United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/2-79-203
November 1979
Research and Development
Sinter Plant Windbox
Recirculation and Gravel
Bed  Filter Demonstration
Phase 2. Construction,
Operation, and

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                  RESEARCH REPORTING SERIES


 Research reports of the Office of Research and Development, U.S. Environmental
 Protection Agency, have been grouped into nine series. These nine broad cate-
 gories were established to facilitate further development and application of en-
 vironmental technology. Elimination of traditional  grouping was consciously
 planned to foster technology transfer and a maximum interface in related fields.
 The nine series are:

    1.  Environmental Health Effects Research

    2.  Environmental Protection Technology

    3.  Ecological Research

    4.  Environmental Monitoring

    5.  Socioeconomic Environmental Studies

    6.  Scientific and Technical Assessment Reports (STAR)

    7.  Interagency Energy-Environment Research and Development

    8.  "Special" Reports

    9.  Miscellaneous Reports

 This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
 NOLOGY series. This series describes research performed to develop and dem-
 onstrate  instrumentation, equipment, and methodology to  repair or prevent en-
 vironmental degradation from point and non-point sources of pollution. This work
 provides  the new or improved technology required for the control and treatment
 of pollution sources to meet environmental quality standards.
                        EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.

This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                         EPA-600/2-79-203

                                            November 1979
  Sinter Plant Windbox Recirculation and
Gravel Bed Filter Demonstration: Phase 2
 Construction, Operation, and  Evaluation
                             by

                          G.P. Current

                      National Steel Corporation
                       Weirton Steel Division
                          P.O. Box 431
                     Weirton, West Virginia 26062
                      Contract No. 68-02-1862
                     Program Element No. 1AB6Q4C
                  EPA Project Officer: Robert C. McCrillis

                 Industrial Environmental Research Laboratory
               Office of Environmental Engineering and Technology
                    Research Triangle Park, NC 27711
                          Prepared for

                U.S. ENVIRONMENTAL PROTECTION AGENCY
                   Office of Research and Development
                       Washington, DC 20460

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                  PHASE ii - FINAL REPORT ABSTRACT
This two-phase research program was initiated with the overall objective
of developing new technology for the reduction of exhaust gas volume and
the control of emissions from the sintering process in the steel industry.
Phase I of the program entailed the engineering and design of a windbox
gas recirculation system for the purpose of reducing effluent gas volume
and related emissions from the National Steel Corporation, Weirton Steel
Division No. 2 Sinter Machine located in Weirton, West Virginia.  This
effort was completed in fulfillment of Contract No. 68-02-1364.  This
Final Report was issued in August 1975 (available from NTIS as Report
No. PB249-564/AS).   Phase II of the program entailed the construction,
operation and evaluation of the windbox gas recirculation system for the
Weirton Steel Division No. 2 Sinter Machine.  In addition, the Phase II
Program called for the construction, operation and evaluation of a gravel
bed filter system which heretofore had been untried technology in the con-
trol of sinter plant emissions.

This Final Report was submitted by the National Steel Corporation, Weirton
Steel Division, as stipulated in Contract 68-02-1862 under the partial
sponsorship of the Federal Environmental Protection Agency.  This work was
completed as of December, 1978.

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                           TABLE OF CONTENTS

                                                                   Page
Abstract	ii
List of Figures	iv
List of Tables	v
Acknowledgments.	vi

SECTIONS
I         - Introduction	   1
II        - Conclusions	   3
III       - Recommendations	   6
IV        - Description of Sintering Process and Air Pollution
            Control Technology
          - (A) Sinter Process 	   7
          - (B) Windbox Gas Recirculation System 	   9
          - (C) Gravel Bed Filter System	13
V         - Evaluation of the Windbox Gas Recirculation and
            Gravel Bed Filter Systems
          - (A) Sinter Strand Operations and Product Quality ...  19
          - (B) Operating Problems 	  40
          - (C) Environmental Aspects	48
          - (D) Energy Aspects	66
          - (E) Capital and Operating Costs	71
VI        - References	76
VII       - Appendix	77
                              111

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                       LIST OF FIGURES

Figure
  No.                                                Page

  1      Schematic Flow Diagram for a Typical Modern    8
         Sinter Plant

  2      General Arrangement - Weirton Steel Division  10
         Sinter Plant Gas Recirculation System

  3      Gravel Bed Filter Flow Sheet                  14

  4      Gravel Bed Filter Module-       Flow Mode     16
  5      Gravel Bed Filter - Backflush Mode            17
  6      Comparative Average Strand Suction Profiles   26

  7      Strand Waste Gas Temperature Profile -        28
         Base Period
  8      Strand Waste Gas Temperature Profile -        30
         Recycle Period
  9      Comparative Average Strand Waste Gas          3.1
         Temperatures Profile
 10      Comparative Average Strand Waste Gas          34
         Oxygen Profiles
 11      Comparative Average Strand Waste Gas          35
         Carbon Dioxide Profiles
 12      Comparative Average Strand Waste Gas          36
         Carbon Monoxide Profiles
 13      Velocity Traverse Stations on the Sinter      51
         Plant Gas Recirculation System
 14      Environmental Protection Agency Method 5 -    53
         Particulate & Hydrocarbon Sampling Train
 15      Sampling Train for S02  Determination         54
                              IV

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                         LIST OF TABLES
   Table
    No.
                                                                Page
    1       Sinter Mix Composition                               22
    2       Operating Data                                       23
    3       Suction Data                                         25
    4       Temperature Data                                     27
    5       Windbox Gas Composition and Temperature              32
    6       Comparative Average Waste Gas Composition            33
    7       Fan Data                                             38
    8       Sinter Properties - Physical and Chemical            39
    9       Summary of Test Results - Test Mode Nos.  1-4         58
    10      No Recycle Test Results - Test Mode No. 1            59
    11      Recycle Test Results    - Test Mode No. 2            60
    12      Gravel Bed Filter-No Recycle Test Results -          61
                                    - Test Mode No. 3
    13      Gravel Bed Filter-Recycle Test Results -             62
                                    - Test Mode No. 4
    14      Sinter Plant Energy Usage                            69
    15      Actual Capital and Operating Costs -                 72
            Windbox Gas Recirculation System
    16      Projected Capital and Operating Costs -              74
            Gravel Bed Filter System
    17      Projected Capital and Operating Costs -              75
            Combined Systems
Appendices
    18-26   Windbox Gas Recycle Sampling Detailed Results        78-86
    27      Velocity Measurement Summary-Sinter Machine Recycle  87
    28      Velocity Measurement Summary-Recycle Fan             88
    29      Velocity Measurement Summary-Waste Gas Fan           89
    30-39   Gravel Bed Filter Sampling Detailed Results          90-99

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                 ACKNOWLEDGEMENTS

The following personnel are recognized  for  their  contri-
bution and assistance in preparation of  this report:

NATIONAL STEEL CORPORATION:
     Weirton Steel Division
     Mr. S. J. Kraynak   - Assistant Project Director
     Mr. D. A. Velegol   - Assistant Project Director
     Mr. F. W. Garrison  - Assistant Project Director
     Mr. R. A. Kinney    - Accounting
     Research and Development
     Mr. K. P. Hass
     Mr. G. W. Hudiburgh
REXNORD INCORPORATED
     Mr. R. E. Shumway
     Mr . D.    Janocik
     Mr. T.    Orr
ENVIRONMENTAL PROTECTION AGENCY:
     Mr. R. C. McCrillis  - Project Officer
     Metallurgical Processes Branch
     Industrial Environmental Research  Laboratory
                         VI

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                               SECTION I

                             INTRODUCTION
Control of emissions from the main windbox system of sintering plants in
the steel industry is a difficult problem.  While technically feasible
control processes exist, improvements to present technology are needed
to achieve more effective, reliable and economical control of these
emissions.  Due to the high percentage of windbox particulate emissions
under ten microns in size, cyclone and multiclone installations have been
proven inadequate in this application.  High moisture, acid salts and
condensible hydrocarbons in the windbox discharge can cause serious oper-
ating problems in wet scrubber, electrostatic precipitator (dry and wet),
and baghouse installations.   Further disadvantages are associated with
the wet-type control technologies due to the related water pollution con-
trol problems.  Dry electrostatic precipitators have been the most common
type of high efficiency collector used on windbox discharges.  However,
with the trend to higher basicity sinter, indications are that the dry
electrostatic precipitator does not perform satisfactorily as a control
technology in this application, in that the higher lime content of the
sinter results in a dust with a resistivity which is not effectively
collected.  These problems have prompted efforts by National Steel Corpor-
ation, Weirton Steel Division, to investigate and develop new technology
which may improve sinter plant emissions control.

Preliminary investigation by National Steel Corporation had indicated
that recirculation of a portion of the gases generated in the windbox
system of the sintering process may significantly reduce particulate and
hydrocarbon emissions to the atmosphere.  Further work completed by the
Company, under the partial sponsorship of the Federal Environmental
Protection Agency, developed the trade-offs of gas recycle ratio versus
oxygen content, moisture content, and temperature of the gases above the
bed, as well as power consumption and other important parameters (1) *.
Preliminary investigation by the Company had also indicated, on a pilot
scale, that gravel bed filtration can remove*  main windbox particulate
emissions with the presence of condensible hydrocarbons in the gas
stream.  Based on these investigations, the technologies of windbox gas
recireulation and gravel bed filtration were recommended for full scale
evaluation.


* - See Section VI, References

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SECTION I - INTRODUCTION (contd)
The above work was considered Phase I of a two-phase research program
jointly funded by National Steel Corporation-Weirton Steel Division and the
Federal Environmental Protection Agency, for development of the new sinter
plant windbox air pollution control technology.  The Final Report for this
Phase I   program was issued in August 1975 (1).  Phase II of the program,
which followed the issuance of the Phase I Final Report, entailed the
construction, operation and evaluation of the windbox gas recirculation
system for the purpose of reducing effluent gas volume and related
emissions from the National Steel Corporation, Weirton Steel Division
No. 2 Sinter Machine located in Weirton, West Virginia.  In addition, the
Phase II program entailed the construction, operation and evaluation of a
gravel bed filter system as the final particulate emission control device
for the sinter machine.

The scope of work in the Phase II program required the issuance of this
Final Report, detailing the results of this demonstration after the
evaluations were completed.

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                          SECTION II - CONCLUSIONS

A.  Windbox Gas Reci.rculati.on System

    1.  The use of windbox recirculation at the Weirton Steel Division
        No, 2 Sinter Machine produced no significant change in the process
        control requirements and product quality,

    2.  Significant operating and maintenance problems noted during this
        demonstration were (1) fan erosion; (2) additional time required
        for routine maintenance of the sinter machine; and (3) expulsion
        of gases from under the sinter machine recycle hood during the use
        of higher than twenty-five percent recycle.

    3.  The percentage mass emissions reduction achieved for particulate
        matter is principally a function of the percentage of gas recir-
        culated,  Recirculation of twenty-five percent of the total waste
        gas volume was achieved,

    4.  The test program indicated that under either operating mode, more
        than 85 percent of the hydrocarbon charge rate was destroyed by the
        sintering process.  However, in view of the questions concerning
        condensable hydrocarbon sampling and analyses procedures, and the
        inconsistencies in the data generated in the test program, it must
        be emphasized that any judgements concerning this parameter must
        be made cautiously.

    5.  The installation of the windbox gas recirculation system resulted
        in a decrease in coke breeze consumption of 146 joules per metric
        ton (125,000 b.t.u,/ton) of sinter, an increase in electrical
        power consumption of 77 joules per metric ton (66,000 b.t.u./ton)
        of sinter, and a decrease in total energy consumption of 69 joules
        per metric ton (59,000 b.t.u./ton) of- sinter.  The trade-off between
        the decreased coke breeze consumption and increased electrical con-
        sumption represents an extremely unfavorable economic balance due
        to the relatively low cost of coke breeze and high cost of
        electricity.

    6.  The capital cost for the windbox gas recirculation system was
        $5,334,000 escalated to 1978 market conditions.  The operating
        and maintenance cost, escalated to 1978 market conditions, was
        $864,000 per year which is equivalent to $0.79 per metric ton
        ($0.72/ton) of sinter produced.

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SECTION II - CONCLUSIONS (cont'd)

B.  Gravel Bed Filter System

    1.  Operating experience has established that moisture condensation
        occurs in the sinter machine exhaust system as a result of the
        waste gas passing through its dew point during the start-up phase
        of operation.  This phenomemon cannot be totally eliminated and
        the detrimental effects of the moisture reaching the gravel bed
        filter system cannot be over-emphasized.  The moisture combines
        with the limeTich sinter dust collected in the beds to form a
        scale on the surface of the support screens.  This blinding action,
        in turn, results in high backflush air velocity which can displace
        the media during the filter cleaning mode and cause short-circuiting
        and inefficiency in the system.

    2.  Test results during the demonstration period indicated a parti-
        culate removal efficiency of eighty-five percent for gravel bed
        filtration alone.  These results were undoubtedly affected by the
        blinding problem cited above.

    3.  Testing indicated that gravel bed filtration reduced condensable
        hydrocarbon emissions by approximately twenty-eight percent.  It
        is presumed that this reduction occurred due to condensation and
        deposition in the system at temperatures below 120  C.  The benefit
        of this condition is questionable since it could be contributing
        to the screen blinding problem.  Again it must be emphasized that
        due to the uncertainties involved in the method of condensable
        hydrocarbon determinations, data generated for this parameter should
        be viewed accordingly,

    4.  The operation of the revised gravel bed filter system will result in
        an increase in electrical power consumption of 46 joules per metric
        ton (40,000 b.t.u./ton) of sinter produced.  Coke oven gas consump-
        tion will increase 47 joules per metric ton (41,000 b.t.u./ton) of
        sinter produced.

    5.  The projected capital cost for the revised gravel bed filter system
        is $5,'101,000 based on 1978 market conditions.  The operating cost,
        projected on 1978 market conditions is $1,198,000 per year which is
        equivalent to $1.10 per metric ton ($1.00/ton) of sinter produced.

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SECTION II - CONCLUSIONS (cont'd)

C.  Combined Systems

    1.  Windbox gas recirculation and gravel bed filtration are compatible
        control technologies.

    2.  An energy analyses of the combined systems indicate an increase
        in electrical power consumption of 86 percent or 123 joules per
        metric ton (106,000 b.t,u,/ton), an increase in coke oven gas
        consumption of 21 percent or 47 joules per metric ton (41,000
        b,t.u./ton) and a decrease in coke breeze consumption of 7 percent
        or 146 joules per metric ton (123,000 b.t.u./ton) of sinter pro-
        duced.  The total energy consumption will increase one percent
        or 24 joules per metric ton (21,000 b.t.u./ton) of sinter.  It
        must, again, be emphasized that the trade-off between the decreased
        coke breeze consumption and the increased electrical power consump-
        tion presents an extremely unfavorable economic balance due to the
        relatively low cost of coke breeze and high cost of electricity.

    3,  The total projected capital cost for the combined systems is
        $10,435,000 based on 1978 market conditions.  The projected oper-
        ating cost of $2,062,000 per year of $1.89 per metric ton ($1.72/ton)
        of sinter produced.

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                        SECTION III - RECOMMENDATIONS
The relative merits of the Sinter Plant Windbox Gas Recirculation and
Gravel Bed Filtration technologies cannot be established until total optimi-
zation of these facilities is achieved.  For this reason, recommendations
concerning the acceptability of these technologies cannot be documented.
However, it is recommended that the economic, energy, and environmental
relationships of the following considerations be thoroughly investigated
by any entity contemplating the future application of these technologies
in the sinter industry:

1.  The size of the final air pollution control device can be minimized
    and the windbox gas recirculation rate can be maximized by reducing
    the leakage rate into the system at the pallet train and windbox
    junctures of the sinter machine.

2.  A practicable method of minimizing the detrimental effects of
    moisture on the gravel bed filter system is necessary to improve
    the efficiency and reliability of the system.

In addition, it is recommended that any judgements concerning the conden-
sable hydrocarbon data in this report be made cautiously.  Considerable
confusion presently exists nation-wide concerning the proper procedures
for accurate condensable hydrocarbon sampling and analysis, and a standard-
ized method should be developed and documented.

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                               SECTION IV

                     DESCRIPTION OF SINTERING PROCESS
                                  AND
                     AIR POLLUTION CONTROL TECHNOLOGY

Section IVA - Description of Sintering Process

The sintering process is utilized by the steel industry to agglomerate
large quantities of iron ore fines and steel mill waste iron oxides into
a suitable raw material for the production of iron in a blast furnace.
Figure No. 1 is a schematic flow diagram for a typical modern sinter plant.
In essence a sintering plant is a solid waste recovery plant which con-
serves our natural resources and eliminates a solid waste disposal problem.
The first step in the production of sinter involves the mixing of ore fines,
thickener sludge, iron scale, and other iron-bearing waste materials with
coke breeze and limestone to form a mass which can be ignited to produce
an aggregate.  The coke breeze is added to provide the required fuel for
downdraft combustion in the sintering process, while the limestone pro-
vides the necessary  flux for the sinter when it is subsequently pro-
cessed in the blast furnace.  These materials, which make up the burden to
the sinter machine, are passed through a balling drum to blend and agglom-
erate the constitutents into a permeable mixture which will result in
rapid and uniform sintering.

After balling, the mixture is charged onto a traveling grate (sintering
machine) to form a bed approximately 30.5 centimeters (12 inches) deep.
Sinter machines operated by National Steel Corporation range in size from
2.45 to 3.96 meters (8 to 13 feet) wide and 31.70 to 60.66 meters (104
to 199 feet) long.  The No. 2 Sinter Machine at Weirton Steel Division is
3.66 meters (12 feet) wide and 44.81 meters (147 feet) long.  Near the
entry or feed end of the machine, the bed is ignited on the surface by
gas burners in a furnace, and as the mixture moves along on the traveling
grate, air is continuously drawn through the bed to support the combustion
of the material.  The combustion process progresses downward through the
bed at temperatures of 1300° to 1500° C. (2372° to 2732° F.) until the
entire depth of the charged material is sintered.  The moving grate then
discharges the sintered material for further processing and subsequent
charging into the blast furnace.

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00
     SINTER
     STORAGE
                TRANSFER CAR
        -».TO BLAST FURNACE
                      (.*.)
CRUSHER l\

      /""T
 ORE
SCREEN
  Ifci
                                -h OVERSIZE
                                - UNDERSIZE
 ORE
SCREEN
                                                      ORE
                   ROD






1

MILL 1
1 »
' 1




*
                        BALLING DRUM
           PUG
           MILL
     IRON MATERIALS BJN
                                     COKE
                                                                       LIME
                                                  COLD
                                                  RETURN
                 f  S~\ HOT RETURNS
                    \^/ SURGE BIN
                         TO HEARTH LAYER
                          SINTER COOLER
                       YYVYVYYVY
                      JH
            hri
 HOT
SCREEN
                                          SINTER BREAK
                                SINTER MACHINE
                              IGNITION
                              FURNACE
                                                               POLLUTION f
                                                                CONTROL L
                         COOLING FAN                         SINTER FAN
                                           FIGURE  I
                              Schematic  flow  diagram for typical  modem sinter plant

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Section IVA  (contd)

Excess air plus  the combustion  products and unagglomerated particulate
matter are drawn through  the  sintering bed and  enter  large chambers  lo-
cated under  the  moving  grates.   These chambers, which run the  length of
the machine  are  referred  to as  windboxes.  A dual arrangement  of fourteen
windboxes is   located under the Weirton Steel Division No. 2 Sinter  Machine
(see Figure  2).   Each windbox is equipped with  facilities to discharge
and return to  the plant, material which has been drawn through  the grates
and collected  in the windboxes.   Other components in  the Weirton Steel
Division No. 2 Windbox  Gas System include pollution abatement  facilities,
induced draft  fans, associated  ductwork, and a  main discharge  stack.
These facilities are discussed  in detail in Sections  IVB and IVC.

Section IVB  -  Description of  Windbox Gas Recirculation System

Windbox gas  recirculation, as applied to a sinter plant, involves the re-
turn of a portion of the  windbox exhaust gas to a hood above the sinter
bed.  The objective is  to reduce the volume of  waste  gas to be cleaned
and to conserve  a part  of the sensible heat in  the windbox exhaust gas.
The portion  of gas recycled to  the machine must pass  through the heat
zone of the  sinter bed  thus providing the potential for the reduction of
hydrocarbons through carbonization.

Figure No. 2 illustrates  the  general arrangement of the Weirton Steel
Division Sinter  Plant Gas Recirculation System.  Two  induced draft fans,
identical in performance  and  construction, operate in parallel to provide
the necessary  air for downdraft combustion and  cooling in the  sinter bed.
The effluent gases and  particulate matter exhausted from the sinter  bed
by these fans  enter the dual  arrangement of fourteen  windboxes under
the sinter strand, and  pass through downcomers  to two parallel waste gas
mains on the east and west sides of the machine.  Each waste gas main
transports fifty percent  of the sinter machine  windbox effluent to  a
series of four cyclone  dust collectors for the  removal of the  larger par-
ticulate matter.  From  the cyclones, the windbox effluent re-combines in
a plenum chamber for distribution  to the two induced  draft fans.   Each
fan was designed  to exhaust 11,082 cubic meters per minute (393,000 ACFM)
at, a temperature of 194° C.   (382° F.),  and a static pressure  of 1290
millimeters  w.ater column  (50.8 In. WC) at a rating of 3357 kilowatts
(4500 bhp).

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                                                   RECYCLE HOOD
               WASTE GAS
             CONTROL HOUSE
                             Figure No. 2
                           General arrangement of system
WEIRTON STEEL DIVISION SINTER PLANT GAS RECIRCULATION SYSTEM

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Section IV-B (cont'd)

The waste gas fan exhausts fifty percent of the total gas volume from
the plenum chamber and delivers it to the stack or the gravel bed filter
system.  The recycle gas fan exhausts the remaining fifty percent of the
gas volume from the plenum chamber, and recirculates, by design, 39 per
cent of the total gas volume to the sinter machine via an insulated re-
cycle gas main, six distribution ducts and a modular recycle hood which
extends from the ignition furnace to the sinter breaker.  The modular
recycle hood is designed for quick removal of individual sections to
facilitate maintenance.  The remaining flow from the recycle fan is de-
livered to the stack or gravel bed filter system.

