vyEPA
United States
Environmental Protection
Agency
Office of Air Qualify
Planning and Standards
Research Triangle Park NC 27711
EPA-450/2-78-024
OAQPS No. 1.2-099
June 1978
Air
OAQPS Guideline
Air Pollutant
Control Techniques
for Electric Arc
Furnaces in the Iron
and Steel Foundry
Industry
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TECHNICAL REPORT DATA
(Please read Instructions on llie reverse before completing)
1. REPORT NO.
EPA-450/2-78-024
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Air Pollutant Control Techniques for Electric Arc
Furnaces in the Iron and Steel Foundry Industry
5. REPORT DATE
June 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Peter D. Spawn and Paul F. Fennelly
8. PERFORMING ORGANIZATION REPORT NO.
GCA-TR-77-35-GU)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
GCA /Technology Division
Burlington Road
Bedford, Massachusetts 01730
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-4143
12. SPONSORING AGENCY NAME AND ADDRESS
U. S. Environmental Protection Agency
Office of Air and Waste Management
Office of Air Qual'ity Planning and Standards
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
U.S. EPA Project Officers: Naum T. Georgieff and Francis L. Bunyard
16. ABSTRACT
This report provides guidance for evaluating air pollutant control technologies for
electric arc furnaces in the iron and steel foundry industry. It includes estimated
emission factors, a discussion of emission characteristics, and lists of references
resulting from an extensive literature search.
ontrol technologies, including equipment for evacuating emissions during melting,
refining, charging, and tapping, as well as dust collection equipment, are presented.
Emission data from several field tests on electric arc furnaces carried out by.EPA
and others are reported. Capital and annualized emission control costs for several
new and retrofitted model plants are presented. The environmental impacts (estimated
emissiqps, solid waste disposal, energy requirements, water pollution, and noise) for
model plants are included.
Several regulatory options corresponding to different levels of emission control costs,
energy requirements, and environmental impacts are presented. !
The document outlines enforcement aspects and contains appendices with detailed field
test data on existing furnaces and cost data for several model furnaces in iron and
steel foundries.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Air pollution
Emissions
Control technology
Electric arc furnaces
Iron and steel foundries
13. DISTRIBUTION STATEMENT
Unlimited
b. IDENTIFIERS/OPEN ENDED TERMS
Air pollution control
Stationary sources
Iron and steel Industry
Electric arc furnaces
19. SECURITY CLASS (This Report)
Unclassified
20. SECURITY CLASS (Thispage)
Unclassified
c. COSATI Field/Group
21.
22. PRICE
EPA Form 2220-1 (9-73)
I
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EPA-450/2-78-024
(OAQPS No. 1.2-099)
AIR POLLUTANT CONTROL TECHNIQUES
FOR ELECTRIC ARC FURNACES
IN THE
IRON AND STEEL FOUNDRY INDUSTRY
by
Paul F. Fennelly and Peter D. Spawn
GCA/Technology Division
Burlington Road
Bedford, Massachusetts 01730
Contract No. 68-01-4143
EPA Project Officers: Naurn T. Georgieff and Francis L. Bunyard
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
June 1978
I
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OAQPS GUIDELINE SERIES
The guideline series of reports is being issued by the Office of Air Quality Planning and Standards
(OAQPS) to provide information to state and local air pollution control agencies; for example, to
provide guidance on the acquisition and processing of air quality data and on the planning and
ana lysis requisite for the maintenance of air quality. Reports published in this series will be available -
as supplies permit - from the Library Services Office (MD-35), U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina 27711, or, for a nominal fee, from the National Technical
Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.
Publication No. EPA-450/2-78-024
(OAQPS No. 1.2-099)
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ABSTRACT
This report summarizes findings of a study to identify control technology
for electric arc furnaces in the gray iron and steel foundry industry. A gen-
eral description of the industry is followed by a presentation of emission rates
and composition of exhaust gases. Emission control technology is discussed for
melting, charging and tapping of the furnace. Several new, or novel control
techniques are discussed in addition to conventional technology. Cost estimates
for several control options are presented. Adverse environmental effects con-
cern energy requirements and dust disposal and are also explored. Sampling
techniques for furnace emissions are discussed, and several formats for writing
an emission regulation are identified. Finally, the effect of each regulatory
format on reducing furnace emissions is summarized.
111
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CONTENTS
Abstract ill
Figures vii
Tables viii
Acknowledgment x
1.0 Introduction 1-1
1.1 Need to Regulate Electric Arc Furnaces In Foundries . . . 1-1
1.2 Sources and Control of Emissions 1-1
1.3 Regulatory Approach 1-2
2.0 Sources and Types of Emissions 2-1
2.1 Industry Description 2-1
2.2 General Operations 2-1
2.3 The Electric Arc Furnace: Operation and Emissions. . . . 2-6
2.4 Industry Growth and Trends 2-14
2.5 Summary of Furnace Emission Factors 2-16
3.0 Emission Control Techniques 3-1
3.1 Introduction 3-1
3.2 Evacuation of Melting and Refining Emissions 3-1
3.3 Evacuation of Charging Emissions 3-9
3.4 Collection of Tapping Emissions 3-36
3.5 Gas Cleaning Devices 3-40
3.6 Summary of Test Data for Particulate Emissions From Fabric
Filters at Iron and Steel Foundry Electric Arc Furnaces.3-47
3.7 Achievable Levels of Particulate Control 3-51
4.0 Cost Analysis 4-1
4.1 Introduction 4-1
4.2 Control Costs for Furnaces Producing Iron 4-5
4.3 Control Costs for Furnaces Producing Steel 4-11
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CONTENTS (continued)
5.0 Environmental Impacts of Applying Control Technology 5-1
5.1 Impact on Particulate Emissions From the Iron and Steel
Foundry Industry 5-1
5.2 Summary of Energy Requirements 5-1
5.3 Generation and Disposal of Dust Generated 5-4
5.4 Disposal of Scrubber Wastewater and Sludge 5-10
5.5 Effect of Emission Control on Plant Noise 5-10
6.0 Compliance Test Methods and Monitoring Techniques 6-1
6.1 Measuring Particulate Emissions 6-1
6.2 Visible Emission Monitors 6-4
6.3 Visible Emissions From Foundry Roof Monitors 6-5
7.0 Enforcement Aspects 7-1
7.1 Introduction 7-1
7.2 Concentration Limits 7-1
7.3 Mass Limits 7-2
7.4 Opacity Limits 7-3
7.5 Equipment Standards 7-3
8.0 Regulatory Options for Control of Electric Arc Furnaces at
Iron and Steel Foundries 8-1
8.1 Summary of Control Technology Options for Iron and
Steel Foundries 8-1
8.2 Format of Regulations for the Electric Arc Furnace at
Iron and Steel Foundries 8-11
8.3 Summary of Regulatory Control Options 8-16
Appendices
A. Summary of Particulate Emissions From Fabric Filters at
Gray Iron and Steel Foundry Electric Arc Furnaces. . . . A-l
B. Detailed Cost Analysis for Furnaces Producing Gray Iron
Castings B-l
C. Detailed Cost Analysis for Furnaces Producing Steel
Castings C-l
D, Technical Report Data D-l
vi
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FIGURES
Number Page
2-1 Iron and steel foundry process flow and emission sources. . . . 2-4
3-1 Roof hood 3-3
3-2 Side draft hood 3-6
3-3 Direct evacuation through fourth hole 3-8
3-4 Canopy hood using building roof as part of the canopy, combined
with direct furnace evacuation 3-11
3-5 Design aspects of building evacuation system 3-18
3-6 Sketch of furnace enclosure design at Lone Star Steel Co. . . . 3-21
3-7 Krupp furnace, sequence of events during charging 3-25
3-8 Hawley close capture hoods .... 3-28
3-9 The Brusa charging and preheating system 3-34
3-10 Hooded charge bucket 3-35
3-11 Marchand design for charging emission control 3-37
3-12 Armco Steel Corporation design for tapping pit enclosure. . . . 3-39
3-13 Ladle car and ladle enclosure by Marchand 3-41
3-14 Mobile tapping hoods 3-42
3-15 Summary of EPA test data for baghouses on EAF's producing iron 3-48
3-16 Summary of reported test data for baghouses on EAF's producing
steel 3-50
4-1 Cost effectiveness of alternative control options for retro-
fitted iron producing furnaces (two-furnace shop) 4-10
4-2 Cost effectiveness of alternative control options for retro-
fitted steel producing furnaces (two-furnace shop) 4-16
vii
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TABLES
Number Page
2-1 Raw Materials Used for Iron and Steel Production 2-3
2-2 Chemical Analysis of Particulate Emissions from an Electric
Arc Furnace 2-11
2-3 Composition of Dust Collected by Fabric Filters at an Iron
Foundry 2-11
2-4 Particle-Size Distribution for Particulate Emissions From Three
Electric-Arc-Furnace Installations 2-12
2-5 Summary of Emission Factors for Iron and Steel Producing
Electric Arc Furnaces 2-17
3-1 Typical Exhaust Flow Rates and Particulate Removal Efficiency
of Melting Control Systems 3-5
3-2 Typical Exhaust Flow Rates and Particulate Removal Efficiency
of Charging and Tapping Control Devices at Model Foundries . . 3-15
3-3 Design Data for Lone Star Steel Company Furnace Enclosure. . . . 3-22
3-4 Summary of Total Particulate Removal Efficiencies for Control
Options at Iron and Steel Foundries 3-53
4-1 Engineering Parameters for Model Foundries Producing Iron and
Steel 4-3
4-2 Summary of Total Annualized Control Costs for Model Existing
Foundries Producing Iron Castings, in Thousands of Dollars
per Year 4-6
4-3 Summary of Reported Capital Costs Compared to EPA Estimates of
Total Installed Costs 4-8
4-4 Summary of Total Annualized Control Costs for Model Existing
Foundries Producing Steel Castings, in Thousands of Dollars
per Year 4-12
5-1 Summary of Total Particulate Emissions From Iron and Steel
Foundry EAF's for Various Control Options 5-2
5-2 Energy Requirements, in Million kWh per Year, for Melting
Compared to Emission Control Options for Model Plants 5-3
5-3 Quantity of Dust Collected at Model Foundries in Megagrams
per Year 5-6
viii
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TABLES (continued)
Number Page
5-4 Trace Metallic Components of Baghouse Hopper Dust (ppm) .... 5-8
8-1 Summary of Regulatory Options for a New Model 9.1 Mg/hr
Furnace Producing Iron 8-17
8-2 Summary of Regulatory Options for a New Model 9.1 Mg/hr
Furnace Producing Steel 8-18
ix
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1.0 INTRODUCTION
This document concerns the control of emissions from electric arc furnaces
in ferrous foundries. Emissions from production of iron and steel in electric
arc furnaces in foundries are primarily particulates of respirable size. Most
of the control techniques discussed herein have been used at foundries, although
several newly developed techniques are also addressed.
1.1 NEED TO REGULATE ELECTRIC ARC FURNACES IN FOUNDRIES
Typically, air pollution control regulations which govern ferrous foun-
dries require that emissions from melting of metal in the furnace be con-
trolled. Recently, there has been interest in control of emissions generated
during charging and tapping of the furnace. Nationally, annual emissions from
electric arc furnaces at foundries are estimated to be 10,000 megagrams (Mg) or
11,020 short tons per year. This represents 0.8 percent of total particulate
emissions from stationary sources, and is of concern since foundries are often
located in populated areas or in localities where National Ambient Air Quality
Standards (NAAQS) are not being attained.
1.2 SOURCES AND CONTROL OF EMISSIONS
Emissions from electric arc furnaces occur when the scrap is charged into
the furnace, during melting and refining of the metal, and during tapping of
molten metal. For steel furnaces, emissions also occur during backcharging;
i.e., when the furnace is charged a second time, after the first charge has
1-1
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melted. Emissions from the electric arc furnace can be reduced to very low
levels through use of proper capture devices on the furnaces and evacuation
of the emissions to a gas cleaning device for collection.
Melting and refining account for about 90 percent of furnace emissions.
Control technology for these emissions is well established, and currently
used by most foundries. The remaining 10 percent of furnace emissions result
from charging and tapping. Technology is available for effective and
economical control of these operations. However, only a few foundries prac-
tice charging and tapping control; and several of the control techniques have
been only recently developed, primarily for large steel-making furnaces.
1.3 REGULATORY APPROACH
In the regulatory approach, emphasis shall be put on successful capture
of melting, charging and tapping emissions (i.e., good evacuation devices) at
the furnace. Regulations should be written in terms of equipment specifications,
especially those pertaining to the type of furnace evacuation devices. Equip-
ment specifications would require some flexibility in a regulation to accommo-
date newly developed techniques and to allow selection of best control options
for individual shops on a case-by-case basis, when necessary.
Regulations in terms of operating procedures; i.e., prescribing avoiding
backcharging, alloying in the ladle, and carbon upgrading by means of carbon
injections, etc. can also be applied. Arc furnace operators currently pay
careful attention to furnace operational procedures because of the complexity
of the process and for safety reasons. It is not anticipated that prescribing
certain additional operating procedures to minimize emissions ;will adversely
affect furnace operation.
1-2
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A regulatory approach which specifies limits on concentration or mass of
emitted participates requires sampling of low exhaust concentrations. Such
sampling is costly for small furnace operators. This approach can be substi-
tuted by opacity standards. Opacity limitations is a more convenient regula-
tion because it is inexpensive and easy to enforce. Visual observation of
the plume opacity from stack and roof monitors can ensure that dust collection
devices are operated properly. Opacity standards for charging, backcharging
and tapping must be judiciously applied if those fumes are unconfined. Such
fumes tend to drift out of the furnace bay area, be diluted, and therefore
the opacity reading is not representative of the mass emissions.
1-3
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2.0 SOURCES AND TYPES OF EMISSIONS
2.1 INDUSTRY DESCRIPTION
As defined for this study, iron and steel foundries are those which produce
gray, white, ductile or malleable iron* and steel castings. The differences
between the types of iron and steel are chemical and physical in nature and
are determined by relative concentrations of carbon, silicon, magnesium,
manganese, sulfur and phosphorus. Particulate emissions are very similar for
each type of iron and steel, and emissions depend mostly on furnace type and
furnace charge materials.
Iron foundries pour about 85 percent of all ferrous castings in the
United States while steel foundries account for the remaining 15 percent. The
electric arc furnace (EAF) and raw materials for iron and steel production are
very similar; consequently, furnace emissions and emission control requirements
tend to be very similar for iron and steel furnaces.
2.2 FOUNDRY OPERATIONS
2.2.1 General Operations
Castings are produced in the foundry by injecting or pouring molten metal
into a mold. Molds are formed by placing a pattern conforming to the external
shape of the desired casting in a supporting frame. Sand is poured and com-
pressed into the frame, around the pattern. The mold is then separated, pat-
terns are removed, and cores are placed in appropriate locations to provide for
internal cavities in the casting. Upon reassembly, the mold is ready to
In this document, the term "gray iron" is used to describe all types of iron.
2-1
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received molten iron from the melting furnace. Molds are formed manually in
small foundries and usually by automatic machines in large foundries.
Raw material used for gray iron or steel castings includes: ferrous scrap
metal, foundry returns, carbon and flux, fuel, refractories (furnace lining) and
molding sand, as outlined in Table 2-1. Most foundries purchase scrap of a size
suitable for charging directly into the furnace. Charging methods range from
hand charging in small shops to mechanized bucket charging in medium-sized shops
and full automatic, computerized bucket charging in new, large foundries.
At iron foundries, the charge is melted in cupola, induction or electric
arc furnaces while steel foundries rely almost exclusively on the electric arc.
Alloy agents are. added to the furnace, after melting, or to the ladle during
tapping of refined metal. After the furnace is tapped, molten metal is poured
into molds by hand or at an automatic pouring station. After a cooling period,
molds are separated and castings removed from mold flasks on a vibrating, im-
pacting shakeout unit. Sand is recycled to the molding sand preparation system.
Castings are further cleaned by shot-blasting and if necessary grinders to
remove fins and smooth rough spots.
Malleable and ductile iron castings may be given various heat treatments
including stress relieving, annealing, normalizing, quenching and tempering.
