)
DESIGN
EFF.
WT. %
99.9 +
99.9+
NA
NA
99.9+
87.5
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NO
NO
YES
(O
CO
-------
ro
Table 84 — continued
Summary of Installation Data for Lead Cupolas
(1)
TEST
NO.
7
8
9
10
11
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
NA
NA
NA
NA
(4)
FUEL
USED
NA
NA
NA
NA
NA
(5)
TYPE
COLLECTOR
Fabric
Shaker
Filtron
Tubes
Fabric
Shaker
Filtron
Tubes
Fabric
Shaker
Orion
Fabric
Fabric
(5a)
YEAR
PLACED
IN
SERVICE
1967
1967
1969
1970
1970
(6)
GAS
VOLUME
ACFM
450,000
450,000
22,500
23,000
16,000
(7)
INLET
TEMP.
°F
230
230
275
200°F.
120°F.
(8a) (8b)
MEASURED
DUST LOADING
GR/ACF
INLET
NA
NA
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99.9+
99.9+
99.9+
99.85
99.85
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NA
NA
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
4. Lead/Aluminum Sweating Furnaces
Table 85 is a compilation of all of the installations reported by the
IGCI member companies.
A total of 18 installations were made by three companies. The furnace
usage was designated as follows:
Fabric
Wet
Total
Lead Sweating
Aluminum Sweating
Lead/Aluminum Sweating
6
6
12
6
6
6
18
The fabric collectors were most frequently represented as "99.9+"
percent efficient, while the scrubbers were all represented to be 98% efficient.
No test data was available for any of the installations.
Several of the lead sweating fabric collectors were represented to serve
more than one furnace. The inclusion of reverberatory furnaces and cupolas in
the same gas handling system is common for fabric collector installations in
lead smelting plants. The scrubbers were apparently special purpose devices
tailored to a single furnace.
-------
CO
Table 85
Summary of Installation Data for Sweating Furnaces
(1)
TEST
NO.
1
2
3
4
5
6
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
(lead)
NA
Clead)
NA
(lead)
NA
(lead)
NA
(lead)
Lead Scrap
(4)
FUEL
USED
NA
NA
NA
NA
NA
NA
(5)
TYPE
COLLECTOR
Fabric
Repressure
Fiberglas:
Fabric -
Shaker
Type with
Orion
Fabric -
:ntermittei
Shaker Tyj
w/Orlon
Fabric -
Shaker
Filtron
Fabric-
Shaker
Dacron
Fabric
(5a)
YEAR
PLACED
IN
SERVICE
d 1960
1964
t 1964
ie
1967
1967
1967
(6)
GAS
VOLUME
ACFM
10,000
40,000
3,800
450,000
7,000
25,000
(7)
INLET
TEMP.
°F
500
250
250
230
NA
250
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99.9+
NA
NA
99.9+
99.9+
99.85
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NO
NO
-------
Table 85 — continued
Summary of Installation Data for Sweating Furnaces
(1)
TEST
NO.
7
8
9
10
11
12
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
NA
NA
NA
NA
(aluminum)
NA
(aluminum)
(4)
FUEL
USED
NA
NA
NA
NA
tet.Gas
#2 Oil
Standby
^lat.Gas
#2 Oil -
standby
(5)
TYPE
COLLECTOR
Fabric
Shaker
Orion
Fabric
Shaker
Orion
Fabric
Shaker
Fire Ret.
Tubes
Fabric
Shaker
Cot.Sateei
Automatic
' Shaker
Dacron
Automatic
Shaker
Daeron
(5a)
YEAR
PLACED
IN
SERVICE
1962
1964
1968
1969
1970
1970
(6)
GAS
VOLUME
ACFM
14,000
30,000
14,112
40,000
37,500
32,500
(7)
INLET
TEMP.
°F
320
NA
150
160
250
250
(8a) (8b)
MEASURED
DUST LOADING
gr./ACF
INLET
10.0
2.0
NA
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99.9+
99.9+
99.9+
99.9+
NA
NA
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NO
NO
NO
to
-------
N)
CO
00
Table 85 — continued
Summary of Installation Data for Sweating Furnaces
(1)
TEST
NO.
13
14
15
16
17
18
(2)
CAP.
OF
UNIT
48
48
48
48
48
48
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Non Ferrous Metal
(Aluminum § Lead
Scrap)
Non Ferrous Metal
(Scrap)
Non Ferrous Metal
(Scrap)
Non Ferrous Metal
(Scrap)
Non Ferrous Metal
(Scrap)
Non Ferrous Metal
(Scrap)
(4)
FUEL
USED
Nat.
Gas
Nat.
Gas
Nat.
Gas
Nat.
Gas
Nat.
Gas
Nat.
Gas
(5)
TYPE
COLLECTOR
Venturi
Scrubber
9"wg
Venturi
Scrubber
on
y wg
Venturi
Scrubber
9"wg
Venturi
Scrubber
9"wg
Venturi
Scrubber
9"wg
Venturi
Scrubber
9" wg
(5a)
YEAR
PLACED
IN
SERVICE
1968
1968
1968
1968
1969
1969
(6)
GAS
VOLUME
ACFM
20,000
20,000
20,000
20,000
20,000
20,000
(7)
INLET
TEMP.
°F
1,600
1,600
1,600
1,600
1,600
1,600
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
1.0
1.0
1.0
1.0
1.0
1.0
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
98.0
98.0
98.0
98.0
98.0
98.0
(10)
IS
PLUME
VISIBLE
NA
NA
NA
NA
NA
NA
-------
Table 86 '
Summary of Instajlation Data for Lead Reverberatory Furnaces
(1)
TEST
NO.
1
2
3
4
5
6
(2)
CAP.
OF
UNIT
T/D
700
NA
NA
342
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Junk Batteries §
by-products
tin
NA
NA
NA
NA
NA
(4)
FUEL
USED
NA
NA
Nat.
Gas
Nat.
Gas
Oil
NA
(5)
TYPE
COLLECTOR
Fabric
Shaker
Orion
Fabric
Shaker
Orion
Fabric
Shaker
Orion
Fabric
Shaker
Orion
Fabric
Shaker
Orion
Automatic
Shaker
Orion
(5a)
YEAR
PLACED
IN
SERVICE
1961
1963
1963
1963
1964
1964
(6)
GAS
VOLUME
ACFM
12,000
25,000
4,920
12,500
30,000
40,000
(7)
INLET
TEMP.
°F
250
260
250
275
250
250
(8a) (8b)
MEASURED
DUST LOADING
./ACF
INLET
NA
NA
8. 4 mg
M3
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. \
99.9+
99.9+
99.9+
99.9+
99.9+
NA
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NO
NO
NO
NJ
GO
-------
IV)
-ti
o
Table 86 — continued
Summary of Installation Data for Lead Reverberatory Furnaces
(1)
TEST
NO.
7
8
9
10
11
i ?
(2)
CAP.
OF
UNIT
T/D
NA
NA
118
NA
106-
120
(3)
• TYPE OF RAW
MATERIAL OR
CHARGE
NA
NA
NA
(4)
FUEL
USED
NA
NA
40 gal.
per hr.
~#2
Fuel Oi
NA
0 NA
3 e
NA
NA
30 gal.
>er hr.