Two hood valves and two stack valves are located in the discharge ducts
from the recycle gas fan.  One hood valve in the recycle gas main, and
one stack valve in the diverter duct on the recycle fan discharge, con-
trol the volume of gas recirculated to the sinter machine.  The control
circuits for the hood valve and the stack valve are so arranged that
either valve can be selected to provide range control of the volume and
pressure of gas recycled to the sinter machine hood while the other valve
provides trim control.  The selected range valve is manually positioned
and the trim valve can be automatically controlled to maintain the de-
sired hood pressure.  In the automatic mode the controller senses hood
pressure, and position in the selected valve in the duct to control the
pressure in the hood.  In addition, two manually operated valves, one
each upstream of the previously discussed hood and stack valves, are
normally used for shut-off of gas flow.  These four valves provide flexi-
bility in the system to permit a once-through operation, or recirculation
rates ranging from zero to fifty percent,

A comprehensive evaluation of the advantages and disadvantages of Windbox
Gas Recirculation was completed prior to committing the installation of
this technology for the Weirton Steel Division No. 2 Sinter Machine. This
technology offers the following potential advantages:

1.  The quantity of gases to be cleaned by the final air pollution
    control facility is reduced by the percentage of waste gas
    recirculated.

2.  The capital investment for the final air pollution control
    facility is reduced,

3.  The recirculated portion of gas passes through the heat zone in
    the sinter bed, thus providing the potential for hydrocarbons
    reduction via carbonization.
                                     11

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Section IVB (cont'd)

4.  The recirculation of hot gases to the sintering process provides
    a potential for energy conservation.

Potential disadvantages of this technology are as follows:

1.  Higher maintenance requirements will result due to the installation
    of additional facilities.  In particular, recycle hoods over  the
    sinter machine limit accessibility for pallet maintenance, etc.

2.  Downtime could result during the retrofit of this technology
    to the Sinter Plant.

3.  A decrease in the oxygen content of the recirculated gas to the
    sinter bed could affect the production rate of the sinter machine,
    as well as sinter quality.

It was concluded that the advantages of this technology outweighed the
disadvantages, and the system was designed to reduce the effects  of the
unfavorable factors cited above.  Special consideration was given to  the
minimization of disadvantages Nos. 2 and 3.  This effort significantly
influenced the design of the system in that it was determined that this
facility should provide for recirculation of a percentage of the  gases
from all windboxes to a recycle hood over the entire length of the machine
(total windbox recirculation) as opposed to the recirculation of  a per-
centage of the gases from the first several windboxes to a recycle hood
over the remaining last several windboxes (front to rear recirculation).
Front to rear recirculation offered the advantage of better accessibility
to the machine, as well as the potential of a higher efficiency in hydro-
carbon reduction through carbonization.  However, total windbox recircu-
lation was more adaptable to sinter machine retrofit and, in addition,
this mode provides for the maximum oxygen content in the recirculation
gas.  Based on these considerations, it was concluded that recirculation
over the entire length of the machine should be employed and design calcu-
lations concluded that a 39 percent recycle could be achieved without
rapidly decreasing the oxygen content in the recirculated gas.(l)
                                 12

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Section IVC - Description of Gravel Bed Filter System

Prior to 1957, the gas cleaning applications  of gravel bed filtration on
an industrial scale were developed in the direction of intermittent type
equipment operation, and the range of potential methods involving contin-
uous gas cleaning  was  neglected.  One of the first examples of gravel bed
filtration was a system applied to the effluent from a carbide furnace in
a German chemical plant.  Here, the dusty waste gases from the carbide
furnace were pre-cleaned in cyclones and then cleaned of fines in a bed
of granular coke, that was also the feed material.  When the coke bed
became saturated with dust, the bed was replaced and the dust saturated
coke was fed into the furnace.

In 1957, Max and Wolfgang Berz, in Germany, succeeded in devising a system
which permitted a continuous,  fully automated cleaning of the filter bed
from the dust load within the  collector.  This technology utilized a
horizontally arranged filter bed, consisting of uniform quartz grains housed
in a flex-spring support casing.  To clean the filter bed, the casing was
virbrated by means of an eccentric motor.  This moved the gravel grains in
an elliptical motion within the bed.  This motion separated the dust and
moved it down into a dust collecting chamber.  Thus the granular bed was
used for the first time for continuous separation of dust from effluent
gases on an industrial scale.  Since that time variations in this design
were developed and utilized as air pollution control devices in the cement
and lime industries.  However, the application of gravel bed filtration
technology at a sinter plant did not occur until 19J76 when a full scale
system was commissioned at Weirton Steel Division of National Steel
Corporation.

The gravel bed filter system installed on the No. 2 Sinter Machine at
Weirton Steel Division is a special unit specifically designed for sinter
plant application.  The system consists of a parallel arrangement of 24
filter modules of equal size (see Figure No. 3).  The filter modules are
assembled into groups of four  and are stacked vertically to utilize space
more efficiently.  There are two such vertically stacked towers, each
containing twelve modules.

The modules are cylindrically  shaped and contain an upper and lower filter
bed.  Each bed includes a horizontal grid and screen which supports 0.62
cubic meters (22 cubic feet) of garnet or steel grit filter media at a
depth of 90 to 100 millimeters (3.5 to 4 inches).  Various sizes of filter
media can be used, but a range from 2 to 4 millimeters (0.08 to 0.16 inches)
has given satisfactory results.
                                   13

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                        RECYCLE
                      DOWNCOMERS
BACKFLUSH
RECYCLE TO
RAW GAS
                                               F i gure No . 3

                                          GRAVEL BED FILTER
                                             FLOW  SHEET
                              14

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Section IVC - Description of Gravel Bed Filter  System  (contd)

The operation of each filter module is identical; 22 modules are  in  the
forward flow cleaning mode of collecting and  filtering sinter dust onto
the minute surfaces of the media while two modules  (one  in each tower)
are isolated in a backflushing mode for removal of  the collected  dust from
the filter beds.  The system is designed to accept  dust  laden gas at a
flux rate of 0.61 cubic meters of  gas per second per square meter of bed
area (120 cubic feet of gas per minute per square foot of bed area) with
a flange -to- flange pressure drop of approximately 330  millimeters of water
column (13 inches of water column).

During the backflush mode, a revolving rake agitates the filter media
while a reverse flow of air flushes the fine  dust particles to a  common
downcomer duct and a screw conveyor for recovery.

A detailed description of the sequence of operation follows below.

Raw dust-laden gas leaving the windbox passes  through  the  pre-cleaning
cyclones and induced draft fans, then enters  the interior raw gas duct of
the gravel bed filter driven by its own induced draft  fan (see Figure
No. 3).

The raw gas (see Figure No. 4) enters from the  raw  gas duct (1 )  into the
upper or raw gas chamber  (14).  The gas flow  passes down through  the
filter media (6) where the entrained dust is  captured.   The gas passes
through the media support screen (7), into the  clean gas chamber  (12), out
the clean air branch (8), and into the clean  air duct  (9).  Note  that this
flow path is determined by having  the raw gas/recycle  valve plates (3) and
the backwashj^clean air valve plate (10) in the  down position. The cleaned gas
    ^ exits- through the I.D. fan to the stack not shown (Figure No. 3).
The above "forward  flow"  or  "dleaning mode"  continues until  the  automatic
cycle timer in  the  main control  panel calls  upon  that module  to  enter  the
"backflush mode"  of operation  (refer to  Figure No.  5).


At this  time, the valve operator (16)  lifts  the backf lush/clean  air  valve
plate (10) into the backflush  position,  isolating the module  from the  I.D.
fan suction and exposing  it  to the  backflush (preheated  ambient) air.   The
valve actuator  (2)  then lifts  the raw gas/recycle valve  plate (3)  into
the backflush position isolating the module  from  the raw gas  dust  (1)
and exposing it to  the recycle downcomer (13)
                                        15

-------
DOWNCOMER
  VALVE
                     RAW GAS
     7
      t_n
                                  4
                               RAKE DRIVE
            CLEAN AIR
             CHAMBER
               12
                                                      UPPER BED

                                                        RAKE  5

                                                       MEDIA 6

                                                      ,'INE MESH SCREEN 7

                                                      SCREEN  SUPPORT GRATE
                                                                        16
                                                             10
                                                         CLEAN AIR a
                                                         BACKFLUSH
                                                           VALVE
DOWNCOMER
  DUCT
             LOWER BED
                               Figure No. 4

                               FILTER MODULE
                             FORWARD FLOW MODE
                                     16

-------
DOWNCOMER VALVE
   4
RAKE DRIVE
                                                      UPPER BED 14
                                                      — RAKE 5
                                                      .r-MEDIA 6
                                                     y-FINE MESH SCREEN  7
                                                     VSCREEN SUPPORT GRATE
                                                             CLEAN AIR 8
                                                            BACKFLUSH VALVE-
                                                                           II
      ^-RECYCLE
        DOWNCOMER
          DUCT
           13
                                                                   M
                                                                PREHEATED
                                                                BACKFLUSH
                                                                  AIR
                                Figure No.  5

                               FILTER MODULE
                               BACKFLUSH MODE
                                     17

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Section IVC - Description of Gravel Bed Filter System (contd)

Backflush air flows into the module through the backflush duct (11)
and upward through the bed  (6).  The backflush air is externally pre-
heated by coke oven gas-fired burners in order to maintain a backflush
temperature of 149° c. (300° F.).  The rake motor/reducer (4) turns the
rake (5) and begins agitation of the bed, which dislodges the agglomerated
dust and allows it to  flow  out  of  the upper chamber  (14) and into  the re-
cycle downcomer (13).  This recycle gas is then passed  through a settling
chamber and cyclones before it  is  introduced  into the raw gas duct to be
added to the incoming  process gas.  The backflush cyclones are small
diameter high efficiency units  motivated by induced  draft backfjush fans.

After the pre-set backflush time interval has elapsed,  both valves (3 and
10) again move and place the module back in the forward flow or "cleaning
mode" position of normal operation:
                                        18

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                              SECTION V

             EVALUATION OF THE WINDBOX GAS RECIRCULATION
                                 AND
                        GRAVEL BED FILTER SYSTEMS
Section V-A - Effects on Sintering Process arid Product Quality


                            Introduction

The installation of a gravel bed filter system as the final air pol-
lution control device on a sinter machine should not have significant
effects on the sintering process and/or product quality.  However, the
installation of a windbox gas recirculation system could have serious
effects in these regards since this technology becomes an integrated
part of the sintering process.

In order to determine any significant differences in the operating para-
meters and product quality derived from the utilization of windbox gas
recirculation, tests were conducted under both conventional operation
(a no-recycle base period of eight days), and maximum permissible waste
gas recirculation to the sinter strand (a recycle period of seven days).
The parameters measured during the base and recycle periods included
sinter mix composition, strand speed, fan characteristics, energy  re-
quirements, gas volume, temperature, pressure and composition data,
product composition, production rate and downtime.  Sufficient data were
obtained for certain parameters to permit a statistical analysis and
establish the standard deviation (6*).  The 2^ value is used in certain
tables of this section to establish variability of the data, and as an
estimate of process stability, where applicable.

This portion of the program did not include the determination of partic-
ulate, condensable hydrocarbon, and sulfur dioxide loadings in the gas
system.  It had been determined in the early planning stages of this pro-
ject  that environmental testing would be deferred until after the oper-
ational and product quality aspects of the system had been established.
                                    19

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Section V-A - Effects on Sintering Process and Product Quality (cont'd)

                             Test Procedure

All operating data were logged hourly during daylight turn for each day
comprising the respective test period.  Gas temperature in Windbox Nos.
3, 5, 7, 9, 13 and 14 and the main temperature were obtained from sinter
plant temperature recorders for both east and west windboxes.  Gas pres-
sures in Windbox Nos. 1, 5, 9, 11, 13 and 14 and the fan inlet and main
pressure were obtained from manometers or recording charts located in  the
plant for both east and west sides.  Also recorded were data obtained
from various charts, meters and gauges for waste and recycle gas fan
current and draft pressure readings, hood pressures for hoods 1 through 4,
plenum pressure and temperature, strand speed, cooler speed, coke oven gas
flow, drum and pug mill moistures and mix temperature.  At certain times
readings were delayed or missed due to sinter plant delays.  Visual ob-
servations of the sinter plant were also made to ascertain the general
operating conditions of the system.

Sinter was sampled for screen and tumble tests for each day of the test
periods.  Sinter samples were obtained at hourly intervals, with samples
being composited to obtain four samples composed of an 8:30 - 9:30 A.M. com-
posite, a 10:30 - 11:30 A.M. composite, a 12:30 - 1:30 P.M. composite  and
a 2:30 - 3:30 P.M. composite.  Each sample consisted of three cuts made
across the width of the product conveyor belt with a shovel, care being
taken to obtain a representative sample.  Two concurrent samples were  placed
into a five-gallon can to form a composite sample for a two-hour period
which contained 50 to 60 pounds of sample.  Standard ASTM screen and tumble
tests for sinter were performed upon the composite sample.  A small sinter
sample was also taken on hourly intervals and composited for the turn  for
later chemical analyses.  As was the case with recording of sinter plant
operating parameters, certain sinter samples for physical testing and
chemistry were either delayed -or cancelled if sinter plant operating con-
ditions dictated this action.

A sample of the sinter feed mixture as it was placed upon the strand was
obtained twice a day at approximately 10:00 A.M. and 1:00 P.M. for moisture
determination.  The moisture determination was performed immediately through
use of a "Moisture Teller" where 100 grams of the material are dried for
15 minutes under a stream of hot air.  This procedure is adequate to pro-
vide accurate moisture measurements for sinter feed mixture.

Other operating data such as sinter mix composition, sinter plant produc-
tion and downtime were obtained from sinter plant operation data sheets.
                                        20

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Section V-A - Effects oil Sintering Process and Product Quality (cont'd)


        Sinter Strand Operation - Test Results and Discussions
The sinter mix composition for both the base and recycle periods was
similar as indicated in Table No.  1.  Only the sinter fines content
differed by an appreciable amount, and this may not be statistically
significant in terms of the +2d variability associated with the two
mean values.  Total fluxstone (dolomite and calcite) input which was
slightly lower during the recycle  period is reflected in the slightly lower
basicity for the sinter that was produced.  On the whole, the sinter mix
composition was more variable during  the base period.  A difference in
sinter mix composition should not  be  a factor influencing any differences
in sinter plant operation or sinter quality.

The plant operating data presented in Table No. 2 exhibit good consistency
between the two periods.  Sinter strand speed was identical, although some-
what more variable during the recycle period.  The lower ignition gas con-
sumption rate during the recycle period was principally attributed to the
rebuild of the ignition furnace during the maintenance shutdown between the
base and recycle periods.  After improved  operation of the system was sub-
sequently achieved, it was discovered that in the recycle mode, lower heat
input to the sinter machine via coke  breeze was required as a result of the
heat content in the recirculated gas  stream (see Section VI-D).

The sinter mix moisture was not significantly different between the two
periods.  During the recycle period more water was added in the pug
mill and less in the balling drum.  There is no indication that the use
of waste gas recycle altered the mix  moisture requirement for proper strand
operation.
                                       21

-------
                           TABLE 1.

                SINTER MIX COMPOSITION  (WT. %)
                      BASE  PERIOD
                    RECYCLE PERIOD
Material

Coke Breeze

Ore "A"

Ore "B"

Ore "C"

Roll Scale

Flue Dust

Sinter Fines

Dolomite

Calcite
Mean
6.
24.
21.
10.
5.
69
48
14
65
05
±2o-
0
6
4
0
—
.55
.49
.54
.54

Mean .±2cr
6.
23.
20
10.
5.
54
44
.15
98
19
0
1
1
0
_
.75
.49
.25
.70

 6.38     4.35

11.26     2.45

14.33     2.47
 8.85       5.42

10.95       0.77

13.90       0.85
     NOTE: - Data do not include hot returns and sludge
             which are not metered into mix at pre-determined
             rate.
                                  22

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                           TABLE 2.

                        OPERATING DATA

                           BASE PERIOD
Item
                      Mean
Cubic Meters per
   Second
                      0.4752
(Cubic Feet per Hour) (60,408)

Mix Moisture
Percent

Waste Gas Fan
   Current
                      6.9
                          342
(Amps)

Recycle Gas Fan
   Current	
(Amps)

Production
Metric Tons per Day    4,668
(Short Tons per Day)  (5,142)
                          325
Delays
Hours per Day
                      0.71
± 2(T
RECYCLE PERIOD
Mean
Strand Speed
Meters per Second
(Feet per Minute)
Cooler Speed
Meters per Second
(Feet per Minute)
Ignition Gas ,
0.0472
(9.3)
0.0386
(7.6)

0.0041
(0.8)
0.0015
(0.3)

0.0472
(9.3)
0.0376
(7.4)

0.0061
(1.2)
0.0041
(0.8)

0.0603
(7,668)
1.9
     13
     22
0.4212   0.0496
(53,543) (6,310)
6.6
1.1
    339
    340
     37
     21
                                         234
                                         (258)
          4,583   1,138
         (5,049) (1,254)
         1.12
                             23

-------
Section V-A - Effects on Sinter Process  and  Product
	g u a 1 i t y ( c o n t d )	

S Lrit_ Ji£_Sjj^n j. 0 peration ~_Te_g__t _R e_ s_u ,11 s_ _aLn_d_DjLs c_u s__s i on  ( c o n t d )
Actual sinter production was  lower and more  variable  during the
recycle period.  When production  is  corrected  to  a  delay-free
basis, both periods averaged  1947 metric  tons  per eight-hour
shift.  The average 12.2 minute per  shift  delay  time  for  the
base period was comprised of  several  short delay  periods.  In
contrast, the 22.5 minute per  shift  average  delay during  re-
cycle is from a single outage  of  135  minutes.  Thus,  the  con-
tinuity of operation was better during the recycle  period.

Bed suction was higher during  the recycle  period  than during
the base period.  As indicated in Table No.  3  and Figure  No. 6
this difference was about 15.3 centimeters of  water (6 inches
of water) over most of the  strand.   A portion  of  the  increase
could be attributed to repair  of  leaks during  the maintenance
outage between test periods.   However, the major  portion  should
be attributed to the recycle  of waste gas.   This  may  have  in-
cluded a greater bed depth  which  could not be  accurately  deter-
mined.  Variability in bed  suction was generally  less during
the recycle period.  Under  normal operation  an increase  in  bed
suction is associated with  a  less permeable  bed which restricts
air flow and reduces production rate.  Total waste  gas flow,
as measured at the plenum,  was slightly lower  during  the  re-
cycle period.

The windbox suction profiles  shown in Figure No.  6  are typical
for the process.  Other than  the  difference  in absolute  suction,
the profiles are similar and would not suggest a  fundamental
difference in the process associated  with  recycling.

The sinter machine waste gas did  not  differ  significantly  in
temperature between the two periods  as measured at  the in-
dividual windboxes.  The strand waste gas  system  is divided
along the strand length with the halves identified  as east
and west side.   Data in Table No. 4  were obtained from the
normal waste gas temperature instrumentation.  These  data  and
Figure No.  7 indicate a somewhat higher waste  gas temperature
for the  east side through windbox ten during the  base period.
                             24

-------
                                 TABLE 3.
                           WINDBOX SUCTION DATA
                            BASE PERIOD
RECYCLE PERIOD
Mean


Location
Windboxes
1W
5W
9W
11W
13W
14W
IE
5E
9E
HE
13E
14E
Waste Fan
Recycle Fan
Plenum
Hood*
#1
#2
#3
#4
Integrated
Milli-
meters
W.C.**

-
418.8
726.4
761.5
742.4
571.8
791.2
748.8
804.2
756.7
-
1042.4
1222.0
1229.1
1174.0

2.62
-1.37
-0.05
2.84
1,93.


Inches
W.

-
(16
(28
(29
(29
(22
(31
(29
(31
(29
-
(41
(48
(48
(46

( 0
(-0
(-0
( 0
( 0
C.


.49)
.60)
.98)
.23)
.51)
.15)
.44)
.66)
.79)

.04)
.11)
.39)
.22)

.103)
.054)
.002)
.112)
.076)
Mil
±26
li-
meters
W.

-
76
205
136
140
253
122
296
125
126
-
351
100
98
99

0
-
-
1
0
C.


.5
.5
.1
.0
.2
.7
.9
.7
.7

.3
.8
.0
.6

.78


.40
.58
Mean ±2o"'
Milli-
Inches
W.C.

-
( 3.01)
( 8.09)
( 5.36)
( 5.51)
( 9.99)
( 4.83)
(11.69)
( 4.95)
( 4.99)
-
(13.83)
( 3.97)
( 3.86)
( 3.92)

( 0.78)
-
-
( 0.055)
( 0.023)
meters
W.

-
723
809
903
894
728
859
883
-
887
-
1182
1395
1342
1279

6
0
4
6
4
C.


.6
.5
.5
. 1
.2
.3
.4

.0

.9
.2
.4
.7

.20
.81
.06
.48
.98
Inches
W.C.

-
(28.49)
(31.87)
(35.57
(35.20)
(28.67)
(33.83)
(34.78)
-
(34.92)
-
(46.57)
(54.93
(52.85)
(50.38)

( 0.244)
(-0.032)
( 0.160)
( 0.255)
( 0.196)
Milli-
meters
W.C.

-
457.2
309.6
103.9
102.6
138. 7
206.0
132.3
-
100.1
-
244.6
223.3
71.1
77.5

2.90
-
2.82
2.82
2.18

Inches
W.C.

-
(18.00)
(12.19)
( 4.09)
( 4.04)
( 5.49)
( 8.11)
( 5.21)
-
( 3.94)
-
( 9.63)
( 8.79)
( 2.80)
( 3.05)

( 0.114)
-
( 0.111)
( 0.111)
( 0.086)
 *  -  Negative value means  positive pressure under  hood
** - W.C.  means Water Column

-------
01
00

cfl
e>
0)
4J
a

 M

0)

3
CO
CO
CD
  1000
    800
    600
    400
                                                                      O
O
•H

o   200

00
                  O

                  A
                        Base


                        Recycle
                                                       10
                                                            11
                                                                 12
1J
                                   Windbox Number
               FIGURE 6  COMPARATIVE AVERAGE STRAND SUCTION PROFILES
                                      26

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          TABLE NO. 4
       TEMPERATURE DATA
BASE PERIOD
RECYCLE PERIOD
Mean
Location
Windboxes
3W
5W
7W
9W
11W
13W
14W
Main
3E
5E
7E
9E
HE
13E
14E
Main
Sinter Mix
Plenum
± 2ff
Mean Jt 2tr'
°C. (°F.) °C. ( ?¥.) °C. (°F. ) °C. (°F.)