Ductile iron may be given a special heat treatment. The castings are then
inspected and shipped.
Figure 2-1 diagrams the process flow for a typical iron or steel foundry,
Each foundry process generates certain quantities of smoke, fume and other
particulate matter. Current data indicates that on the average, the furnace
contributes roughly 60 percent of uncontrolled particulates emitted from
foundries which melt with the EAF.1
2-2
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TABLE 2-1. RAW MATERIALS USED FOR IRON AND STEEL PRODUCTION
Metallics
Pig iron
Cast iron scrap
* Steel scrap
* Turnings and borings (loose or briquettes)
Foundry returns
Ferroalloys
Inoculants, including magnesium alloys
Carbon additive
4 Graphite
* Electrode scrap
Calcined gilsonite
Anthracite
Coke breeze
Fluxes
Carbonates (limestone, dolomite, soda ash)
* Florldes (fluorspar)
Carbides (calcium carbide)
Fuel
Refractories
Firebrick: alumina, silica, magneeite, graphite
Mold preparation
Sand
Additives, binders
2-3
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to
METALLICS
FLUXES
FINISHING
DUST
1-.)' GAS AND
PARTICULATE
I \U
GAS AND V..'.P
DTir*l II ATC *' P*
PARTICULATE 'I-
EMISSIONS «
METAL
MELTING '
f, PARTICULATE
EMISSIONS
SHIPPING
«l-
_, DUCTILE IRON
_-rJ INNOCULATION
,.', DUST nl|cT
CASTING
SHAKEOUT
RETURN
DUST SAND
COOLING AND
CLEANING
POURING
. SPILL
DUST SAND
MOLDING
CORE
MAKING
SAND
PREPARATION
Figure 2-1. Iron and steel foundry process flow and emission sources.
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2.2.2 Furnaces Used in Iron and Steel Foundries
About 70 percent of all iron is produced in the cupola, which is a verti-
cal, refractory lined, cylindrical steel shell charged at the top with layers
of metal, coke and flux materials. Compared to other furnace types, cupolas
produce significantly greater quantities of gaseous (carbon monoxide) and
particulate emissions because air is blown through the cupola to support com-
bustion of coke as a source of heat. Emission controls are usually more expen-
sive and precise control of metallurgy is difficult with cupolas; nevertheless,
cupolas are likely to remain prominent in iron foundries because they handle
any type of scrap and their energy consumption ia often lower than arc furnaces.
However, cupolas are rarelv used in steel foundries today.
Coreless induction furnaces are typically small in size and melt iron or
steel through heat generated by a changing electrical flux created by an in-
duction coil placed around the furnace shell. Unlike the situation with cupo-
las and electric arc furnaces, the furnace charge for an induction furnace must
be free from oil and water to avoid explosions. To avoid these problems, the
scrap charge to an induction furnace is often dried, cleaned and/or preheated.
Emissions from induction furnaces are considerably less than cupolas or arc
furnaces except during charging. Channel induction furnaces are often used
to hold and superheat molten iron received from the primary melting furnace,
and operation commonly termed "duplexing."
Reverberatory furnaces are primarily used in malleable iron foundries to
receive and hold molten iron from a cupola and some open hearths which are
still used in steel operations. Fired by oil, coal or gas, these large capa-
city furnaces provide additional refining and superheating prior to pouring.
A second type of reverberatory furnace is small in size and used for melting.
2-5
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Capacities are less than 2 tons, and emission levels are low, which makes the
furnace popular for small foundries.
The electric arc furnace is the primary melting furnace used at steel
foundries. It is also widely used at iron foundries, although not as exten-
sively as the cupola furnace. A more detailed discussion on the EAF and its
operation is provided below.
2.3 THE ELECTRIC ARC FURNACE: OPERATION AND EMISSIONS
The electric arc furnace (EAF) is a refractory lined, cylindrical vessel
constructed of heavy, welded steel plates. Three graphite electrodes mounted
overhead can be raised and lowered into the furnace through water cooled holes
in the roof. With electrodes in the raised position, the furnace roof can be
swung aside to allow for charging. Top charging is most prevalent since it can
be accomplished quickly, although some small or older furnaces are charged
through side doors. Overhead cranes are used to transfer material within the
foundry and to charge the furnace. Chemical agents, as required, are added
with the scrap charge, at a later time through side or slag doors, or to the
ladle during tapping. Alloy addition to the ladle increases availability of
the furnace and can increase overall production. The entire furnace can be
tilted to facilitate slag removal and tapping of the hot metal. After melting,
molten iron is poured into a ladle or a holding furnace and then cast into
molds.
Electric arc furnaces for steel foundries are very similar to those used
for iron. At foundries which pour both iron and steel, both metals can be
produced in the same furnace. Steel production often uses an oxygen lance to
dislodge scrap which adheres to furnace walls, to adjust the furnace chemistry
or to increase the melt rate. Steel furnaces are often backcharged with
2-6
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additional scrap during the melt period. The oxygen lance and backcharging
temporarily increase emission rates from steel furnaces. Iron production
does not ordinarily use these operations. The chemical composition of emis-
sions from iron and steel production for the most part is very similar except
for some differences in relative amounts of certain metal oxides.
Compared with other types of furnaces, the EAF offers several advantages.
An induction furnace requires a clean charge, but an arc furnace can melt
dirty or oily scrap provided the furnace is charged in a manner which avoids
localized high concentrations of combustibles. However, excessive oil may
cause premature deterioration of the furnace roof and fume collectors in addi-
tion to substantially increasing emissions. Electricity consumption is lower
for an arc furnace compared with an induction furnace. Advantages of the arc
furnace over the cupola include: better control of melt chemistry, and some-
times lower costs for emission control equipment, and relative ease of inter-
mittent operation.
2.3.1 Charging
Iron and steel scrap is loaded into a charge bucket with an overhead
crane, and the filled bucket is weighed on a scale. Typical charge composition
for gray iron is:2'3'4
50 to 60 percent iron (approximately 80 percent foundry
returns and 20 percent cast iron turnings or borings).
37 to 45 percent steel (approximately 70 to 100 percent
steel pieces and 0 to 30 percent steel turnings).
0.5 to 1.1 percent silicon (usually as ferro silicon).
1.3 to 1.7 percent carbon raiser.
Foundry returns include sprues, end gates, risers (scrap pieces from a
casting), defective castings, and borings from machining operations. In some
2-7
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cases, pig iron may be included with the scrap. Carbon raiser is in the form
of pure carbon (graphite) or coke breeze.
Charge composition for steel production differs from iron production in
that the foundry returns are mostly steel, and no carbon raiser is added to the
charge. In producing steel, the carbon level is substantially reduced, about
6 to 7 times lower than for iron production.
Charging a hot electric arc furnace produces emissions from:
vaporization and partial combustion of oil introduced with
any borings, turnings, and chips.
oxidation of organic and other foreign matter which may
adhere to the scrap.
liberation of sand particles which are introduced into the
furnace on the surface of casting returns.
Charging emissions consist of particulates, carbon monoxide, hydrocarbon
vapors, and soot, and are typically vented to the atmosphere through monitors
or vents in the foundry roof. Charging with dirty, oily scrap causes heavy
emissions of fume, hydrocarbon and other vapors while a clean charge sub-
stantially reduces fume generation. The magnitude of charging emissions has
not been extensively measured as such emissions are often unconfined and
difficult to segregate from other foundry emission sources. Extrapolation of
limited emission test data from charging and tapping at steel-making EAF's5
indicates that charging and tapping at iron and steel foundries account for
10 percent of total furnace emissions, when alloying is conducted in the ladle.
When there are no alloys added to the ladle, as sometimes the case with iron
production, then charging and tapping are estimated to produce 5 percent of
total furnace emissions.
2-8
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A steel furnace is sometimes backcharged with additional scrap once the
initial charge has melted. Backcharging causes a violent eruption of iron
oxide fume with a strong thermal driving force. Particulates and significant
quantities of carbon monoxide are evolved during backcharging; however, no
quantitative data regarding particulate emissions during backcharging are
available.
2.3.2 Melting and Refining
After charging, the furnace roof is replaced and electrodes slowly lowered
into the charge while applying electrical power. Melting is accomplished by
heat generated from electrical arcing between the electrodes and the charge.
As electrodes bore into the solid charge, much fume and noise results.
Automatic controls maintain the desired current by activating motors which
raise or lower electrodes. A demand limiter device is often used to auto-
matically control power which is delivered to the electrodes through a trans-
former. When electricity consumption in the foundry exceeds a preset limit,
a cycle of raising the electrodes, reducing transformer output, and lowering
electrodes is initiated. Termed a "shed," this operation generally causes
a momentary increase in furnace emissions. During melting and refining,
electrodes lose 4 to 6 kilograms of their weight per megagram of iron produced,
which results in carbon monoxide emissions.6
After the charge is melted, the molten bath is manually skimmed to remove
impurities which have collected in the slag. The furnace is tilted about
15 degrees from the vertical, and slag is withdrawn into a slag pit. After
slagging, power is restored for 15 to 30 minutes to further refine and super-
heat the melt, and the iron chemistry and bath temperature are checked and
adjusted as necessary.
2-9
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During melting and slagging, emissions consist mainly of:
particulates as metallic and mineral oxides generated from
vaporization of iron and transformation of mineral additives.
carbon monoxide from combustion losses of the graphite electrodes,
carbon raisers and carbon in the metal.
hydrocarbons from vaporization and partial combustion of oil
remaining in the charge.
During melting, fumes escape from the furnace through electrode annuli
(holes), slag doors, the roof ring (the joint between the furnace shell and
roof) and sometimes the tap spout. Proper maintenance of the furnace will
minimize escape of fume through these openings, and improve the efficiency of
fume evacuation systems used for control of melting emissions.
The rate of emissions from iron EAF's during melting and refining varies
substantially with quality and cleanliness of scrap, and is dependent to a
lesser degree on charge composition, melting rate and tapping temperature.
While the literature reports emission rates ranging from 2 to 20 kilograms of
particulate per megagram of iron charged (4 to 40 pounds per ton) a study
conducted for EPA concluded that on the average, emissions are 7.0 kg/Mg
(14 lb/ton).6 The dependency of emission rate on charge quality was demon-
strated by source tests which showed that emissions increased by up to 100 per-
cent when dirty substandard scrap was substituted for clean scrap in an
electric arc furnace.7
The composition of particulate emissions from iron EAF's during melting
and refining was determined for three iron foundries, as shown in Table 2-2.
Iron oxide and silicon dioxide were the main components, while trace amounts
of several other metal oxides were also present. Analysis of dust collected
by a fabric filter at a fourth iron foundrv EAF is shown in Table 2-3.
2-10
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Table 2-2. CHEMICAL ANALYSIS OF PARTICULATE EMISSIONS
FROM AN ELECTRIC ARC FURNACE8
Constituent
Proportion of total
partlculate, weight
percent
Iron oxide
Silicon dioxide
Magnesium oxide
Manganese oxide
Lead oxide
Alumina
Calcium oxide
Zinc oxide
Copper oxide
Lithium oxide
Tin oxide
Nickel oxide
Chromium oxide
Barium oxide
Foundry A
75-85
10
2
2
1
0.5
0.3
0.2
0.04
0.03
0.03
0.02
0.02
0.02
Foundry B
74-85
10
0.8
2
2
1
0.2
2
0.03
0.03
0.3
0.03
0.07
0.07
Foundry C
75-85
10
1
2
0.5
0.5
0.8
0.3
0.01
0.03
0.02
0.01
0.01
0.01
Table 2-3. COMPOSITION OF DUST COLLECTED BY
FABRIC FILTERS AT AN IRON
FOUNDRY9
Constituent
Weight percent
Ferrous oxide - FeO
Ferric oxide - Fe 0_
Silicon dioxide SiO_
Magnesium oxide - MgO
Aluminum oxide - MgO
Manganese dioxide - MnO_
Calcium oxide - CaO
8.75
41.2
34.9
5.0
4.7
8.0
1.4
2-11
-------
This analysis indicates substantial amounts of oxides of manganese, aluminum
and magnesium in addition to iron and silicon. Particulates generated during
melting and refining have very small median diameters; data presented in
Table 2-4 shows that 80 percent of the dust is smaller than 5 microns.9
Table 2-4. PARTICLE-SIZE DISTRIBUTION FOR PARTICULATE EMISSIONS
FROM THREE ELECTRIC-ARC-FURNACE INSTALLATIONS9
- - - -
Cumulative percent by weight
- . , , . . . for indicated particle diameter
Pnrticlc size, micrometers v
Less than 1
Less than 2
Less than 5
Less than 10
Less than 15
Less than 20
Less than 50
Foundry A
5
15
28
41
55
68
98
Foundry B
8
54
80
89
93
96
99
Foundry C
18
61
84
91
94
96
99
While emissions from steel-producing furnaces are similar to those from
iron melting, there are some differences. The oxygen lance, when used, temporar-
ily produces a large gas volume, increased particulate emissions and substantial
amounts of carbon monoxide. Carbon monoxide from lancing is typically combusted
at the furnace by air drawn through furnace openings, or by mixing furnace exhaust
gases with outside air. Unlike iron furnaces, steel furnaces are often back-
charged which results in a violent eruption of iron oxide fume. Melting and
refining emissions from steel furnaces average about 8.0 kg/Mg of steel
(16 Ib/ton). ° Peak emission rates which occur during oxygen lancing and
backcharging are two or three times larger than the average.
2-12
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2.3.3 Tapping
When the proper chemistry and metallurgy are reached, the melt is tapped
at a temperature of about 1,500°C (2730°F) for iron and 1600°C (2910°F)
for steel. The electrodes are raised, the furnace tilts up to 45 degrees, and
refined metal flows into a ladle. The melt is then poured into molds, or tem-
porarily stored in the molten state in holding furnaces. During tapping, sparks
and fumes consisting of molten iron or steel are generated in abundant quanti-
ties and become a source of ferrous oxide particulate emissions. Tapping of
iron generally produces considerably less fume than the charging of the furnace.
However, when alloys are added to the ladle, tapping emissions are somewhat
increased. Tapping of steel furnaces typically generates fumes at a rate some-
what greater than charging, and considerably greater than tapping of iron.
Higher emission rates from tapping of steel furnaces are due to the higher
temperature of steel production and the fact that more alloys are generally
added to steel, compared to iron. Tapping emissions are often unconfined and
escape as fugitive emissions through foundry roof vents.
2.3.4 Furnace Yields
The yield of the arc furnace is high, as 94 to 98 percent of the charge
is recovered as iron. About 0.70 percent of the charge escapes as partic-
ulate emissions while the remainder is lost to the slag. Yields for steel
foundries are in the order of 92 to 94 percent.9
2.3.5 Energy Considerations
The EAF consumes 450 to 625 kilowatt hours (kWh) per ton of iron
melted, and 410 to 570 kWh for steel, depending on the bath temperature and
quantity of borings in the charge.9 The lower figure is based on a charge
containing 10 percent borings while the higher consumption relates to a charge
2-13
-------
with over 50 percent uncompressed, oxidized borings. Borings are seldom used
in steel production. In the case of steel production, power consumption is a
function of the bath temperature, amount of oxygen applied, and type of steel
being produced.
2.4 INDUSTRY GROWTH AND TRENDS
Production of ferrous casting is largely influenced by the general econo-
mic climate and consequently, shipments from iron foundries decreased from
18.1 million short tons in 1973 to 15.3 million tons in 1976. Shipments of
steel castings dropped slightly from 1.89 million tons in 1973 to 1.80 million
tons for 1976. However, production of ferrous castings in 1976 was substantially
improved over 1975 due to an easing of material shortages, increased demand by
the automobile industry and general improvement of the economy. Future demand
for ferrous castings is considered to be strong. Foundrymen anticipate an in-
crease in iron production of 25 percent by 1981, accompanied by a 30 per-
cent increase in steel castings.11 Recent projections by the Department of
Commerce are more optimistic, suggesting that annual demand for iron castings
will reach 24 million tons by 1985, a substantial 75 percent increase over
1976.12 The projected demand will be met by existing, unused capacity and by
construction of new facilities. Only 73 percent of available capacity was used
in 1976, and current plans for new equipment will increase foundry capacity
by 18 percent in 1981.11 It is anticipated that major expenses for air
pollution control at existing foundries will soon peak, thus freeing capital
for equipment purchases. Of the 10 billion dollars expected to be spent by
the metal casting industry by 1986, 1.2 billion is budgeted to meet current
and anticipated environmental regulations. Although demand for castings is
2-14
-------
subject to cyclical swings, iron is expected to account for a majority (85 per-
cent) of ferrous metal castings in the future.