#5
-uel Oi
ich
NA
(5)
TYPE
COLLECTOR
Fabric
Shaker
Acrylic
Fabric
Shaker
Orion
Fabric
Shaker
Cotton
Jateen
Fabric
Shaker
Filtron
Fabric
Shaker
Orion
(5a)
YEAR
PLACED
IN
SERVICE
1963
1965
1965
1967
1967
1967
(6)
GAS
VOLUME
ACFM
8,000
12,000
22,500
5,000
15,000
15,000
(7)
INLET
TEMP.
°F
NA
250
250
180
250
260
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
(very :
NA
NA
OUTLET
NA
NA
NA
ight)
NA
NA
(9)
DESIGN
EFF.
WT. %
99.85
99.9+
99.9+
99.9+
99.9+
99.9+
(10)
IS
PLUME
VISIBLE
NA
NO
NO
NO
NO
NO
-------
Table 86 - continued
Summary of Installation Data for Lead Reverberatory Furnaces
(1)
TEST
NO.
13
14
15
16
17
(2)
CAP.
OF
UNIT
NA
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
2 eac
NA
NA
NA
NA
NA
(4)
FUEL
USED
V
n
NA
NA
NA
NA
NA
(5)
TYPE
COLLECTOR
Fabric
Shaker
Orion
Automatic
Shaker
Orion
Automatic
Shaker
Orion
Fabric
Fabric
Shaker
Orion
(5a)
YEAR
PLACED
IN
SERVICE
1967
1967
1969
1970
1970
(6)
GAS
VOLUME
ACFM
20,000
19,000
40,000
6,000
18,000
(7)
INLET
TEMP.
°F
260
230
230
120
275
-
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
NA
NA
OUTLET
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99.9+
NA
NA
99.85
99.9+
(10)
IS
PLUME
VISIBLE
NO
NO
NO
NA
NO
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
5.
Zinc Calcination Furnace
Although little information regarding the calcination of secondary zinc
oxide was uncovered, five applications of fabric collectors on "zinc kilns" were
reported. No information was available with regard to the process other than
the gas flow and temperature. In fact, even the gas flow was not reported for
one of the five.
For each application, the gas temperature was limited to the range
where Dacron bags are generally suitable if there is no acid condensation
problem. The efficiency was specified as 99.85% or 99.9+% by the
manufacturer in each case. These applications are listed in Table 87.
-------
Table 87
Summary of Installation Data for Zinc Calcination Furnaces
(1)
TEST
NO.
1
2
3
4
5
(2)
CAP.
OF
UNIT
T/D
NA
NA
NA
NA
NA
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
NA
NA
NA
NA
NA
(4)
FUEL
USED
NA
NA
NA
NA
Nat.
Gas
(5)
TYPE
COLLECTOR
Fabric
Fabric
Tubes
fur. by
Customer
Fabric
Fabric
:abric
Tubes .
fur. by
Customer
(5a)
YEAR
PLACED
IN
SERVICE
1960
1965
1966
1967
1969
(6)
GAS
VOLUME
ACFM
10,300
450,000
10,000
NA
30,000
(7)
INLET
TEMP.
CF
230
250
275
NA
260
(8a) (8b)
MEASURED
DUST LOADING
gr/ACF
INLET
NA
NA
NA
NA
30
OUTLET
NA
NA
NA
NA
NA
(9)
DESIGN
EFF.
WT. %
99.85
99.9+
99.85
99.85
99. 9+
(10)
IS
PLUME
VISIBLE
NA
NO
NA
NA
NO
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
6.
Aluminum Chlorination Station
Four manufacturers reported installation of a total of six systems for
chlorination of secondary aluminum. The scrubbers and results obtained varied
widely from one application to another.
Three of the scrubbers were of the "mobile packing" variety, in which
plastic spheres or glass marbles serve as the packing. These varied from 25" wg
to 55" wg, with efficiencies as follows:
AP in wg E.%
25
30
55
96
99
99.1 to 99.8
The efficiency varied with grain loading at the scrubber inlet, as well as
with pressure drop, indicating that the scrubbers were most effective on the
paniculate material where the concentration was high.
The other three installations were Venturi scrubbers operating at 14 to
45" wg. These showed outlet grain loadings lower than the mobile packed
scrubbers, but the only efficiencies reported are 90-95 and 95%, which is lower
than for the mobile packed scrubbers. This appears to relate to the very low
inlet grain loading for the Venturi scrubber, however, rather than to the
performance characteristics of Venturis. Very low inlet loadings are more
typical of primary chlorination than secondary.
The installation data reported is given in Table 88.
-------
Table 88
Summary of Installation Data for Aluminum Chlorination Stations
(1)
TEST
NO.
1
2
3
4
5
6
(2)
CAP.
OF
UNIT
T/D
37.5
28.5
NA
45
NA
50
(3)
TYPE OF RAW
MATERIAL OR
CHARGE
Scrap Aluminum
Chlorine Rate NA
Scrap Aluminum,
750 Ib/hr chlorine
(Producing Alloy
380Z3)
Secondary Scrap
and Chlorine
Chlorination in
Secondary Alumi-
num Smelter
NA
Mill ends, pig
aluminum-210 Ib/hr.
Cl2 (Producing
Alloy 3003)
(4)
FUEL
USED
NA,
jrob-
ably
^lat.Gas
Nat.
Gas
Gas
Nat.
Gas
NA
Nat.
Gas
(5)
TYPE
COLLECTOR
Scrubber
@30" w c
Scrubber
@25" w c
Venturi §
'recooler
29" wg
3-Bed
Hi-Energy
Wet
Scrubber
Wet
Scrubber
14" AP
Scrubber
'Venturi)
!45" w c
(5a)
YEAR
PLACED
IN
SERVICE
1964
1965
1967-
1968
1968
1969
1969
(6)
GAS
VOLUME
ACFM
NA
(1600)
NA
(2000)
15,000
(9,000)
5,000
to !
6,230
3,000
(2500)
(7)
INLET
TEMP.
°F
810
(82°)
NA
(135°)
800
(140)
138°
Jcrubber
Outlet
'emp.98°
120
(175)
(8a) (8b)
MEASURED
DUST LOADING
GR/ACF
INLET
50
12.
- •
2.79 t<
11.80
Avg.
F 6.70
NA
1.5
OUTLET
0.5
0.5
0.05
• 0.0046
to
0.084
Avg.
. I) 34
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
VI. CONCLUSIONS AND RECOMMENDATION
The data collected and reported substantiate several conclusions:
A. All of the applications covered can be treated adequately with
conventional air pollution control equipment.
B. Electrostatic precipitators are currently limited to the lime kiln
application by the economics of small precipitators relative to
fabric collectors or scrubbers.
C. Fabric collectors are acceptable for all the applications except
aluminum chlorination.
D. Wet scrubbers are acceptable for all of the applications, but are
less frequently used for'fine fumes in secondary smelting than
fabric collectors.
E. Wet scrubbers must be used for aluminum chlorination stations.
F. Mechanical collectors are not adequate for good pollution
control in any of the areas, although they are often used as
precleaners.
In addition to these generalizations with.respect to the data presented,
several conclusions were drawn regarding the program organization and scope:
A. The combination of the rotary lime kiln application area with
the secondary smelting areas detracts from the continuity of the
report. The data might be more easily read and interpreted if
these two areas were reported separately.
B. The several smelting areas covered do not embrace all secondary
smelting operations. For example, zinc sweating, various
crucible operations, etc. were omitted. The value of the data
would be enhanced by filling these gaps at some future time.