89
85
98
126
175
281
226
116
95
95
125
119
219
218
202
122
43
_

.4
.6
.9
.1
.6
.1
.7
.1

.6
.0
.4
.4
.9
.2
.2
.3


(193)
(186)
(210)
(259)
(348)
(538)
(440)
(241)
(203)
(204)
(257)
(247)
(427)
(426)
(396)
(252)
(110)
—

38
ii
48
39
80
121
75
53
30
47
4_0
101
110
68
88
23
13
-

•9( 70)
. i( 20)
. 9( 88)
.4( 71)
.6(145)
.1(218)
. (135)
.9( 97)
•6v 55)
.8( 86)
•6( 73)
.1(182)
(198)
.5(124)
.3(159)
•3( 42)
.9( 25)
-

88
90
102
131
154
269
240
120
98
95
120
-
218
265
236
120
44
117

.3

.8
.1
.4
.4

.6
.3

.6

.3
.0
.1
.6
.4
.2

(191)
(194)
(217)
(268)
(310)
(517)
(464)
(249)
(209)
(203)
(249)
-
(425)
(509)
(457)
(249)
(112)
(243)

18
3.3
35
30
56
106
95
30
27
18
43
-
109
146
170
30
13
26

.3
.3
.6

.7
.

.6
.2
.3
.3

.4
. 1
.6
.6
.3
.1

( 33)
( 60)
( 64)
( 54)
(102)
(191)
(171)
( 55)
( 49)
( 33)
( 78)
-
(197)
(263)
(307)
( 55)
( 24)
( 47)
             27

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     300
     250
ai
>-i
01

I
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     200
     150
     100
      50
A



O
East Side



West Side
                                    I
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                                   Windbox Number
                                 10
                                11    12    13    14
            FIGURE 7  STRAND WASTE GAS TEMPERATURE PROFILE  -  BASE  PERIOD
                                    28

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Section V-A - Effects on Sinter Process and Product Quality  (cont'd)

Sinter Strand Operation — Test Results and Discussion (cont'd)

This is not necessarily an abnormal condition; it may reflect leakage more
than process conditions.  The lower east side temperature at the discharge
end of the strand (windboxes 12 - 14) is probably due entirely to leakage.
During the test period both sides had virtually the same temperature char-
aceristics along the length of the strand as shown in Figure No. 8.  Re-
pairs during the maintenance outage between the two periods reduced leakage
in the east side windboxes.  The combined windbox temperature data for the
two periods are shown in Figure No. 9.  Only at the end of the strand
(windboxes 12-14) did the temperature differ between the two periods. This
reflects the low temperature level of the east side windboxes during during
the base period.  All curves in Figures 4-6 exhibit typical waste gas pro-
files for the process.  Temperature profiles based on measurements taken
at the windboxes during the waste gas sampling given in Table No. 4 cor-
respond to the profile shown in Figure No. 9.  However, the actual tem-
peratures tend to  run higher during the base period for the last four or
five windboxes.

Assuming no other changes in energy input, recycling should produce an in-
crease in waste gas temperature since ambient air is partially replaced by
a hotter waste gas.  During approximately the first half of the process,
an increased gas temperature might not be noted since the raw sinter mix
has a high heat capacity which can absorb the additional thermal energy.
During the latter stage of the process, however, this is not necessarily
true and an increase in waste gas temperature should be observed. All data
on individual windbox temperature measurements indicate no significant
difference in thermal conditions between conventional and recycle modes of
processing changes in energy input.  Waste gas temperatures were generally
more uniform during recycle which further suggests no problems with process
control.
Composition of the waste gas from the individual windboxes, given in Table
No. 5 and compared for two periods in Table No. 6 and Figures Nos. 10-12
differed between conventional and recycle modes of operation.  Under waste
gas recycle the oxygen content decreased and the carbon monoxide and carbon
dioxide contents increased.  These are the results that would be antici-
pated.  The composition prof iles shown in Figures Nos. 10 - 12 are typical
of the sintering procesa and exhibit no significant change in shape between
conventional and recycle operation.  Beyond ignition (windboxes 1 to 3)
the waste gas oxygen content was reduced about three percent with recycle
out to windbox 10 or 11.  After windbox 10 or 11 the reduction in oxygen
content decreased from three percent to about two percent at windbox 14.
The corresponding changes in other constituents were a four percent increase
in carbon dioxide content and 0.15 percent increase in carbon monoxide
during most of the process.  As with the oxygen, these differences dimin-
ished during the latter stage of sintering.
                                    29

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     300
     250
     200
t-i
0)
H
     150
     100
                                                         O
                               O
      50
                  A

                  O
East Side

West Side
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                                    Windbox Number
                               10
                        11
                        12
                        13   14
           FIGURE 8  STRAND WASTE GAS TEMPERATURE PROFILE - RECYCLE  PERIOD
                                          30

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   300
   250
   200
 o
o
 2
 a 150
 4-J
 01
 H
  100
   50
                O Base



                A Recycle



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                                 6789



                                 Windbox Number
                   10    11    12    13    14
      FIGURE 9  COMPARATIVE  AVERAGE  STRAND WASTE GAS TEMPERATURE PROFILES
                                       31

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                                             TABLE NO.  5
                               WINDBOX GAS COMPOSITION  AND TEMPERATURE
                               BASE
PERIOD
RECYCLE PERIOD
to
Percent Bv Volume

East Side
1
2
3
4
5
6
7
8
9
10
11
12
13
14
West Side
1
2
3
4
5
6
7
8
9
10
11
12
13
14
o2 %

17.5
-
13.4
14.1
13.1
14.3
14.3
16.2
15.4
15.4
17.2
17.4
19.2
19.3

20.7
14.7
16.3
14.0
14.8
16.5
14.7
15.5
14.7
17.9
17.5
19.7
18.6
19.5
co2%

2.5
—
7.9
7.3
9.4
7.8
8.3
6.0
7.4
7.3
3.8
4.0
0.8
1.3

-
2.6
6.1
8.2
7.3
5.2
7.3
8.4
7.8
6.4
4.7
1.5
2.8
1.3
CO %

0.24
—
1.26
1.05
1.09
0.86
1.07
0.57
0.92
0.81
0.30
0.29
0.16
0.05

0.20
0.65
0.65
0.80
0.95
0.87
0.97
1.10
1.03
0.73
0.71
0.13
0.25
0.20
Temperature
°C.

126.7
_
91.7
87.8
97.2
121.1
130.6
148.9
163.9
165.6
225
240.6
298.9
341.7

76.7
82.2
93.3
93.3
98.9
93.3
123.9
110
148.9
190.6
271.1
246.1
321.1
353.3
(°F.)

(260)
_
(197)
(190)
(207)
(250)
(267)
(300)
(327)
(330)
(437)
(465)
(570)
(647)

(170)
(180)
(200)
(200)
(210)
(200)
(255)
(230)
(300)
(375)
(520)
(475)
(610)
(668)
Percent By
o2%

18.2
—
13.3
12.2
13.3
12.6
11.4
12.0
12.4
14.9
15.3
16.8
17.6
19.7

18.2
15.0
12.5
14.6
9.8
10.8
10.9
12.0
11.7
13.6
13.3
18.4
14.7
15.9
co2 %

2.4
_
10.0
11.0
10.3
12.1
13.2
12.3
11.5
8.3
6.8
4.5
3.9
1.6

2.6
6.5
11.0
9.8
14.3
12.7
12.5
11.0
11.4
9.5
9.0
3.7
7.3
5.5
Volume
CO %

0.18
_
0.89
1.28
0.96
0.94
1.32
1.27
1.11
0.74
0.70
0.16
0.21
0.03

0.42
0.51
0.94
0.73
1.31
1.03
1.00
0.88
1.01
0.82
0.55
0.27
0.39
0.47
Temperature
oc.

97.8
-
9'0.6
86.1
92.2
98.9
103.3
113.9
139.4
136.1
208.9
219.4
228.3
282.2

82.2
87.8
87.8
112.8
93.3
101.7
115.6
135
137.8
171.1
221.1
215.6
248.9
326.7
(°F.)

(208)
-
(195)
(187)
(198)
(210)
(218)
(237)
(283)
(277)
(408)
(427)
(443)
(540)

(180)
(190)
(190)
(235)
(200)
(215)
(240)
(275)
(280)
(340)
(430)
(420)
(480)
(620)

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                           TABLE 6.




      COMPARATIVE AVERAGE WASTE  GAS  COMPOSITION (% VOLUME)





                             CONSTITUENT
OXYGEN
Windbox
1
2*
3
4
5
6
7
8
9
10
11
12
13
14
Base
19
1.
14
14
14
15
14
15
15
16
17
18
18
19
.1
47
.8
.1
.0
.4
.5
.8
.1
.6
.3
.5
.9
.4
Recycle
18
15
12
13
11
11
11
12
12
14
14
17
16
17
.2
.0
.9
.4
.6
.7
.2
.0
.1
.2
.3
.6
.2
.8
CARBON DIOXIDE
Base
2.
2.
7.
7.
8.
6.
7.
7.
7.
6.
4.
2.
1.
1.
5
6
0
7
3
5
8
2
6
8
2
7
8
3
Recycle
2
6
10
10
12
12
12
11
11
8
7
4
5
3
.5
.5
.5
.4
.3
.4
.8
.7
.4
.9
.9
.1
.6
.4
CARBON
Base
0
0
0
0
1
0
1
0
0
0
0
0
0
0
.22
.65
.95
.93
.02
.87
.02
.84
.97
.77
.50
.21
.20
.13
MONOXIDE
Recycle
0
0
0
1
1
0
1
1
1
0
0
0
0
0
.30
.51
.92
.00
.13
.99
. 16
.08
.06
.78
.62
.22
.30
.25
* - Only west side
                                    33

-------
           20
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      pq
      C
      a)
      o
       0)
       4J
       c
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       01
       60

       fr
       o
           18
16
14
12
           10
                                         I
                                    I
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                                          6789




                                         Windbox Number
                                                  10
              11   12   13   14
                FIGURE 10  COMPARATIVE AVERAGE  STRAND WASTE GAS OXYGEN PROFILES

-------
1
iH
O
c
cu
o
a
0)
4-1
G
O
CN
O
CJ
    14
12
    10
                                           I
                                             I
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                                           678



                                             Wlndbox Number
                                                                10
                  11
12
13
14
                 FIGURE 11  COMPARATIVE AVERAGE STRAND WASTE GAS  CARBON  DIOXIDE PROFILES

-------
u>
    1.2
S~*\

I

o  1.0
      PQ
4-1

C
01
y
       C
       0)
       .u
       C
       O
       U
          0.8
          0.6
    0.4
      o
      0   0.2
                                               Recycle
                                          , A

                                          "o"
                                           O



                                          Base
                                                 O
                                                                           10
                                                                          11
                                                                                 12
13
14
                                                    Windbox Number
                         FIGURE 12  COMPARATIVE AVERAGE STRAND WASTE GAS  CARBON  MONOXIDE PROFILES

-------
geetion V-A -'Effects on Sinter Process and Product Quality  (cont'd)

Sinter Strand Operation <- Test Results arid Discussion  (cont'd)

Table No. 7 indicates the gas flow rates, temperatures and compositions
at the waste gas and recycle gas fans during the base  and recycle periods.
In addition, the plenum and stack flows, recycle distribution  and leakage
rate in the windbox system are tabulated.


                Sinter Quality - Test Results and Discussion

The chemical and physical characteristics of the sinter produced during
the base and recycle periods are given in Table No. 8.  Sinter chemical
composition was similar between the  two periods.  The  slightly higher iron
oxide content for the recycle period could be due to the restricted oxygen
availability decreasing the degree of re-oxidation during cooling on the
strand.  However, the 10.98 percent  value is within the range of iron oxide
content encountered under normal processing.  Overall  chemical variability
was similar for the two periods, and is more a function of variation in
the composition of the raw materials rather than processing conditions.

Sinter physical quality was indentical for the two periods.  While the
plus 6.35 millimeter (1/4 inch) screen index is about  1.3 percent lower
during recycle, the difference is not statistically significant.  For the
recycle period, the screen indicies  were slightly less variable, but the
tumble index slightly more variable.  There is no evidence that the use of
waste gas recirculation had a significant effect on sinter chemical com-
position or physical quality.
                                 37

-------
Waste Gas  Fan

Flow, Nm^/min
       (sc£m)(wet)

Temperature ,  °C .
 Compos it ion, (% by Volume)
 02
 C02
 CO

 Recycle Gas  Fan

 Flow,
       (scfmXwet)
 Temperature,  °C,
 Composition,  % by Volume
 02
 C02
 CO
               o
 Pnenum Flow,  Nnr/min
              (scfmXwet)

 Stack Flow, Nm3/min
            (scfmXwet)

 Recycle Flow,
% Recycle

Recycle Dist. ,
               (scfmXwet)
No,
No,
No.
No.
No,
No,
1 Hood
2 Hood
3 Hood
4 Hood
5 Hood
6 Hood
Recycle Flow Temperature
TABLE
FAN
NO, 7
DATA
BASE PERIOD
Mean
8,500
(300,130)
107,8
(226)
17.85
4.17
0,41
7,587
(267,904)
108,9
(228)
17,58
4.06
0.59
16,087
(568,034)
16,087
(568,034)
t*
^*
T*.

-------
                  TABLE 8.




SINTER PROPERTIES - P.HYSICAL AND CHEMICAL
               BASE  PERIOD
RECYCLE PERIOD
Item
Chemistry, Wt . %
Iron
FeO
Mn
Sulfur
sio2
A1203
CaO
MgO
Basicity
Quality
+ 6.35 Millimeter
Screen, %
+ 3.17 Millimeter
Screen, %
Tumble Index. %
Mean ±2
-------
Section V-B - Operating Problems

1.  Windbox Gas Recirculation System

    Three significant operating probems were noted during the demonstra-
    tion phase of waste gas recirculation.  These were (1) fan erosion;
    (2) additional time required for routine maintenance of the sinter
    machine; and (3) expulsion of particulate and gases from under the
    sinter machine recycle hood during the use of higher than 25 percent
    recycle.

    Four months_after the start-up of the windbox gas recirculation system,
    an imbalance problem developed in the recycle and waste gas fans. An
    inspection of these fans revealed that the impellor liners had eroded
    from a thickness of 9.5 millimeters (3/8 inch) to 3 millimeters
    (^.1/8 inch) at or near tip of the blade.  Impellor wear was a problem
    prior to the installation of the windbox gas recirculation system and
    the new fans, but it is apparent that an acceleration of the wear
    rate occurred as a result of this installation of the new fans.

    The new fans operate at a speed approximately twenty-five percent
    higher than the old fans (900 rpm versus 720 rpm).   This equates to an
    impellor tip speed of 10,092 meters per minute (33,110 feet per minute)
    for the new fans versus 7,986 meters per minute (26,200 feet per minute)
    for the old fans.

    As a result of this problem it was necessary to implement an intensive
    maintenance program to restore the eroded areas of the fan impellors
    during the sinter machine downturns.  This program consisted of the
    application of cladding to the eroded areas, on a weekly basis, using
    welding rods.  The techniques utilized in the welding program are
    critical in that extreme care must be employed to maintain fan balance.

    Efforts were immediately directed toward the minimization of the
    erosion problem.  Replacement of the original impellor liner material
    with specially hardened steels did not appreciably extend impellor life.
    It wasn't until the installation of a specially constructed armored
    plate that the erosion problem subsided.   The armored liner consisted
    of a 3.2 millimeter (1/8 inch) tungsten carbide overlay on an 8 milli-
    meter (5/16 inch) carbon steel plate.   This material is presently
    serving well, and it is anticipated that the past impellor life span
    of nine to twelve months will increase to two years.   The welding
    program is still necessary on a periodic basis to restore eroded area
    at (1) the juncture of the tungsten carbide overlay and carbon steel
    plate; (2) holddown bars and angles at the side and intake end of the
    liners;  and (3)  flat head bolts securing  the liner plates.
                                   40

-------
Section V~B - Operating Problems (cont'd)
1.  Windbox Gas Recirculatibn System (cont'd)

    The second problem noted during the operation of the windbox gas
    recirculation system was the increased time required to perform
    routine repairs and maintenance,  Access to the machine is limited
    since the hood system covers the entire length of the sinter strand.
    In some instances, such as pallet replacement, the time required to
    perform routine maintenance tasks have doubled.  Visual observations
    of the sinter bed are also limited due to the hood assembly.  This
    problem is considered inherent with the system, and the advantages
    of this technology are considered to outweigh  this disadvantage.

    The third and most important problem during this demonstration con-
    cerned the expulsion of particulate and gases from under the sinter
    machine recycle hood.  During the design phase of this system, it was
    anticipated that the volume of gas returned to the machine would be
    limited by the oxygen content of the recirculated waste gas. However,
    in actual practice it was found that recycle rates higher than twenty-
    five percent resulted in air quality problems in the operating area.

    At thirty percent recycle, significant quantities of particulate and
    gas were discharged into the plant at several locations along the
    perimeter of the hood system.

    The reasons for the recirculation limitation of twenty-five percent
    are not totally known at this time, but the major contributing factor
    is leakage to the windbox system.  It is estimated that excess air
    at the rate of fifty percent of the total effluent volume is enter-
    ing the windbox system via routes other than through the sinter bed.
    This condition is not uncommon in older sinter machines, since the
    economic advantage of minimal leakage was not apparent until the
    1970's.  In an effort to decrease the leakage rate, increase the
    windbox recirculation rate and farther reduce the requirements for
    the final air pollution control device, the Company has initiated
    programs for improved sealing facilities at the pallet train and
    windbox junctures of the sinter machine,  In addition, an aggressive
    maintenance program has been established for the repair of leakage
    in the windbox collecting main and cyclone systems.  Repair of
    leakage from erosion in these areas is a never-ending, but essential,
    task.
                                    41

-------
Section V-B - Operating Problems (cont'd)

2,  Gravel Bed Filter System

    Many problems were confronted during the early stages of optimization
    of the gravel bed filter system which have been totally resolved or
    minimized.  Observations conducted immediately after the start-up of
    the system disclosed that a problem existed with the hydraulic down-
    comer valves which isolate the incoming Sinter Plant gas from the
    gravel bed backflush air cleaning system (see Figure 4). Occasions
    arose in which individual downcomer valves were observed in a par-
    tially open position.  When this condition occurred the gravel bed
    filter system was short-circuited and uncleaned incoming gas from the
    sinter machine bypassed the filter module to the backflush cyclones.
    As a result, the volume and velocity of the backflush air available
    for bed cleaning was drastically reduced and satisfactory bed cleaning
    was not achieved.  It has been determined that two downcomer valves
    in the open position render the bed cleaning cycle ineffective.   It
    should be noted that this installation was the first to utilize this
    valve design and also the first to utilize valves on the inlet (dirty)
    side of the gravel bed filter.   Forty-eight valves out of a total of
    seventy-two valves in the system were affected.

    As a part of the original design, a deflector baffle was welded to
    one side of the disc-type downcomer valve to minimize dust deposits
    on adjacent ductwork which might hinder valve travel.  This de-
    flector baffle caused a weight  imbalance to exist in the valve and
    the single-point guide system was insufficient to maintain rigid
    vertical travel.  Once the valve left the guide system it was free
    to rotate when in the raised position.   If rotation occurred, the
    deflector baffle struck the angular bottom of the valve housing
    during the downward stroke of the valve, and travel was restricted.
    Experimentation indicated that  this condition is improved by the
    addition of a counterweight on  the valve opposite the deflector
    baffle.  The counterweight  stablizes the valve during travel and
    the program to install the counterweight on each of the forty-
    eight valves with the deflector baffle  design has been completed.
                                  42

-------
SectionV-B -Operating Problems (cont'd)

2.  Gravel Bed Filter System (cont'd)

    Modifications have also been incorporated in the valve guiding
    system and the hydraulic cylinder to eliminate the problem of
    restricted travel.  The shafts of the hydraulic cyclinders were
    extended approximately twenty inches and a pedestal was fabri-
    cated to raise the hydraulic cylinder, thus minimizing its sub-
    jection to the dirty atmosphere.  The pedestal consists of a
    section of three inch pipe with a rectangular piece of plate
    welded to each end.  After welding, two slots 180 degrees apart
    were machined the full length of the pipe.  The slots serve as
    a  guide for a pin which is threaded in the shaft extension.
    A supplemental advantage of the improved guiding system was the
    incorporation of external indication of valve position, which
    was previously non-existent.

    A second problem also associated with the backflush cycle was
    the replacement requirements for the filter media support
    screens.  The necessity for replacement generally resulted froff
    damage caused by insufficient clearance between the rake and the
    screen.  In addition, it became evident that the tear resistance
    of the screens was inadequate for this application.  The adjust-
    ment of rake clearance and the installation of heavier gauge
    support screens have essentially eliminated this problem.

    A third problem of consequence developed during the early stage"
    of gravel bed filter operating due  to the build-up of dust on
    the garnet filter media.  After three months of operation, ob-
    servations indicated that the filter beds had doubled in depth
    from the original 100 millimeters (4 inches) to approximately
    200 millimeters (8 inches).  At that time the increased bed
    depth began affecting the system in that individual modules
    became inoperative due to overloading of the rakes during the
    backflush cycle.
                                     43

-------
Section V—B - Operating Problems (cont'd)

2.  Gravel Bed Filter System (cont'd)

    It became necessary to remove a portion of the filter media  from the
    beds in order to place them back in operation.  Results from testing
    conducted during this time interval indicated a monthly growth rate
    for the garnet filter media of 25 percent on a weight basis.  Visual
    observations indicated that this growth occurred at different rates
    for individual particles in the bed.   It became evident that the
    garnet filter media had an inherent disadvantage of rapid growth in
    this environment.1

    Additional testing was immediately initiated to document.the physical
    changes of various types of filter media in the same environment.
    Observations continued during subsequent months to document the physi-
    cal characteristics of other filter medias contained in selected test
    modules of the gravel bed filter system.   Samples of media from these
    test modules were removed periodically,  and physical analyses were
    performed to establish growth trends.   This testing demonstrated that
    of all the filter medias tested, steel grit was superior with respect
    to growth trends and filtering efficiency.   Based on these conclu-
    sions, the gravel bed filter system was  temporarily shut down and  the
    garnet filter media was totally replaced with steel grit filter media.