New installations of electric arc furnaces at foundries have increased
steadily over the years. The American Foundrymen's Society has indicated that
the melting capacity of arc furnaces was 3.5 million tons/yr in 1974 and will
likely increase to 5.0 million tons by I960.13 At a typical operating time of
4000 hours per year and an average furnace production of 9.1 Mg/hr (10 tons/hr),
about seven new arc furnaces per year would be required to meet these projections.
Steel foundries use the electric arc furnace almost exclusively, although
there are a few open hearth furnaces operating at older foundries. There are
about 350 electric arc and about 25 open hearth furnaces operating at steel
foundries in the country.
For new installations, arc furnaces are somewhat more common than the tradi-
tional cupola because of improved metallurgical control, reliable energy sources
and relative ease of air pollution control. However, escalating electricity costs
coupled with improvements in the design and operation of the cupola suggests
that a significant percentage of iron will continue to be melted in this type
of furnace. When high production rates are required, the cupola is generally
preferred over an electric furnace. Induction furnace installations are also
expected to continue to increase substantially in number because of their
operating flexibility and low rate of emissions. One estimate suggests that
80 furnaces per year will be built with a combined total capacity of about 340
Mg/hr (370 tons/hr) each year.14 Reverberatory furnaces are not expected to
become more prominent since they require substantial amounts of fossil fuel.
Presently, about 60 percent of all ferrous castings are poured by indepen-
dent jobbing foundries, for sale to others. These foundries tend to be small
2-15
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and generally pour a variety of speciality castings and alloys. The remaining
40 percent of ferrous foundries are the "captive" shops which produce castings
for use by the parent company.
2.5 SUMMARY OF FURNACE EMISSION FACTORS
Emissions from iron furnaces during melting and refining have been docu-
mented to range from 2 to 20 kg particulate per megagram of iron charged to
the furnace (4 to 40 Ibs/ton), with an average value of 7.0 kg/Mg (14 Ib/ton)
charged.6 Average emission rates from steel furnaces have been reported at
8.0 kg/Mg charged (16 Ib/ton), but the range of values is unavailable. "
Emission factors for charging and tapping at foundries have not been
documented to date. Fumes generated by charging and tapping are ordinarily
uncollected at foundries, and it is therefore difficult to quantitatively
measure emission rates. However, extrapolation of limited emission test data
from EAF's in the steel-making industry5 has provided the following best avail-
able estimates for foundry EAF's. Charging and tapping together are estimated
to account for 10 percent of total uncontrolled emissions from both iron and
steel producing EAF's, when alloying is conducted in the ladle. When there is
no alloying in the ladle, charging and tapping produce about 5 percent of
total furnace emissions. Tapping emissions are normally greater at steel
foundries because of the greater amount of alloys added to the ladle during
tapping, and the somewhat greater temperature of molten steel (by about 200°F
or 90°C) as compared to iron production. Based on these data, Table 2-5 lists
emission factors which will be used in the cost analysis, Section 4 of this
report.
2-16
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TABLE 2-5. SUMMARY OF EMISSION FACTORS FOR IRON AND
STEEL PRODUCING ELECTRIC ARC FURNACES
Uncontrolled emissions, kg/Mg
Iron furnaces Steel furnaces
Melt and refine
Charge and tap
7.0
*
0.7
8.0
0.8
*
With alloys added to the ladle.
2-17
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REFERENCES
*
1. Gutow, B.S. An Inventory of Iron Foundry Emissions, Modern Casting,
61(l):46-48. January 1972.
2. Burgess, Price Hayes-Albion Corporation. Albion Malleable Division.
Letter to N.T. Georgieff, Emission Standards and Engineering Division.
Office of Air Quality Planning and Standards (OAQPS). U.S. Environmental
Protection Agency. May 17, 1974.
3. Ferguson, W.O. Gray and Ductile Iron Founders' Society. Letters to
N.T. Georgieff, Emission Standards and Engineering Division, OAQPS.
U.S. Environmental Protection Agency. May 29, 1974 and October 14, 1975.
4. Weber, Dr. Technical University, Essen, Germany. Personnal Communication
to N.T. Georgieff. Emission Standards and Engineering Division, OAQPS.
U.S. Environmental Protection Agency.
5. Background Information for Standards of Performance: Electric Arc
Furnaces in the Steel Industry. U.S. Environmental Protection Agency.
Research Triangle Park, North Carolina. EPA-450/2-74-017b. October 1974.
6. Davis, J.A., E.E. Fletcher, R.L. Wenk and A.R. Elsea. Screening Study
on Cupolas and Electric Furnaces in Gray Iron Foundries. Final Report.
Battelle Columbus Laboratories, Columbus, Ohio. Prepared for U.S. En-
vironmental Protection Agency, Office of Air Quality Planning and
Standards, Research Triangle Park, Durham, North Carolina. Contract No.
68-01-0611, Task No. 8. August 1975.
7. Coulter, R.S. Smoke, Dust, Fumes Closely'Controlled in Electric Furnaces.
Iron Age. 173(1):107-110. January 1954..
8. Systems Analysis of Emissions and Emissions Control in the Iron Foundry
Industry, Volume I. Prepared by A.T. Kearney and Company, Inc. EPA
Publication Number APTD 0644. February 1971.
9. In-House Data From N.T. Georgieff, Emission Standards and Engineering
Division, OAQPS. U.S. Environmental Protection Agency. October 1976.
10. Baum, Kurt. Removal of Dust from Electric Arc Furnaces. Stahl und Eisen.
84(11):1497-1500. November 1964.
11. Gaultier, M. Have You Been to the Market Lately. Modern Casting.
65(9):15. September 1976.
2-18
-------
12. Great Growth Predicted for Metal Casting. Modern Casting. 65(3).
March 1976.
13. Trends Panel, Foundry Management and Technology. 103(1) :48-51.
January 1975.
14. Hakkl, A., Brown Boverl Corporation, New Brunswick, New Jersey.
Private Communication to N. T. Georgieff, Emission Standards and
Engineering Division, OAQPS, U.S. Environmental Protection Agency.
April 197A.
2-19
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3.0 EMISSION CONTROL TECHNIQUES
3.1 INTRODUCTION
Control of emissions from the electric arc furnace (EAF) requires two
separate steps:
Evacuation or containment of fumes
Removal of particulates from the evacuated exhaust gas.
This section discusses emission control techniques in common use and also
discusses control techniques which may be widely used in the near future.
Control of fumes from the melting phase of furnace operation is straight-
forward, and currently practiced at most foundries. Control of fumes from
charging and tapping is not widely practiced at existing foundries. Recently,
new designs for control of charging and tapping have been installed on
several EAF's and appear promising for economical fume control. In addition,
several conceptual designs for charging and tapping control have been de-
veloped, and are also addressed in this chapter.
3.2 EVACUATION OF MELTING AND REFINING EMISSIONS
Virtually all EAF's in iron and steel foundries collect furnace
emissions during melting and refining with one of three basic systems:
Roof hoods
Side draft hoods
Direct furnace evacuation
Selecting the best system for an EAF depends on physical and structural
constraints at the foundry and metallurgical requirements of the furnace.
3-1
-------
When properly designed and maintained, each system can provide efficient cap-
ture of melting emissions and direct them to a gas cleaning device (usually
a fabric filter). However, there is normally a small leakage of fume from
the furnace or furnace evacuation systems. Some fume inevitably escapes
through electrode holes, improperly sealed roof rings and slag doors, es-
pecially during initial meltdown and oxygen lancing, if used.
Melting contol systems are not designed to collect emissions from charging
and tapping. The collection hoods or ducts are attached to the furnace roof
and become inoperative during charging (when the roof is removed) and tapping
(when the furnace tilts and disconnects from the main exhaust duct). This
section discusses basic control equipment for melting and refining emissions
with the understanding that variations of each system are often encountered
in the field. Later sections within this chapter address control technology
for charging and tapping.
3.2.1 Roof Hoods
N
The roof hood is attached directly to the EAF, completely enclosing the
furnace top as illustrated in Figure 3-1. Extensions of the hood may also
collect fumes from the pouring spout, and slag or working door. Hood suction
maintains a slight draft through electrode holes and through small gaps between
the roof ring and furnace top, effectively drawing fumes into the hood. A
disadvantage of roof hoods is that access to electrodes and water cooling
glands is restricted, making maintenance and repairs more difficult. This
problem is partially eliminated by providing access doors on the hood assembly.
The full roof hood is the heaviest of the furnace evacuation systems. When
retrofitting an EAF, allowances must be made for increased structural loads
3-2
-------
Figure 3-1. R°of hood
3-3
-------
on both the furnace roof, base and the mechanisms which remove the roof for
charging.
A modification of the roof hood design, called a two-section hood, re-
duces access and weight problems which may be associated with the full roof
hood. This two-section hood has separate subhoods, one located over the
electrodes and the other located above the space around the furnace roof
gap. Collection efficiency is slightly reduced over that of a full roof
hoodi The full roof hood can provide most reliable collection of melting
and refining emissions as some storage capacity is provided by the hood to
contain an instantaneous increase in emissions. As shown in Table 3-1,
control efficiency ranges from 95 to 100 percent of melting and refining
emissions with 99 percent being a typical, maximum level encountered at
foundries. Exhaust flow rates typically range from 7.7 m3/sec (16,000 acfm)
for a 3.9 Mg/hr furnace to about 30.0 m3/sec (64,000 acfm) for a large,
22.7 Mg/hr furnace. These are about 60 percent of flow rates encountered by
side draft hoods of comparable efficiency.
3.2.2 Side Draft Hoods
The side draft hood is the most common of the three fume evacuation
systems. It is also mounted on or near the furnace roof as illustrated in
Figure 3-2. The hood is designed with one side open for the electrodes so
their travel is not restricted. As fumes escape from electrode holes they
are drawn into the open side of the hood. Vanes for directing air flow are
provided on the ends of the finger ducts. Hoods may also be installed over
the pouring spout and slag door to capture fumes which may escape during
melting. Larger exhaust volumes are required for side draft as compared to
the roof hood since enough suction must be maintained to draw fumes laterally
3-4
-------
TABLE 3-1. TYPICAL EXHAUST FLOW RATES AND PARTICULATE REMOVAL EFFICIENCY OF MELTING
CONTROL SYSTEMS*
Ul
Typical exhaust flow rate for model
furnaces in m3/sec
Furnace size
3.9 Mg/hr 9.1 Mg/hr 22.7 Mg/hr
Particulate removal efficiency
Range
Typical maximum
Side draft hood
Roof hood
Direct evacuation
12.9
7.7
3.2
19.8
11.9
5.0
50.00
30.0
12.5
90-100
95-100
90-100
99
99
99
Data source: Reference 1.
-------
m
^
Ssi
Figure 3-2. Side Draft Hood
into the hood. The larger exhaust flow insures combustion of carbon monoxide
and reduces downstream exhaust temperatures. The side draft hood is simpler
than a roof hood, places less weight on the furnace and furnace tilting
mechanism, and improves access for maintenance of electrodes and cooling
glands. To insure effective capture of melting emissions, the furnace roof
must be sealed tightly to avoid the escape of fume. This is not a require-
ment of roof hoods which enclose the entire furnace top.
Retrofitting an existing furnace with a side draft hood generally presents
few problems. However, one large, new foundry reported severe deterioration
of the finger-like projections which collect fumes from electrode ports. The
furnace was directly evacuated, with the side hood designed to catch fugitive
emissions from the electrodes. Heavy stainless ductwork was eroded in a
matter of weeks, and after many attempts at solving the problem, the company
installed a roof hood.2 However, this is not considered a common problem as
many side draft hoods are operating quite satisfactorily on EAF's of all
sizes.
3-6
-------
Side draft hoods have the greatest exhaust flow rate of the three devices
for control of melting and refining emissions. Flow rates range from about
12.9 m3/sec (27,000 acfm) for a 3.9 Mg/hr furnace to about 50 m3/sec
(106,000 acfm) for the large, 22.7 Mg/hr furnace. These flow rates are
typical of nearly recent installations; older, less efficient side draft
hoods used lower flows. The maximum collection efficiency expected from a
side draft hood is 99 percent, ranging from 90 to about 100.1
3.2.3 Direct Furnace Evacuation
Direct evacuation is accomplished through a fourth hole (sometimes termed
a "snorkel") in the furnace roof or sidewall, as illustrated in Figure 3-3. A
slight negative pressure in the furnace is maintained by a damper in the exhaust
duct, which is often automatically controlled by pressure sensors. Furnace
fumes are withdrawn through an elbow which is water cooled or refractory lined.
Direct evacuation is the most effective method for collecting melting emis-
sions and also results in the lowest exhaust volume. Unlike roof and side
draft hoods, direct evacuation requires greater cooling of exhaust gases
before entering the gas cleaning device. Cooling is usually accomplished by
introducing dilution air, although atomizing water spray chambers, radiant-
convection coolers, and air or water cooled duct work may also be used.
When exhaust volume is minimized, the gas cleaning device can be of a smaller
size and both capital and operating costs are reduced.
While direct evacuation is the most efficient method for collecting melt-
ing emissions, it cannot be applied to all EAF's because the internal furnace
atmosphere is affected, which in turn influences the chemistry of the melt.
The slight, but constant influx of outside air to the furnace cools the slag,
makes temperature control difficult and oxidizes carbon in the bath to form
3-7
-------
Figure 3-3. Direct Evacuation Through Fourth Hole
carbon monoxide. As a result, direct evacuation systems are least applicable
to EAF's which pour high carbon alloys and certain other specialty iron and
steel. Direct evacuation is more common with steel making EAF's than with
foundry furnaces. It is rarely used, if at all, with iron foundry EAF's.
Formation of excessive carbon monoxide, which can occur with direct
evacuation systems, also causes some potential for explosions downstream in
the exhaust duct work. This potential problem is usually eliminated by leav-
ing gaps between the furnace and fourth-hole elbow or between the elbow and
exhaust duct. This allows introduction of outside air to the exhaust. Because
of prevailing high temperatures and excess air, carbon monoxide is readily
oxidized to carbon dioxide. Inflow of air also cools the exhaust, reducing
deterioration problems in downstream duct work from high temperatures.
Direct evacuation is generally not applicable to iron-producing EAF's
because the inflow of fresh air to the furnace causes excessive oxidation of
carbon, and it is difficult to maintain adequate carbon in the melt. On
small steel furnaces, direct evacuation is not always a viable option because
3-8
-------
of (1) lack of space for fourth hole in furnace roof and (2) pressure fluc-
tuations in furnace, which are too rapid for automatic control of dampers in
the exhaust duct.
The direct evacuation system is probably the device most easily retro-
fitted to an existing furnace. However, problems reported concerning some
EAF's which were retrofitted with direct evacuation include: additional
weight on the furnace roof, excessive deterioration of shell refractories and
roofs, water cooling problems and clearance problems with roof rotation for
charging.
Typically, exhaust flow rates for direct evacuation are 25 percent
of those required for comparable fume control with side draft hoods. Table 3-1
shows flow rates ranging from 3.2 m3/sec (7,000 acfm) for the 3.9 Mg/hr fur-
nace to about 12.5 m3/sec (26,000 acfm) for the large 22.7 Mg/hr furnace.
Because the exhaust gas temperature is considerably greater with direct evac-
uation systems, compared to side draft hoods, substantial dilution air is
normally introduced to cool gases prior to the gas cleaning device (baghouse).
Particulate removal efficiency is comparable to side draft hoods, ranging
from 90 to 100 percent, with a typical maximum level of 99 percent for well-
designed systems.