C. The program organization employed was effective in achieving
the goals set up. That is, the data in possession of the member
companies was obtained in a cooperative atmosphere which
would not ordinarily exist if a contractor other than IGCI was
assigned to collect it.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
The combination of Coordinating Engineer — Project Director
— member company participants provided a good distribution
of work load.
The ability of the member companies to produce information
of the type required here varied in accord with how closely the
functions relate to normal business practice. The various
information producing functions are listed in accord with the
ease of production (as judged by the Coordinating Engineer and
Project Director):
Bid Prices — easiest
Specifications
Narratives
Data on old installations
Non-routine clerical or statistical work — most difficult
The installation and test data was limited by the lack of air
pollution control in the secondary metals area. If an industrial
area were chosen for a similar study which was more generally
serviced by the air pollution control equipment manufacturers,
the information would be more complete and detailed than that
contained in this report. Examples of such industrial areas are:
Paper mills
Utility power generation
Rock products
Primary Metals
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
APPENDIX I
Program Planning & Execution
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
PROGRAM PLANNING AND EXECUTION
The initial work on this program was aimed toward providing a suitable
work plan and subdivision of the functions among the IGCI member
companies, the Executive Secretary, various IGCI committees and the
Coordinating Engineer.
Program execution began during the first week in July, which was used
by members of the IGCI Government Relations Committee to interview
candidates for employment as Coordinating Engineer. Several candidates were
considered, all of whom were formerly associated with member companies, but
no longer have any affiliation with either member companies or with IGCI.On
the basis of these interviews, L. C. Hardison of Air Resources, Inc. in Palatine,
Illinois was selected. Herbert R. Herington, Executive Secretary of IGCI, was
named Project Director.
Division of Functions
The Project Director, Coordinating Engineer and Government Relations
Committee agreed upon a division of work among the parties involved, which
was followed during the course of the program. This division is as follows:
1. Drafting of reports, forms, instructions, etc., plus technical
editing of all material - Coordinating Engineer (L. C. Hardison)
2. Preparation of mailings, correspondence with member
companies, preparation of material in final form — IGCI Project
Director (Herbert R. Herington)
3. Approval of all technical material to be made available for
publication, general review and approval of program progress,
and selection of member companies for preparation of narrative
descriptions and bid price data — Engineering Standards
Committee (Harry Krockta, Chairman)
4. Basic Program direction — Government Relations Committee,
(Hugh Mullen, Chairman) with Project Director, Herbert R.
Herington.
This working arrangement was put into effect during the second week
of July, with the preparation of the Work Plan Draft.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
The Work Plan Draft was prepared by L. C. Hardison after a review of
the pertinent contract documents and conferences with Hugh Mullen for the
Government Relations Committee and Project Director Herington.
The draft was reviewed by the members of the IGCI Engineering
Standards Committee and revised after comments were received. The final draft
was prepared by the Coordinating Engineer and the Project Director, and
submitted to NAPCA on July 31, 1970.
Subdivision of the Program
In order to complete the work in the scheduled time period, it was
necessary to carry out some of the steps in each of the three categories
simultaneously. A work plan was drawn up which treated the three categories
as separate projects insofar as possible in order to operate them in parallel
throughout the 6-month period of the project. The work plan centers around
detailed calendars of events in each of the three areas.
Some'necessary interrelations were taken into account. For example,
three companies were selected as most qualified to prepare narrative
descriptions of the processes. These were adjudged most likely to be best
qualified to prepare bid prices. Some of the schedule dates in the work plan
were adjusted so that they were the same in each of the parallel programs.
Preparation of the Narratives
The preparation of a concise narrative description of the process, the
types of gas cleaning equipment applicable, and the technical problems
inherent in the application was done by an individual employee of a member
company.
Several steps were taken to assist the individual in each case in
preparing an authoritative and readable document. As a preliminary step, a
brief survey of applicable literature was made by the Coordinating Engineer,
and references were furnished the company selected for preparation of the
narrative. A general outline was furnished each participating company in order
to avoid omissions and secure some consistency in form.
All of the IGCI member companies known to have applications in the
process area in question were solicited to determine their degree of interest
prior to selecting the companies most qualified. From among those exhibiting
significant interest, the three deemed most qualified by the members of the
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
IGCI Engineering Standards Committee were selected to participate in a
predraft seminar to cover the process in question with the Coordinating
Engineer. The representatives of the three companies selected chose one of
their employees to prepare the draft of the narrative, along with a flow
diagram.
The draft was edited by the Coordinating Engineer and the final draft
reviewed with the Engineering Standards Committee prior to submission.
page.
A detailed schedule of the steps in this process is given on the following
Compilation and Tabulation of Installation and Test Data
The requirements of NAPCA as described in the contract documents
were followed as closely as possible in this area. However, the data forms were
revised considerably by the Coordinating Engineer, with NAPCA concurrence,
during the course of the project.
The detailed steps in the process of review, issue, retrieval and
compilation are given on the following page.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
i
No.
of
Event
N-1
N-2
N-3
N-4
'N-5
N-6
N-7
N-8
N-9
N-10
N-11
N-12
N-13
N-14
Detailed Calendar for Narratives
WORK DONE BY
Coor. Ex. Engr. .. . .-..
Name of Event Engr. Sec. Stds. Memb' Other
Literature survey of
applicable general X
articles.
List Member Companies
cross referenced with
known areas of appli- X X
cation.
Solicit member
companies for level X
of interest (0-10 scale)
Prepare list of member
companies indicating
interest for review by X X
Engr. Stds. Comm.
Select three companies
in each category X
Schedule meetings of
representatives in X X
9 areas
Hold meetings X X
Prepare drafts of
narratives X
Review drafts X
Distribute drafts to
other participating X
member companies
Comment on drafts X
Review & Consolidate X
Final Draft Review X
Print and Distribute X
PROJECTED
COMPLETION
DATE
7-31
7-31
7-31
8-18
8-18
8-18
9-15
9-30
10-15
10-20
10-30
11-15
11-20
11-30
AC-
TUAL
DATE
7-31
7-31
7-31
8-18
8-18
8-18
9-3
10-20
11-5
11-11
11-15
11-19
12-17
12-31
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Detailed Calendar for Forms
No.
of
Event Name of Event
WORK DONE BY
Coor. Ex. Engr.
Engr. Sec. Stds.
Memb. Other
F-1 Propose forms for X
submission to members
F-2 Review with Chrm. of X
Engr. Stds. Comm.
F-3 Distribute to members
F-4 Receive returns and
followup on non-return
F-5 Edit returns
F-6 Make statistical
averages as required
F-7 Prepare in final form
for typing
F-8 Final review
F-9 Print and distribute
X
PROJECTED AC-
COMPLETION TUAL
DATE DATE
7-31
7-31
XXX
X
X X
1
X
X
X
X
X
7-31
8-15
9-15
9-31
10-5
10-30
11-15
11-30
7-31
8-8
11-16
11-16
11-16
11-18
12-17
12-31
'Date of receipt of last form
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Solicitation and Tabulation of Bid Prices for Systems
This section comprises the most difficult and probably the most
significant part of the project. Several of the steps involved are discussed in the
following paragraphs.
Emission standards for each application were selected. In the case of
the LA-Process Weight * limitation, the problem was relatively simple. For the
high efficiency specification, a relationship between particle size distribution,
grain loading, plume depth and the visible threshold was investigated. This
relationship has not been established for the sources involved here. An arbitrary
definition was proposed at a meeting between IGCI and the NAPCA Project
Officer on August 12, and accepted. This is discussed in more detail in the
Technical Data Section of the Report.