    An inspection of the modules containing  either the garnet or steel
    grit filter media also revealed a severe  problem of blinding and
    adhesion of sinter dust to form a 1 to 10 millimeters (0.04 to 0.4
    inches) cake on the support screens.   Since clearance between the  rakes
    and the support screens is maintained  at approximately 13 millimeters
    (0.5 inches) to avoid screen damage,  this  layer is not disturbed during
    the backflush cleaning cycle.   Once the  screens start to blind,  uneven,
    high velocity backflushing of the bed  occurs and sections of the sup-
    port screens are left without media cover after the completion of  the
    cycle.  This phemomenon is of a very  serious nature since it causes
    short-circuiting of the system and results  in a reduction in par-
    ticulate removal efficiency.

    It has been concluded that the principal cause of the screen blinding
    problem is the condensation of moisture  on the screens and the com-
    bination of this moisture with the lime-rich sinter dust in the waste
    gas.   Since there are numerous interrelated factors which could con-
    tribute to this problem,  it has been  difficult to implement a total
    solution.   The factors presently hindering the optimized operation of
    the  system could be one or any combination of the following:
                                      44

-------
Section V-B - Operating Problems (cont'd)

2.  Gravel Bed Filter System (cont'd)

    (a) Insufficient backflush air.
    (b) Malfunction of backflush air preheat system.
    (c) Reaction of coke oven gas consitutuents with sinter
        plant dust.
    (d) Inadequate raking action.
    (e) Frequency of start-up and shutdown modes of operation.
    (f) Fluctuating incoming waste gas temperatures.

    During the early operational stage of the system, it was suspected
    that the backflush fans were not of a sufficient capacity to
    thoroughly purge the bed of dust.  An investigation indicated that
    these fans were of marginal capacity.  However, it was recognized
    that a critical balance must be maintained to achieve the highest
    velocity possible through the bed without displacing the filter
    media.  A program to replace the backflush fans was implemented prior
    to the decision to change from garnet to steel grit filter media.
    The success of this fan replacement program is indeterminate but in
    retrospect its implementation was essential in view of the conversion
    to the higher specific gravity steel grit filter media.

    The backflush preheat system appears to be one of the significant causes
    of screen blinding since it has not yet been proven to perform with
    adequate reliability.  Due to condensed deposits from the coke-oven
    gas in the valve train ahead of the burner system, malfunctions have
    continued to occur, although less frequently in the summer than in
    the winter months.  The re-design and conversion of the piloting system
    to natural gas was a major step in obtaining improved reliability,
    but additional steps are required.  It is evident that any program to
    clean up the coke-oven gas would not only assist in improving the re-
    liability of the backflush preheat system, but would also minimize
    any inter-action   which may be occurring between the combusted
    coke-oven gas and the collected sinter dust.  An effort to improve
    the quality of the coke-oven gas via the installation of a baffled
    separator in the supply line was only moderately successful.  The
    Company is presently testing a chemical additive which is injected
    in the coke-oven gas feed line upstream of the backflush preheat
    system.  Thus far, this program has shown promise in improving the
    reliability of the preheat system.
                                        45

-------
Section V^B TV Opera ctrig pgeblems Ceent'd)

2,  Gravel Bed Filter System (cont'd)

    The influence of the raking action ©n the screen blinding problem
    is not known at this time,   However, it has been concluded that the
    redesign of rake tines could improve the effectiveness of the back-
    flushing cycle, and a program to modify one module for experimental
    purposes will be implemented in the near future.

    The frequency of the start-up and shut'-down modes of the sinter
    machine, and the fluctuation of incoming waste gas temperatures
    to the gravel bed filter system are a function of production
    schedules and equipment maintenance and malfunction.  These factors
    are suspected to be the most significant contributors to the screen
    blinding problem since the probability of dew point condensation
    from the waste gas to the filter beds is extremely high.  As would
    be expected, the probability of dew point condensation is much
    higher in the winter than in the summer months.   Unfortunately,
    these conditions cannot be totally avoided unless the gravel bed
    filter system is by-passed during these critical intervals.

    The detrimental effects of the screen blinding problem on the
    operating reliability and performance cannot be over-emphasized.
    Under optimized conditions, the gravel bed filter system has demon-
    strated the capability of producing  an effluent concentration of
    approximately 68.6 mg/Nm  (0.03 grains/dscf) of particulate.  During
    periods of malfunction with blinded  screens, the effluent concen-
    tration is more than tripled.

    In order to establish the requirements for improved reliability
    and performance of the system,  a testing program was initiated
    utilizing one filter module.   This testing program included an
    expansion of fan capacity for  the gravel bed filter system to
    permit the treatment of additional effluent volume from the sinter
    machine.
                                    46

-------
Section V-B - Operating Problems (cont'd)

2.  Gravel Bed Filter System (cont'd)

    One module in the gravel bed filter system was modified to permit
    monitoring of inlet and outlet dust loadings.  The volume directed
    to this module was increased to the design flux rate of 36.6 cubic
    meters per minute per square meter of bed area (120 cubic feet per
    minute per square foot of bed area).  Experience gained on this
    and other applications of gravel bed filtration has indicated that
    the effluent quality will be improved by the increased velocity
    through the bed since the particle agglomeration process is en-
    hanced.  It was therefore concluded that the system can accept the
    additional flow of waste gas providing that the fan capacity is ex-
    panded .

    Additional test work was directed toward establishing the effect of
    filter media particle sizing and backflush air volume on the re-
    liability and performance of the system.  This testing concluded
    that the steel grit filter media sizing could be increased from a
    nominal diameter of 1.04 millimeters (0.041 inch) to 1,40 milli-
    meters (0.055 inch) without a sacrifice in effluent quality.  In
    addition, the testing indicated that a 10 percent increase in
    backflush fan speed would be beneficial.  The use of large media will
    permit the conversion to a larger opening support screen which
    should reduce the opportunity for the screen to blind.  An equally
    important advantage in increasing the media size is that the pres-
    sure drop will be lower for a given gas volume.  In addition, the
    use of large filter media in combination with increased backflush
    fan speed will allow more efficient cleaning of the beds.

    Based  on these test results the following revisions to the system
    will be implemented by July 1979:

    1.  The existing gravel bed filter fan will be replaced to in-
        crease the capacity from 4531 normal cubic meters per minute
        (160,000 standard cubic feet per minute) to 6800 normal cubic
        meters per minute (240,000 standard cubic feet per minute).

    2,  The steel grit filter media will be changed from a nominal
        diameter of 1.04 millimeters (0.041 inch) to 1.40 millimeters
        (0,055 inch).
                                     47

-------
Section V-B - Operating Problems (cont'd)

2.  Gravel Bed Filter System (cont'd)

    3.  The filter media support screens will be changed from 0.89
        millimeter diameter wire, 0.81 millimeter clear opening
        (15 mesh 0.035 inch diameter wire, 0.032 inch clear opening)
        to 1.04 millimeter diameter, 1.27 millimeter clear opening
        (11 mesh 0..041 inch diameter wire, 0.050 inch clear opening).

    4.  The speed of the existing backflush fans will be increased by
        10 percent from 2055 to 2260 revolutions per minute.

    It is anticipated that the above program will significantly improve
    the operating reliability and performance of the gravel bed filter
    system.  However, it is recognized that a major factor in obtaining
    sustained operation is the implementation of a comprehensive pre-
    ventative maintenance program in screen cleaning.  In past practices,
    such a program was not feasible due to inadequate material handling
    facilities to remove the filter media from the module to permit access
    for screen cleaning.  For this  reason, the above program was expanded
    to include the installation of a filter media material handling and
    storage system sized to permit the cleaning of the screens in four
    modules (eight beds) in an eight-hour period.  This installation will
    facilitate the implementation of a preventative maintenance program
    of screen cleaning during the scheduled weekly sinter machine down
    turn on a repeat cycle of six weeks.


Section V-C - Environmental Aspects

As defined in the scope of work for this contract, testing and evaluation
in various modes of operation for a sinter plant windbox exhaust gas system
were accomplished.  Tfiese modes included (1) a base study (no windbox gas
recirculation )j (2) optimum recycle of windbox gas system; (3) no windbox
gas recirculation with gravel bed filtration; and (4) optimum recycle of
windbox gas and gravel bed filtration.   These studies were performed on
Weirton Steel Division's No.  2 Sinter Machine and included such parameters
as flow rate,  gas composition, particulate, sulfur dioxide and hydrocarbon
determinations for each of the above mentioned test modes.   The goal of
the contract endeavor was directed toward lowering total air pollutants
from steel industry sinter machines using windbox gas recirculation and/or
gravel bed filtration.  This  section presents the final results of these
tests as related to the environmental benefits realized from the use of
these technologies.
                                  48

-------
Section V-C - Environmental Aspects (cont'd)


                              TEST PROGRAM

Test Plan (General)

In order to expedite the completion of the testing and evaluation require-
ments in the contract, testing was conducted in two distinct phases.
Phase A involved only the base study (no recycle) and optimization of the
recycle system with the submission of a draft interim report to the
Environmental Protection Agency, while Phase B dealt with gravel bed filtra-
tion and recycle or no recycle of windbox gases.  Phase A testing occurred
in August and September of 1977 and Phase B during late July 1978.  Gravel
bed operations during Phase A were not included in the interim report due
to problems encountered in its operation.  These problems have been dis-
cussed in detail in Section V-B of this report.

Test Plan (Phase A; Sinter Machine Operation With and Without Windbox
	Recycle)	

Due to the configuration of the Windbox Recycle System it was necessary
to traverse several locations to determine recycle flows.  In addition, the
configuation of the ductwork did not present ideal sampling conditions.  To
minimize these problems, three traverse stations were selected; (1) prior
to the waste gas fan; (2) prior to the recycle fan; and (3) the recycle
ductwork leading back to the machine (see Figure B3). The primary sampling
station selected for Phase A testing was the Mo.1 Traverse Station(Waste Gas
fan) which was the only truly vertical run of ductwork in the system.  All
other locations were horizontal runs which presented problems inherent
with operating a sampling train in a vertical position and potential severe
stratification of particulate concentrations.

Once the selection of the primary sampling station was finalized a second
problem had to be reconciled.  The variability of charge materials to the
sinter machine could have a significant effect on the sampling results.
In order to minimize these problems a test schedule was arranged so that
the recycle and non-recycle modes could be sampled on the same day.
Velocity traverses, gas composition samples, particulate sampling, raw
materials composites, sinter composites and condensible organics were
collected for each mode of operation on each sampling day.  Sulfur dioxide
samplings were performed on the following day after the particulate deter-
mination.  Nine complete sets of sampling data were collected.  On any
day when the complete test of each mode could not be accomplished the col-
lected data were not used in the analysis.
                                   49

-------
Section V-C - Environmental Aspects (cont'd)

Test Program (cont'd)

Test Plan (Phase B; Gravel Bed Filtration With and Without Windbox
	  Recycle)                   	

Two additional traverse locations:  (1) inlet of gravel bed filters;  and
(2) gravel bed stack discharge, were selected for the completion of Phase
B.  The three Phase A traverse stations were utilized to determine flow
distributions (1) prior to waste gas fan; (2) prior to the recycle fan;
and (3) the recycle ductwork leading back to the machine.  Test schedules
were arranged to accomplish complete testing of the recycle and non-
recycle operational modes within the same day.  On any day when the com-
plete test of each mode could not be accomplished due to equipment failure
or operational interruptions, the collected data were not used in the
analysis.

Testing Procedures (Stack Gas Flow Rates)

Under recycle conditions twenty-four point velocity traverses were per-
formed at each of the three traverse stations (Figure No. 13).  Total
flow was obtained by adding the measured flow of the waste gas and recycle
fans.  The amount of recycle was then determined by measuring the volume
sent back to the sinter machine hood system.  The stack gas volume under
no recycle conditions was eimply an addition of the waste gas and recycle
fan volumes.  All gas velocity traverses were made according to Reference
Methods 1 and 2 as published by the Environmental Protection Agency in the
FEDERAL REGISTER. (3) A summary of the measurements for each traverse
location are included in the Appendix Tables 22 through 24.

Testing Procedures (Waste Gas Composition)

Waste gas grab samples were collected before each sampling run in 250 ml.
glass sampling cylinders equipped with side arms for convenient extraction
of a syringe sample.  The gas cylinder samples were then transferred  to the
laboratory and analyzed using a Model 900 Perkin-Elmer Gas Chromatograph,
calibrated with gases of a similar composition.  The analyses included
oxygen, carbon dioxide, carbon monoxide and nitrogen.  Detailed results
are included in the Appendix on the sampling summary sheets.
                                    50

-------
                                                RECYCLE HOOD
              WASTE GAS
            CONTROL HOUSE
               PIGURS 13  VELOCITY TfiAVlJiRSE STATIONS

WEIRTON STEEL DIVISION SINTER PLANT GAS RECIRCULATION SYSTEM

-------
Section V-C - Environmental Aspects (cont'd)

Test Programs (cont'd)

Testing Procedures (Particulates)

Particulate sampling was performed employing a standard U.S. Environmental
Protection Agency Method 5 (4) sampling train assembly as indicated in
Figure No. 14.  Minor modifications, such as the use of stainless steel
liner and filter holder were used.  A five-foot heated probe was utilized
in order to traverse sample in four directions.  In addition to the front
half or particulate collection half, an impinger assembly was used.  It
consisted of four impingers in series, the first two containing 200 ml.
of distilled water each, the third empty and the fourth containing 200
grams of silica gel.  The impinger assembly was utilized in order to
measure waste gas moisture and condensable hydrocarbons.  Traverse
sampling included twelve points on a diameter or twenty-four total points.
All conditions and procedures, as specified by Method 5, were followed as
closely as possible during the sampling program.

Testing Procedures  (Sulfur Dioxide)

A sampling train was assembled according to the specification of U. S.
Environmental Protection Agency Reference Method 6 published in the
FEDERAL REGISTER  (5) (see Figure No.  15).  The  option of using Greensburg-
Smith bubblers and  impingers was employed.  In  addition the train consisted
of a heated probe with  three inch fiber glass  filter, impinger train,
vacuum pump and gas meter.  The probe was positioned in a pre-selected lo-
cation and the waste gas sampled at a constant  rate.  The impinger train
consisted of  four impingers, the first containing 200 ml. of eighty percent
isopropanol,  the second and third 200 ml. of three percent hydrogen per-
oxide and the last  impinger 200 grams of silica gel.  After completion of
the sampling  run the isopropanol was  discarded  and the hydrogen perioxide
transferred to the  laboratory for sulfur dioxide analysis using the pre-
scribed barium-thorin titration method.

Testing Procedure (Hydrocarbons)
                                                              __j
In an effort  to establish a mass balance for condensable organics associated
with sinter production, three sampling locations were selected in Phase A
testing:  (1) raw material mix as fed to the sinter machine was composited
during each sampling run; (2) sinter product was collected in a likewise
manner; and (3) waste gas condensables were collected using the Method 5
particulate sampling train.  The impinger catch was analyzed for organic
condensables.  All samples collected were submitted to the laboratory and
analyzed using a choloroform-ether extraction method for condensable or-
ganic emissions for sinter plants. (2)  The raw materials and sinter


                                     52

-------
                                                   f OVEN ME ATER.
  Ul
  Ui
               STACK TEMPERATURE T.C.
                                                                                               IMPINGERS
                PROBE TEMPERATURE T.C.
                 REV. TYPE
                 PITOT
                   = 0.828
                   PITOT AP
                   MAGNEHELIC
                     200 ml
                      H20
  200 gr
Silica Jel
                                                                                  ICE BATH
                                                                          FINE ADJUSTMENT
                                                                          BY PASS VALVE
                                                                                                     VACUUM
                                                                                                     LINE
                   ORIFICE AP
                   MAGNEHELIC GAGE1
                                                   DRY TEST METER
                                           - VACUUM
                                             GAGE
                                  	COARSE
                                     ADJUSTMENT
                           AIR TIGHT  VALVE
                           VACUUM
                           PUMP
to
-4
         Figure 14
EPA - Method 5 Sampling Train

-------
                             FIGURE ±*>  - SAMPLING TRAIN FOR S02 DETERMINATION
Ol
        Velocity Determination


5s>

Magnahelic
Gauges
       CD
      -p
       g
       CD
           Stack Wall
                             ilter
Tempera tiire
                                                            Vacuum Gaugef
                                                         TemperatureQ

00
0


r?r
t




\. 'V N 'v^
/
1



v////////
'/////// S\
v

1 /

^

\\\\
1

Jv
— 1 —
^r
    ^sopropyl  3% -^-HgO^   ^-Silica
Bath   Alcohol 200 ML         Gel
       200 ML                 200  gm
                                                                           Dry Test
                                                                             Meter
             Pump

-------
Section V-C - Environmental Aspects  (cont'd)

Test Program (cont'd)

Testing Procedure: (Hydrocarbons) (cont'd)

product were grab sampled at frequent intervals during the testing.  The
samples collected for each test period were thoroughly mixed and quartered
in preparation for analyses by the gravimetric-extraction method.  The
pre-weighted sampleswere extracted utilizing chloroform and ether in a soxh-
let apparatus.  The extract was processed by volume reduction through dis-
tillation and drying, and the quantity of organic material was determined
gravimetrically.  Representative samples were very difficult to obtain and
several data points had to be discarded as suspect.  Phase B testing did
not include raw material or product  samples.  Hydrocarbon determinations
were made only of the inlet and discharge gas streams from the gravel bed
system.

                                TEST RESULTS

Phase A Testing (Partieulates)

Test Mode No. 1; Base Study - Sampling of the main windbox gas system with
no recirculation was performed to determine the emission rate without con-
trols.  With no recycle of waste gas to the sinter machine an average par-
ticulate concentration of 1182 mg/Nm (0.515 grains/dsdf) resulted.  Dis-
charge flow rate was measured at 14240 Nm^/min. (503,197 dscfm).  The cal-
culated mass particulate emission rate, based on these measurements, was
1007 kg/hr (2215 Ibs/hr), or 3.2 g/kg (6.4 Ibs/ton) of sinter strand feed
(refer to Tables Nos. 9 and 10).

Test Mode No. 2; Windbox Recycle - Sampling tests performed during recir-
culation of an average of 25 percent of the waste gas resulted in an aver-
age particulate concentration of 1094 mg/Nm-* (0.477 grains/dscf).  This
concentration and an average discharge gas flow of 10330 NmJ/min.
(365,025 dscfm) produced a particulate mass emission rate of 681 kg/hr
(1498 Ibs/hr), which is equivalent to 2,17 g/kr (4.34 Ibs/ton) of sinter
strand feed (refer to Tables Nos. 9  and 11),

Comparison of the test results for the two operational modes indicates a
mass reduction of thirty-two percent of the particulate matter emitted
from the main windbox gas system,  A slight decrease in concentration
during recycle was noted.
                                       55

-------
Section V-C - Environmental Aspects (cont'd)
Test Results (cont'd)

Phase B Testing (Particulates)

Test Mode No. 3; Gravel Bed With No Windbox Gas Recirculation - Sampling of
the inlet to the gravelled filters resulted in an average particulate emis-
sion rate of 1299 mg/Nm  (0.568 grains/dscf).  This concentration and a flow
rate of 2569 Nm /min. (90,744 dscfm) produced a loading 195.9 kg/hr
(431.4 Ibs/hr).

Outlet stack testing simultaneous with inlet samples indicated an average
particulate emission rate of 146.7 mg/Nm  (0.064 grains/dscf).  This con-
centration and a flow rate of 3309 Nm /min. (116,854 dscfm) resulted in a
mass loading of 30.3 kg/hr (66.7 Ibs/hr) (see Table No. 12 for individual
test results).
The results of the tests indicated an average reduction of eighty-five
percent across the gravel bed filters with a range of seventy percent to
ninety-two percent of particulate removal.

Test Mode No. 4; Gravel Bed With Windbox Gas Recirculation - Particulate
concentrations were determined while maintaining an average recycle rate
of 24.8 percent.  The inlet to the gravel bed filter system contained an
average 1565 mg/Nm  (0.68 grains/dscf).  A flow rate of 2419 Nm^/min.
(85,377 dscfm) and this concentration resulted in a mass loading of
234.7 kg/hr (517 Ibs/hr).
Outlet stack gas samples simultaneously taken with the inlet samples showed
a concentration of 156 mg/Nm3 (0.068 grains/dscf).  This concentration and
an average flow rate of 3096 Nm-Vmin. (109,355 dscfm) resulted in a mass
loading of 31.7 kg/hr (69.7 Lbs/hr) in the stack discharge.  (see Table
No. 13 for individual test results).

The average particulate removal efficiency during this mode of operation
was eighty-seven percent with a range from eighty-one percent to ninety-
five percent.

Phase A Testing (Sulfur Dioxide)

Test Mode No. 1 - With zero recycle the waste gas steam contained 320
mg/Nm3 (0.14 grains/dscf) of sulfur dioxide.  This concentration and a
flow rate of 14,240 Nm3/min. (503,197 dscfm) produced a sulfur dioxide
emission rate of 271 kg/hr (597 Ibs/hr), which is equivalent to 0.86 g/kg
(1.72 Ibs/ton) of sinter strand feed (see Tables Nos. 9 and 10).
                                     56

-------
Section V-C - Environmental Aspects  (cont'd)

Test Results (cont'd)

Phase A Testing (Sulfur Dioxide)  (cont'd)

Test Mode No. 2 - Results of the  testing effort  for  sulfur dioxide indi-
cated a concentration of 350 mg/Nm3(Q.153 grains/dscf) at a 25 percent
recycle rate.  This concentration combined with  an average waste gas dis-
charge rate of 10,330 Nnr/min.  (365,025 dscfm) produced a sulfur dioxide
emission rate of 223 kg/hr (491 Ibs/hr) which equates to 0.71 g/kg
(1.42 Ibs/ton) of strand feed (see Tables Nos. 9 and 11).