3.3 EVACUATION OF CHARGING EMISSIONS
EAF's are normally charged by removing the entire roof-electrode-fume
hood assembly and dropping scrap into the furnace with drop-bottom charging
buckets. As scrap contacts the hot furnace, fumes consisting of hydrocarbon
vapors and soot (from entrained oil), iron oxides (from splashing and oxida-
tion of iron) , and smoke (from dirt on the scrap) are generated. Charging
emissions have traditionally been vented to the atmosphere through roof
3-9
-------
monitors, since conventional fume collection devices only collect melting
emissions. However, because charging and tapping often result in substantial
visible emissions, it is becoming more common for regulatory agencies to re-
quire control of charging and/or tapping operations.
There are four basic techniques applicable for collecting charging emis-
sions:
Canopy hoods
Building evacuation
Furnace enclosures
Specially designed, "close capture" hoods
Each technique also applies to control of tapping emissions, which is dis-
cussed in Section 3.4. Additional techniques are available for control of
charging emissions. For example, charging emissions can be reduced by use of
clean scrap. Although most foundries currently seek high quality scrap,
dirty scrap can be cleaned prior to charging by preheaters or a degreasing
process. Conceptual designs for collecting charging emissions include the
hooded charge bucket and closed charging systems, althogh these are not in
use at domestic foundries.
3.3.1 Canopy Hoods
The canopy hood is the most common device in current use for collecting
charging and tapping emissions at foundries. Located above the overhead
crane, canopies are normally operated only during charging and tapping, when
the melting collection system is inoperative. A typical canopy hood collector
is illustrated in Figure 3-4.
3-10
-------
u>
I
CANOPY / CROSS DRAFTS
Figure 3-4. Canopy Hood Using Building Roof as Part of the Canopy,
Combined with Direct Furnace Evacuation
-------
The configuration and proper location of a canopy is dependent mainly on
structural and geometric considerations within the shop. Clearance for over-
head cranes and furnace electrodes must be maintained and thus, the most
effective position, closely spaced above furnace electrodes, generally cannot
be attained. Rather, canopies are either suspended 7 to 13 meters above the
furnace, or attached directly to the shop roof. Umbrella-shaped hoods of a
diameter larger than the furnace are one design option, while other designs
incorporate the foundry roof and side walls. The canopy can be constructed in
sections with separate dampers to vary suction exerted by each section.
Dampers can then be preset or controlled by an operator to provide a greater
suction to areas which receive the most fume.
Because canopies are constructed some distance above the furnace to pro-
vide clearance for overhead cranes, exhaust flows must be high to ensure
effective capture of fumes. Although thermal currents from the hot furnace
help direct fumes upwards to the canopy, flow rates necessary for fume capture
are several times greater than that required for control of melting emissions.
Consequently, the size and costs of a final gas cleaning device (normally a
baghouse) are substantially increased over costs for melting control.
Effective fume capture is not always attained with use of a canopy hood.
As the furnace is charged, fumes are sometimes diverted away from the canopy
because of impingement on overhead cranes and the charge bucket. Another
problem is caused by cross drafts in the shop which have a pronounced, adverse
effect on canopy hood collection efficiency. Upward flow of the fume is easily
disrupted by drafts from openings along foundry walls and doors, passage of shop
vehicles, and even suction hoods which may ventilate other nearby foundry
processes. High pressure systems and low humidity tend to allow efficient
3-12
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upward flow of fume to the canopy. However, during periods of low pressure,
high humidity, or strong winds, thermal columns above the furnace may not be
sufficient to carry fumes directly into the canopy. For small furnaces, a
canopy hood is not generally as effective because there is less thermal up-
lift generated by the smaller furnace.
Several techniques have been used to reduce effects of cross-drafts and
improve upwards flow of fumes to the canopy. Many of these techniques are
more prevalent at large steel-making EAF's at the steel mill, since emissions
are usually greater than at smaller foundry EAF's. At foundries it is common
to provide scavenger openings (see Figure 3-4) immediately above the canopy
in the exhaust duct work to collect fumes which have escaped and accumulated
under the shop roof. Curtain walls constructed of sheet metal have been used
to screen sensitive portions of a steel-making furnace area from drafts and
improve upward flow of charging and tapping emissions.3 Another technique
recently applied to both foundry4 and steel-making5 EAF's is the use of an
air curtain. An upwards flow or curtain of air is directed around the furnace
to contain and help direct fumes to the canopy. Mobile air curtains have
provided an effective method for locating proper positions or counteracting
daily variations in cross draft flow patterns at a steel-making shop.6 Un-
fortunately, the air curtain often cannot completely overcome the force of
cross drafts.
Control of cross-drafts often involves reworking shop ventilation systems.
For example, an exhaust hood of a pouring line adjacent to a furnace may
create a negative pressure which impedes upwards flow of fume from the furnace.
At many foundries, the scrap handling area is adjacent to the furnace and has
large doors which open to the atmosphere. Influence of outside winds on
3-13
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canopy efficiency must be reduced by closing these and other openings in the
foundry walls.
Particulate collection and removal efficiency attainable with canopy hoods
were evaluated during a research and development program conducted by a large
British steel company.7 Canopy hood size and exhaust flow rates were optimized
in the development program, and it was determined that 90 to 100 percent of
charging and tapping emissions were collected under optimum conditions. However,
during periods of strong prevailing winds outside the shop, up to 30 percent of
charging and tapping emissions drifted away from the canopy. To control the
influence of cross-drafts deflecting the rising plume, vertical sheeting was
installed over the entire length of a four-furnace melt shop, roof vents were
blocked off, and doors fitted on large openings in the shop wall.
Table 3-2 summarizes exhaust flow rates and particulate removal effi-
ciencies for canopy hoods and other control techniques for charging (and tap-
ping) emissions. Exhaust requirements for canopies are high, ranging from about
65 m3/sec (140,000 acfm) for a 3.9 Mg/hr furnace to 81 m3/sec (172,000 acfm)
for the large 22.7 Mg/hr furnace. Larger furnaces require proportionally less
flow than the smaller because of the benefits of thermal uplift provided by the
larger heat source. Flowrates shown are averages of typical values since the
physical layout of a particular foundry dictates canopy location and size, and
also flowrates. Collection efficiency of the canopy is listed at 80 to 90
percent; with 80 percent considered a typical level because of potential for
fume deflection by cross-winds. Efficiency can be much lower for improperly de-
signed canopies, especially in shops which do not control cross-drafts.
3-14
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TABLE 3-2. TYPICAL EXHAUST FLOW RATES AND PARTICULATE REMOVAL EFFICIENCY OF CHARGING AND
TAPPING CONTROL DEVICES AT MODEL FOUNDRIES
Typical exhaust flow rate for model
furnaces in m3/sec
Model furnace size
1 rj
Canopy hoods, charge and tap1"
Building evacuation, charge and tap1'8
Furnace enclosure charge1
tap
Close capture hoods charge1
tap
Ladle pit enclosure, tap only1
3.9 Mg/hr
65.1
81.0
122.8
J
112.9
12.9
9.1 Mg/hr
73.2
91.5
25.6
19.8
19.8
22.7 Mg/hr
81.0
101
28.3
50.0
50.0
Particulate removal efficiency
(percent)
80-90
95-100
195-100
(90-95
J60-90
/60-90
90-100
Typical maximum
80*
99
99
90
80,
80f
99
Collection efficiency substantially reduced if cross-drafts are present in shop.
Tapping efficiency considerably reduced with increasing alloy additions to ladle; i.e., at steel furnaces.
-------
Retrofitting an existing furnace with canopy hoods sometimes requires
extensive structural modifications. Trusswork and roof beams must often be
relocated, reconstructed and/or strengthened to accommodate the canopy and
exhaust duct work. In some shops, there may not be enough clearance between
the crane and the roof, or the roof configuration itself may not be adaptable
to a canopy installation. Also, space must be provided for the baghouse
which will necessarily be of a large size to handle the high exhaust volume.
3.3.2 Complete Building Evacuation
Several large iron foundries operate ventilation systems which completely
evacuate the shop, exhausting fumes from charging, tapping and other foundry
operations to a gas cleaning device.4'9 Building evacuation systems are
similar to canopy hoods but operate at greater flow rates, exhausting fumes
which accumulate under the shop roof. Factors which influence installation
of building evacuation over other systems for control of charging and tapping
emissions are:
Insufficient space, or structural limitations to use of a canopy-hood
Need to collect other fugitive or miscellaneous emissions
A roof configuration well suited to complete evacuation. Often,
the roof can be modified to serve as a collection hood, as shown
previously in Figure 3-4
Desire to exhaust the entire foundry internal atmosphere to
reduce pollutant concentration for reasons of industrial hygiene
and also to reduce heat stress.
Major considerations in design of a building evacuation system are con-
trol of air flow patterns through the building and maintenance of an effective
flow rate. Ideally, floor level air inlets surround sources of heat and the
3-16
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fumes are exhausted to a central outlet located overhead in the shop roof.
However, compromises in the ideal situation are usually necessary because of
structural and shop operational constraints. Excessive turbulence and dead
zones must be avoided to ensure proper removal of fumes. Flow control is
enhanced by isolating emission sources with partitions constructed to provide
maximum feasible containment without interferring with foundry operations.
These concepts are illustrated in Figure 3-5.
Air velocity through inlet openings of the building must be adequate to
induce flow through proper locations of the shop. Louvers or vertical
traveling adjustable doors are sometimes used as inlet openings through
building external walls. Air outlets in the roof can be designed to avoid
the necessity for large evacuation hoods, relying on the building roof truss
area or plenum as a fume reservoir and collection chamber.
The volume of air typically withdrawn for building evacuation systems is
difficult to generalize because each foundry is of a different size and
building configuration. To maintain a clean internal atmosphere, about five
air changes per hour is a typical design factor at steel mills.*° Data de-
veloped for steel-making, EAF shops shows that typical building evacuation
systems evacuate about 25 percent more air than an efficient canopy hood.
This criterion was used for flow rates summarized in Table 3-2, 81 m3/sec
(170,000 acfm) for the small 3.9 Mg/hr furnace, ranging to 101 m3/sec
(214,000 acfm) for the large 22.7 Mg/hr furnace. Particulate collection
efficiency is listed in Table 3-2 as typically 99 percent, ranging from 95 to
100 percent, in recognition of the fact that a few small openings may exist
through which some emissions escape.
3-17
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///////// ROOFTOP EXHAUST DUCT
CO
I
oo
AIR INTAKE
OPENINGS
TO DUST
COLLECTOR
PARTITION
SHIELD AREA
FROM CROSS -
DRAFTS
rr
Figure 3-5. Design Aspects of Building Evacuation System
-------
There is a trend towards enclosing roof monitor vents to contain charging,
tapping and other fugitive emissions and avoid violation of visible emission
codes. A multiple, manifold-type exhaust system ducts contained fumes to the
gas cleaning device, normally a baghouse. These systems are not designed as
complete building evacuation systems, but are intended to simply remove fumes
which accumulate under the shop roof. In this manner, charging, tapping and
other fugitive furnace emissions are eliminated at an exhaust flow rate somewhat
less than complete building evacuation systems since the exhaust flow rate is
only adequate to remove accumulated fumes, not to evacuate the entire building.
Although most emissions are collected and removed, a small amount will often
escape the foundry through open windows and doors. The new Michigan casting
facility of Ford Motor Company11 is an example of this type of charging (and
tapping)control.
3.3.3 Furnace Enclosure
A metal shell which completely encloses the furnace and tapping area can
effectively capture emissions from melting, charging, and tapping. A large
exhaust duct or hood near the enclosure top removes charging and melting emis-
sions while a separate, local hood contains tapping fumes. Tapping fumes are
collected by diverting exhaust flow from the enclosure to a local hood adjacent
to the ladle. Several pairs of sliding doors allow entry of the charge
bucket by conventional crane, and also provide for slagging, chemical addition
and oxygen lancing.
The first domestic application of the shell enclosure concept began opera-
tion in 1976 on two 60-ton capacity steel-making EAF's at the Lone Star Steel
Company, Lone Star, Texas. The furnaces are part of a new melt shop and each
furnace was enclosed as an economical alternative to canopy hoods for control
3-19
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of charging and tapping emissions. Furnace enclosures have not yet been
installed in foundries.
Furnace enclosures collect charging and tapping emissions with an air
volume 30 to 40 percent of that required by an efficient canopy hood, con-
siderably reducing both capital and operating costs for exhaust duct work,
fans and gas cleaning device. These savings are partially offset by the
greater capital cost of the enclosure, compared to canopy hoods or building
evacuation. Major factors which reduce effectiveness of a canopy hood,
namely, cross-drafts and diversion of fumes by the crane, are eliminated with
a shell enclosure. As a secondary benefit, furnace noise is somewhat reduced
outside the enclosure.
Figure 3-6 shows the basic design at Lone Star Steel Co., and pertinent
design parameters are summarized in Table 3-3. Constructed of riveted steel
plates, each enclosure is a cube with a domed or rounded top measuring 44 feet
on edge. The enclosures contain the minimum volume which provides clearance
for furnace roof removal during charging and for furnace electrodes when
tilted for a tap. Pneumatic cylinders operate large vertical doors on the
front of the enclosure, and an electric motor operates a segmental, horizontal,
cable-guided top door to allow furnace charging by conventional crane.
Smaller vertical doors at rear of enclosure allow access for oxygen lancing,
slagging and chemical additions.
When charging, the crane operator has a line of sight to the furnace
through the top enclosure doors. Final positioning of the charge bucket is
aided by radio contact with a worker inside the enclosure. When a charge is
dropped into the furnace, the front, charge doors are closed but the top,
horizontal door remains open. A fan-type air curtain directs fumes past the
3-20
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FRONT CHARGE
DOOMS
REAR SLA*
ond Of
LANCC DOORS
.ALLOY ADDITION
CHUTE EXTENDS
THROUGH ENCLOSURE
SCRUBBER O
SHOP FLOOR
LL
44'
FAN TO CONTNl
CHARGING
runes
AREA OF
MAJOR TAP
FUME <%.
ESCAPE ^
! LADLE
-EXHAUST DUCT FOR TAPPING,
TO SCRUBBER
U U
FltOHT VIEW
Figure 3-6. Sketch of Furnace Enclosure Design at Lone Star Steel Co.
3-21
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TABLE 3-3. DESIGN DATA FOR LONE STAR STEEL COMPANY FURNACE ENCLOSURE12
I. Steel-Making Facilities
Two 60 ton Whiting EAF's, each enclosed in
114,000 cu ft enclosure. Enclosures measure
44 feet on edge; furnaces are 20 feet above
ground level. Average 2-1/2 hours per heat.
II. Gas Flow Rate, per Enclosure
Charge, melt, refine and tap
35 to 42 m3/sec
(75,000 to 90,000 afcm)
III. Exhaust Gas Temperatures
A. Charge, melt and refine
80°C (175°F)
B. Tap
120°C (250°F)
IV. Dust Concentration Measured by Lone Star Steel Co.
(EPA Method 5)
A. Inlet to Steam-Hydro Scrubber
1.0 gr/scf
B. Outlet from Steam-Hydro Scrubber
0.0045 gr/scf
V. Suction Required
Inlet to scrubber units
7.5 in. w.g.
VI. Capital Cost
A. Enclosures, ducting, and auxiliary equipment,
excluding gas cleaning device, $900,000 per
enclosure
B. Steam-Hydro gas cleaning units only: $200,000
per enclosure.*
*
Utilized existing waste heat boiler and slurry treatment facilities.
3-22
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open top doors to the exhaust duct. During melting, doors are closed and fumes
are exhausted from the enclosure by a large rectangular exhaust duct located
1.2m (4 ft) below the enclosure top, above the furnace. Between 75,000 and
90,000 afcm is withdrawn from each enclosure by suction developed by Lone Star's
proprietary Steam-Hydro scrubber which cleans furnace exhaust. Slagging,
chemical additions and oxygen lancing are conducted through a third set of
doors at the furnace rear. The furnace is tapped in a ladle which is placed
on a rail car by the overhead crane, then rolled into position under the en-
closure. Tapping fumes are collected by diverting flow from the main exhaust
duct to a hood which is adjacent to the ladle. Both furnaces and enclosures
rest on a platform about 6.3m (20 ft) above the melt shop floor. This provides
room for the tapping ladle car and also provides air flow from underneath the
furnaces to effectively carry fumes to the main exhaust duct.