Specification form exerts a significant influence on the contractor's
price, particularly when equipment is to perform to a specification such as "the
stack shall be clear". For this reason it was important that each company
preparing a specification worked to a common set of standards. This required a
high degree of unanimity among the member companies on the form of the
specification.
In order to minimize the time required in completing this section of the
program, the Coordinating Engineer drafted a general specification to apply to
all of the processes, which was reviewed by the Engineering Standards
Committee and all the participants.
In the preparation of the bid prices, companies chosen as most qualified
by the Engineering Standards Committee were brought together to discuss the
specifications (this meeting coincided with the seminar described in connection
with writing the process narratives), after which the Engineering Standards
Committee reviewed the specifications. The three companies each prepared
prices for two levels of abatement and three sizes of process. The required
information from the bid forms was entered on the appropriate summary form
by the Coordinating Engineer without reference to the name of the firm
submitting the proposal.
The results were submitted to the Engineering Standards Committee for
final approval. A detailed listing of the steps involved in this process, and a
tentative completion date for each step is given on the following page.
*AirPollution Control District County of Los Angeles Rule 54. See Appendix
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
No.
of
Event
P-1
P-2
Detailed Calendar for Price Quotes
WORK DONE BY
Name of Event
Coor. Ex. Engr.
Engr. Sec. Stds.
Memb. Other
PROJECTED AC-
COMPLETION TUAL
DATE DATE
P-3
P-4
P-5
P-6
P-7
P-8
P-9
P-10
P-11
P-12
Obtain pertinent sec-
tions of LA-APCD pro- X
cess weight standard
Establish approximate
basis for weight emission
at "clear stack" con- X
dition, for review by
Engr. Stds.
7-31
7-31
7-31
7-31
Prepare uniform speci-
fication for system X
for review by Engr. Stds.
Prepare form sheets for
installation data and X
Review with Engr. Stds. XXX
Submit to companies X
selected for narratives
Prepare cost estimates X
Receive completed X
estimates
Review and edit results X
Approve or revise X
Put in final form X
Print & distribute X
8-15
8-15
8-18
8-30
9-30
9-30
10-15
10-30
11-15
11-30
8-15
8-15
8-18
9-3
11-15
11-15
11-19
11-19
12-17
12-31
* Date of receipt of last estimate
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
I.3.C.I. H.E.W. CONTRACT SURVEY
DEADLINE IS APRIL 24
Since 1960, we have sold the following number of installations
of gas clearing equipment in the following applications:
1. Lime industry
a. Rotary lime kiln (not including lime sludge kilns)
Number sold since January 1, 1960
2. Secondary non-ferrous metallurgical industry
Number sold since January 1, 1960
a. Brass reverberatory furnace
b. Lead cupola (blast furnace)
c. Lead sx/eating furnace
d. Lead reverberatory furnace
e. Zinc calcining kiln
f. Aluminum sweating furnace
g. Aluminum Chlorination station
h. Bronze reverberatory furnace
Keep one copy and send one copy by April 24 to:
Mr. Hugh Mullen
Buell Engineering Co., Inc.
253 North Fourth St.
Lebanon, Pa. 17042
Name
Company
Date
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
NAPCA CONTRACT INTEREST SURVEY
Please indicate your company's interest in participating in
each of the following areas with respect to each type of equipment
using a scale from 0-10, with
0 = no interest whatsoever
10 « very strong interest
Area
Interest Level
Elec.Precip. Fabric Wet Scrubbers
la Rotary Lime Kiln
2a Brass Reverberatory Furnace
2b Lead Cupola
2c Lead Sweating Furnace
2d Lead Reverberatory Furnace
2e Zinc Calcining Kiln
2f Aluminum Sweating Furnace
2g Aluminum Chlorination station
2h Bronze Reverberatory Furnace
Signed
Company
DEADLINE - JULY 28. 1970
MAIL TO:
H. R. Herington
P. 0. Box 448
Rye, N. Y. 10580
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
APPENDIX II
Detailed Instructions for Preparing Specifications
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
DETAILED INSTRUCTIONS FOR PREPARING SPECIFICATIONS
The I.G.C.I, as the contractor is to furnish NAPCA with an
analysis of cost requirements for collection systems that can meet
two levels of abatement:
1) The LA-APCD Process Weight Regulation
2) An arbitrary outlet grain loading as shown
in the attached Table I.
The second specification represents a higher efficiency level
than the LA-APCD process weight regulation. While these numbers
are frequently at or below the visible threshold, they do not define
conditions at which a clear stack can be obtained.
Three sizes or capacities are to be figured for each of the
collection systems involved. This means that the specification
given to a member company for preparation of a bid price must con-
tain enough information to define six cases like this:
SMALL
LOW EFF.
MEDIUM
LOW EFF.
LARGE
LOW EFF.
SMALL
MEDIUM
LARGE
HIGH EFF. HIGH EFF, HIGH
The six cases are to be repeated for each collector type
applicable to the industrial area. The I.G.C.I. Engineering Stan-
dards Committee has agreed upon the types of equipment applicable
to each area as shown in the attached Table II.
(There are 20 combinations of equipment type and application
areas which should require 120 separate quotations from the 9
application groups.)
In order to provide a uniform basis to each of the companies
participating in the bid price preparation, it is recommended that
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
- 2 -
this application group prepare a complete specification for the
equipment, consisting of the following items:
1. Scope
2. Process Description
3. Operating Conditions
4. Process Performance Guarantee
5. General Conditions
For most cases, a single set of specifications will suffice
for items 1, 4 and 5 above, regardless of the equipment type or
application area. The Engineering Standards Committee has approved
the wording of the sections of the sample specification attached
for use in this way. These are given page numbers 1, 2, 5 and 6.
Page 3, to be written by the application group, should contain:
(1) A simple description of the equipment that is included,
covering the basic collector and items such as:.
a) type of fabric (for fabric collectors)
b) bag cleaning method (for fabric collectors)
c) materials of construction (for wet scrubbers)
(2) A concise definition of items that are to be included in
the auxiliary equipment cost such as:
a) fans
b) dampers
c) pumps
(3) A brief description of the circumstances involved in
installation of the equipment.
Page 4, to be written by the application group, should summarize
the operating conditions to which the equipment is to be designed
and for which operating costs are to be developed. The following
items should be specified for each of three sizes:
a) Process capacity in appropriate units
b) Inlet gas volume to the collector in ACFM
c) Inlet temperature, °p.
d) Inlet contaminant loading
e) Efficiency, wt 7»
f) Controlled, or outlet contaminant loading
g) Outlet temperature (if different from inlet)
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
- 3 -
h) Outlet gas volume, ACFM (if different from inlet)
i) Type of charge fed to the furnace: - dirty, oily,
scrap, shavings, volatile metals, etc.
Any additional information which will add clarity to the cost
estimates should be included.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
TABLE I
DEFINITION OF OUTLET GRAIN LOADINGS FOR
SECOND EFFICIENCY LEVEL BIDS
1-a Rotary Lime Kilns
2-a Brass Reverberatory Furnaces
b Lead Cupola
c Lead Sweating Furnace
d Lead Reverberatory Furnace
e Zinc Calciner
f Aluminum Sweating Furnace
g Aluminum Chlorination Station
h Bronze Reverberatory Furnace
Outlet
Loading
gr/ACF
0.03
0.01
0.03
0.03
0.01
0.01
0.03
0.02
0.03
-------
10
o
TABLE II
DEFINITION OF COLLECTOR TYPES APPLICABLE TO
VARIOUS INDUSTRIAL AREAS
Collector
Type
Electrostatic
Precipitator
Fabric
Collector
Wet
Scrubber
la
Lime
Kiln
Yes
Yes
Yes
2a
Brass
Reverb .