Comparison of the test results  for the two operational modes indicates
a mass reduction of seventeen percent  of the sulfur  dioxide emitted
from the main windbox gas system.  A slight increase in concentration
during recycle was noted.

Phase B Testing (Sulfur Dioxide)

Test Mode No. 3 - Sulfur dioxide  concentrations  in the inlet gas of the
gravel bed filter.system averaged 175.2mg/Nm3 ( 0.076'grains/dscf). The
mass loadings based on a measured average flow of 2569 Nm3/min. (90 744
dscfm) was 27.0 kg/hr (59.5 Ibs/hr).
                                                               O
Stack gas measurements indicated  a concentration of  244.3 mg/Nm  (0.1
grains/dscf).  Mass emission rate calculated at  a measured stack flow of
3309 Nm3/min (116,854 dscfm) resulted  in an average  of 45.5 kg/hr
(100.2 Ibs/hr) (see Table No. 12).

The increase in sulfur dioxide  across  the gravel bed filters was due to
the use of coke oven gas to preheat  backflush air.

Test Mode No. 4 - Inlet gravel bed sulfur dioxide average concentrations
with an average 24.8 percent recycle operational mode were 257 mg/Nm3
(0.112 grains/dscf).  This concentration and a flow  rate of 2419 Nm3/min.
(85,377 dscfm)resulted in a mass  sulfur dioxide  emission rate of 35.5
kg/hr (78.3 Ibs/hr).
                                                                     o
Stack outlet samples produced an  average concentration of 280.5 mg/Nm
(0.122 grains/dscf).  A flow rate of 3096 Nm3/min (109,355 dscfm) re-
sulted in a mass loading of 52.1 kg/hr (114.6 Ibs/hr) (see Table No. 13).
As in the case of Test Mode No. 3, an  increase in sulfur dioxide occurred
across the filter due to the utilization of coke oven gas as a fuel.
                                    57

-------
Ul
oo
                                            TABLE  NO.  9
                                        SUMMARY  TEST RESULTS
                                           (METRIC UNITS)

     DESCRIPTION:   Test Mode No.  1 -  Base  Study  of Uncontrolled  Sinter Machine Operation
                   Test Mode No.  2 -  Optimum Recycle of Main Windbox Waste Gas
                   Test Mode No.  3 -  Gravel Bed  Filtration  Only
                   Test Mode No.  4 -  Optimum Recycle and Gravel  Bed Filtration Combination
    Sinter  Charge   Rate,  MTph
    Sinter  Product  Rate,  MTph
    Recycle %
    Discharged to atmosphere,  Nm^/min
    Particulate,
                 kg/hr
                  g/kg sinter  feed
                                    O
    Condensable Hydrocarbons, mg/Nm
                              kg/hr
                               g/kg sinter  feed
                                                                     TEST MODE
No.
314
186
0
14,240
1,183
1,007
3
7
6
0
1 No. 2
314
186
25.0
10,330
1,094
681
.2 2.17
.0 6.4
.0 4.0
.019 0.013
No. 3(1)
320
190
0
3,309
146.7
30.3
—
4.2
0.92
-
No. 4
320
190
24.8
3,096
156
31.7
—
4.25
0.85
-
    NOTE 1: - Results of tests on flowrate processed through gravel bed  system  only.

-------
                                                                    TABLE NO. 10

                                                      NO RECYCLE TEST RESULTS - TEST MODE #1
Ui
vo
TEST DATE
8/ 3/77
8/ 4/77
8/ 9/77
8/11/77
8/30/77
9/20/77
9/23/77
9/28/77
10/1/77
Average
Stack Effluent Flow
Nm3/min
(dscfm)
Temp. °C.(°F.)
Particulate
mg/Nm^
(grains/c'.scf )
kg/hr
(Ib/hr)
Sulfur Dioxide
tng/Nm3
(grains/dscf )
kg/hr
(Ibs/hr)
Hydrocarbons
Charge - kg/hr
(Ibs/hr)
Product- Kg/hr
(Ibs/hr)
Stack Gas mg/Nm^
(grains/dscf)
kg/hr
(Ibs/hr)
14,28?
(504,834)
134(274)

1,657
( 0.723)
1,421
( 3,129)

231
( 0.101)
199
( 437)

93
( 205)
10
( 22)
. 4.1
( .0018)
3.5
( 7.8)
13,995
(494,556)
109(228)

999
( 0.436)
839
( 1,848)

398
( 0.174)
336
( 737)

155
( 341)
38*
( 84)
7.0
( .003)
6.0
( 13.1)
14,318
(505,952)
110(231)

980
( 0.428)
843
( 1,856)

49.3*
( 0.022)
42 . 4*
( 93.3)

124
( 272)
5.4
( 11.9)
6.8
( .003)
5.8
( 12.8)
14,882
(525,878)
135 (276)

756
( 0.330)
676
( 1,487)

-
-
-
-

103
< 227)
6.5
( 14.4)
8.3
( .0036)
7.5
( 16-4)
14,201
(501820 )
98(208)

1,282
( 0.56 )
1,094
( 2,408)

415
( 0.181)
354
( 779)

129
( 283)
6.0
( 13.2)
8.7
( .0038)
7.5
( «.4)
13,222
(467,184)
101(214)

1,523
( 0.666)
1,212
( 2,666)

263
( 0.115)
209
( 460)

111
( 244)
9.5
( 20.5)
10.0
( .0044)
7.9
( 17.5)
15,312
(541,093)
133 (272)

989
( 0.432)
911
( 2,005)

197
( 0.086)
181
( 399)

107
( 236)
10.4
( 22.8)
5.0
( .0022)
4.6
( 10.2)
14,218
(502,372)
101(214)

1,324
( 0.578)
1,132
( 2,490)

527
( 0.230)
451
( 991)

264*
( 580)
9.2
( 20.2)
4.8
( .0021)
4.0
( 8.8
13,728
(485,083)
110(231)

1,128
( 0.493)
932
( 2,050)

206
( 0.09 )
170
( 375)

47.8*
( 105.2)
4.8
( 10.5)
8.0
( .0035)
6.9
( 15.1)
14,240
(503,197)
115(239)

1,182
( 0.515)
1,007
( 2,215)

320
( 0.140)
271
( 597)

117
( 258)
7.7
( 17 )
7.0
( .0031)
6.0
( 13.1)
        * - Data not used to obtain average since they don't fall within a normal distribution of values

-------
                                                           TABLE NO. 11
                                               RECYCLE TEST RESULTS - TEST MODE #2
TEST DATE
8/
3/77
8/ 4/77
8/ 9/77
8/11/ 77
8/30/77
9/20/77
Stack Effluent Flow
Nm3/min
(dscfm)
Temp. °C.(°F.)
Recycle %
Particulates
mg/Nin-*
(grains/dscf)
kg/hr
(Ibs/hr)
Sulfur Dioxide
0 mg/Nm3
(grains/dscf)
kg/hr
(Ibs/hr)
Hydrocarbons
Charge - kg/hr
(Ibs/hr)
Product - kg/hr
(Ibs/hr)
Stack Gas-Mg/Nm3
(grains/dscf)
kg/hr
(Ibs/hr)
11 j
(419
128


3
( 1
2
( 5


( 0

(


(

(

864
,233)*
(263)
18.8*

,256
,422)*
,321
j'110)*

313
.137)
225
492)

313
688)*
62
137)*
7.6
( .0033)

(
5.4
11. 9)
10,851
(383 ,'435)
115 (240)
21.2

1,390
( 0.607)
906 "
( 1,995)

411
( 0.179)
267
( 588)

311
( 684)*
64.5
( 142)*
5.0
( .0022)
3.3
( 7.2)
9,606
(339,436)
136 (278)
25.0

994
( 0.434)
574
( 1,263)

15.7
( .0068)*
9.1
( 19.9)

266
( 585)*
81.6
( 180)*
4.0
( .0017)
2.3
( 5.2)
10,742
(379,588)
130 (266)
22.8

723
( 0.316)
468
( 1,028)

_
-
_
-

79
( 174)
6.5
( 14.4)
8.0
( .0035)
5.1
( 11.2)
10,851
(383,430)
111 (231)
22.8

1,020
( 0.445)
666
( 1,462)

380
( 0.166)
248
( 545;)

19
( 261)
5.0
( 11.0)
5.8
( .0025 )
3.7
( 8.-°)
9,534
(336,900;
117.8(244)
28.6

887
( 0.387)
507
( 1,117)

227
( 0.095)
124.6
( 274)
;
98
( 216)
9.7
( 21.3)
5.1
( .0022)
3.0
( 6.5 )
9/23/77

10,535
(372,246)
122 (251)
25.5

1,168
( 0.510)
739
( 1,627)

417
( 0.182)
264
< 58*)

144
( 317)
10.4
( 22.8)
6.7
( .0029)
4.3
( 9.5)
9/28/77

9,915
(350,336y
111 (232)
27.7

1,266
( 0.553)
754
( 1,661)

530
( 0.232)
317
( 697)

194
( 427)
7.7
( 17)
5.7
( .0025)
3.3
( 7.3)
10/1/77
W£f\ O
, oUo
(374,828-
105 (221)
26.4

1,301
( 0.568)
830
( 1,828)

183
( 0.080)
16.7
( 257)

80.2
( 176.5)
6.3
( 13.9)
9.5
( .0041)
6.0
( 13.2)
Average
1 f\
i.U
(
118.



(

(


(

(


(

(

(

(
OQfl
, JJU
5,025)
4(245)
25

1,094
0.477)
681
1,498)

350
0453)
223
491)

119
262)
7.6
16.7)
6.4
.0028)
4.0
8.9)
* - Data not used to obtain average since they don't fall within a normal distribution of values

-------
                                                              TABLE NO.  12
                                      GRAVEL BED FILTER TEST RESULTS - NO RECYCLE - TEST MODE  #3
  TEST DATE
  % Recycle

  Gas Flow
  (A) Inlet,  Nm3/min
            (dscfm)
             °C.(°F.)
  (B> Stack,  Nm3/min
            (dscfm)
            °C.  (°F.)
  Particulates
  (A) Inlet mg/Nm3
       (grains/dscf)
       kg/hr (Ibs/hr)
  (B) Stack mg/Nm3
       (grains/dscf)
       kg/hr (Ibs/hr)
  Sulfur Dioxide
  (A) Inlet mg/Nm3
       (grains/dscf)
       kg/hr (Ibs/hr)
  (B) Stack mg/Nm3
       (grains/dscf)
       kg/hr (Ibs/hr)
*%ydrocarbns
  (A) Inlet mg/Nm3
       (grains/dscf)
      Kg/hr (Ibs/hr)
  (B) Stack mg/Nm3
      (grains/dscf)
      kg/hr (Ibs/hr)
 * - Data not used to
** - Back half only
7/18/78
0
1,996
( 70,496)
104 (220)
3,292
(116,206)
89 (192)
1,705
( 0.745)
204.4 (450)
153.2
( 0.0669)
31 (68.4)
9.7*
( 0.004)*
1.09 (2.4)*
292.6
( 0.128)
57.9 (127.5)
14.1
( 0.0062)
1.8 (4.0)
0.188
( 0.000082)
0.039 (0.086)
7/19/78
0
2,885
(101,875)
103.4 (218)
2,947
(103,699)
91.2 (196)
1,352
( 0.591)
241 (530)
157.0
( 0.0686)
28.5 (82-7)
72.6
( 0.0317)
12.6 (27.7)
261
( 0.0848)
34.2 (75.4)
0.121
( 0.00005)
0.034 (0.075)
1.0
( 0.00043)
0.18 (0.4)
7/21/78
0
2,101
( 74,192)
94 (201)
2,362
( 83,406)
79 (174)
1,746
( 0.763)
226 (418)
119.4
( 0.0521)
17.4 (38.3)
177
( 0.077)
22.2 (49)
229
( 0.10)
32.5 (71.5)
5.65
( 0.00247)
0.73 (1.61)
3.87
( 0.00169)
0.57 (1.24)
7/27/78
0
3,106
(109,774)
112.3 (234)
3,833
(135,409)
94 (201)
922
( 0.403)
177.1 (390)
149
( 0.0649)
35.1 (77.4)
325.7
( 0.142)
60.7 (133.6)
339
( 0.148 )
78 (171.8)
17.6
( 0.0077)
3.38 (7.44)
13.9
( 0.0061)
3.27 (7.2)
7/28/78
0
2.758
( 97,383)
127.9 (262)
4,122
(145,550)
105 (221)
771
( 0.337)
131.2 (289)
155
( 0.0675)
39.3 (86.5)
75.9
( 0.0331)
12.5 (27.6)
100.0
( 0.0439)
24.9 ( 54.8)
2.48
( 0.0011)
0.42 (0.93)
2.08
( .00091)
0.53 (1.16)
Average
0
2,569
( 90,744)
108.3 (227)
3,309
(116,854)
91.6 (196.8)
1,299
( 0.568)
195.9 (431.4)
146.7
( 0.064)
30.3 (66.7)
175.2
( 0.076)
27.0 (59.5)
244.3
( 0.1)
45.5 (100.2)
7.99
( 6.0035)
1.27 (2.81)
4.2
( 0.0018)
0.92 (2.02)
obtain average since they don't fall  within  a  normal distribution of values

-------
                                                                        TABLE NO. 13
                                                   GRAVEL BED FILTER TEST RESULTS - RECYCLE - TEST MODE #4
NJ
  TEST DATE

  % Recycle

  Gas Flow
  (A) Inlet Nm3/min
            (dscfm)
            °C.(OF.)
  (B) Stack Nm3/min
            (dscfm)
            °C.(°F.)
  Particulates
  (A) Inlet mg/Nm3
           (grains/dscf)
           kg/hr (Ibs/hr)
  (B) Stack Mg/Nm3
           (grains/dscf)
           kg/hr (Ibs/hr)
  Sulfur Dioxide
  (A) Inlet mg/Nm3
           (grains/dscf)
           kg/hr( 'Ibs/hr)
  (B) Stack mg/Nm3
           (grains/dscf)
           kg/hr (Ibs/hr)
**Hydrocarbons-Condensible
  (A) Inlet mg/Nm3
           (grains/dscf)
            kg/hr (Ibs/hr)
  (B) Stack mg/Nm3
           (grains/dscf)
           kg/hr (Ibs/hr) \
   * - Data not used to obtain
 ** - Back Half Only
7/18/78
21.2
1,754
( 61,737
114 (237)
2,847
(100,535)
98.4 (209)
1,664
( 0.727)
174.7(385)
134.4
( 0.0587)
23.6 (51.9)
267
( 0.116)
27.9 (61.4)
218.9
( 0.0956)
37.4 (82.4)
14.3
( 0.0063)
1.6 (3.5)
0.286
( 0.000125)
0.053 (0.116)
7/19/78
31.9
2,784
( 98,313)
95.6 (204)
2,851
(100,677)
94 (201)
1,834
( 0.801)
315 (693)
85.8
( 0.0374)
15.1 (33.2)
93.5
( 0.0408)
15.6 (34.4)
373
( 0.163)
63.9 (140.7)
3.16
( 0.0014)
0.55 (1.2)
6.98
( 0.00305)
1.2 (2.7)
7/21/78
17.3
1,984
( 70,046)
105.6 (222)
2,198
( 77,626)
90 (194)
1,037
( 0.453)
126.7 (279)
111.5
( 0.0487)
15.1 (33.3)
412
( 0.180)
49 (108)
416
( 0.182)
55 (121.1)
5.82
( 0.00254)
0.71 (1.57
3.22
( 0.00171)
0.53 (1.17)
7/27/78
27.1
2,760
( 97,534)
118.4 (245)
3,710
(131,119)
100.6 (213)
1,806
( 0.789)
307.9 (678)
245
( 0.107)
55.9 (123)
366.4
( 0.160)
60.7 (133.8)
11.6*
( 0.0051)*
2.6 (5.73)*
15.2
( 0.0062)
2-6 (5.72)
8.7
( 0.0038) .
2.0 (4.4)
7/28/78
26.4
2,811
( 99,255)
118.4 (245)
3,875
(136,818)
109.5 (229)
1,482
( 0.648)
249.3 (549)
204
( 0.0889)
48.6 (107)
145.5
( 0.0635)
24.5 (54)
2.78*
( 0.00121)*
0.64 (1.4) *
1.24
( 0.00054)
0.21 (0. 46)
2.05
( 0.00089)
0.49 (1.08)
Average
24i 8.
2.419
( 85,377)
110.4 (230.6)
3,096
(109,355)
98.5 (209.2)
1,565
( 0.6836)
234.7 (517)
156
( 0.068)
31.7 (69.7)
257
( 0.112)
35.5 (78.3)
280.5
( 0.122)
52.1 (114J6)
7.9
( 0.0034)
1.13 (2.49)
4.25
( 0.0019)
0.85 (1.89)
                                          average since they don't fall within a normal distribution of values

-------
Section V-C - Environmental Aspects  (cont'd)

Test Results (cont'd

Phase A Testing  (Hydrocarbons)

Test Mode No. 1  - The  condensable hydrocarbon emission  rate  under" normal
operation with no recycle was  7.0 mg/Nm3(0.0031 grains/dscf).  A volume  of
14,240 Nnr/min.  (503,197 dscfm)  produced a mass emission  rate  of 6.0 kg/hr
(13.1 Ibs/hr) or 0.019 g/kg  (0.038  Ibs/ton) of burden to  the sinter
machine (see Tables Nos. 9 and  10 for individual test results).

Test Mode No. 2  - With an average 25  percent  recycle of waste  gas it was
determined that  the waste gas  contained a  condensable hydrocarbon con-
centration of 6.4 mg/Nm3 (0.0028 grains/dscf).   With an average  flow rate
of  10,330 Nnr/min. (365,025  dscfm)  the mass emission rate was  4.0 kg/hr
(8.9 Ibs/hr)'which is  equivalent to  0.013  g/kg (0.026 Ibs/ton)  of sinter
strand feed (see Tables Nos. 9  and  11 for  individual results).

A comparison of  the test results shows a reduction  of thirty-two percent
of  condensable hydrocarbons  discharged under  recycle conditions.

Phase B Testing  (Hydrocarbons)

Test Mode No. 3;  No Recycle/Gravel Bed Filter  Only - Tests conducted on the
gravel bed inlet gas using the  back-half of the Environmental Protection
Agency method train produced hydrocarbon concentrations of 7.99  mg/Nm3
(0.0035 grains/dscf).   The calculated mass  emission rate using  a measured
average flow rate of 2569 Nm3/min.  (90,744 dscfm) was 1.27 kg/hr
(2.81 Ibs/hr).

Stack gas concentrations determined  simultaneously  with the  inlet were
4.2 mg/Nm3 (0.0018 grains/dscf).  An  average  stack  flow of 3309  Nm3/min.
(116,854 dscfm)  and the measured concentration  produced a mass  loading of
0.93 kg/hr (2.02  Ibs/hr) of condensable hydrocarbons (see Table No. 12 for
individual test  results).

Although the deviation in individual  data was  extreme,  the average result
indicated a twenty-eight percent reduction  of  condensible hydrocarbons in
the gravel bed filter  system.
                                     63

-------
 Section  V-C - Environmental Aspects  (cont'd)

 Test  Results (cont'd)

 Phase B  Testing  (Hydrocarbons)  (cont'd)

 Test  Mode No. 4;  Recycle  and  Gravel  Bed Operation  - While maintaining an
 average  twenty-five  percent windbox  gas recycle, samples of  the  gravel
 bed inlet were collected.  Results indicate an  average  concentration  of
 7.9 mg/Nm3  (0.0034 grains/dscf) and  a mass emission rate of  1.13 kg/hr
 (2.49 Ibs/hr) based  on  a  flow rate of 2419 Nm3/min (85,377 dscfm).

 Stack samples taken  concurrent with  the inlet samples resulted in an
 average  concentration of  4.25 mg/Nm3 (0.0019 grains/dscf).   Based on  a
 flow  rate  of 3096 Nm3/min. (109,55 dscfm) a mass hydrocarbon loading
 of 0.85  kg/hr (1.89  Ibs/hr) was calculated (see Table No. 13 for in-
 dividual test results).

 The average data indicated a  condensable hydrocarbon reduction of
 twenty-five percent  in  the gravel bed filter system, but as  in the  case
 of Mode  No. 3, variation  in individual results was excessive.

              TEST RESULTS DISCUSSION AND CONCLUSIONS

 Phase A  Testing  (Test Modes Nos. 1 and 2) - An  analysis of test  results
 indicates  that reductions of  thirty-two percent particulate,  eighteen
 percent  sulfur dioxide  and thirty-two percent condensable hydrocarbon mass
 emissions  closely parallel the amount of recycled  gas.  No appreciable
 increase or decrease in concentrations of these parameters were  noted.
 Some  slight decrease, approximately  seven percent, in particulate con-
 centration was measured under recycle conditions.  However,  this  is
 considered to be  within the normal variation of stack sampling results
 for a Method 5 determination.

 Hydrocarbon emission concentration data also indicated  a reduction  of
 approximately nine percent in the recycle operational mode.   These  results
 were  somewhat disappointing in that  a higher reduction was expected.
 Attempts to perform  a material balance by analyzing feed and product
 samples  during the test effort produced mixed results.  Under recycle
 conditions only 9.8  percent of the condensable hydrocarbons  present in
 the charge materials could be accounted for in the sinter product and
 waste  gas with a  65.2 percent and 34.8 percent contribution  respectively.
With no recycle,   11.7 percent of the condensable hydrocarbons in the  charge
materials were present in the sinter product and waste  gas components.  The
sinter product contained 57 percent  and the waste  gas 43 percent  of the
accountable hydrocarbons.   This would indicate that under either mode of
operation approximately 90 percent of the hydrocarbon charge  rate was
destroyed by the  sintering process.  However, there have been many  questions

                                      64

-------
Section V-C - Environmental Aspects  (cont'd)

Test Results Discussion and Conclusions  (cont'd)

Phase A Testing (Test Modes Nos.  1 arid 2)  (cont'd)

raised over the methods of analysis of condensable hydrocarbons and possible
interferences in these procedures.   Therefore,  the  data generated by this
test program should be viewed with an air  of  caution until  the "definitive
method" is developed to analyze  condensable hydrocarbons with some degree
of confidence.