Lone Star Steel has encountered no major problems in using the enclosures.
Almost all charging emissions are contained by the enclosure and exhausted
from the shop. Presently, only clean, in-plant steel scrap is used as charge.
Lone Star has run trial heats charging No. 2 bundles (autobodies processed
through a compactor). Because of combustion of contaminating oil and organic
matter, flames from the hot furnace reached to the top of the enclosure. Lone
Star indicated that the trial runs showed additional enclosure height would
be necessary if dirty scrap were to be used routinely. When clean scrap is
charged, roughly 95 to 99 percent of charging emissions appear to be collected.
This estimate is based on observations of engineers who visited the plant on
behalf of EPA, and on statements of plant engineers, and the local air pollu-
tion control agency.12
3-23
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Melting emissions are also effectively contained by the enclosures. When
viewing the enclosure interior during melting, fumes appear to flow directly
upwards in a column towards the exhaust duct near the top. The space around
the inside perimeter of the enclosure is relatively free from fume, as the
rising column does not fill the entire enclosure. Flames and fumes violently
escape furnace electrode holes during melting. The absence of visible emis-
sions from the top of the enclosure suggests that almost 100 percent of melt-
ing emissions are captured. Opening of rear enclosure doors for oxygen lancing
or slagging did not noticeably affect the uniform flow of melting fumes up-
wards to the exhaust duct.12
Fumes generating during tapping appear considerably greater in magnitude
than charging emissions. A tap lasts 6 to 8 minutes. Alloys are continously
added to the ladle through a special chute extending through the enclosure
side. Tapping fumes are drawn laterally into a rectangular side draft hood
adjacent to the ladle top. Most fume was drawn into the hood, as the entire
75,000 to 90,000 cfm exhaust rate is diverted from the enclosure to the tap
hood, and capture velocity is quite high. Roughly, 10 percent of tapping
fumes escape collection, exiting the enclosure primarily through the alloy
addition chute, and to a lesser degree, through enclosure doors. Fumes es-
caping the alloy addition chute dissipate substantially by the time they
reach the melt shop roof. Lone Star's smoke observers have read opacity of
fumes escaping the roof monitors ranging from 0 to 40 percent during tapping,
averaging about 8 percent.12
Another steel-making EAF enclosure was scheduled for operation in Europe
in 1977. This system, shown in Figure 3-7, is offered by the Krupp Co. It re-
lies on an enclosure somewhat larger than at Lone Star Steel. A direct roof
3-24
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OJ
tsi
Ul
DIRECT .c-
EVACUATION
CHEMICAL ADDITION
CHUTE
Figure 3-7. Krupp Furnace, Sequence of Events During Charging
-------
evacuation tap supplements fume control during melting. Instead of sliding
doors, a section of the enclosure side wall moves horizontally to allow pas-
sage of a specially-designed charging crane. The crane is designed with a
section which seals the enclosure during charging (see Figure 3-7). Proce-
dures for tapping and alloy additions are similar to methods used at Lone Star.
Available data indicates that the enclosure volume for a 128 megagram (140 ton)
steel EAF is 11,000 m3 and enclosure exhaust rate is 135 m3/s (290,000 afctn)
during charging and tapping and 105 m3/s (226,000 acfm) during melting. No
other details are readily available on the Krupp design.
While the enclosure concept appears to be a very effective method for
capturing furnace emissions with minimum exhaust volume, it would either be
difficult to retrofit this technology to existing furnaces or the effective-
ness of the system would be reduced for several reasons:
Lack of adequate space at existing furnaces may preclude
installation of the enclosure, which is larger than the
furnace. Adjacent walls, furnaces or foundry process equipment
would, in many cases, interfere with enclosure placement.
At most foundries, the furnace rests on the shop floor and
the tapping pit is located below grade. Tapping pits may
be too small to accommodate the rail car necessary for carry-
in the ladle under the enclosure.
Where existing furnaces rest on the shop floor, airflow through
the bottom of the enclosure cannot be optimized as in the case
of Lone Star Steel where the furnaces are 6 meters above the
shop floor.
3-26
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Location and configuration of charging cranes may not be
amenable to operating around and within the enclosure.
Slagging, alloy addition and oxygen lancing procedures must
be somewhat modified with use of an enclosure, but this is
of minor importance.
3.3.4 Close Capture Hoods
The "close capture" concept for controlling charging, melting and tapping
emissions, as supplied by the Hawley Manufacturing Company, is illustrated
in Figure 3-8.13 Melting and refining emissions are evacuated by a circular
hood which completely encompasses the electrodes, unlike conventional side
draft hoods which are open on one side. This allows improved collection of
fumes with minimum exhaust volumes. Capture of charging emissions is accom-
plished by an annular hood which encompasses the furnace roof ring during
charging. The charging hood is designed to rotate onto the furnace during a
charge, and then rotate back to the furnace side during melting. Charging
fumes are withdrawn radially through slots in the inner hood circumference;
the slots serve to increase capture velocity and improve fume collection.
When charging, dampers in the exhaust duct work divert the exhaust flow from
the circular hoods to the charge hood.
Tapping emissions are collected by enclosing the tap spout with an in-
verted u-shaped hood which is exhausted through one of the vertical sides.
When charging or tapping, dampers divert most of the exhaust flow from the
electrode hood to the charge or tapping hoods. A telescoping joint allows
the electrode hoods to withdraw a moderate amount of fume from the furnace
during tapping, supplementing the tapping hood exhaust. The tap hood only
encloses the. furnace tap spout and a portion of the ladle, as opposed to
3-27
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HOOD EXHAUSTING
SLAG DOOR
ELECTRODE AREA
ENCLOSED WITH
CIRCULAR HOOD
SWIVEL JOINT
HOOD ENCLOSING
TAP SPOUT
TO
BAGHOUSE
ANNULAR RING HOOD
SWINGS OVER
FURNACE TOP
DURING CHARGING
ANNULAR RING HOOO
IN PLACE TO COLLECT
CHARGING EMISSIONS
HOOD ENCLOSING
TAP SPOUT
BAGHOUSE
Figure 3-8. Hawley Close Capture Hoods
3-28
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other designs (furnace enclosure, ladle pit enclosure) which enclose the
entire ladle for more complete fume containment. A small, separate hood is
also provided for the slag door.
The advantage of the close capture design is that control of charging and
tapping are provided at an exhaust flow rate much less than for canopy hoods
or furnace enclosures. This significantly reduces the quantity of exhaust gas
delivered to the particulate control device, thus reducing costs of gas
cleaning. Also, the close capture hoods are simpler and considerably less
expensive to install than a furnace enclosure or canopy hood. The disadvantage
is the complete control of charging and tapping may not always be provided
because the charge/tap hoods do not completely enclose emission sources.
Exhaust flow rates of the close capture design are comparable to those
used with conventional side draft hoods. For example, a 3.9 Mg/hr model
furnace would require about 12.9 m3/sec (27,400 acfm) for the close capture
hoods, contrasting sharply with 65 m3/sec for canopy hoods and 23 m3/sec for
a furnace enclosure. The manufacturer guarantees total particulate removals
of 100 percent for melting and 80 percent for charging and tapping (of iron).
However, these efficiencies have not been verified by EPA. As alloys are
added to the ladle (i.e., steel foundries), tapping control efficiency is
expected to be substantially reduced. Control of backcharging is also likely
to be less than 80 percent.
The close capture design is applicable to most new foundries where the
furnace area can be designed to accomodate the hoods. The close capture
design has recently been applied to several foundries. At one particular
steel foundry, visited by representatives of EPA,111 there was not enough clear-
ranee between the furnace and the transformer room wall to allow employment
3-29
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of the annular charging ring. In this retrofit case, only a partial charging
hood could be used, mounted to the furnace shell to partially encompass
charging emissions. Collection efficiency of charging emissions was observed
to be substantially lower than that expected from the complete charging hood.
Many existing foundries will likely have similar space restrictions which
limit control options such as the Hawley design (and also furnace enclosures,
and certain other options).
3.3.5 Control of Charging Emissions by Use of Clean_Scrap
Charging clean scrap to an EAF substantially reduces charging emissions.
When dirty scrap contacts a hot furnace, oil and other volatile impurities
combust, releasing dense clouds of soot and smoke. .Oily scrap can also cause
premature roof failure around electrode ports, damage dust evacuation hooding
and ducts and also clog or "blind" a fabric filter control device. Use of
dirty, substandard scrap has been estimated to increase overall furnace emis-
sions by up to 100 percent - although quantitative test data for charging
emissions are generally not available.15 Contact with several state and
local air pollution agencies indicated that quite often, foundries are re-
quired to use a clean scrap to control charging emissions.16 For example, the
Los Angeles County Air Pollution control district issues operating permits
to furnaces which use clean scrap as the method to control charging emissions.
No visible emissions are detected at roof vents above the furnace during
charging.
3.3.6 Preheating or Degreasing Scrap _tp Reduce Charging Emissions
Charge preheaters are standard equipment on induction furnaces for
cleaning the charge, removing water, and avoiding operating problems of charg-
ing dirty scrap. Few preheaters are used in EAF foundries although they
3-30
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have been used overseas as a method for producing clean scrap for reduction
of charging emissions on electric arc furnaces in foundries.
The most efficient preheater is the conveyor type which applies a fossil
fuel flame to the scrap under a fume collection hood. The conveyor typically
discharges clean, hot scrap to a charge bucket although a few systems have
been designed to charge directly to the induction furnace.17'18 Preheating
in a special charge-preheat bucket has been used but does not result in uni-
form preheating. Ultra hot, intense flame jets must be directed into the
scrap for certain periods to heat the entire charge, increasing the danger of
over-oxidation of thin pieces of scrap. Excessively oxidized scrap requires
considerably more energy for melting.
Some preheaters are designed with a secondary combustion chamber which
acts as an afterburner for controlling emissions from the preheater. One
manufacturer of preheaters for induction furnaces reports that air pollution
codes of Los Angeles County are met by a local facility using this type of
preheater. Emission data for preheaters is not readily available.17
Preheaters used for induction furnaces reportedly reduce overall power
costs for melting because the preheaters more efficiently heat the metal, and
costs for fossil fuel have traditionally been less than electricity. Net
energy savings with preheaters have been quoted on the order of 75 kWh per
ton of metal,17'18 compared to normal melt requirements of about 500 kWh/ton.
Application of preheaters to EAF's will likely be severely limited by
fuel shortages. Natural gas supplies to industry were severely reduced this
past year, and many industries expect shortages throughout the next few years.
Other gases, such as producer gas, if available, could be used also.
3-31
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Retrofitting existing EAF's with a conveyor-type preheater could require sub-
stantial reconstruction of scrap bins and scrap bucket handling systems.
A degreasing process to remove oil and dirt from the charge can also be
used to reduce emissions caused by dirty scrap. Degreasing operations involve
washing scrap in a tank with either a solvent or detergent and water. Exces-
sive amounts of oil may be removed from turnings and other machining wastes
by centrifugirg which typically reduces oil content to about 2 percent.
Degreasing has been traditionally used to remove oils from valuable scrap
such as brass, bronze and copper, but is not usually applied to ferrous scrap
at the foundry. Rather, degreasing is typically used by scrap dealers, as in
the case of motor blocks which are often crushed and cleaned by the scrap
dealer, then sold to the foundry.
Problems with use of degreasing at foundries center about disposal of
solvent residues and air emissions of hydrocarbons from the solvents. About
2 to 5 pounds of solvent per ton of charge cleaned requires disposal, when
boring and turnings are the charge material. Of more importance, the mass
of solvent emissions from the degreaser has been estimated to exceed emis-
sions which would be generated by charging of dirty scrap.1 Thus, degreasing
is not considered an environmentally acceptable option for reducing charging
emissions from unclean scrap.
3.3.7 Briquetting to Reduce Charging Emissions
In many foundries, particularly steel foundries, up to about 20 percent
of each charge is "swarf" - turnings and borings produced by machining of
castings. The swarf itself is readily oxidized upon charging, and also con-
tains oils from machining. Thus, charging swarf to the EAF results in greater
generation of emissions, compared to charging of heavier scrap pieces. A
3-32
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briquetter can be used to compress the swarf into a more solid form which
serves to minimize oxidation of metal during charging, thus reducing charging
emissions. Briquetters are not common at foundries, and no data is available
to quantitatively indicate potential reduction in charging emissions.
3.3.8 The Brusa Closed Charging System
The Brusa closed charging system, illustrated in Figure 3-9, has been
operating on a steel-making furnace in Italy for several years.19'2^ Exhaust
gases from the hot furnace are vented through a rotary kiln or drum. Charge
material is fed continuously down through the kiln, into the furnace, and is
preheated by furnace gases to about 1000°C. Volatile matter entrained in the
charge is thus oxidized, and withdrawn at the top of the kiln along with
furnace exhaust gases.
This system has the advantages of heat recovery, and containment of
charging emissions in a fashion allowing for simple collection and ducting to
a control device. However, this type of steel-making is the continuous pro-
cess, where charge material is continuously added, and the furnace frequently
tapped. There is a trend towards this type of operation in steel-making fur-
naces, but only one domestic foundry EAF is known to use continuous charging.
The Brusa and other conceptual designs for closed charging systems require
small-sized scrap in order to pass through the enclosed conveyor system.
3.3.9 Hooded Charge Bucket
The hooded charge bucket, illustrated in Figure 3-10, is designed to fit
snugly over the top of the furnace during charging. Charging emissions pass
3-33
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3535S321S
2i!!j|£89O!Z?6%CI9!%£5£^%S^3^^
Figure 3-9. The Brusa Charging and Preheating System
-------
u>
I
u>
UI
COVER
TO CONTROL DEVICE
Figure 3-10. Hooded Charge Bucket
-------
upwards through the bucket and into an attached hood. The majority of fumes
evolved from charging would be collected and exhaust volumes would be sub-
stantially lower than with a canopy collector. While hooded charge buckets
are commercially available,21 none are known to be operating at present.
A similar approach under study in Europe is the Marchand design, a local,
mobile hood which can be clamped above the charge bucket, or suspended over the
furnace by overhead crane, shown in Figure 3-11. This system is very similar
in function to a canopy, but is smaller in size and can be lowered close to the
furnace, minimizing air volumes necessary to effectively capture the fumes.
This variation of the hooded charge bucket concept has not been applied to
foundry EAF's in this country.
3.4 COLLECTION OF TAPPING EMISSIONS
The EAF is tapped by raising the electrodes, tilting the entire furnace
up to 45°, and transferring the melt to a ladle through the pouring spout.
Sparks and fumes of molten metal particles are ejected from the flowing metal.
Alloys are usually added to the ladle, and the ensuing reaction substantially
increases tapping emissions.
Some of the fume collection systems described previously for control of
charging emissions; i.e., canopy hoods, building evacuation, furnace enclosures
and close capture hoods, also collect tapping emissions. At certain foundries,
it may be desirable to control only tapping emissions. Tapping emissions can
be collected by enclosing and exhausting the ladle pit, or by use of a tapping
hood. Armco Steel Corporation holds a U.S. patent on a tapping pit enclosure,
while several designs for tapping hoods have been used at steel-making furnaces.
These tapping control systems are discussed below in more detail.
3-36
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DESIGN I
DESIGN 2
TO CONTROL DEVICE
TO CONTROL DEVICE
SMOKE CAPTURE
BELL
CHARGING BUCKET
ELECTRIC ARC
FURNACE
Figure 3-11. Marchand Design for Charging Emission Control
-------
3.4.1 Armco Steel Tapping Pit Design
Armco Steel Corporation was granted a U.S. patent22 for the tapping pit
enclosure shown in Figure 3-12. In this relatively simple design, the ladle
is placed under the furnace in a tapping pit by conventional overhead crane.
A powered, removable cover effectively seals the tapping pit after the crane
is retracted. Molten metal flows from a short spout in the furnace to a
launder, or chute which extends through a side wall of the ladle pit. An
exhaust duct near the top of the pit withdraws tapping fumes to a gas cleaning
device.