No*
Yes
Yes
2b
Lead
Cupola
No*
Yes
Yes
2c 2d 2e 2f 2g 2h
Lead Lead Zinc Alum. Alum. Bronze
Sweat. Reverb. Calcin. Sweat. Chlor. Reverb.
No* Yes Yes No* No No*
Yes Yes Yes Yes No Yes
Yes Yes Yes -Yes Yes Yes
* Note that Electrostatic Precipitators are not applicable to these areas
only because the sources are too small to make precipitator application
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
APPENDIX III
Rule 54 of the Air Pollution Control
District of Los Angeles County
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Air Pollution Control District
County of Los Angeles
RULES AND
REGULATIONS
December 4, 1969
434 South San Pedro Street, Los Angeles, California, 90013
MA 9-4711
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Rule 54. Dust and Fumes
A person shall not discharge in any one hour from any source
whatsoever dust or fumes in total quantities in excess of the
amount shown in the following table: (see next page)
To use the following table, take the process weight per hour
as such is defined in Rule 2(j).* Then find this figure on the
table, opposite which is the maximum number of pounds of contam-
inants which may be discharged into the atmosphere in any one hour.
As an example, if A has a process which emits contaminants into
the atmosphere and which process takes 3 hours to complete, he will
divide the weight of all materials in the specific process, in this
example, 1,500 Ibs. by 3 giving a process weight per hour of 500
Ibs. The table shows that A may not discharge more than 1.77 Ibs.
in any one hour during the process. Where the process weight per
hour falls between figures in the left hand column, the exact
weight of permitted discharge may be interpolated.
* Rule 2 (j)
Process Weight Per Hour. "Process Weight" is the
total weight of all materials introduced into any
specific process which process may cause any discharge
into the atmosphere. Solid fuels charged will be
considered as part of the process weight, but liquid
and gaseous fuels and combustion air will not. "The
Process Weight Per Hour" will be derived by dividing
the total process weight by the number of hours in
one complete operation from the beginning of any
given process to the completion thereof, excluding
any time during which the equipment is idle.
(k). Dusts. "Dusts" are minute solid particles released
into the air by natural forces or by mechanical
processes such as crushing, grinding, milling, drilling,
demolishing, shoveling, conveying, covering, bagging,
sweeping, etc.
(1). Condensed Fumes. "Condensed Fumes" are minute solid
particles generated by the condensation of vapors
from solid matter after volatilization from the molten
state, or may be generated by sublimation, distillation,
calcination, or chemical reaction, when these processes
create air-borne particles.
-------
INDUSTRIAL GAS CLEANING
\
^••••••^^^••••^^^^^^^^^•^^^•^^^•^^•^^••M
'Process
Wt/hr(lb»)
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
3100
3200
3300
•See Definition
TABLE
Maximum Weight 'Process
0!sch/hr(lb«) Wt/hr(lbs)
.24
.46
.66
.85
1 ..03
1.20
1.35
1.50
1.63
1.77
1.89
2.01
2.12
2.24
2.34
2.43
2.53
2.62
2.72
2. 80
2.97
3.12
3.26
3.40
3.54
3.66
3.79
3.91
4.03
4.14
4.24
4.34
4.44
4.55
4.64
4.74
4.84
4.92
5.02
5.10
5.18
5.27
5.36
3400
3500
3600
3700
3800
3900
4000
4100
4200
4300
4400
4500
4600
4700
4800
4900
5000
5500
6000
6500
7000
7500
8000
8500
9000
9500
10000
11000
12000
13000
14000
15000
16000
17000
18000
19000
20000
30000
40000
50000
60000
or
more
in Rule 2(j).
INSTITUTE, INC.
Maximum Weight
Disch /hr( Ibi)
5.44
5.52
. 5.61
5.69
5.77
5.85
5.93
6.01
6.08
6.15
6.22
6.30
6.37
6.45
6.52
6.60
6.67
7.03
7.37
7.71
8.05
8.39
8.71
9.03
9.36
9.67
10.0
10.63
11.28
11.89
12.50
13.13
13.74
14.36
14.97
15.58
16.19
22.22
28.3
34.3
40.0
37
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
APPENDIX IV
Sample Specification for
Air Pollution Abatement Equipment
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Page 1
Specifications for Abatement Equipment
1. SCOPE
A. This specification covers vendor requirements for a
to serve as the principal abatement
device in a secondary smelting process. The intent of the specifi-
cation is to describe the service as thoroughly as possible so as
to secure vendor's proposal for equipment which is suitable in
every respect for the service intended. Basic information is
tabulated on pages 2, 3 and 4. The vendor should specify any of
the performance characteristics which cannot be guaranteed without
samples of process effluent.
B. The vendor shall supply all labor, materials, equipment,
and services to furnish one together with
the following auxiliaries:
1. All ladders, platforms, and other accessways to pro-
vide convenient access to all points requiring
observation or maintenance.
2. Foundation bolts as required.
3. Six (6) sets of drawings, instructions, spare parts
list, etc., pertinent to the above.
The vendor shall not include in his base bid the following:
1. Erection
2. Foundation
3. External piping
4. Pumps
5. Fans (if not an internal part 'of the collector)
6. Dust or slurry handling systems
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Page 2
C. The vendor shall furnish the equipment FOB point of
manufacture, and shall furnish as a part of this project competent
supervision of the erection, which shall be by others.
D. Vendor shall furnish the following drawings, etc., as
a minimum:
1. With his proposal:
a. Plan and elevation showing general arrangement.
b. Typical details of collector internals proposed.
c. Data relating to projected performance with
respect to pressure drop, gas absorption effi-
ciency and particulate removal efficiency to
gas and liquor flows.
2. Upon receipt of order:
a. Proposed schedule of design and delivery.
3. Within 60 days of order:
a. Complete drawings of equipment for approval
by customer.
b. 30 days prior to shipment:
1) Certified drawings of equipment, six sets
2) Installation instructions, six sets
3) Starting and operating instructions, six sets
4) Maintenance instructions and recommended
spare parts lists, six sets
E. The design and construction of the collector and auxili-
aries shall conform to the general conditions given on page 6, and
to good engineering practice.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
2. PROCESS DESCRIPTION
The scrubber is to handle the exhaust gas from a rotary lime
kiln fired by natural gas. The filter will be used to remove lime-
stone and lime dust from the exhaust gas. The rotary kiln is fed
with V to V limestone. There is no preheater on the kiln and the
feed end of the kiln is equipped with a dust fall-out chamber. The
dust chamber is followed by a wet scrubber with pre-cooling sprays
or saturation chamber as required. Such pre-cooling equipment is
to be located at the discharge from the fall-out chamber, and must
cool the ductwork to a maximum of 550°F. It will be considered as
an integral part of the scrubber for this quotation.
The exhaust gas will be brought from the precooling section to
a point twenty feet outside the building where a fan will be located.
(The fan outlet is five (5) feet above grade.) The scrubber will
be located in an area beyond the fan. The area is free of space
limitations. The scrubber is to be designed to withstand the full
discharge pressure developed by the fan.