Sulfur dioxide concentrations with twenty-five  percent recycle indicated
a seventeen percent reduction.   A slight increase in the waste gas sulfur
dioxide concentration under recycle  conditions  was  noted, approximately
nine percent.  This indicates some build-up of  sulfur dioxide, however,
net reductions with recycle are  realized.

The test results obtained for this test  period  should represent sinter
operations with a range of 2.4 to 3  basicity.

Phase B Testing (Test Modes Nos.  3 and 4)

An analyses of the data representing Test  Mode  No.  3 indicate an eighty-five
percent decrease in particulate  emissions, a  sixty-eight percent increase
in sulfur dioxide emissions and  a twenty-eight  percent decrease in conden-
sable hydrocarbon emissions through  the  gravel  bed  filter system. Similarly,
an analyses of the data for Test Mode No.  4 indicate an eighty-eight percent
decrease in particulate emissions, a forty-seven percent increase in sulfur
dioxide emissions, and a twenty-five percent  decrease in condensable hydro-
carbons .

In both modes of operation, the  particulate concentration in the gravel
bed filter effluent was approximately 150  mg/Nm^ and the efficiency of the
system was less than ninety percent.  However,  as stated previously in
Section V-B of this report, the  detrimental effects of the  screen blinding
problem on the operating reliability and performance of the gravel bed
filter system cannot be over-emphasized. Under  optimized conditions,  the
gravel bed filter system has demonstrated .the capability of producing an ef-
fluent concentration of less than 70 mg/Nm^ of particulate. During periods of
malfunction with blinded screens, the effluent  concentration is more than
tripled.
Although the data for certain test runs  were  suspect, the increase in
sulfur dioxide emissions from the gravel bed  filter system  was expected
in that the backflush air for the filter modules was heated in a direct
fired system utilizing coke—oven gas.  This increase in emission rate  is
minor in magnitude, and is considered insignificant.  However, a ninety
                                 ' 65

-------
 Section  V-C - Environmental Aspects  (cont'd)

 Test  Results Discussion  and Conclustion  (cont'd)

 Phase B  Testing  (Test Modes Nos.  3 and 4)  (cont'd)

 percent  reduction  in these emissions will  occur in  1980 when the Company's
 coke-oven  gas desulfurization program  is completed.

 It  is presumed that the  twenty-five  to twenty-eight  percent  reduction in
 condensable hydrocarbons  occurs due  to the deposition  of this  organic
 material on the  filter mediaj support  screens  and sinter dust  as the
 effluent gas cools below  120° C.  (248° F.).  The benefit of  this condition
 is  questionable  since it  could be contributing to the  blinding problem
 documented in Section V-B of this report.   In  view of  the questions  concern-
 ing condensable  hydrocarbon sampling and analysis procedures,  and the in-
 consistencies in the data generated in the  test program,  it  must again be
 emphasized that  any judgements concerning  this parameter must  be made
 cautiously.

 An  analyses of the environmental  capabilities  of the combined  windbox gas
 recirculation and gravel  bed filter systems cannot be  accurately docu-
 mented until the systems  are totally optimized.  As  stated in  Section V-B,
 the Company is aggressively pursuing programs  to reduce  the  total effluent
 volume from the  sinter machine.
Section V-D - Energy Aspects

Windbox Gas Recirculation System

The replacement of two existing 1865 kw (2500 bhp) fans with two new 3357
kw (4500 bhp) fans is a major consideration in the analysis of the energy
aspects of this system.  The new fans were installed to accommodate (1) the
increased capacity requirement due to the anticipated elevation in windbox
gas temperature, and (2) the additional resistance of the new ductwork from
the fans to the sinter machine hoods.  The design calculations for the gas
flows, temperatures and pressure drops at a 39 percent recirculation rate
are documented in the Phase I Report (1).
                                    66

-------
Section V-D - Energy Aspects  (cont'd)
Windbox Gas Recirculation System (cont'd)

In actual operating practice,  the  anticipated elevation in windbox gas
temperature did not occur.  The  design  calculations  were based on a windbox
gas temperature of 194°  C.  (382   F.) whereas  a temperature averaging  approx-
imately 121° C. (249° F.) was  documented after the system was  optimized.
This lower temperature was  a  result of  an  adjustment in the quantity  of
coke breeze in the sinter burden,  which was necessitated by excessive sinter
bed temperature.  To alleviate the excessive  bed temperature and  associated
operating and maintenance problems,  the quantity of  coke breeze in the
burden was reduced by 7  percent.   Thus,  during actual operation,  the  temper-
ature below the strand burden  is   essentially the same with or without
recirculation.

During the demonstration period,  tests  were conducted to determine the
actual pressure drops in the  system for comparison with the calculated de-
sign pressure drops.  It must  be  noted  that the test data varied  signifi-
cantly as a result of the uncontrollable variations  in the sintering  process.
The tests indicate that  the total  system pressure drop with a  39  percent
recirculation rate is approximately 1473 mm w.c.  (58 in.  w-c.) or 15  percent
higher than predicted in the Phase I Report.   This contradicts what would
be expected with the lower  temperature  waste  gas. Further,  investigations
indicate that the losses in the  ductwork are  indeed  less  than  calculated
in the design.  However, the pressure drop across the sinter bed  is sub-
stantially higher than design  calculation  predictions.  It is  difficult to
ascertain the reasons for this higher pressure drop  due to the many vari-
ables involved.  Numerous possibilities may be responsible,  such  as (1) the
flow of the dirty recirculation  gases through the bed; (2) the change in
the sinter mix due to excessive  temperatures;  or (3) unknown changes  in
the mode of operation.   Measurements of the pressure drop across  the  cyclones
have varied both above and  below the design prediction of 229  mm  w.c.
(9.0 in. w.c.).

Although the total system drop is  higher than design calculations,  the fans
have ample capacity.  As stated previously, the original fan curves were
developed for a temperature of 194° C.  (382°  F)  The lower gas temperature,
which is encountered in  actual operation,  shifts the fan curve upward.  It
appears that the system  pressure  requirements are slightly below  the  new
fan curve for the desired flow.   The fans  are controlled by maintaining a
constant motor current and  by  throttling fan  louvers.  Therefore, the dif-
ference in pressure between the  fan curve  and actual system pressure  is
dissipated across the louvers.   This results  in an inefficient use of
energy, however, some margin of  reserve is required  to accommodate the pres-
sure variations in the system.  A  cursory  review indicates the present
margin of reserve at 10  to  15  percent.   One series of pressure drop
measurements exemplified the need  for a margin of reserve when significantly
higher losses were measured across the  bed and cyclones than observed
during previous tests.

-------
Section V-D - Energy Aspects (cont'd)

Windbox Gas Recirculatibn System (cont'd)

Energy data for the Sinter Plant were tabulated from the Company's monthly
energy reports for seferenee periods before and after the installation of
the windbox gas recirculation system (see Table 14).  As a result of the
fan replacement, electrical power consumption increased 77 joules/m.t. of
sinter or 54 percent from 143 joules/m.t. prior to recirculation to 220
joules/m.t. after recirculation.  As expected, the coke-oven gas con-
sumption remained constant before and after the installation.  Coke breeze
consumption decreased 146 joules/m.t. of sinter or 7 percent from 2146
joules/m.t. before recirculation to 2000 joules/m.t. after recirculation.
As stated previously, this adjustment was necessary to eliminate the
problems associated with overheating the sinter bed.  The total energy
consumption per unit of sinter production decreased 69 joules/m.t. or
3 percent from 2510 joules/m.t. prior to recirculation to 2441 joules/m.t.
after recirculation.  The decrease in the energy requirement can be at-
tributed to the recovery of heat from the recirculated waste gas and the
reduction in coke breeze consumption.  These data can be very misleading
if taken out of context.  While it is true that the windbox gas recircu-
lation permits the recovery of waste heat, the fact remains that an in-
expensive source of energy (coke breeze) is being replaced by an expensive
source of energy (electricity).  It must be emphasized that the trade-off
between decreased coke breeze consumption and increased electrical power
consumption represents an extremely unfavorable economic balance, as in-
dicated in Section V-E of this report.
                                   68

-------
                                             TABLE 14

                                  SINTER PLANT ENERGY CONSUMPTION
Sinter Plant Energy Consumption per unit
of Sinter Production Prior to the In-
stallation of the Windbox Gas Recircula-
tion and Gravel Bed Filter Systems.

Sinter Plant Energy Consumption per unit
of Sinter Production after the Installa-
tion of the Windbox Gas Recirculation
System.

Pollution Control Energy Consumption per
Unit of Sinter Production and Percent
Change due to the Installation of the
Windbox Gas Recirculation System.

Projected Sinter Plant Energy Consump-
tion per Unit of Sinter Production After
the Installation of the Windbox
circulation and Gravel Bed Filter System

Projected Pollution Control Energy Con
sumption per Unit of Sinter Production
and Percent Change Due to the Installa
tion of the Gravel Bed Filter System.
Projected Pollution Control Energy Con
sumption per Unit of Sinter Production
and Percent Change due to the Combined
Installation.
Coke Oven Coke
r unit
In-
rcula-
•
r unit
tal la-
ion
on per
ent
the

ump-
. After
s Re-
System.
Con-
tion
alla-
em.
Con-
:tion
dned

joules/m. t.
(mmbtu/ton)

joules/m. t.
(mmbtu/ton)
joules /m.t .
(mmbtu/ton)
% Change
joules/m. t.
(mmbtu/ton)


joules /m.t.
(mmbtu/ton)
% Change

joules /m.t.
(mmbtu/ton)
% Change
Electricity
143
(0.123)

220
(0.189)
77
(0.066)
54%
266
(0.229)


46
(0,040)
32%

123
(0.106)
86%
Gas

221
0.190)

221
(0.190)
0
0
0
268
(0.230)


47
(0.041)
21%

47
(0.041)
21%
Breeze

2146
(1.845)

2000
(1.720)
-146
(-0.125)
-7%
2000
(1.720)


0
0
0

-146
(-0.125)
( -7% )
Total

2510
(2.158)

2441
(2.099)
-69
(-0.059)
-3%
2534
(2.179)


93
(0.081)
4%

24
(0.021)
1%

-------
Section V-D - Energy Aspects (contd)

Gravel Bed Filter

During the demonstration period the flux rate through^che gravel bed2filter
system was well below the design of 36.6 cu.m./min./m   (120 acfm/ft ) of
filter area due to the limitations of the induced draft fan.  This fan
limited the filtration process to only 40 percent of the total sinter
machine windbox volume, and forced an effluent bypass of 35 percent assuming
a windbox recirculation race of 25 percent.  As described more fully in
Section V-B2 of this report, revisions to the system are in progress which
will permit the treatment of the effluent gases currently being bypassed.

Due to the higher volume of gas and the resulting additional pressure drop,
a significant increase in electrical energy requirements will occur after
the completion of this program.  The existing 746 k.w. (1000 b.h.p.) fan
with a capacity of 6780 m /min. (240,000 acfnt) at 149  C. (300  F.^ will be
replaced by a 2013 k.w. (2700 b.h.p.) fan with a capacity of 900 m /min.
(350,000 acfm) at 116° C. (240° P.).  At that time, total electrical energy
requirements, including auxiliary motors for backflush fans and hydraulic
pumps will increase from ilOO k.w. (1475 b.h.p.) to 2368 k.w. (3175 b.h.p.).
In addition to the increased electrical power consumption, coke oven gas
will be utilized at a rate of 7.08 m^/min. (250 c.f.m.) to heat the filter
backflush air from ambient temperature to 149° C. (.300° F.).

The projected Sinter Plant energy consumption at that time will increase
46 joules/m.t. or 21 percent for electricity and 47 joules/m.t. or 21 percent
for coke«oven gas (see Table 14).  The projected total Sinter Plant energy
consumption will increase 93 joules/m.t. or 4 percent from 2441 joules/m.t.
to 2534 joules/m.t. of sinter production.

Combined Systems

Table 14 also projects the change in Sinter Plant energy consumption due to
the combined windbox gas recirculation and gravel bed filter systems.  This
projection indicates an increase in electrical power consumption of 86
percent or 123 joules/m.t. of sinter production, an increase in coke oven
gas consumption of 21 percent or 47 joules/m.t. of sinter production, and
a decrease in coke breeze consumption of 7 percent or 146 joules/m.t. of
sinter production.  The projection also indicates that the total energy
consumption will increase 1 percent or 24 joules/m.t. of sinter.  Again,
it must be emphasized that the trade-off between the decreased coke breeze
consumption and the increased electrical power consumption presents an
extremely unfavorable e a: onomic balance due to the relatively low cost of
coke breeze and high cost of electricity.
                                     70

-------
Section V-E - Capital and Operating Costs

Windbox Gas Recirculation System

During the period from August 1,  1975  to September  30,  1977, provisions
were made to record the operating and  maintenance costs  (labor, material,
utilities and depreciation) for the Sinter Plant Windbox Gas Recirculation
System.  The boundaries of the system  were identified  to permit reliable
cost documentation.  In the case  of labor costs, only  maintenance and re-
pair expenditures were accrued, since  the addition  of  operating personnel
was not required for this installation.  Weirton Steel Division Sinter
Plant personnel recorded the time and  labor  class required for the main-
tenance and repair of the system  during the  designated twenty-six month
period.  In addition, the cost of repair materials  was also recorded.

Utility cost for the operation of the  recirculation system was limited
to electrical power consumption.  It was necessary  to  prorate the electrical
cost for fan operation since only a portion  of  the  power consumed is attri-
buted to recirculation of the gas.  It was determined  that the most appro-
priate method for prorating this  cost  would  be  based on  the difference in
electrical energy required for the sintering process before and after the
recirculation system was installed.  These requirements  were 3728 kilowatts
(5000 h.p.) before recirculation  and 6711 kilowatts (9000 h.p.) after
recirculation.  Since the fan motors were fully loaded in both cases, it
was concluded that the power consumed  would  be  a calculated value based
on this difference of 2983 ki-lowatts (4000 h.p.) and the actual operating
hours of the system.

The capital cost for the windbox  gas recirculation  system was $5,334,000
when escalated to 1978 market conditions.  Depreciation  cost for the
recirculation system was calculated utilizing this  capital cost and an
estimated useful life of eighteen years.  The periodic straight-line
depreciation method was used and  it was assumed that the probable terminal
salvage value for the equipment was negligible.

It was necessary to develop a credit for the 7  percent reduction in coke
breeze consumption which occurred as a result of the optimization of the
windbox gas recirculation system  (see  Section V-D concerning Energy
Aspects).  This credit was derived utilizing a  coke breeze market price
of $23.00/m.t. ($20.86 per ton).

A summary of the projected capital and operating costs for the windbox
gas recirculation system is tabulated  in Table  15.   The  operating cost
for this facility averaged $864,000 per year which  is  equivalent to $0.79
per metric ton ($0.72 per short ton) of sinter  produced.
                                        71

-------
                                TABLE  15


                TABULATION OF CAPITAL  AND  OPERATING  COSTS
                                FOR THE
              SINTER PLANT WINDBOX GAS  RECIRCULATION  SYSTEM
         A.   Capital  (1978  Dollars)*              -  $5,334,000

             Life:                                -  18 Years


         B,   Actual operating  costs based  on  data for the  26-month
             period from August  1, 1975  to September 30, 1977,
             escalated  to 1978 dollars:

             Cost Description                 Annual Operating Cost

             Repair Labor                        -  $  70,000

             Repair Material                      -    96,000

             Electricity                         -   560,000

             Depreciation                        -   296,000

             Credit for Coke Breeze Reduction    -   (158,000)

                 TOTAL                          -  $ 864,000

             Annual Sinter  Production

             Metric Tons per Year                -  1,090,000
            (Short  Tons per Year)                -(1,200,000)

             Cost per Unit  of  Sinter  Production

             Cost per Metric Ton                 -  $    0.79
            (Cost per Short Ton)                -($    0.72)
* - Capital Costs Adjusted to 1978 Dollars Using ENGINEERING NEWS RECORD
    Index

                                    72-

-------
Section V-E - Capital and Operating Costs (cont'd)


Gravel Bed Filter System

Although provisions were made to record the operating and maintenance
costs for the gravel bed filter system during the demonstration period,
utilization of these data would lead to serious inaccuracies in the
analyses of pollution control economics for the system.  As stated in
previous sections of this report, fan limitations prevented the treat-
ment of the total effluent volume from the sinter machine windbox gas
recirculation system.  In addition, the excessive downtime of the gravel
bed filter system during the demonstration period made it impractical
to perform an economic analyses on a basis of cost per unit of sinter
produced.  It was, therefore, concluded that a more accurate analyses
could be accomplished utilizing actual material and labor costs expended
during the demonstration period in combination with projected utility
and capital costs for the revised system (see Section V-B; page 47).

The capital cost for the revised gravel bed filter system is $5,101,000
when equated to 1978 market conditions.  Depreciation cost for the gravel
bed filter system was calculated utilizing this capital cost and an es-
timated useful life of eighteen years.  The periodic straight-line depre-
ciation method was used and it was assumed that the probable terminal
salvage value for the equipment was negligible.  Costs for electrical
power and coke oven gas consumption were derived utilizing design data.

A summary of the projected capital and operating costs for the gravel bed
filter is tabulated in Table 16.  The projected operating costs for the
system is $1,198,000 per year which is equivalent to $1.10 per metric
ton ($1.00 per short ton) of sinter produced.

Combined Systems

Table 17 indicated the projected total capital and operating costs for
the windbox gas recirculation and gravel bed filter systems.  The total
projected capital cost for the combined systems is $10,435,000 based on
1978 market conditions.  The projected operating cost for the combined
systems is $2,062,000 per year or $1.89 per metric ton ($1.72 per short
ton) of sinter produced.
                                           73

-------
                               TABLE 16
               TABULATION OF CAPITAL AND OPERATING COSTS
                               FOR THE
                SINTER PLANT GRAVEL BED FILTER SYSTEM
        A,  Capital (1978 Dollars)*             - $5,101,000
            Life:                               - 18 Years

        B.  Projected Annual Operating Cost (1978 Dollars):
            Cost Description              Annual Operating Cost
            Repair Labor               -        $  110,000
            Repair Material            -           103,000
            Coke Oven Gas              -           150,000
            Electricity                -           552,000
            Depreciation               -  	283,000	
                 TOTAL                          $1,198,000

            Annual Sinter Production
            Metric Tons per Year                 1,090,000
            (Short  Tons per Year)               (1,200,000)
            Coat per Unit of Sinter Production
            Cost per Metric Ton                 $    1.10
            (Cost per Short  Ton)               ($    1.00)
* - Capital Costs Adjusted to 1978 Dollars Using ENGINEERING NEWS RECORD
    Index
                                       74

-------
                       TABLE 17

       TABULATION OF CAPITAL AND OPERATING COSTS
       FOR THE COMBINED SINTER PLANT WINDBOX GAS
      RECIRCULATION AND GRAVEL BED FILTER SYSTEMS

A.  Capital (1978 Dollars)                   10,435,000
    Life:                                     18 Years

B.  Projected Annual Operating Cost (1978 Dollars):
    Cost Description              Annual Operating Cost
    Repair Labor           -           $  180,000
    Repair Material        -              199,000
    Coke Oven Gas          -              150,000
    Electricity            -            1,112,000
    Depreciation           -              579,000
    Credit for Coke Breeze Reduction	(158,000)	
         TOTAL                         $2,062,000

    Annual Sinter Production
    Metric Tons per Year                1,090,000
    (Short Tons per Year)              (1,200,000)
    Cost per Unit of Sinter Production
    Cost per Metric Ton                 $    1.89
    (Cost per Short Ton)               ($    1.72)
                               75

-------
                       SECTION VI - REFERENCES
1 - Pengidore, D. A.,Sinter Plant Windbox Gas Recirculation
    Demonstration; Phase J.; Engineering and Design, Environmental
    Protection Technology Series, Publication No. E.P.A.-600/2-75-014,
    August, 1975. Available from National Technical Information Service
    (NTIS) Springfield, VA, as Report No. PB249-564/AS.

2 - Draft Method Determination £f Particulate ^ Condensable Organic
    Emissions from Sinter Plants.  To be published at a later date by
    the Environmental Protection Agency, Research Triangle Park,
    North Carolina.

3 - Method 1 - Sample and Velocity Traverses for Stationary Sources;
    Method 2 - Determination of Stack Gas Velocity and Volumetric
    Flow Rate; FEDERAL REGISTER, Vol. 42, No. 160, August 18, 1977,
    p.p. 41755 to 41768.

4 - Method 5 - Determination of Patriculate Emissions from Stationary
    Sources; FEDERAL REGISTER, Vol. 42, No. 160, August 18, 1977,
    p.p. 41776 to 41782.