Armco Steel Corporation uses the ladle pit enclosure design at the
Torrance, California steel-making plant. The exhaust flow which evacuates the
furnace during melting is diverted to the ladle enclosure, and this provides
a high capture velocity to remove tapping fumes. (Exhaust flow rates are thus
comparable to those representative of side draft hoods.) The enclosure is
designed to minimize openings through which fumes can escape and high partic-
ulate removals would be anticipated, about 90 to 100 percent, with typical
optimum performance of 99 percent. While this technology can be easily de-
signed into a new melt shop, retrofitting existing furnaces will depend largely
on available space in the tapping area. At many shops there may be clearance
problems when the tapping pit roof is retracted for ladle removal.
3.4.2 Hoods for Control of Tapping
Small umbrella-shaped hoods located immediately above the ladle can col-
lect tapping emissions from the ladle area. This type of tapping hood is
sometimes used with steel-making EAF's, but not at foundries. Such a design
could be employed more frequently at foundries where tapping control is
necessary.
3-38
-------
TO CONTROL
DEVICE
Figure 3-12. Armco Steel Corporation Design for Tapping Pit Enclosure
3-39
-------
There are several approaches to designing a tapping hood. Figure 3-13
shows one technique where a tapping ladle car receives the ladle by overhead
crane, then Is pushed into position underneath a permanent tapping enclosure.
Such a system is most amenable to new foundries, as space limitations will
often limit retrofit potential. Another concept, shown in Figure 3-14, in-
volves a ladle placed in a tapping pit. Further, as shown, a two-piece hood
mounted on a track is placed over the ladle, around the crane cables. Another
design calls for removing the crane and placing a hood into position over the
ladle. Flexible or easily matched duct work connections are required for
both designs. In general, the hood systems are somewhat more complicated
than the enclosed ladle pit (Armco Steel Corp. design), but there may be cases
where a hood is the best approach when local control of tapping is necessary.
Particulate removal efficiency of this type of hood at foundries is not known,
but high collection efficiencies would be expected for properly designed hoods.
3.5 GAS CLEANING DEVICES
While each major gas cleaning device - fabric filter, wet scrubber, and
electrostatic precipitator (ESP) has been applied to foundry emissions to some
extent, virtually all foundry EAF's in the U.S. use fabric filters. Fabric
filters use considerably less power than scrubbers, are normally more efficient
collectors of fine particles characteristic of EAF fume, and also collect dust
in a dry form which is readily disposed of. Scrubbers produce wastewater
which must be treated prior to recirculation to scrubbing units. Electrostatic
precipitators have received only limited application to EAF's, and mostly in
other countries. Recent improvements in precipitator collection efficiency
may increase interest in the U.S., but relatively high installation costs will
likely preclude common use on electric arc furnaces.
3-40
-------
U>
EVENTUAL DUCT
CONNECTION TO
EXISTING CONTROL
DEVICE
Figure 3-13. Ladle Car and Ladle Enclosure by Marchand
-------
CONNECTING DUCT TO CONTROL DEVICE
t
u>
JN
N5
MOVEMENT OF THE HOOD HALVES
/ (ON TRACKS)
Figure 3-14. Mobile Tapping Hoods
-------
3.5.1 Fabric Filters
Exhaust gas from the EAF contains fine participates dispersed in a gas
stream that changes considerably in temperature, dust concentration and volume
during the various furnace phases. Fabric filter collectors (baghouses) are
regarded as the most versatile and efficient device for cleaning these fumes,
because they are relatively insensitive to process variations. Baghouses can
be operated under positive or negative pressure and are cleaned intermittently
by shaking, reverse air flow or pulse jet mechanisms. Typical filter media
used for bag construction includes woven or felted glass, Dacron or Orion and
other synthetic fibers.
Positive pressure baghouses force exhaust gas through the bags using a
fan placed between the fume collection duct and the baghouse. Maintenance
and bag inspection is easier than negative pressure units, as the baghouse is
not airtight and can be entered while in service. Dirty gas enters the inside
of each bag, is filtered through the cloth, then vented to the atmosphere
through louvers or vents along the top of each compartment. New baghouses
installed on EAF's tend to be the pressure type because of lower capital costs
and simple inspection procedures for detecting damaged bags. With suction or
negative pressure-type baghouses, a fan on the clean air side of the baghouse
pulls air through the bags. Bag compartments must be kept airtight, and thus
inspection for defective bags requires the compartment to be taken off line.
Suction baghouses usually require less fan maintenance, and less operating
horsepower than the pressure type.
Fabric filter bags periodically become clogged with a dust cake and
require cleaning to avoid excessive pressure loss. So-called intermittent
systems are designed to run without cleaning until the end of a furnace heat,
3-43
-------
at which time flow stops and the bags can be manually shaken. Intermittent
baghouses generally cost less than, and are easier to maintain than the auto-
matic continuous service.baghouse. The intermittent filter is most appli-
cable to small single furnace shops where there is adequate time between heats
to manually clean the filter.
Automatic cleaning baghouses are much more common than intermittent sys-
tems as they are capable of continuous, unattended service, and precise con-
trol can be maintained over pressure loss and thus fume capture efficiency.
Cleaning methods in common use are: mechanical shaking, reversing the air
flow, and pulse jet mechanisms, all of which dislodge collected particles
from the bags to a hopper located underneath.
3.5.2 Wet Scrubbers
Wet scrubbers mix and entrain particulates in the exhaust stream with
water and collect dust laden water droplets by inertial mechanisms. There
are two basic scrubber types - wet impingement and venturi. In a wet impinge-
ment scrubber, furnace exhaust gas enters through the scrubber bottom, is
cooled in a water spray zone, and passes through one or more impingement
baffles which separate dust laden water droplets from the gas stream. In a
venturi scrubber, pressurized nozzles inject a water spray into the venturi
section. Intense turbulence within the venturi constriction causes entrain-
ment of particulates into the water droplets. The water-dust mixture is
removed from the gas stream both within the venturi section itself and in a
following cyclone separator. For either scrubber type, collection efficiency
can approach 98 to 99 percent, but it is dependent on pressure drop (or energy
expended) in the scrubbing (venturi) section.
3-44
-------
Venturi scrubbers are commonly used with cupolas and steel-making basic
oxygen and electric arc furnaces overseas, but there are no known installations
on iron or steel foundry EAF's in the U.S.8 Fabric filters are preferred over
scrubbers for several reasons. Although installation costs and space require-
ments for the scrubber are somewhat lower, power costs are high, especially
for high efficiency scrubbers which operate at high pressure drops. Disposal
of scrubber wastewater requires water treatment and/or water recirculation
systems at the plant. Most importantly, wet scrubbers are generally not as
efficient as baghouses for collecting fine particles generated by the EAF.8
Because of low capital costs, and low space requirements, high-efficiency
scrubbers may be a useful control option for existing EAF's in areas of the
country with low power costs.
There is one commercially available high energy scrubber which has been
shown capable of meeting stringent concentration standards for an EAF. The
Steam-Hydro scrubber (Lone Star Steel Company) achieves high removal effi-
ciency on submicron particles by means of steam injected at supersonic velocity
in a mixing section. This unit was designed to operate with waste process
heat from an integrated iron and steel mill. Where sufficient waste heat Is
available, this scrubber appears quite economical as compared to fabric fil-
ters. However, in a foundry with only an electric arc furnace, waste heat
from the EAF alone is sufficient to provide only a portion of the required
energy.1? An auxiliary fan must provide the remainder, about twice as much
energy as a fabric filter system. Maintenance and capital costs are less for
the scrubber, and this scrubber may be one alternative to the baghouse for
efficient collection of the fine particulates from the EAF.
3-45
-------
3.5.3 Electrostatic Precipitation
Electrostatic precipitators (ESP's) operate by electrically charging
partlculute matter and collecting charged particles on oppositely charged
plates by coulombic attraction forces. The plates which collect particulates
are periodically cleaned by mechanically shaking with hammers called rappers,
or by flushing with water. ESP's are very efficient collectors of particles
larger than several microns, but collection efficiency has traditionally
dropped markedly for smaller particles. However, recent developments in ESP
technology have improved performance for the smaller particulates. Successful
ESP operation is strongly dependent on the electrical resistivity of the par-
ticles. Dusts from metallurgical processes must sometimes be wetted with water
to decrease resistivity to an acceptable range.23
Installed costs for ESP's are somewhat greater compared to fabric filters
while energy consumption is comparable for the two devices. Baghouse main-
tenance requires periodic bag replacement, but baghouses can normally operate
continuously. ESP's, however, periodically require a certain amount of down-
time for maintenance purposes. ESP's are often used in the control of
particulates from basic oxygen steel-making furnaces, but no ESP's are
currently in operation on domestic foundry EAF's.
3.5.4 Comparison of Particulate Removal Efficiency of Gas Cleaning Devices
Since virtually all foundry EAF's are controlled by fabric filters, there
is a lack of performance data for scrubbers and ESP's. Particulate emissions
from the EAF are predominately less than 1 micron in size and fabric filters
are generally recognized as the most efficient collectors of submicron
particulates.8
3-46
-------
Based on EPA test data presented in Section 3.6 and standard emission
factors, particulate removal efficiency for properly designed and operated
fabric filters is 99.5 percent or better, with effluent concentrations of
12 mg/dsm3 (0.005 gr/dscf) or better. The technical literature confirms this
efficiency.8'23'24 Wet scrubbers can, reportedly, be designed for 98 to 99
percent removal of EAF dusts, with effluent concentrations of about 46 mg/dsm3
(0.02 gr/dscf).8 However, other references indicate that scrubber performance
on submicron dusts from steel mills is 95 to 98 percent, for a scrubber with a
60-inch pressure drop (fairly high).
ESP efficiency on submicron metallurgical dusts is reported by one ref-
erence as 95 percent. Recent data reported for a large steel-making EAF
showed effluent concentrations of 69 mg/dsm3 (0.03 gr/dscf) are obtainable
with ESP's,25 and other data shows ESP's at steel mill EAF's capable of
6 mg/dsm3 (0.0025 gr/dscf).
3.6 SUMMARY OF TEST DATA FOR PARTICULATE EMISSIONS FROM FABRIC FILTERS AT
IRON AND STEEL FOUNDRY ELECTRIC ARC FURNACES
3.6.1 Test Data for EAF's Producing Iron
EPA obtained data from six iron foundry EAF"a to establish typical levels
of control capable by fabric filtration. Test data from these furnaces are
summarized in Figure 3-15. All furnaces were fitted with side draft hoods,
except at Foundry C which has roof hoods for control of melting emissions.
Figure 3-15 indicates average emissions ranging from 8.7 to 23 mg/dsm3 (0.0038
to 0.010 gr/dscf) for five of the tested furnaces. However, Furnace C showed
average grain loadings of 48 mg/dsm3. This is a foundry with a manually
cleaned baghouse and carbon black injection to the furnace. A detailed summary
of these test results appear in Appendix A-l.
3-47
-------
0.000 r
0.028
O.O20
0.015
-*;
O.OIO
* 0.009
* O.OO8
-------
Opacity readings were made on both the baghouse stack outlet and foundry
roof monitors above the furnaces. Stack opacity generally ranged from 0 to
6 percent during melting with many of the readings showing 0 percent.
Facility C, which had emission concentrations considerably greater than the
other five, showed somewhat greater opacities, ranging up to 20 percent from
the stack. Visual observations of foundry roof vents during melting also in-
dicated an opacity ranging from 0 to 6 percent, but several foundries tested
averaged only a few percent opacity. A detailed summary of these opacity data
also appears in Appendix A-l.
3.6.2 Test Data for EAF's Producing Steel
Performance data for fabric filters operating on steel producing EAF's is
summarized in Figure 3-16. Data for plants A through F were obtained from
acceptance tests on newly installed baghouses. Plants A and B collect melting
emissions via side draft hoods while plants C through F rely on direct evacua-
tion roof taps. Plant G represents the typical level of performance for about
30 fabric filters installed on German EAF's producing steel castings. Plant H
shows data from a French control device manufacturer for baghouses on steel-
making furnaces the size of those used in foundries. Data from well controlled
EAF's at steel foundries in Italy are shown by Plant I. Emissions from a
recent domestic application of the close capture design on two small steel
foundry EAF's are shown by Plant J, the final data points.11* This facility
operates a shaker type baghouse with a low air-to-cloth ratio designed by a
major control device manufacturer. Emission data for steel foundries is re-
ported in Appendix A-2.
Opacity observations were also reported for several of these plants, and
EPA personnel observed two of the plants. No visible emissions from the
3-49
-------
KEY'
DATA BY ASME TEST METHOD
O DATA BY VDI TEST METHOD
C DATA BY EPA METHOD 5
I 1 AVERAGE OF TESTS
0.010
0.009
*_ 0.008
e
£ 0.007
|
to 0.006
y
O
(O
2 0.005
Ul
w 0.004
o 0.003
t-
£ 0.002
0.001
O
-
l
-
^^
- "
i
i t
!
i
" ^ «i
- H A jj
^ i ! ! i . ! ' .
B
1 1
U
i i i
0
-
0
1
H
O
p
b
i i
q
1
tJ
i
|
/
'
i-
-)
"
b
i
P
H-
J
(C
p,
1 1
A i
1
*T~I
i
i
i
o
i i
B C D E F G
PLANT DESIGNATION
H I
*
Grains/dscf x 2290 - mg/dsm3
Figure 3-16.
Summary of Reported Test Data for Baghouses on EAF's
Producing Steel
3-50
-------
baghouse were reported during normal operations, including oxygen lance periods.
The maximum stack opacity reportedly seldom exceeds 5 percent during normal
operating conditions. Opacity of baghouse exhaust at steel foundries is
typically lower than for iron because carbon black added to iron is not com-
pletely absorbed by the melt. Five to 40 percent of carbon added to iron
furnaces escapes in the furnace exhaust gas, and these extremely fine particles
also pass through the baghouse. This tends to create a more opaque plume at
iron foundries than at steel foundries.
Maximum opacity reported from roof vents and monitors is 16 percent at one
facility and 10 percent at another (6 minute average). These opacities are
highest during tapping, because of alloy addition to the ladle. Charging gen-
erated substantially less visible emissions at the shop roof while back-
charging emissions were between tapping and charging in magnitude. Because of
the quantity of alloys added to the ladle and the hotter tap temperature,
fugitives from a steel furnace are generally somewhat greater in magnitude
than those from iron production. The opacity data for steel foundries is
reported in Appendix A-3.
3.7 ACHIEVABLE LEVELS OF PARTICIPATE CONTROL
Based on the preceding analysis of particulate control devices, the
following control options were selected for further cost analysis in Section 4:
1. Control of melting emissions with side draft hoods (iron and
small steel furnaces) or direct evacuation (steel) and fabric
filtration.
2. Control of melting emissions with side draft hoods or direct
evacuation with wet scrubbing.
3-51
-------
3. Combination of item (1) and charging emission control by use
of clean scrap (scrap preheaters or briquettes).
4 Control of charging and melting with close capture hoods as
exemplified by the Hawley System, with fabric filtration.
5 Control of charging, melting and tapping with canopy hoods
and side draft hoods (iron, small steel furnaces) or direct
evacuation (larger steel furnaces).
6. Control of charging, melting, tapping and alloying with close
capture hoods (Hawley) and an enclosed ladle pit with fabric
filtration.
Total particulate removal efficiency of each control option is shown
in Table 3-4. The efficiency ratings are based on the particulate removal
efficiency of the control option under consideration, and emission factors
developed in Section 2. The melting and refining emission factors for iron
and steel production are 7.0 kg/Mg (14.0 Ib/ton) charged and 8.0 kg/Mg
(16.0 Ib/ton) charged, respectively. Charging and tapping emissions for both
iron and steel production are taken as an additional 10 percent of the melting
emission factor, when a typical dirty charge is used. For the clean charge
option, charging and tapping are considered to be 5 percent of total furnace
emissions. This approach is probably somewhat conservative for estimation of
charging and tapping emissions from iron production, since less alloying is
normally conducted in the ladle, and tapping emissions from iron production
are likely to be somewhat less than for steel. In preparing Table 3-4, bag-
house effluent grain loadings were taken to be 12 mg/dsm3 (0.0052 gr/dscf)
and scrubber effluent loadings at 46 mg/dsm3 at (0.02 gr/dscf).8 Total
particulate removal efficiency for side draft hoods fitted with baghouses,
3-52
-------
TABLE 3-4. SUMMARY OF TOTAL PARTICULATE REMOVAL EFFICIENCIES FOR CONTROL
OPTIONS AT IRON AND STEEL FOUNDRIES
u>
I
Ln
U>
*
Side draft hoods and baghouse
*
Side draft hoods and scrubber
Side draft hoods, preheater,
baghouse
Side draft hoods, briquetter,
baghouse
Close capture hoods, baghouse
Close capture hoods and ladle
enclosure , baghouse
*
Side draft hoods, canopy hood,
baghouse
. Emissions controlled
Melting
and Charging Tapping
refining
X
X
X X
X X
XXX
XXX
XXX
Total particulate
(percent)''"
Iron
87
87
92
92
96
97.5
95
removal
Steel
89.5
89.5
-
93
93
97.5
97
Direct evacuation used for medium and large steel furnaces.