The scrubber is to operate in such a manner as to continuously
attain the efficiency levels specified in the following section.
The scrubber shall have a conical bottom designed to avoid the
collection of sediment or deposits. Liquor effluent is to be piped
to a recirculation tank from which the recirculation pump takes
suction. Fresh makeup water is to be added to the system at this
point. Discharge from the recirculation pump is to be partially
returned to the scrubber and part withdrawn to a slurry settling
basin to be provided by the customer. The slurry withdrawal is to
be set to maintain about 10 weight percent solids when the kiln is
operating at design capacity.
The scrubber and external piping are to be constructed of
carbon steel. Packing glands are to be flushed with fresh water
to prevent binding of the seals.
For purposes of this quotation, the following is to be con-
sidered auxiliary equipment:
(1) pumps and reservoir
(2) fan
(3) external piping
(4) controls
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
3. OPERATING CONDITIONS
Three sizes of scrubbers are to be quoted for each of two
levels of efficiency.
Furnace capacity, ton
Production rate, Ib/hr
Process weight rate, Ib/hr
Inlet gas volume, ACFM
Inlet gas temperature, OF
Inlet loading, Ib/hr
Inlet loading, gr/ACF
Outlet gas volume, ACFM
Outlet gas temperature, °F
(B)
Medium
125
10,400
18,700
35,000
1,200
015
2.32
19,000
164
250
20,800
37,400
85,000
1,200
1,960
2.69
46,000
164
500
41,600
74,800
150,000
1,200
3,500
2.72
81,000
164
Case 1 - LA Process Weight
Outlet loading, #/hr
Outlet loading, gr/ACF
Efficiency, wt %
15.40
0.094
93.1
26.7
0.068
98.6
40
0.053
98.9
Case 2 - High Efficiency
Outlet loading, #/hr
Outlet loading, gr/ACF
Efficiency, wt 7.
4.09
0.03
99.4
11.85
0.03
99.4
20.8
0.03
99.4
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Page 5
4. PROCESS PERFORMANCE GUARANTEE
A. The
will be guaranteed to reduce
the particulate and/or gas contaminant loadings as indicated in
the service description.
B. Performance test will be conducted in accordance with
I.G.C.I, test methods where applicable.
C. Testing shall be conducted at a time mutually agreeable
to the customer and the vendor.
D. The cost of the performance test is to be included in
vendor's proposal as an alternate.
E. In the event the
fails to comply
with the guarantee at the specified design conditions, the vendor
shall make every effort to correct any defect expeditiously at his
own expense. Subsequent retesting to obtain a satisfactory result
shall be at the vendor's expense.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Page 6
5. GENERAL CONDITIONS
A. Materials and Workmanship
Only new materials of the best quality shall be used in the
manufacture of items covered by this specification. Workmanship
shall be of high quality and performed by competent workmen. ,
B. Equipment
Equipment not of vendor's manufacture furnished as a part of
this collector shall be regarded in every respect as though it
were of vendor's original manufacture.
C. Compliance with Applicable Work Standards and Codes
It shall be the responsibility of the vendor to design and
manufacture the equipment specified in compliance with the practice
specified by applicable codes.
D. Delivery Schedules
1. The vendor shall arrange delivery of equipment
under this contract so as to provide for unloading
at the job site within a time period specified by
the customer. Vendor shall provide for expediting
and following shipment of materials to the extent
required to comply with delivery specified.
o 0 o
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
APPENDIX V
Detailed Instructions for Preparing
Bid Price Proposals
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
INSTRUCTIONS FOR COMPLETING TABLE III
Items (1) through (6); The information requested in items (1)
through (6) of Table III is to be taken from the specification.
Item (7): System horsepower is to include the estimated horsepower
at design conditions for the fan and pump drivers.
Item (8); Equipment costs are for immediate delivery.
A. The collector is to be figured on a flange-to-flange
basis and to include no auxiliaries.
B. The Process Description section of the specification
spells out what is to be included as "auxiliaries" in
each case.
C. Gas conditioning equipment includes such items as water
quench systems, and chemical additive systems for altering
flyash resistivity.
D. Waste equipment includes such items as wet scrubber slurry
disposal and dry collector solids handling equipment.
E. "Other" can be used for such equipment items as standby
or safety equipment, water reservoirs, and chemical
storage tanks.
Item (9); Covers the expected difference between the total turnkey
cost of the complete system, and the equipment cost listed in
item (3). This is to be estimated alternately for a complete
new facility (grass roots), and for back-fit into an existing
plant (add-on). For purposes of this study, the turnkey
prices are to be figured as though the installation were to be
made in Milwaukee, Wisconsin where hourly labor rates in the
construction trades are near the average for the U. S. A
tabulation of an hourly rate index for major U. S. cities,
along with a list of the average hourly rates for various
trades is attached.
Item (10); The nominal life of the equipment in years is to
represent your best estimate of actual service life. This
does not constitute a representation which can be applied to
any future specific sale, but should be your best estimate
for the average life equipment in this kind of service.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Page 2
Item (11); An estimate of yearly maintenance costs is required
here. This should include an estimate of man-hours for
service, plus a dollar figure for replacement parts, etc.
NOTE; Please use one form for the high efficiency case, and
another for the low efficiency case.
o 0 o
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
August 24, 1970
TO: Participants in NAPCA Project
FROM: L.C. .Hardison, Coordinating Engineer
SUBJECT: Bid Price Proposals for Erection
The contract with NAPCA specifies that turnkey prices are
to be submitted and that variations in cost from area to area
are to be discussed. Gary Evans, the NAPCA Project Officer }
has suggested a relatively simple way of handling this.
Attached is a copy of City Cost Indexes taken from "Building
Construction Cost Data, 1970"*. This gives a construction
cost index for 90 cities, using 100 as the national average.
These are for the building trades, as reported by the U.S.
Department of Labor. A copy of the rates by trade is also
attached.
While these figures do not take productivity differences into
account, it will be acceptable to NAPCA if we choose a base
location with a labor index of about 100 (such as Milwaukee,
Wisconsin) . The variation in labor rate can be discribed by
using the "City Cost Index" table. Variations in productivity
can be handled by soliciting comments from the companies pre-
paring bid prices as to areas where productivity is likely to be
unusually high or low.
L.C. Hardison
Coordinating Engineer
* by Robert Sturgis Godfrey, published by Robert Snow Means
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
..U..1OI' rates used in this edition are as listed below for 1970. They are averages of
tiie 30 largest cities in the U.S. as reported by the U.S. Dept. of Labor and are
subs tent ial ly tiie same as listed by Engineering News—Record. The rates have been
roundec out to the nearest 5^ and include fringe benefits but do not include insurance
or taxes.