5 - Method 6 - Determination of Sulfur Dioxide Emissions from Staionary
    Sources; FEDERAL REGISTER, Vol. 42, No. 160, August 18, 1977,
    p.p. 41782 to 41784.
                                   76

-------
SECTION VII
APPENDICES
   77

-------
00
      Parameter Measured
       (1)  Charge  Rate
       (2)  Product Rate
       (3)  Standard Stack  Gas  Flow
       (4)  Total Waste Gas Flow
       (5)  Percent Recycle
       (6)  Stack Gas Temperature
       (7)  Actual  Stack Gas Flow
       (8)  Stack Gas
      (9) Moisture Percent
     (10) Particulates

     (11) Sulfur Dioxide

     (12) Stack Gas Condensable
          Hydrocarbons
     (13) Charge Condensable
          Hydrocarbons
     (14) Product Condensable
                                              TABLE  NO.  18
                                       WINDBOX GAS RECYCLE SAMPLING
                                       DATE:  August 3,  1977
mt/h
rat/h
o
Nm /min.
Nm3/min.
7
/a
°c.
m /min. *
% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen

mg /Niti-*
kg/hr
mg /NnH
kg/hr
mgi/Nm^
kg/hr..
kg/hr.
(t/h)
(t/h.)
(dscfm)
(dscfm)

(°F. )
(acfm)


(grs ,/dscf)
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. . )
Ubs/hr. )
Recycle
286 ( 315)
178 ( 195)
11,864 (419,233)
14,603 (516,006)
18.8
128 ( 263)
19,394 (684,826)
17.16
0.595
6.545
74.79
11.8
3,256 ( 1,422)
2,321 ( 5,110)
313 ( 0.137)
224 ( 492 )
7.56 ( .0033)
5.4 ( 11.9 )
313 ( 6.88)
No Recycle
286 ( 315)
178 ( 195)
14,287 (504,834)
14,287 (504,834)
0
134 ( 274)
25,016 (883,360)
18.195
0.555
5.095
75.80
7.0
1,657 ( 0.723)
1,421 ( 3,129)
231 ( 0.101)
199 ( 437)
4.1 ( .0018)
3.5 (7.8 )
93 ( 205)
kg/hr.
(Ibs . /hr . )
                                                                            62  (
                                                 137)
                                         10 (
22)

-------
vo
     Parameter Measured

       (1) Charge Rate
       (2) Product Rate
       (3) Standard Stack Gas Flow
       (4) Total Waste Gas Flow
       (5) Percent Recycle
       (6) Stack Gas Temperature
       (7) Actual Stack Gas Flow
       (8) Stack Gas
       (9) Moisture Percent

      (10) Particulates


      (11) Sulfur Dioxide


      (12) Stack Gas Condensable
           Hydrocarbons

      (13) Charge Condensable
           Hydrocarbons

      (14) Product Condensable
                                              TABLE NO. 19
                                       WINDBOX GAS RECYCLE SAMPLING

                                       DATE:  August 4, 1978
mt/h
mt/h
o
Ntn /min.
NnP /min .
(t/h)
(t/h.)
(dscfm)
(dscfm)
  /
m  mn.
                  (acfm.)
% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen
     rt
mg /NmJ
kg/hr

mg /NnH
kg/hr
kg/hr..

kg/hr.


kg/hr.
                  (grs. /dscf)
                  (Ibs/hr. .)

                  (grs/dscf)
                  (Ibs/hr..)

                  (grs/dscf)
                  (Ibs/hr. .)

                  Ubs/hr. )
                   (Ibs ./hr .)
Recycle

    339 (   373)

    19.7 (   217)

 10,851 (383,435)

 13,776 (486,793)

     21.2

    115 (   240)

 16,995 (600,098)

     15.88
     0.72
     7.14
    76.26 '

     9.9

  1,390 (0.607)
    906 (  1,995)

    411 (  0.179)
    267 (    588)

   5.02 (  .0022)
   3.3   (7.2   )

    311 (    684)


     65 (    142)
No Recycle

    330 (   383)
    197 (   217)
 13,995 (494,556)
 13,995 (494,556)
     0
    109 (   228)

 23,782 (839,748)
     8.5
    999   (0.436)
    839   (  1,848)
   398
   335
(0.174 )
(   737 )
   7.0   (  .0031)
   6.0   (13.1   )
   155   (   341)
    38   (
     84)

-------
                                               TABLE NO. 20
                                       WINDBOX GAS RECYCLE SAMPLING
CO
o
      Parameter Measured
       (1) Charge Rate
       (2) Product Rate
       (3) Standard Stack Gas Flow
       (4) Total Waste Gas Flow
       (5) Percent Recycle
       (6) Stack Gas Temperature
       (7) Actual Stack Gas Flow
       (8) Stack Gas
       (9) Moisture Percent
      (10) Particulates

      (11) Sulfur Dioxide

      (12) Stack Gas Condensable
           Hydrocarbons
      (13) Charge Condensable
           Hydrocarbons
      (14) Product Condensable
i«ij..u . n.ugua.1. j}

mt/h
mt/h
o
Nnr/min.
Nm^/min.
%
°C.
o
m /min.

% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen

mg /Nm^
kg/hr
mg /Nm3
kg/hr
kg/hr.,
kg/hr.
j.? / /
y * v
(t/h)
(t/h)
(dscfm)
(dscfm)

(°F. )
(acfm.)





(grs ./dscf)
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. . )
Ubs/hr. )
Recycle
322 ( 354)

181 ( 199)
9,606 (339,436)
12,817 (452,885)
25.0
136 ( 278)
16,323 (576,364)
i f. i
i. \j . j.
0.66
6.18
77.0
9.4
994 ( 0.434)
574 ( 1,263)
15.7 (0.00684)
9.9 ( 19.9)
3.96 ( .0017 )
2.3 (5.2 )
266 ( 585)
No Recycle
322 ( 354)

181 ( 199)
14,318 (505,952)
14,318 (505,952)
0
110 ( 231)
24,209 (854,826)
17 1
,1. * * -*•
0.505
4*7 O C
.735
M m— •••
77 .7
9.1
980 ( 0.428)
844 ( 1,856 )
49.3 ( 0.022 )
42.4 ( 93.3 )
23.2 ( 0.003 )
5.8 ( 12.8 )
124 ( 272 )
kg/hr.
(Ibs . /hr . )
82 (
180)
5.4 (
12 )

-------
00
    Parameter Measured
      (1) Charge Rate
      (2) Product Rate
      (3) Standard Stack Gas Flow
      (4) Total Waste Gas Flow
      (5) Percent Recycle
      (6) Stack Gas Temperature
      (7) Actual Stack Gas Flow
      (8) Stack Gas
      (9) Moisture Percent
     (10) Particulates

     (11) Sulfur Dioxide

     (12) Stack Gas Condensable
          Hydrocarbons
     (13) Charge Condensable
          Hydrocarbons
     (14) Product Condensable
                                             TABLE NO.  21
                                      WINDBOX GAS RECYCLE SAMPLING
                                      DATE:  August 11,  1977

mt/h
mt/h
o
Nm /min.
Nm3 /min .
„
o
m /min.

% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen

mg /Nm-*
kg/hr
mg /Nm3
kg/hr
mg;/Nm3
kg/hr..
kg/hr.

(t/h)
(t/h)
(dscfm)
(dscfm)

(°F )
(acfm.)






(grs ,/dscf)
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. . )
Ubs/hr. )
Recycle
304 ( 334)
177 ( 195)
10,742 (379,588)
13,909 (491,522)
22.8
130 ( 266)
17,685 (624,467)
17.05
0.575
6.165
76.05

10.2
723 ( 0.316)
468 ( 1,028)
-
-"
8.0 ( .0035)
5.1 (11.2 )
79 ( 174)
No Recycle
304 ( 334)
177 ( 195)
14,882 (525,878)
14,882 (525,878)
0
135 ( 276)
25,865 (913,305)
17.20
0 63
\J 9 V *J
5 86
*J • \J \J
76 40
/ \J * ^T \J
9.6
756 ( 0.330)
676 ( 1,488)
-
—
8.3 ( .0036)
7.5 (16.4 )
103 ( 227)
kg/hr.
(Ibs . /hr . )
7 (
14)
7 (
14)

-------
00
NJ
     Parame ter Measured
        (1) Charge Rate
        (2) Product Rate
        (3) Standard  Stack Gas Flow
        (4) Total Waste Gas Flow
        (5) Percent Recycle
        (6) Stack Gas Temperature
        (7) Actual Stack  Gas Flow
        (8) Stack Gas
        (9) Moisture  Percent
       (10) Particulates

       (11) Sulfur Dioxide

       (12) Stack Gas Condensable
            Hydrocarbons
       (13) Charge Condensable
            Hydrocarbons
       (14) Product Condensable
                                               TABLE NO. 22
                                        WINDBOX GAS RECYCLE SAMPLING
                                        DATE:   August 30, 1977
mt/h
int/h
Nm /min.
Nm^/min.
 ,*J
m /min.
% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen
mg  rn
kg/hr
mg
kg/hr
kg/hr..
kg/hr.

kg/hr.
(t/h)
(t/h.)
(dscfm)
(dscfm)
(acfm.)
                   Ubs/hr.  )
                   (Ibs . /hr . )
Recycle
    272 (    300)
    162 (    178)
 10,851 (383,430)
 14,051 (496,497)
     22.8
    111 (    231)
 16,707 (589,911)
No Recycle
    272 (     300)
    162 (     178)
 14,201 (501,820)
 14,201 (501,820)
     0
     98 (     208)
 23,634 (806,048)


(grs . /dscf)
(Ibs/hr. .)
(grs/dscf )
(Iba/hr. .)
(grs/dscf )
(Ibs/hr. .)
15.5
0.72
7.14
76.9
8.2
1,020 (
666 (
380 (
249 (
5.83 (
3.7 (


0.445)
1,462)
0.166)
545)
.0025)
8.0 )
16.1
0.68
5.69
77.5
9.4
1,282 ( 0.560)
1,094 ( 2,408)
415 ( 0.181)
354 ( 779)
8.73 ( .0038)
7.75 (16.4 )
                                      119  (
                            261)
                        129 (
              283)
                                                                           5.0 (11.0   )
                                                         6.0 (13.2   )

-------
00
Co
      Parameter Measured
       (1) Charge Rate
       (2) Product Rate
       (3) Standard Stack Gas Flow
       (4) Total Waste Gas Flow
       (5) Percent Recycle
       (6) Stack Gas Temperature
       (7) Actual Stack Gas Flow
       (8) Stack Gas
       (9) Moisture Percent
       (10) Particulates

       (11) Sulfur  Dioxide

       (12) Stack Gas  Condensable
           Hydrocarbons
       (13) Charge  Condensable
           Hydrocarbons
       (14) Product Condensable
                                              TABLE NO. 23
                                       WINDBOX GAS RECYCLE  SAMPLING
                                       DATE:  September 20, 1977
mt /h
mt/h
o
Nm /min.
Nm3/min.
(t/h)
(t/h)
(dscfm)
(dscfni)
  /
m  ran.
                  (acfm.)
7, Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen
m
kg/hr
mg /Nm
kg/hr
kg/hr.,
kg/hr.

kg/hr.
                  (grs ,/dscf)
                  (Ibs/hr..)
                  (grs/dscf)
                  (Ibs/hr..)
                  (grs/dscf )
                  (Ibs/hr..)
                  (Ibs/hr. )
                  (Ibs . /hr . )
Recycle
    314 (    345)
    190 (    209)
  9,534 (336,900)
 13,391 (473,181)
     28.8
    118 (    244)
 13,830 (488,354)
     20.96
      0.21
      0.75
     78.08
      9.2
    887 (   0.387)
    507 (   1,117)
    218 (   0.095)
  124.6 (     274)
    5.12(   .0022)
    3.0 (  6.5    )
     98 (     216)

    9.7 (21.3    )
No Recycle
    314 (     345)
    190 (     209)
 13,222 (467,184)
 13.,222 (467,184)
     0
    101 (     214)
 22,703 (801,665)
     20.96
      0.75
      0.21
     78.08
     11.2
  1,528  (  0.666)
  1,212  (  2,667)
   263  (  0.115)
   209  (    460)
  9.96  (  .0044)
  7.9   (17.5   )
   111  (    244)

   9.5  (20.9   )

-------
      Parameter Measured
       (1) Charge Rate
       (2) Product Rate
       (3) Standard Stack Gas Flow
       (4) Total Waste  Gas Flow
       (5) Percent Recycle
       (6) Stack Gas Temperature
       (7) Actual Stack Gas Flow
oo      (8) Stack Gas
       (9) Moisture Percent
      (10) Particulates

      (11) Sulfur Dioxide

      (12) Stack Gas Condensable
           Hydrocarbons
      (13) Charge Condensable
           Hydrocarbons
      (14) Product Condensable
                                              TABLE NO. 24
                                       WINDBOX GAS RECYCLE SAMPLING
                                       DATE:  September 23, 1977
mt/h
mt/h
o
Nm /min.
Nm-Vmin.
%
°C.
m /rain.
% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen

mg /Nm-'
kg/hr
mg /Nm
kg/hr
kg/hr..
kg/hr.
(t/h)
(t/h)
(dscfm)
(dscfm)

(°F. )
(acfm.)




(grs ./dscf)
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. . )
Ubs/hr. )
Recycle
329 (
199 (
No Recycle
362)
219)
10,535 (372,246)
14,134 (499,188)
25.5
122 (

251)
16,996 (600,134)
14.73
0.176
8.26
76.83
10.2
1,168 ( 0
739 ( 1
417 ( 0
264 (
6.68 ( .
4.3 ( 9.
144 (




.510)
,627)
.182)
581)
0029)
5 )
317")
329 ( 362)
199 ( 219)
15,312 (541,093)
15,312 (541,093)
0
133 ( 272)
28,112 (992,638)
16,30
0.475
5.80
77.43
9.6
989 ( 0.432)
911 ( 2,005)
197 ( 0.086)
181 ( 399)
5.02 ( .0022)
4.6 (10.2 )
107 ( 237)
kg/hr.
(Ibs . Air . )
                   10.4  (22.8    )
10.4 (22.8   )

-------
00
    Parameter Measured
      (1) Charge Rate
      (2) Product Rate
      (3) Standard Stack Gas Flow
      (4) Total Waste Gas Flow
      (5) Percent Recycle
      (6) Stack Gas Temperature
      (7) Actual Stack Gas Flow
      (8) Stack Gas
       (9) Moisture  Percent
      (10) Particulates

      (11) Sulfur Dioxide

      (12) Stack Gas Condensable
          Hydrocarbons
      (13) Charge Condensable
          Hydrocarbons
      (14) Product Condensable
                                              TABLE NO. 25
                                      WINDBOX GAS RECYCLE SAMPLING
                                       DATE:  September 28,  1977
                                Recycle
                                                    No RecycLe
mt/h
mt/h
o
Nm /min.
NmVmin.
%
°C.
m /min.
% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen

mg /NtrH
kg/hr
mg /Nm->
kg/hr
mg;/Nm-*
kg/hr.,
(t/h)
(t/h.)
(dscfm)
(dscfm)

(°F. )
(acfm.)





(grs ,/dscf)
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
329 ( 362)
219'( 241)
9,915 (350,336)
13,668 (482,965)
27.5
111 ( 232)
15,530 (548,404)
16.24
0.77
7.08
75.92
8.9
1,266 ( 0.553)
754 ( 1,661)
530 ( 0. 232)
317 ( 697)
5.69 ( .0025)
3.3 ( 7.3 )
329 ( 362)
219 ( 241)
14,218 (502,372)
14,218 (502, 372)
0
101 ( 214)
24,050 (849,272)
16.17
0.78
7.035
76.02
7.9
1,324 ( 0.578)
1,132 ( 2,490)
527 ( 0.230)
451 ( 991)-
4.81 ( .0021)
4.0 ( 8.8 )
kg/hr.
kg/hr.
                  Ubs/hr.  )
                  (Ibs . /hr . )
                                    194
                                                                         7.7  (17
                                             427)
264
580)
                                                       9.2 (20.2   )

-------
                                             TABLE  NO.  26
                                      WINDBOX GAS RECYCLE SAMPLING
                                      DATE:   October 1,  1977
00
    Parameter Measured
      (1) Charge Rate
      (2) Product Rate
      (3) Standard Stack Gas Flow
      (4) Total Waste Gas Flow
      (5) Percent Recycle
      (6) Stack Gas Temperature
      (7) Actual Stack Gas Flow
      (8) Stack Gas
      (9) Moisture Percent
     (10) Particulates

     (11) Sulfur Dioxide

     (12) Stack Gas Condensable
          Hydrocarbons
     (13) Charge Condensable
          Hydrocarbons
     (14) Product Condensable

mt/h
mt/h
o
Nm /min.
Nia3/min.
*
°C.
rt
m /min.
% Oxygen
% Carbon Monoxide
% Carbon Dioxide
% Nitrogen

mg /Nm3
kg/hr
mg/Nm3
kg/hr
mg;/Nm3
kg/hr..

kg/hr.

kg/hr.


(t/h)
(t/h.)
(dscfm)
(dscfni)

(°F. )
(acfm)



•

(grs./dscf)
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)
(grs/dscf )
(Ibs/hr. .)

Ubs/hr. )

(Ibs . /hr . )

Recycle
328 ( 360)
171 ( 188)
10,608 (374,828)
14,358 (507,360)
26.1
105 ( 221)
15,756 (5.56,322)
17.14
0.75
6.5
75.6
9.3
1,301 ( 0.568)
830 ( 1,825)
183 ( 0.0799)
116.7 ( 257)
9.54 ( .0041)
6.0 (13.2 )

80.2 (176.5 )

6.3 (13.9 )
No Recycle
328 ( 360)
171 ( 188)
13,728 (485,083)
13,728 (485,083)
0
110 ( 231)
23,306 (822,957)
17.15
0.725
6.4
75.7
8.4
1,128 ( 0.493)
932 ( 2,050)
206 ( 0.0900)
170 ( 375)
7.95 ( 0.00335)
6.9 (15.1 )

47.8 (105.2 )

4.8 (10.5 )

-------
                              TABLE NO. 27

                     VELOCITY MEASUREMENTS SUMMARY
                              RECYCLE FAN
                                    DUCT DIAMETER 3.35 METERS
*Position (Meters)
(0.058) S
(0.183) S
(0.323) S
(0.493) S
(0.686) S
(0.973) S
(1.778) N
(2.057) N
(2.261) N
(2.413) N
(2.565) N
(2.692) N
(0.058) E
(0.183) E
(0.323) E
(0.483) E
(0.686) E
(0.973) E
(1.778) W
(2.057) W
(2.261) W
(2.413) W
(2.565) W
(2.692) W
High
ift/min
1248
1309
1309
1309
1309
1367
1338
1367
1423
1476
1476
1528
1581
1627
1578
1528
1476
1476
1476
1367
1476
1423
1367
1367
Low
m/min
1088
1157
1157
1116
1144
1074
1157
1130
1197
1197
1248
1309
1184
1309
1367
1248
1248
1248
1184
1150
1184
1150
1116
1116
Average
m/min
1159
1210
1216
1203
1210
1210
1223
1248
1273
1315
1350
1444
1384
1444
1455
1439
1401
1355
1321
1284
1291
1266
1260
1229
* - Position indicates measurements from stack wall
                                       87

-------
                              TABLE NO.  28
                     VELOCITY MEASUREMENT SUMMARY
                              RECYCLE FAN
                                     DUCT DIAMETER 3.35 METERS	
                                High            Low          Average
^Position (Meters)              m/min          m/riiin          m/ihin
 (0.058) N                      2178            008           1572
 (0.183) N                      2100           1068           1650
 (0.323) N                      1980           1146           1644
 (0.483) N                      2358           1182           1644
 (0.686) N                      2358           1146           1608
 (0.973) N                      1764           1188           1494
 (1.778) S                      1566            990           1296
 (2.057) S                      1566      '     1032           1320
 (2.261) S                      1620           1008           1356
 (2.413) S                      1668            948           1380
 (2.565) S                      1620            906           1326
 (2.692) S                      1566            990           1254
 (0.058) W                      1812            990           1494
 (0.183) W                      1980            906           1602
 (0.323) W                      1900            906           1626
 (0.483) W                      2022            990           1590
 (0.686) W                      1812            990           1560
 (0.973) W                      1668           1068           1470
 (1.778) E                      1812           1146           1404
 (2.057) E                      1980           1110           1428
 (2.261) E                      1980           1146           1410
 (2.413) E                      1980           1248           1476
 (2.565)  E                       1980           1146           1446
 (2.692)  E                       1980           1110           1350
* - Position indicates measurement  from  stack wall
                                      88

-------
                               TABLE NO. 29
                      VELOCITY MEASUREMENTS SUMMARY
                              MACHINE RECYCLE

                                     DUCT DIAMETER 3.35 METERS	
                                 High           Low          Average
^Position (Meters)              m/min          m/min          m/min
 (0.058) S                        666            486            570
 (0.183) S                        666            516            583
 (0.323) S                        709            486            608
 (0.483) S                        750            516            620
 (0.686) S                        709            516            620
 (0.973) S                        788            486            620
 (1.778) N                        709            455            596
 (2.057) N                        788            421            620
 (2.261) N                        788            486            620
 (2.413) N                        688            486            608
 (2.565) N                        750            455            608
 (2.692) N                        688            486            596
 (0.058) E                        688            544            596
 (0.183) E                        688            516            583
 (0.323) E                        709            544           620
  (0.483) E                        729            516           608
  (0.686) E                        769            455            620
  (0.973) E                        709            516            632
  (1.778) W                        750            486            632
  (2.057) W                        750            486            620
  (2.261) W                        769            516            620
  (2.413) W                        750            516            632
  (2.565)W                        750            421            596
  (2.692) W                        709            421            596
  * - Position indicates measurements from stack wall
                                        89

-------
VD
O
        - Parameter Measured
(1)  Sinter 'Product

(2)  Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(3)  Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight
(4)  Percent Recycle
(5)  Particulates
    (Filterable)
(6)  Condensable Hydrocarbons
    Filter Fraction

    Back-Half

(7)  Sulfur Dioxide
                                       TABLE NO.  30
                                 GRAVEL BED FILTER SAMPLING-INLET

                                DATE:  July 18,  1978
                                             mt/h
                                              o
                                             m /min.