Based on charging and tapping emissions equal to 10 percent of total melting and refining
emissions.
-------
compared to scrubbers, is shown to be equivalent. This reflects the fact that
most of the emissions result from charging and tapping, which are not controll*
ed. These uncollected emissions overshadow the fact that the fabric filter is
a more efficient gas cleaning device than the scrubber.
The total furnace enclosure is not considered in this analysis because of
a lack of data for evaluating control costs.
3-54
-------
REFERENCES
1. Georgieff, N. T. Emission Standards and Engineering Division, Office
of Air Quality Planning and Standards, U.S. Environmental Protection
Agency. Private Communication to GCA/Technology Division. March 1978.
2. Andrews, W. Wayne County Air Pollution Control Agency. Private Communi-
cation to GCA/Technology Division. March 1977.
i
3. Wood, R. M., Superintendent, Electric Furnace. Design Aspects of the
Ford Steel Division Electric Furnace Shop. Ford Motor Company, Dearborne,
Michigan. Unpublished paper. 1976.
4. Wright, Andrew. Puget Sound Air Pollution Control Agency, Seattle,
Washington. Private Communication to GCA/Technology Division.
April 1977.
5. Kaercher, L. T. and J. D. Sensenbaugh. Air Pollution Control for an
Electric Furnace Melt Shop. Iron and Steel Engineer. 51(5):47-51.
May 1974.
6. Bintzer, W. W. and R. A. Malehorn. Air Curtains on Electric Furnaces
at Lukens Steel Co. Iron and Steel Engineer. 53(7) :53-55. July 1976.
7. Flux, J. H. Containment of Melting Shop Roof Emissions in Electric Arc
Practice. Iron and Steelmaking (Quarterly), No. (3):121-133. 1974.
8. Davis, J. A., E. E. Fletcher, R. L. Wenk, and A. R. Elsea. Screening
Study on Cupolas and Electric Furnaces in Gray Iron Foundries. Final
Report. Battelle-Columbus Laboratories, Columbus, Ohio. Prepared for
U.S. Environmental Protection Agency, Office of Air Quality Planning,
Research Triangle Park, Durham, North Carolina. August 1975.
9. Hoenstine, J., Director, Anderson Air Pollution Control Agency, Anderson,
Indiana. Private Communication to GCA/Technology Division. March 1977.
10. Hansen, M. and H. Spitzer. Die Hallenlueftung in Huettenbetrieben,
Stahl und Eisen, 77(2):204-215. February 1957.
11. Aschinger, T., Director, Wayne County Air Pollution Control Agency,
Detroit, Michigan. Private Communication to GCA/Technology Division.
March 1977.
12. Lone Star Steel Company, Lone Star, Texas. Plant Visit by GCA/Technology
Division. September 1977.
13. U.S. Patent Number 3979551 Assigned to Hawley Manufacturing Corporation,
Indianapolis, Indiana.
14. Hensley Foundry Company, Dallas, Texas. Plant Visit by GCA/Technology
Division. September 1977.
3-55
-------
15. Coulter, R. S. Smoke, Dust, Fumes Closely Controlled in Electric
Furnaces. The Iron Age, 173(1):107-110. January 1954.
16. Telephone Survey, GCA/Technology Division. March 1977.
17. Sharpless, Ronald, Melting Systems, Inc., Burlington, New Jersey.
Private Communication toGCA/Technology Division. April 1977.
18. Spencer, P. L. The Case for Conveyor Preheating. Foundry Management
and Technology. 103(4):100. April 1975.
19. United States Patent Kemmetmueller, No. 3,645,515. February 29, 1972.
20. Neuman, F. et al. Dag BBC-Brusa-Verfahren Zum Schmelzen von Stahl.
Stahl und Eisen 95(l):16-23. January 8, 1975.
21. The Pennsylvania Engineering Corp. Brochure on Electric Arc Furnace
Co.ntrol.
22. U.S. Patent Number 3 791638, Assigned to Armco Steel Corp., Middletown,
Ohio. February 12, 1974.
23. Varga, J., et al. A System Analysis Study of the Integrated Iron and
Steel Industry. Battelle Memorial Institute, Columbus, Ohio. EPA
Publication Number APTD 1279. May 15, 1969.
24. Steel and the Environment: A Cost Impact Analysis. A Report to the
American Iron and Steel Institute by Arthur D. Little, Inc. Report Number
C-76482. May 1975.
25. Feazel, C. E., Editor. Proceedings: Particulate Collection Problems
Using ESP's in the Metallurgical Industry. EPA Publication Number
EPA-600/2-77-208. October 1977.
3-56
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4.0 COST ANALYSIS
4.1 INTRODUCTION
4.1.1 Control Options
This section presents cost estimates for several control options for reduc-
ing particulate emissions from electric arc furnaces (EAF's) at iron and steel
foundries. Cost data were developed for emission control of charging, melting,
tapping and alloying (steel foundries) during production of iron and steel.
Cost data were prepared for new facilities and existing (retrofitted) plants.
Emission control technology is almost identical for iron and steel pro-
ducing EAF's. Cost estimates were developed for the following fume collection
systems and gas cleaning devices.
1. Control of melting emissions with side draft hoods (iron and small
steel furnaces) or direct furnace evacuation (steel furnaces), and
fabric filtration.
2. Control of melting emissions with side draft hoods or direct
evacuation with wet scrubbing
3. Combination of item (1) and charging emission control by use
of clean scrap (scrap preheaters or briquettes).
4. Control of charging, and melting with close capture hoods as
exemplified by the Hawley System, with fabric filtration.
5. Control of charging, melting and tapping with canopy hoods and
side draft hoods (iron and small steel furnaces) or direct
evacuation (larger steel furnaces), with fabric filtration.
6. Control of charging, melting, tapping and alloying with close
capture hoods and an enclosed ladle pit, with fabric filtration.
The total furnace enclosure is not evaluated because of the lack of data;
however, capital costs appear somewhat greater than canopy hoods while operation
4-1
-------
costs should be low based on data from the only domestic enclosure in operation
(See Section 3.3.3).
4.1.2 Model Plants
To illustrate costs of each emission control option, parameters which
describe model, or typical EAF shops were developed for both gray iron and
steel foundries. These parameters include typical furnace size, number of
furnaces per shop and exhaust ventilation rates. Control costs are dependent
on a variety of factors and often vary appreciably for installing similar
equipment at different plants. Use of model plants is one method to establish
typical control costs so the various control options can be compared on a
common basis. These model plant parameters thus provide the basis for esti-
mating capital costs and annual costs of operating emission control equipment.
Control costs are based on model plant parameters which were developed in
Section 3 and shown here in Table 4-1. Two shop configurations are considered:
(1) single furnace shops and (2) two furnace shops. Three furnace sizes are
evaluated for each shop configuration. For the two-furnace shop, furnaces are
assumed to be equal in capacity and symmetrical with respect to shop layout,
although this does not always occur in actual practice.
Ventilation (exhaust) flow rates shown in Table 4-1 were used to size gas
cleaning equipment (baghouses, scrubbers) required for each control option.
For control of melting emissions, direct evacuation requires the minimum flow-
rate, but is applicable only to larger steel furnaces. Thus, side draft hooda
are used for gray iron and small steel furnaces.
Costs for hoods, ductwork, supports, and other construction items for
the close capture hoods and ladle pit enclosures were obtained from contacts
in the industry. Operating hours shown in Table 4-1 are based on single 8-hour
4-2
-------
TABLE 4-1. ENGINEERING PARAMETERS FOR MODEL FOUNDRIES PRODUCING IRON AND STEEL
Single- furnace shop
Small
Plant capacity,
megagram/hr 3 . 6
(tons/hr) (4)
Ventilation, m3/sec (acfm)
a. Side draft evacuation, 12.9
(Iron and small steel (27,400)
furnaces), and close
capture/close
capture-ladle pit
b. Direct evacuation -
steel furnaces
c. Canopy hood and side
draft evacuation 78.0
(Iron and single fur- (165,000)
nace steel shops)
d. Canopy hood and direct
evacuation
(Medium and large, two-
furnace steel shops)
Annual operating hours 1,600
Uncontrolled emission rate,
kg/hr
Iron 28
Steel 32
Medium
9.1
(10)
19.8
(42,000)
7.0
(15,000)
93.0
(197,000)
-
1,920
70
80
Large
22.7
(25)
50.0
(106,000)
16.5
(35,000)
131
(278,000)
-
2,800
175
200
Two-furnace
Small Medium
7.3 18.2
(8) (20)
25.9 40.1
(54,800) (85,000)
14.1
(30,000)
*
104 133
(219,800) (282,000)
107
(227,000)
1,600 1,920
56 140
64 160
shop
Large
45.4
(50)
100
(212,000)
33.0
(70,000)
JL
232
(491,000)
164
(348,000)
2,800
350
400
Iron furnaces only; medium and large two-furnace steel shops controlled by option b, d.
Note: Data in Table is developed in Section 3, Emission Control Techniques.
-------
shifts per day for all model plants. Small plants typically operate 200 days
per year, medium plants, 240 days, and large plants, 350 days per year.
4.1.3 Capital Cost Estimates
Capital cost estimates reflect the cost of designing, purchasing, and
installing a particular capture system and control device. These estimates
include costs for both major and auxiliary equipment, rearrangement or removal
of existing equipment, site preparation, equipment installation, and design
engineering. Estimates do not account for production lost during equipment
installation or start-up. Lost production can sometimes be recovered by over-
time work or rescheduling vacation periods. Information for capital costs was
developed through contacts with foundry operators, equipment vendors, design
engineering firms, EPA contractor studies1'2'3 and EPA in-house files. Capital
costs reflect first quarter 1977 costs.
4.1.4 Annualized Costs
Annualized cost estimates include operating costs (labor, maintenance and
utilities) and capital charges (depreciation, interest, administrative over-
head, property taxes, and insurance). Operating cost estimates were based on
EPA contractor studies and contacts with vendors. The cost of electricity is
assessed at 4 cents per kilowatt-hour.1* Maintenace and bag replacement costs
for baghouses and maintenance costs for scrubbers were determined from a cost
estimation manual developed for EPA.3 These maintenace costs are 1 percent of
installed cost for baghouses and 4.4 percent of installed costs for scrubbers.
The major capital charges - depreciation and interest - were determined by
EPA based on the capital recovery factor, an interest rate of 10 percent, and
an equipment life of 10 years. Capital costs also include 4 percent of in-
stalled cost to account for administrative overhead, property taxes, and
insurance.
4-4
-------
4.2 CONTROL COSTS FOR FURNACES PRODUCING IRON
4.2.1 Annualized Costs
Total annualized costs for each emission control option for existing
(retrofitted) and new EAF's producing iron are summarized in Table 4-2
for single and two furnace shops of various melt capacity. Approximate parti-
culate removal efficiency of each control option is also indicated. Costs
include installed capital costs amortized for 10 percent over 10 years, operat-
ing and maintenance costs, and miscellaneous capital charges as described above.
Detailed cost breakdowns for each shop configuration are given in Appendix B.
The side draft hood included in all control options captures particulate
emissions from melting only. Options for controlling charging emissions are
use of clean scrap by preheating or briquetting, installing a canopy hood, or
installing an annular hood located just above the furnace cover, illus-
trated by the close capture concept. Tapping emissions are controlled by
the canopy hood, or by encompassing the ladle with a close capture hood, or an
enclosed ladle pit.
Control costs were first determined for model new facilities. Capital
costs for side draft evacuation and capopy/side draft evacuation systems are
based on the cost estimation manual developed for EPA,^ and information from
the Industrial Gas Cleaning Institute.2 Costs for the close capture system
are based on data obtained from the Hawley Engineering Company.5 Sources of
cost data for the preheater and the briquetter were studies by Battelle
Columbus Laboratories1 and Combustion Engineering,6 respectively. Costs for
the ladle pit enclosure are based on data obtained from Armco Steel Company.7
Costs for existing model facilities were developed by scaling up new
source costs with the appropriate retrofit factors. Retrofit factors apply
4-5
-------
Table 4-2. SUMMARY OF TOTAL ANNUALIZED CONTROL COSTS FOR MODEL EXISTING FOUNDRIES
PRODUCING IRON CASTINGS, IN THOUSANDS OF DOLLARS PER YEAR*
Control option:
Gas cleaning device:
Total particulate^control effi-
ciency, percent
j.
Single-furnace shops!
3.6 Mg/hr Existing shops
New shops
9.1 Mg/hr Existing shops
New shops
22.7 Hg/hr Existing shops
New shops
l^o-furnace shops
7.3 Mg/hr Existing shops
New shops
18.2 Mg/hr Existing shops
New shops
45.4 Mg/hr Existing shops
New shops
Side draft
hoods
Baghouse
87
A3
43
70
70
168
168
88
88
130
130
311
311
Side draft
hoods
Scrubber
87
151
141
206
195
439
419
235
221
328
311
727
703
Side draft
hoods,
preheater
Baghouse
92
66
66
103
103
254
254
123
123
195
195
484
484
Side draft
hoods,
brlquetter
Baghause
92
94
94
206
206
482
482
162
162
401
401
942
942
Close capture
hoods
Baghouse
96
54
50
86
80
207
192
110
102
162
150
381
356
Close capture
hoods ,
ladle enclosure
Baghouse
97.5
66
58
106
94
233
220
134
119
196
173
458
408
Canopy and
side draft
hoods
Baghouse
95
309
246
340
272
509
399
374
288
461
369
806
655
Data summarized fron detailed cost analysis in Appendix B which shows capital and operating costs for both new and
retrofitted (existing) facilities.
4.
For this analysis, charging and tapping emissions are considered to be 10 percent of total melting emissions which
reflects alloy addition to the ladle.
j.
J.
'Total melt capacity, Mg/hr (aegagrWhr) - 1.10 ton/hr.
-------
only to evacuation systems that would incur spatial restrictions when Installed
in existing plants. This applies specifically to installing canopy hoods which
might require numerous changes in the building; the Hawley system, which
may require some space to freely swing the annular ring hood; and the ladle
enclosure, which would require construction of a pit or rearrangement of
existing foundry equipment. The retrofit factor for canopy hood installations
was taken as 33 percent, based on a study of building evacuation systems for
EAF's in the iron and steel industry.8 Retrofit factors of 10 percent and 15
percent were applied, respectively, to the close capture/enclosed ladle pit sys-
tem. The latter two retrofit factors are considered best judgment for retrofit
installations at this time. They are based on a contingency allowance used in
standard engineering practice to cover items of an uncertain nature. A normal
assumption for contingency allowance is 10 to 15 percent of capital investment.
Table 4-2 indicates annual emission control costs ranging from $43,000 for
side draft hoods on small, existing furnaces to $942,000 for side draft hoods
and a briquetter for two large furnaces. To obtain overall control efficiency
in the range of 92 to 96 percent, the least cost option is the close capture
hoods for any sized shop. For the highest level of control, 97.5 percent, close
capture hoods plus ladle enclosures are shown considerably less costly than the
canopy-side draft hood combination.