Trade
Common Building Labor
Ski 1 led Average
Helpers Average
foremen (usually 35c over trade)
Bricklayers
Bricklayers Helpers
Carpenters
moment Finis hers
£ lectricians
G laz iers
Hoist n ng ineers
Lathers
Marble & Terrazzo Workers
Painters, Ordinary
Pointers, Structural Steel
Paperhangers
P lasterers
Plasrcrers Helpers
? lumbers
Power Shovel or Crane Operator
Rodmen (Reinforcing)
Roofers, Composition
Roofers, Tile & Slate
Roofers Helpers (Composition)
Steamf itters
Sprinkler Installers
Structural Steel Workers
T ile Layers ( F loor)
T ile Layers Helpers
Truck Drivers
Welders, Structural Steel
1970
$5.00
6.85
5.15
7.20
7.15
5.20
6.95
6.75
7.50
6.25
7.05
6.60
6.45
6.20
6.50
6.30
6.60
5.30
7.75
7.20
7.30
6.30
6.35
4.75
7.70
7.70
7.45
6.50
5.25
5.15
7.15
1969
$4.55
6.05
4.65
6.40
6.40
4.70
6.15
5.90
6.45
5.50
5.90
5.95
5.60
5.45
5.80
5.60
5.95
4.85
6.90
6.20
6.35
5.55
> 5.60
4.45
6.90
6.90
6.45
5.60
4.80
4.60
6.35
1968
$4.10
5.50
4.20
5.85
5.85
4.30
5.40
5.30
5.95
5.10
5.40
5.45
5.25
5.05
5.30
5.15
5.50
4.45
6.15
5.65
5.80
5.05
5.10
4.00
6.10
6.10
5.90
5.20
4.35
4.30
5.80
1967
$3.85
5.15
4.00
5.50
5.55
4.05
5.10
5.05
5.60
4.75
5.10
5.20
5.05
4.75
4.95
4.75
5.15
4.15
5.75
5.35
5.45
4.75
4.85
3.75
5.70
5.70
5.55
4.90
4.15
3.95
5.45
1966
$3.65
4.90
H
3.85
5.25
5.35
3.95
4.90
4.85
5.45
4.60 ".
4.85
5.05 *
4.90
4.50 :
4.8C
4.55 I
5.00
4.00
5.55
5.05
5.15
4.65
4.80
3.55
5.50
5.50
5.25
4.80
4.05
3.65
5.10
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
(p. i)
Tabulated below are average construction cost indexes for 90 major U.S. and Canadian
cities. There are two index figures, one for Labor Rates as compared io the 30 major cities
with U.S. average of 100, the other for Overall or Total construction costs using 100 as ihe
average for 1969 for the 30 major cities. (Cor.f'd on next page)
Average 1969 Construction Cost & Labor Indexes
City
Albany, N.Y.
Albuquerque, N.M
Arnarillo, Tx.
Anchorage, Ak.
Atlanta, Ga.
Baltimore, Md.
Baton Rouge, La.
Birmingham, Al.
Boston, Mo.
Bridgeport, Ct.
Buffalo, N.Y.
Burlington, Vt.
Charlotte, N.C.
Chattanooga, Tn.
Chicago, III.
Cincinnati, Oh.
Cleveland, Oh.
Columbus, Oh.
Dallas, Tx.
Dayton, Oh.
Denver, Co.
Des Moines, la.
Detroit, Mi.
Edmonton, Cn.
El Paso, Tx.
Erie, Pa.
Evansville, In.
Grand Rapids, Mi.
Harrisburg, Pa.
Hartford, Ct.
Honolulu, Hi.
Houston, Tx.
Indianapolis, In.
Jackson, Ms.
Jacksonville, Fl.
Kansas City, Mo.
Knoxville, Tn.
Las Vegas, Nv.
Little Rock, Ar.
Los Angeles, Ca.
Louisville, Ky.
Madison, Wi.
Manchester, N.H.
Memphis, Tn.
Miami, Fl.
!nc
Labor
98
86
87
131
88
90
83
79
106
104
104
86
70
31
107
108
121
106
86
100
94
93
117
80
77
93
93
103
90
104
99
92
97
73
78
94
82
115
78
113
92
95
89
83
98
ex
Total
100
95
84
148
94
93
88
S6
103
102
107
90
75
84
103
104
112
99
89
103
91
96
111
83
83
99
97
99
92
100
109
89
98
75
79
93
82
107
81
102
93
98
92
82
94
City
Milwaukee, Wi.
Minneapolis, Mn.
Mobile, Al.
Montreal, Cn.
Nashville, Tn.
Newark, N.J.
New Haven, Ct. •
New Orleans, La.
New York, N.Y.
Norfolk, Vo.
Oklahoma City, Ok.
Omaha, Nb.
Philadelphia, Pa.
Phoenix, Az.
Pittsburgh, Pa.
Portland, Me.
Portland, Or.
Providence, R.I.
Richmond, Va.
Rochester, N.Y.
Rockford, III.
Sacramento, Ca.
St. Louis, Mo.
SaltLakeCity, Ut.
San Antonio, Tx.
San Diego, Ca.
San Francisco, Ca.
Savannah, Ga.
Scranton, Pa.
Seattle, Wa.
| Shreveport, La.
| South Bend, In.
Spokane, Wa.
Springfield, Ma.
Syracuse, N.Y.
Tampa, Fl.
Toledo, Oh.
Toronto, Cn.
Trenton, N.J.
Tulsa, Ok.
Vancouver, Cn.
Washington, D.C.
Wichita, Ks.
Winnipeg, Cn.
Youngstown, Oh.
1 ndex
Labor
103
99
94
77
79
122
102
89
132
73
82
90
106
101
110
82
102
98
76
no
109
117
no
93
82
111
124
72
94
104
82
99
101
99
105
81
105
84
114
85
81
98
85
62
107
Total
108
98
90
89
82
109
100
95
118
77
88
93
101
97
106
87
103
97
79
107
109
110
103
95
82
107
109
77
96
99
89
97
100
97
103
84
105
93
103
89
91
94
90
82
106
Historical Average
Year
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956
1955
1954
1953
1952
1951
1950
1949
1948
1947
1946
1945
1944
1943
1942
1941
1940
1939
1938
1937
1936
1935
1934
1933
1932
1931
1930
1929
1928
1927
1926
1925
1924
Index
100
91
86
83
79
78
76
74
72
71
69
67
65
63
59
58 -
57
55
53
49
48
48
43
35
30
29
29
28
25
24
23
23
23
20
20
20
18
17
20
22
23
23
23
23
23
23
138
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
APPENDIX VI
Detailed Instructions for
Listing Installations
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
IGCI
HERBERT R. HERINGTON
Executive Secretary
National Association of Manufacturers of Industrial Gas Cleaning Equipment
Box 448, Rye, N. Y. 10580
Telephone: Area Code 914
WOodbine 7-7044
August 8, 1970
TO: All Corporate Representatives
FROM: L. C. Hardison, Coordinating Engineer
SUBJECT: Summary of Installation Data
The NAPCA contract with I.G.C.I, specifies that the member
companies prepare, for each of the sources below, a listing of all
the installations made since January 1, 1960, and all the pertinent
test data in the I.G.C.I, members' files. The sources to be included
in this tabulation are:
1. Lime Industry (not including pulp or paper mill applications)
a. Rotary lime kiln
2. Secondary non-ferrous metallurgical industry
a. Brass reverberatory furnace
b. Lead cupola (blast furnace)
c. Lead sweating furnace
d. Lead reverberatory furnace
e. Zinc calcining kiln
f. Aluminum sweating furnace
g. Aluminum chlorination station
h. Bronze reverberatory furnace
All of the material requested is to be listed in Table I. An
example entry is included with your copies of the blank forms to
assist you in filling them out. Duplicate forms are included so you
may retain a copy for your files. In addition, some detailed
instructions follow.
Some comments apply generally. An installation consists of
all of the equipment installed to process gas from a single source.