                                             NnH/min.
                                             % Weight
                                             Ibs/lb. mole
                                                 mn .
                                              % Weight
                                              Ibs/lb. mole
                                             mg /Nm3
                                             kg/hr.
                                             mg
                                             kg/hr.
                                             mg
                                             kg/hr.
(t/h)

(acfm)
(dscfm)



(acfm)

(dscfm)
                                             kg/hr.
(grs/dscf)
(Ibs/hr.  )


(grs,/dscf)
(Ibs./hr, )

(grs./dscf"1
(Ibs./hr. )

(grs./dscf)
(Ibs./hr. ^
                                                                           OPERATIONAL MODE-MAIN WINDBOX GAS
 Recycle
   179 (  197.0)
 2,742 ( 96,827)
   114 (    237)
 1,755 ( 61,737)
  16.2
  27.5
19,424 (685,845)
   114 (    237)
12,380 (437,031)
  16.2
  27.5

  21.2

 1,664 (  0.727)
 174.7 (    385)


  15.3 ( 0.0067)
   1.6K 3.55  )
  14.3 (  .0063)
   1.6 ( 3.50  )

   267 (  0.116)
    27 ( 61.4  )
No Recycle
   179 (  197.0)
 2,667 ( 94,188)
   104 (    220)
 1,996 ( 70,496)
   4.0
  28.8
19,424 (685,845)
   104 (    220)
14,537 (513,174)
   4.0
  28.8

  0
 1,705 (  0.745)
 204.4 (    450)


  13.5 ( 0.0059)
   1.82C 3.57   )
  14.1  (   .0062)
   1.8  ( 4.0    )
    9.7  (
    1.09(
0.004)
2.4  )

-------
                                        TABLE NO.  31
                                  GRAVEL BED FILTER SAMPLING -INLET
Parameter Measured
 (1)  Sinter  Product
 (2)  Gas  Flow to Gravel Bed
       @  Temperature
       @  Standard Cond.
       Moisture
       Molecular Weight

 (3)  Gas  Flow-Total  Windbox
       @  Temperature
       @  Standard Cond.
       Moisture
       Molecular Weight

 (4)  Percent Recycle
 (5)  Particulates
     (Filterable)
 (6)  Condensable Hydrocarbons
     Filter Fraction
     Back-Half
 (7) Sulfur Dioxide
DATE:  July 19,  1978
    mt/h

    m /min.
    °C.
    NnH /min.
    % Weight
    Ibs/lb. mole

    m-Vmin.
    °C.
    Nm^ /min.
    % Weight
    Ibs/lb. mole
    mg /Nm-^
    kg/hr.
                                      m
                                      kg/hr.
    m
    kg/hr.

    mg./Nrn-'
    kg/hr.
(t/h)
(acfm)
(OF.  )
(dscfm)
(acfm)
(°F.)
(dscfm)
(grs/dscf)
(Ibs/hr.  )


(grs./dscf)
(Ibs./hr,  )

(grs./dscf^
(Ibs./hr.  )

(grs./dscf)
(Ibs./hr.  ">
OPERATIONAL MODE
Recycle
  182.7  (     201)

 3,857  (136,197)
  95.6  (     204)
 2,784  (  98,313)
   9.6
  28.2
19,146  (676,086)
  95.6  (     204)
13,819  (487,841)
   9.6
  28.2
  32.0

 1,834  (   0.801)
   315  (    693)

  15.6 ( 0.0068)
   2.6 ( 5.73
   3.16( 0.0014)
  0.545( 1.2    )
  93.5 ( 0.0408)
  15.6 (34.4    )
-MAIN WINDBOX GAS
    No Recycle
      182.7 (    201)

     4,009 (141,568)
      103.4(    218)
     2,885 (101,875)
       7.9
      28.4
    19,146 (676,086)
     103.4 (    218)
    13,789 (486,751)
       7.9
      28.4

       0

     1,352 (  0.591)
       241 (    530)

      16   (  0.007)
       2.78(  6.11  )
     0.121 (  0.00005)
     0.034 (  .075   )
     72.6
     12.6
                                        ( 0.0317  )
                                        (27.7     )

-------
                                                TABLE  NO.  32
                                          GRAVEL BED FILTER SAMPLING-INLET
N3
  Parameter Measured


(1) Sinter Product

(2) Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(3) Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4) Percent Recycle

(5) Particulates
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction


    Back-Half


(7) Sulfur Dioxide
                                           DATE:   July  21,  1978

mt/h
•3
m /min.
°C.
Nm3/min.
% Weight
Ibs/lb. mole
m3/min.
°C.
NnH /min .
% Weight
Ibs/lb. mole

(t/h)
(acfm)
(OF. )
(dscfm)


(acfm)
(Op )
(dscfm)


Recycle
206 ( 227)
2,895 (102,237)
105.6 ( 222)
1,984 ( 70,046)
11.9
27.9
20,270 (715,747)
105.6 ( 222)
13,882 (490,034)
11.9
27.9
OPERATIONAL MODE-MAIN WINDBOX GAS
                    No Recycle
                       206 (    227)

                     2,823 ( 99,670)
                        94 (    201)
                     2,101 ( 74,192)
                       7.1
                      28.2

                    20,270 (715,747)
                        94 (    201)
                    15,103 (533,150)
                       7.1
                      28.2
                                                                          17.3
                        0
mg /Nm-*
kg/hr.
mg /Nm3
kg/hr.
mg /Nm-'
kg/hr.
kg/hr.
(grs/dscf) 1,037 (
(Ibs/hr. ) 126.7 (
(grs./dscf )
(Ibs./hr, )
(grs./dscf^
(Ibs./hr. )
(grs ./dscf )
(Ibs./hr. ^
10.1 (
1.2 (
5.82C
0.71(
412 (
49 (
0.453)
279)
0.0044)
2.64 )
0.0025)
1.57 )
0.180 )
108 )
1,746 (
226 (
0.763)
498)
40.7 ( 0.0178)
5.14(11.32 )
5.65(
0.73(
177 (
22.2 (
0.00247)
1.61 )
0.077 )
49)

-------
                                      TABLE NO. 33
                                 GRAVEL BED FILTER SAMBLING-INLET
  Parameter Measured
(1) Sinter Product

(2) Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(3) Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4) Percent Recycle

(5) Particulates
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction
    Back-Half
 (7)  Sulfur Dioxide
.DATE:  July 27, 1978
                                                                OPERATIONAL MODE-MAIN WINDBOX GAS
mt/h
o
m fiain.
°C.
Nm^/min.
% Weight
Ibs/lb. mole
m-Vmin.
NnH /min .
% Weight
Ibs/lb. mole
7
/o
o
rng/Nnr3
kg/hr.
kg/hr.
mg /Nm-^
kg/hr.
mg./Nm-'
kg/hr.
(t/h)
(acfm)
(dscfm)
(acfm)
(dscfm)

(grs/dscf )
(Ibs/hr. )
(grs ./dscf )
(Ibs./hr, )
( Q"I~ ^ / H Q <** "F* '
\£2 J. o • / U- o v- J.
(Ibs./hr. )
(grs. /dscf )
(Ibs./hr. ^
Recycle
176 ( 194)
4,046 (142,868)
118.3 ( 245)
2,760 ( 97,534)
9.14
28.49
19,110 (675,103)
118.3 ( 245)
14,198 (501,397)
9.14
28.5
27.1
1,806 ( 0.789)
307.9 ( 678)
_
15.2 ( 0.0062)
2.6 ( 5.72 )
366.4 ( 0.160 )
60.7 (133.8 )
No Recycle
176 ( 194)
4,393 (155,122)
112.3 ( 234)
3,109 (109,774)
7.37
28.69
19,110 (675,103)
112.3 ( 234)
13,537 (477,983)
7.37
28.7
0
922 ( 0.403)
177 ( 390)
:
17.6 ( 0.0137)
3.38( 7.44 )
325.7 ( 0.142 )
60.7 (133.6 )

-------
VO
-P-
          Parameter Measured
 (1) Sinter Product

 (2) Gas Flow  to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

 (3) Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4) Percent Recycle

(5) Particulars
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction
            Back-Half
        (7) Sulfur Dioxide
                                       TABLE NO. 34
                                  GRAVEL BED FILTER SAMPLING-  INLET

                                  DATE:  -July 28, 1978
                                                                           OPERATIONAL MODE-MAIN WINDBOX GAS

mt/h
•3
m /min.
QC.
Nm-Vmin.
% Weight
Ibs/lb. mole
BH/min.
°C.
NtrH /min .
% Weight
Ibs/lb. mole

(t/h)
(acfm)
(OF. )
(dscfm)


(acfm)
(°F.)
i » *
(dscfm)


Recycle
194 ( 213.5)
4,119 (145,442)
118.3 ( 245)
2,811 ( 99,255)
9.3
28.4
19,682 (694,971)
118.3 ( 245)
13,424 (473,871)
,•9.3
28.4
No Recycle
194 ( 213.5)
4,083 (144,173)
127.9 ( 262)
2,758 ( 97,393)
8;0
28.6
19,682 (694,971)
127.8 ( 262)
13,297 (469,345)
8.0
28.6
mg /Nnr*
kg/hr.
                                                            (grs/dsc
                                                            (Ibs/hr.
f )
 )
                                             kg/hr,
                                             mg,
                                             kg/hr.
                                             kg/hr.
(grs./dscf)
(Ibs./hr,  )

(grs./dscf^
(Ibs./hr.  )

(grs./dscf)
(Ibs./hr.  1
                26.4

               1,482 (  0.648)
               249.3 (    549)
         7.6 (  0.0033)
         1.28 ( 2.81  )

         1.24 (0.00054)
         0.21 (0.46   )

       145.5  (0.0635 )
        24.5  (     54)
   0

  771 (  0.337)
131.2 (    289)


  5.5 ( 0.0024)
  0.9K 2.0   )

  2.48( 0.0011)
  0.42( 0.93  )

 75.9 ( 0.0331)
 12.5 (27.6   )

-------
Ui
Parameter Measured


(1)  Sinter Product

(2)  Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(3)  Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4)  Percent Recycle

(5)  Particulates
    (Filterable)

(6)  Condensable Hydrocarbons
    Filter Fraction


    Back-Half


(7)  Sulfur Dioxide
                                              TABLE NO. 35
                                        GRAVEL BED FILTER SAMPLING ~ STACK
                                         DATE:  July 18, 1978
                                            mt/h

                                            m /min.
   /mm.
% Weight
Ibs/lb. mole
                                            m
 3/min.
Nm3 /min.
% Weight
Ibs/lb. mole
mg/Nm3
kg/hr.
                                            mg / Nm ->
                                            kg/hr.

                                            mg/Nm3
                                            kg/hr.
               (t/h)

               (acfni)
                                                           (dscfm)
(acfm)
(°F.)
(dscfm)
                                            kg/hr.
(grs/dscf)
(Ibs/hr.  )


(grs./dscf)
(Ibs./hr,  )

(grs./dscf^
(Ibs./hr.  )

(grs ./dscf)
(Ibs./hr.  ^
                                                                         OPERATIONAL MODE-MAIN WINDBOX GAS
                                                                         Recycle"No Recycle
                                                                         •"179  (     197)        179  (     197)
 3,937 (139,011)
  98.4 (    209)
 2,847 (100,535)
   8.67
  28.35

19>24 (685,845)
  98.4 •(    209)
14,058 (496,237)
   8.67
  28.35
  21.2
 134.4 (  0.0587)
  23.6 ( 51.9   )

   1.35(0.00059)
   0.23(0.51    )
 3,291 (152,011)
    89 (     192)
 3,292 (116,206)
   5.9
  28.48

19',424 (685,845)
    89 (    192)
14,861 (524,619)
   5.9
  28.48
                                                                                               153.2 ( 0.0669)
                                                                                                  31 (68.4   )
                                              ,-4>
                                0.286(1.25 x 10  )
                                0.053(0.116      )
                              218.9 (   .0956)
                               37.4 (82.4   )
   0.53(  0.00023)
   0.10(  0.23    )

   0.0188(0.82 x :
   0.039  (0.086
                       292.6
                        57.9
          (0.128
          (127.5

-------
vo
       Parameter Measured
 (1) Sinter Product

 (2) Gas Flow  to  Gravel  Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular  Weight
 (3) Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight
(4) Percent Recycle
(5) Particulates
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction
           Back-Half
       (7)  Sulfur  Dioxide
                                              TABLE NO.  36
                                        GRAVEL BED FILTER SAMPLING - STACK
                                         DATE:  July 19,  1978
                                                                OPERATIONAL MODE-MAIN  WINDBOX GAS


mt/h
o
m /min.
°C.
o
Nm-Vmin.
% Weight
Ibs/lb. mole
*"J
m-Vmin .
°C.
*2
Nm-Ymin.
% Weight


(t/h)
(acfm)
(OF. )
(dscfm)


(acfm)
(°F.)
(dscfm)

Recycle
182.7 ( 201)
3,838 (135,521)
94 ( 201)
2,851 (100,677)
7.4
28.5
19,146 (676,086)
94 ( 201)
14,221 (501,981)
7.4
28.5
No Recycle
182.7 ( 201)
3,935 (138,936)
91.2 ( 196)
2,937 (103,699)
7.7
28.3
19,146 (676,086)
91.2 ( 196)
14,282 (504,168)
7.7
29.3
Ibs/lb. mole
%
                                                m
mg/Ni
kg/hr.
                                            mg
                                            kg/hr.
                                           mg,
                                           kg/hr.
                                           kg/hr.
(grs/dscf)
(Ibs/hr.  )


(grs./dscf)
(Ibs./hr, )

(grs./dscf1*
(Ibs./hr.  )

(grs ./dscf)
(Ibs./hr.  ">
32.0

85.8 (  0.0374)
15.1 ( 33.2   )
                              0.25 (0.00011)
                             15.1  (33.2   )

                              6.98 (0.00305)
                              1.2  (2.7    )

                              373 (  0.0163)
                             63.9 (140.7   )
   0
157.1 (  0.0686)
 28.5 ( 62.7   )


157.1 (  0.0686)
 28.5 ( 62.7   )

  1.0 (0.00043 )
  0.18(0.4     )

  261 (  0.0848)
 34.2 ( 75.4   )

-------
      TABLE NO.  37
GRAVEL BED FILTER SAMPLING ~ STACK
 Parameter Measured


(1) Sinter Product

(2) Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(3) Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4) Percent Recycle

(5) Particulates
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction


    Back-Half


(7) Sulfur Dioxide
DATE:   July 21,  1978
OPERATIONAL MODE-MAIN WINDBOX GAS


mt/h
o
m /min.
°C.
Nm-Vmin.
% Weight
Ibs/lb. mole

m3/min.
Nm3 /min .
% Weight
1 * i -m . —


(t/h)
(acfm)
(OF. )
(dscfm)



(acfra)
(dscfm)

Recycle
206~7 227)
3,027 (106,885)
90 ( 194)
2,198 ( 77,626)
10.3
28.1

20,270 (715,747)
90 ( 194)
14,739 (520,296)
10.3
28.1
No Recycle
206 ( 227)
3,140 (110,858)
79 ( 174)
2,362 ( 83,406)
9.4
27.9

20,270 (715,747)
79 ( 174)
15,357 (542,093)
9.4
27.9
    Ibs/lb. mole
    %
 17.3
mg /NmJ
kg/hr.
mg /Nm3
kg/hr.
mg /Nm3
kg/hr.
kg/hr.
(grs/dscf )
(Ibs/hr. )
(grs ./dscf )
(Ibs./hr, )
(grs./dscf^
(Ibs./hr. )
(grs. /dscf )
(Ibs./hr. ^
-L 4. A » -^ V « • V/T'v* * /
15.1 ( 33.3 )
0.62 (0.00027)
0.08 (0.18 )
3.22 (0.00171)
0.53 (1.17 )
416 ( 0.182)
55 ( 121)
   0

119.4 (  0.0521)
 17.4 ( 38.3   )


  No Sample


  3.87 (0.00169)
  0.56 (1.24   )

  229 (   0.10 )
 32.5 (  71.5  )

-------
                                             TABLE NO. 38
                                      GRAVEL BED FILTER SAMPLING - STACK
vO
00
  Parameter Measured

(1) Sinter 'Product

(2) Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond,
      Moisture
      Molecular Weight

(3) Gas Flow-Total Windbox
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4) Percent Recycle

(5) Particulates
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction


    Back-Half


(7) Sulfur Dioxide
DATE: July 27,

mt/h
o
m /min.
°C.
Nm3 /min .
% Weight
Ibs/lb. mole
m3/min.
Nm3/min,
% Weight
Ibs/lb. mole
%
mg /Nm
kg/hr.
mg /NnP
kg/hr.
mg /Nm3
kg/hr.
kg/hr.
1978

(t/h)
(acfm)
(OF. )
(dscfm)


(acfm)
(dscfm)


(grs/dscf )
(Ibs/hr. )
(grs . /dscf )
(Ibs./hr, )
(grs. /dscf ^
(Ibs./hr. )
(grs. /dscf )
(Ibs./hr. 1
OPERATIONAL MODE-MAIN WINDBOX GAS
Recycle
176 ( 194)
5,110 (180,445)
100.6 ( 213)
3,710 (131,119)
7.8
28.6
19,110 (675,103)
100.6 ( 213)
14,198 (501,397)
7 7
/ • /
28.55
27.1
245 ( 0.107)
55.9 ( 123)
8.7 ( 0.0038)
2.0
No Sample
_
11.6 ( 0.0051)
2.6 ( 5.73. )
No Recycle
176 ( 194)
5,053 (178,431)
94 ( 201)
3,833 (135,409)
5.4
28.8
19,110 (675,103)
94 ( 201)
13,537 (477,982)
5 36
J * M « V>
28.82
0
149 ( 0.0649)
35.1 ( 77.4 )
13.9 ( 0.0061)
3.27( 7.2 )
,No Sample
-
339 ( 0.148 )
78 (171.8 )

-------
                                       TABLE NO.  39
                                 GRAVEL BED FILTER SAMPLING-STACK
Parameter Measured
(1) Sinter Product

(2) Gas Flow to Gravel Bed
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(3) Gas Flow-Total Windbox -
      @ Temperature
      @ Standard Cond.
      Moisture
      Molecular Weight

(4) Percent Recycle

(5) Particulates
    (Filterable)

(6) Condensable Hydrocarbons
    Filter Fraction
    Back-Half
(7) Sulfur Dioxide
DATE:-  July 28, 1978
                                                                OPERATIONAL MODE-MAIN  WINDBOX GAS

mt/h
nr/min.
°C.
Nm-'/min.
% Weight
Ibs/lb. mole
m->/min.
°C.
*^ *
Nm^ /min .
% Weight
Ibs/lb. mole

(t/h)
(acfm)
(°F. )
\ Jk • /
(dscfm)


(acfm)
(°F )
v r • '
(dscfm)


Recycle
194 ( 213.5)
5,474 (193,303)
109. 4( 229)
3,875 (136,818)
s:o
28.5
19,682 (694,971)
109.4 ,( 229)
13,933 (491,824)
8.0
28.5
No Recycle
194 ( 213.5)
5,620 (198,466)
105 ( 221)
4,122 (145,550)
5.8
28.7
19,682 (694,971)
105 ( 221)
14,433 (509,501)
5.8
28.7
    mg/Nm3
    kg/hr.
mg<
kg/hr.

mg/Nm3
kg/hr.
                                     kg/hr.
(grs/dscf)
(Ibs/hr.  )


(grs./dscf )
(Ibs./hr,  )

(grs. /dscf'^
(Ibs./hr.  )

(grs./dscf )
(Ibs./hr.  ^
26.4

 204 (  0.0889)
48.6 (    107 )


 0.78 (0.00034)
 0.18 (0.40   )

 2.05 (8.93 x 10
 0.49 (1.08

 2.78 (0.00121)
 0.64 (1.4     )
                                                    0
                                                    155  (   0.0675)
                                                   39.3  (  86.5   )
                                                       0.92  (  0.0004)
                                                       0.23  (  0.5   )
                                                                                  ~4
                                                        2.08  (9.07  x 10
                                                        0.53  (1.16
                                                         100  (0.0439
                                                       24.9  (54.8
                                                                       ~4
)
)
)
)

-------
                                 TECHNICAL REPORT DATA
                          (Please read Instructions on the reverse before completing)
 1. REPORT NO.
  EPA-600/2-79-203
                                                       3. RECIPIENT'S ACCESSION NO.
 4. TITLE AND SUBTITLE
 Sinter Plant Windbox Recirculation and Gravel Bed
  Filter Demonstration: Phase 2. Construction,
  Operation, and Evaluation	
            5. REPORT DATE
             November 1979
            6. PERFORMING ORGANIZATION CODE
 7. AUTHOR(S)

 G. P.  Current
                                                       8. PERFORMING ORGANIZATION REPORT NO.
 9. PERFORMING ORGANIZATION NAME AND ADDRESS
 National Steel Corporation
 Weirton Steel Division
 P.O.  Box 431
 Weirton, West Virginia  26062
                                                       10. PROGRAM ELEMENT NO.
             1AB604C
             11. CONTRACT/GRANT NO.

             68-02-1862
 12. SPONSORING AGENCY NAME AND ADDRESS
 EPA,  Office of Research and Development
 Industrial Environmental Research Laboratory
 Research Triangle Park, NC  27711
             13. TYPE OF REPORT AND PERIOD COVERED
              Phase 2: 2/75 - 9/78	
             14. SPONSORING AGENCY CODE
              EPA/600/13
 15. SUPPLEMENTARY NOTES ffiRL-RTP project officer is Robert C. McCrillis, Mail Drop 62,
 919/541-2733. EPA-600/2-75-014 was the Phase 1 report.
 IB. ABSTRACTThe report gives results of phase 2 of a program to demonstrate new tech-
 nology for reducing exhaust gas volume and controlling emissions from the steel
 industry sintering process. Phase 1 (report EPA-600/2-75-014) entailed the engi-
 neering and design of a windbox gas recirculation system. Phase 2 entailed construc-
 tion, operation, and evaluation of the system and, in addition, the construction,
 operation,  and  evaluation of a gravel bed filter system for particulate control.  Wind-
 box gas recirculation reduced particulates, hydrocarbons, SO2,  and CO by an amount
 equal to the recycle rate (25%   average). Capital and operatings costs (1978 dollars)
 were $5. 3 million and $0. 863 million,  respectively. The gravel bed filter system
 achieved an average particulate removal rate of 84. 5%.  Capital and operating costs
 (1978 dollars) were #5.101 million and #1.197 million, respectively.
 7.
                             KEY WORDS AND DOCUMENT ANALYSIS
                 DESCRIPTORS
                                           b.lDENTIFIERS/OPEN ENDED TERMS
                         c. COSATI Field/Group
 Pollution
 Sintering Furnaces
 ron and Steel Industry
 Dust
  ost Effectiveness
Pollution Control
Stationary Sources
Windbox
Gas Recirculation
Particulates
Gravel Bed Filter
13B
13A
11F
11G
14A
 8. DISTRIBUTION STATEMENT
 Release to Public
                                           19. SECURITY CLASS (ThisReport)
                                           Unclassified
                         21. NO. OF PAGES

                         	100
20. SECURITY CLASS (This page)
Unclassified
                                                                    22. PRICE
EPA Form 2220-1 (9-73)
                                   100

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