For example, if two scrubbers are operated in parallel on the gas
from an aluminum chlorination station, they should be covered by
a single entry. The gas volume, etc., relates to the total flow
through both scrubbers.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Summary of Data
- 2 -
8/8/70
It has been generally agreed that none of the applications
involved in the study can be handled adequately by a mechanical
collector alone. However, there are many installations which incor-
porate a mechanical ahead of a precipitator, scrubber or filter.
Where this is the case, please treat the mechanical as a part of
the gas cleaning device, and call attention to the tandem arrange-
ment in the "remarks".
Where only a part of the data requested is available, please
indicate the information which is not available in your files by
entering "NA" in the appropriate space. The same abbreviation may
be used to indicate that information called for is not applicable
to the installation in question.
Please note that there is no space for the name of your company
on the forms. Be sure to attach something to identify the company
to the completed forms, but don't put your company name on the forms
themselves. Return the completed forms to Herb Herington.
The remainder of the comments and instructions pertain to the
individual columns in Table I, which are numbered across the top of
the pages.
1. Column 1 is for the purpose of indexing the summary of tests
from all of the member companies. Please enter the data
serially according to the date the installation was put into
service, starting with January 1, 1960 and working toward
the present. Number the earliest installation #1, so that
the last "Test number" on your form represents the total
number of installations your company has made since January
1, 1960. If you wish to use another test number for your
own reference, enter it in parenthesis below the sequential
numbers.
2. Capacity - The capacity of the source will be presented in
appropriate units (tons/day, tons/heat, or tons/hr.). The
capacity reported will be the design capacity for the piece
of source equipment or the maximum design condition for the
collector.
3. Type of raw material or charge - The composition of the raw
material or charge will be presented on a percent by weight
basis.
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INDUSTRIAL GAS CLEANING INSTITUTE, INC
Summary of Data
- 3 -
8/8/70
4. Fuel Used - The type of fuel used in firing the source equip-
ment will be presented. Sulfur and ash contents for coal and
oil will be reported.
5. Type collector and year placed in service - The type of
collector will be described (i.e., - venturi- 30" W.G.,
Fabric Filter - Orion bags, ESP - collector surface area)
and the year placed in service will also be listed.
6. Gas Volume - The gas volume at the design capacity will be
presented in acrual cubic feet per minute. For the case of
wet scrubbers, the capacity of the source should be reported
in ACFM, and the capacity of the scrubber reported in ACFM
saturated beneath the hot gas figure.
7. Temperature - The temperature at the collector inlet in °F
will be presented. Where a saturated gas volume is presented
for a wet scrubber capacity, the saturation temperature should
be given in parenthesis below the hot gas temperature.
8. Measured Grain Loading - The inlet and outlet grain loadings,
at the collector, measured by a source test, will be presented
in grains per ACF.
9. Design Efficiency - The design collection efficiency for the
collector will be presented. The measured or test efficiency
of the collector, calculated from the grain loadings in column
8, should be entered in parenthesis below the Design Efficiency.
10. Plume Visibility - Is plume visible after collection? Answer
yes or no. If yes, an explanation as to % opacity, time
span, and process step during which plume is visible (i.e.,
charging, melting, pouring), should be presented on the
remarks sheet, and referenced in column 15. jtfLts^/b */••
11. Particle size distribution and method - The particle size
distribution and the method of measurement will be presented.
12. Dust Resistivity and method of measurement - The contractor
shall present information on the dust resistivity (ohm - cm)
and the temperature (°F) at which the measurement was made.
The method of measurement, laboratory or in situ, shall also
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INDUSTRIAL GAS CLEANING INSTITUTE, INC.
Summary of Data
- 4 -
8/8/70
be presented. The dust resistivity measurement is applicable
only to precipitator installations, but should be reported,
if known, regardless of the type of collector installed.
13. Chemical composition of particles - The chemical composition
of the particles on a percent by weight basis shall be pre-
sented.
14. Chemical composition of gas stream - The chemical composition
of the gas stream on a percent by volume basis shall be
presented.
15. Any remarks which might serve to clarify or enhance the value
of the reported data should be presented on a separate sheet
with reference numbers indicated in column 15. For example,
a mechanical collector is frequently included in a scrubber
or filter application. This pertinent fact should be clearly
indicated in the "remarks".
LCH:js
Addendum:
Item No. 10: For wet scrubbers only:
If the plume appears to consist x^holly
of condensed water vapor, answer "no"
in column 10, and note in the remarks
that there was a visible steam plume.
-------
TABLE I page 2 SOURCE:
to
8
OUPWIAKI LIT 11NO1 ALLiAl 1UJN JJ J\ 1 t\
CD
TEST
NO.
(ID
PARTICLE
SIZE
*L
<
>
WT.%
IN
RANGE
METHOD
OF
ANALYSIS
(12)
RESISTIVITY
OHM- CM
RESIST.
TEMP . F
METHOD
OF
ANALYSIS
(13)
CHEMICAL
COMP. OF
PARTICLES
COMP .
WT.%
(14)
CHEMICAL
COMP. OF
GAS
COMP .
VOL.1
(15)
REMARKS
NOTE
5
5. Remarks which might serve to clarify or enhance the value of the reported data should be
-------
TABLE I SOURCE:
SUMMARY OF INSTALLATION DATA
(1)
TEST
NO.
(2)
CAP.
OF
UNIT
(3)
TYPE OF RAW l
MATERIAL OR
CHARGE
(4)
FUEL2
USED
(5)
TYPE3
COLLECTOR
(Sa)
YEAR
PLACED
IN
SERVICE
(6)
GAS
VOLUME
ACFM
(7)
INLET
TEMP.
°F
(8a) (8b)
MEASURED
DUST LOADING
GR/ACF
INLET
OUTLET
(9)
DESIGN
EFF.
WT. %
(10)
IS4
PLUME
VISIBLE
1.
2.
3.
4.
ro
oo
co
The composition of the raw material or charge should be presented on a wt.% basis.
The type of fuel used in firing should be presented. Report sulfur and ash content of coal.
Describe^ the type of collector. Examples: Venturi-30" w. c.jFabric Filter, Orion BagsjESP, Area.
Is the plume visible after collection? Answer yes or no here. If yes, an explanation as to time
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC.
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
APPENDIX VII
List of IGCI Publications
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
-------
INDUSTRIAL GAS CLEANING INSTITUTE, INC
APPENDIX VII
LIST OF IGCI PUBLICATIONS
"Test Procedure for Gas Scrubbers" (WS-1)
"Terminology for Electrostatic Precipitators" (E-P 1)
"Procedure for Determination of Velocity and Gas Flow Rate"
(Electrostatic Precipitators Div.) (E-P 2)
"Criteria for Performance Guarantee Determinations"
(Electrostatic Precipitators Div.) (E-P 3)
"Evaluation Bid Form" (Electrostatic Precipitators Div.) (E-P 4)
"Information Required for the Preparation of Bidding
Specifications for Electrostatic Precipitators" (E-P 5)
"Pilot Electrostatic Precipitators" (E-P 6)
"Gas Flow Model Studies" (E-P 7)
"Cyclonic Mechanical Dust Collector Criteria"
(Mechanical Collectors Div.) (M-2)
"Gravity, Louver and Dynamic Mechanical Collector Criteria" (M-3)
"Gaseous Emissions Equipment: Product Definitions and
Illustrations" (Gaseous Control Div.) (G-1)
"Fundamentals of Fabric Collectors and Glossary of Terms" (F-2)
"Operation and Maintenance of Fabric Collectors" (F-3)
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