4.2.2 Comparison of Installed Capital Cost Estimates with Actual Data
Because only limited cost data are currently available from actual instal-
lations, the above analysis was used to develop cost estimates. Data obtained
by EPA for installed costs of canopy hood and close capture systems is sum-
marized in Table 4-3 along with estimates derived by the cost analysis. The
discrepancies between the actual and estimated costs emphasise the basic fact
4-7
-------
Table 4-3. SUMMARY OF REPORTED CAPITAL COSTS COMPARED TO EPA
ESTIMATES OF TOTAL INSTALLED COSTS*
Capital cost Total installed
reported by costs, based
facility on EPA analysis
($) ($)
Retrofitted canopy hood,
215 m3/s (457,000 afcm) 1,950,0003
Retrofitted canopy hood,
231 m3/s (491,000 afcm) - 1,984,000
Retrofitted canopy hood,
89 m3/s (190,000 afcm) 805,OOO10
Retrofitted canopy hood,
93 m3/s (197,000 afcm) - 1,610,000
New close capture hoods,
10 m3/s (22,500 afcm) 125,OOO11
New close capture hoods,
13 m3/s (27,400 afcm) - 236,000
Retrofitted close capture hoods,
20 m3/s (42,000 afcm) 250,OOO12
Retrofitted close capture hoods,
20 m3/s (42,000 afcm) - 370,000
Costs updated to 1976 levels by appropriate cost index.
4-8
-------
that emission control costs can vary widely between individual foundries.
Actual installed costs as reported by various facilities often do not include
labor supplied by plant personnel and capital charges such as taxes and in-
surance; these costs are included in the EPA cost estimates.
4.2.3 Cost-Effectiveness of Control Options for Furnaces Producing
Iron
This section provides a graphical analysis of cost-effectiveness of alter-
nate control options for retrofit of model two-furnace shops. Annual!zed cost
per kilogram of particulate removal is plotted versus plant capacity for three
selected control options. The options are indicative of three discrete levels
of pollutant removal efficiency which comprise the range of control capability
for gray iron EAF's:
Control of melting emissions only by side draft evacuation
with an 87 percent efficiency.
Control of melting and charging emissions with a
close capture system at 96 percent efficiency.
Control of melting, charging, and tapping emissions with the
close capture/ladle pit enclosure combination system at 97.5
percent efficiency.
These control options represent least expensive options for the given level of
efficiency. This criteria eliminates consideration of the canopy hood system,
the clean scrap option, and wet scrubbers.
The curves developed to show cost effectiveness of three control options
are shown in Figure 4-1. For the smallest (7.3 megagram per hour) plant, the
cost per kilogram removed ranges from $1.09 for control of melting emissions
(low efficiency) to $1.49 per kilogram for controlling melting, tapping, and
charging emissions (high efficiency). For the 18.2 megagram per hour plant
control costs fall sharply to $0.54 and $0.72 per kilogram removed for the
low and high removal levels, respectively.
4-9
-------
I
l->
o
o
b)
u 2.00
k)
5 1.80
o
fe 1.60
$
, 1.40
<
(9
1.20
5 i.oo
Q.
saeo
u
ui 0.60
o
ui 0.40
ui
0.20
0
O 97.5 percent EMISSION REDUCTION
(CLOSE CAPTURE SYSTEM PLUS LADLE ENCLOSURE)
Q 96 percent EMISSION REDUCTION
(CLOSE CAPTURE HOODS)
A 87 percent EMISSION REDUCTION
(SIDE DRAFT HOODS)
10
15 20 25 30 35
PLANT CAPACITY, megagram per hour
40
45
Figure 4-1. Cost Effectiveness of Alternative Control Options for Retrofitted Iron
Producing Furnaces (Two-Furnace Shops).
-------
There is an anomaly between single-furnace and two-furnace shops of
approximate equal melt capacity which points out the effect of one variable,
shop configuration, on control costs. Control costs for the two-furnace shop
of a 7.3 megagram per hour melt capacity are roughly 100 percent greater than
for the single-furnace shop of a 9.1 megagram per hour capacity. Clearly,
economies of scale can be very important when considering control costs for
various shop configurations.
4.3 CONTROL COSTS FOR FURNACES PRODUCING STEEL
4.3.1. Annualized Costs
Total annualized costs for each emission control option for existing
(retrofitted) and new EAF's producing steel are summarized in Table 4-4 for
single- and two-furnace shops of various melt capacity. Approximate particu-
late removal efficiency of each control option is also indicated. Costs in-
clude installed capital costs amortized for 10 percent over 10 years, operating
and maintenance costs and miscellaneous capital charges as described previously
in the Introduction subsection 4.1.4. Detailed cost breakdown for each shop
configuration are given in Appendix C. Model plant parameters for each shop
configuration were also outlined in the introduction of this section.
Ventilation flow rates for melting control of medium and large steel
furnaces are lower than for gray iron furnaces because larger steel furnaces
can be evacuated directly through a fourth hole cut into the furnace shell.
Direct shell evacuation can be used for steel furnaces of 9.1 megagram per
hour or greater without jeopardizing the metallurgy involved in producing
steel. However, direct shell evacuation cannot generally be used in gray iron
furnaces as it tends to reduce carbon content in the melt.
4-11
-------
I
I-1
N>
Table 4-4. SUMMARY OF TOTAL ANNUALIZED CONTROL COSTS FOR MODEL EXISTING FOUNDRIES PRODUCING
STEEL CASTINGS, IN THOUSANDS OF DOLLARS PER YEAR*
Control option:
Gas cleaning device:
Total participate control effi-
ciency, percent
Single-furnace shops'
3.6 Mg/hr Existing shops
New shops
9.1 Mg/hr Existing shops
Sew shops
22.7 Mg/hr Existing shops
New shops
Two-furnace shop
7.3 Mg/hr Existing shops
New shops
18.2 Mg/hr Existing shops
New shops
45.4 Mg/hr Existing shops
Sew shops
Direct
evacuation
Baghouse
89.5
43*
43
28
28
61
61
88*
88
52
52
115
115
Direct
evacuation
Scrubber
89.5
151?
141
106
99
198
188
235*
221
163
154
321
306
Direct
evacuation
clean scrap
(briquette*)
Baghouse
93
94*
94
164
164
372
372
162*
162
324
324
747
747
Cloie capture
ytten
Baghouse
93
54
49
86
80
207
192
110
102
162
150
382
356
Close capture
system plug
ladle enclosure
Baghouie
97.5
66
58
106
94
223
220
134
119
196
173
458
. 408
Canopy and
direct
evacuation
- Bagboute
97
309
246
374
288
510
399
374
288
386
308
5%
483
Data suaurized from a detailed cost analysis in Appendix C which shows capital and operating costs for both new and retro-
fitted (existing) facilities.
Total *elt capacity; Mg/hr (egagraa/hr) - 1.10 ton/hr.
rCoats for side draft hoods, not direct evacuation; direct evacuation not feasible for the snail furnace size.
-------
When combining canopy hood exhaust with direct shell evacuation, total
flow rates are noticeably reduced only for the two-furnace configuration.
The reduction in ventilation resulting from direct shell evacuation is not
substantial enough to offset the canopy hood exhaust requirements on single-
furnace shops.
Side draft hoods or direct shell evacuation, included in all control
options, capture particulate emissions from melting only. Emissions from
charging (and back-charging) are controlled by using clean scrap, a canopy hood,
or an annular hood located immediately above the furnace such as the close
capture system. Emissions from tapping and alloying in the ladle are controlled
by enclosing the ladle with a local hood or an enclosed pit, with evacuation to
a control device. Use of clean scrap does not substantially reduce emissions
from back-charging and thus only the briquetter is considered for analysis of
steel foundries.
Table 4-4 indicates annual emission control costs ranging from $28,000 for
direct evacuation of a medium furnace to $747,000 for direct evacuation with
scrap pretreatment on large furnaces. To obtain an overall control efficiency
of 93 percent, the least cost option is the close capture system for all fur-
nace sizes. For a 97 percent level of control, close capture hoods with a
ladle enclosure are less costly than canopy hoods combined with direct
evacuation.
The methods and basis for developing these cost estimates are analogous
to those used for gray iron furnaces. Costs are nearly identical to those
for gray iron, with the exception of medium and large furnaces with melting
control by direct evacuation. In this case, exhaust flow rates are lower
than for side draft hoods, and thus, capital and operating costs are reduced.
4-13
-------
Costs for canopy hood systems in existing model facilities were developed by
scaling up new source costs in exactly the same manner as was done for gray
iron foundries. Retrofit costs for the close-capture system and the ladle pit
enclosure were developed by taking the actual dollar differences between new
and existing gray iron plants and transferring them to plants similar in con-
figuration and capacity for steel foundry production. Developing retrofit
costs for these two particular systems was done this way to be consistent with
previous assumptions.
Another difference between gray Iron and steel furnaces is the particulate
removal efficiencies. Removal efficiencies for steel foundries are generally
1 or 2 percent greater than for the respective iron foundries.
4.3.2 Cost Effectiveness of Control Options for Furnaces Producing Steel
This section provides a graphical analysis of the cost effectiveness of
alternate control options for retrofit of two-furnace shops. Annualized cost
per kilogram of particulate removal is plotted versus plant capacity for three
selected control options. These options are indicative of three discrete
levels of pollutant removal efficiency which comprise the range of control
capability for steel producing EAF's:
Control of melting emissions only by side draft or direct shell
evacuation at 89 percent efficiency.
Control of melting and charging emissions with a close capture
system at 93 percent efficiency.
Control of melting, charging, and tapping emissions with the
close capture and ladle pit enclosure system at 97 percent
efficiency.
These control options considered in this presentation represent the least
expensive options for the given level of efficiency. This criteria eliminates
consideration of the canopy hood system, the clean scrap option, and wet
scrubbers.
4-14
-------
Curves developed to show cost effectiveness of three control options are
shown in Figure 4-2. For the smallest two-furnace shop (7.3 megagram per hour)
plant, the cost per kilogram removed ranges from $1.06 for control of melting
emissions (low efficiency) to $1.49 per kilogram removed for controlling melt-
ing, tapping, and charging emissions (high efficiency). These costs are nearly
identical to those for an equivalent size iron EAF. For the 18.2 megagram
per hour plant, costs drop sharply to $0.21 per kilogram removed for control of
melting (low efficiency) emissions and $0.73 for total furnace control by close
capture hoods/ladle enclosures (high efficiency). For the large, 45.4 mega-
gram plant, costs range from $0.13 for control of melting only (low efficiency)
to $0.46 for close capture/ladle enclosure (high efficiency). Costs for high
efficiency control of steel furnaces are comparable to high efficiency control
of iron furnaces. However, for low efficiency control (melting only), costs
are about 50 percent less for steel furnaces than iron furnaces because of
lower gas volumes from the direct evacuation system used on steel furnaces.
4-15
-------
O
hi 2.00 r
u
u
DC
§
1.60
1.40
1.20
5 i-oo
-------
REFERENCES
1. Davis, J. A., et al. Economic Impact of the Proposed New Source Per-
formance Standards Upon Construction of Arc Furnaces in the Gray Iron
Foundry Industry. Battelle-Columbus Laboratories, EPA Contract No.
68-02-1323, Task No. 28. Unpublished report. August 29, 1975.
2. Air Pollution Control Technology and Costs for Electric Arc Furnaces in
Gray Iron Foundries. Industrial Gas Cleaning Institute. EPA Contract
No. 68-02-1473, Task No. 1. December 16, 1974.
3. Kinkley, M. L. and R. B. Neveril. Capital and Operating Costs of
Selected Air Pollution Control Systems. CARD, Inc., EPA Contract No.
68-02-2072. May 1976.
4. Anon. Typical Electric Bills 1976. Federal Power Commission.
5. Nijhawan, Pramodh. Hawley Engineering Company, Indianapolis, Indiana.
Private Communication with Frank L. Bunyard. Strategies and Air Stan-
dards Division, OAQPS, U.S. Environmental Protection Agency. April 26,
1977.
6. Schultz, A.C., W.F. and W.F. Tyler, Inc. Private Communication with
N.T. Georgieff. Emission Standards and Engineering Division, OAQPS.
U.S. Environmental Protection Agency. September 18,1975.
7. Treloar, E.R. Armco Steel Corp., Torrance, Calfornia. Private Communi-
cation to Stanley T. Cuffe. Emissions Standards and Engineering Division,
OAQPS. U.S. Environmental Protection Agency. February 24, 1977.
8. Anon. Investment and Operating Costs for Control of Particulate Emissions
From Electric Arc Furnaces in the Iron and Steel Industry. Vulcan-
Cincinnati, Inc., EPA Contract No. 68-02-0299, Task No. 1. November 8,
1972.
9. Sims, Toni. Texas Steel Company, Fort Worth, Texas. Private Communi-
cation to Frank L. Bunyard. Strategies and Air Standards Division,
OAQPS. Environmental Protection Agency. May 2, 1977.
10. McGawen, D.H. ESCO Corporation, Portland, Oregon. Private Communication
to Don R. Goodwin, Director, Emissions Standards and Engineering Division,
OAQPS. Environmental Protection Agency. February 10, 1977.
4-17
-------
11. Scully, R.E. Foundry Division of Joy Manufacturing Co., Claremont, N.H.
Private Communication to Don R. Goodwin, Director, Emissions Standards
and Engineering Division, OAQPS. Environmental Protection Agency.
June 8, 1977.
12. Hens ley, Rue, President. Hens ley Manufacturing Co, Dallas., Texas.
Plant Visit. GCA/Technology Division. September 1977.
13. Blair, Thomas. Lone Star Steel Co., Lone Star, Texas. Private Communi-
cation, Plant Visit, GCA/Technology Division. September 1977.
4-18
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5.0 ENVIRONMENTAL IMPACTS OF APPLYING CONTROL TECHNOLOGY
5.1 IMPACT ON PARTICULATE EMISSIONS FROM THE IRON AND STEEL FOUNDRY
INDUSTRY
Table 5-1 summarizes estimates of total annual emissions from ferrous
foundries for three levels of control. Annual emission totals were based on
the annual production of castings from EAF's in ferrous foundries (about 4 mil-
lion tons annually), and by averaging emission factors and control efficiencies
for iron and steel foundries presented in Section 3. It was necessary to
average these values because the exact level of iron production compared to
steel production is unknown. Most ferrous foundries control melting and
refining emissions with side draft hoods (or equivalent) and baghouses, but
provide little or no control of charging and tapping emissions. Total annual
emissions for ferrous foundries are estimated at about 10,000 Mg, or 11,020
short tons, as shown in Table 5-1. Control of charging and tapping by canopy
hoods would reduce annual emissions to about 1,800 Mg per year, while retro-
fitting close capture systems and ladle pit enclosures would result in annual
emissions of about 1,150 Mg. Retrofitting all existing furnaces with the fur-
nace enclosure would result in annual emissions of 460 Mg, a substantial 96
percent reduction from current levels.
5.2 SUMMARY OF ENERGY REQUIREMENTS
Table 5-2 shows electricity consumption of air pollution control equipment
relative to electricity required for melting for single furnace model plants.
A review of recent foundry installations indicates roughly five horsepower per
5-1
-------
Table 5-1. SUMMARY OF TOTAL PARTICULATE EMISSIONS FROM IRON AND STEEL
FOUNDRY EAF'S FOR VARIOUS CONTROL OPTIONS
Level of control
Total particulate^
removal efficiency
(percent)
Total annual
emissions
(Mg/yr)
Current situation: control
of melting and refining only
Improved control: melting,
refining, charging, tapping
10,000
By canopy and side draft hoods
By close capture system and
ladle pit enclosure
By complete furnace enclosure
96
97.5
99
1,800
1,150
460
Average efficiency for iron and steel furnaces.
5-2
-------
Ul
LO
Table 5-2. ENERGY REQUIREMENTS, IN MILLION kWh PER YEAR, FOR MELTING COMPARED TO
EMISSION CONTROL OPTIONS FOR MODEL PLANTS
Total particular
removal
(percent)
Melting and refining
Direct evacuation
Side draft hoods
Close capture system
Close capture system
plus ladle pit enclosure
Side draft plus canopy hood
Direct evacuation
plus canopy hood
-
89.5
88
93
97.5
95
97
Furnace size
k
Small Medium
3.6 Mg/hr 9.1 Mg/hr
3.2 9.6
0.10
0.16 0.30
0.16 0.30
0.16 0.30
0.30 0.54
0.34
Large
22.7 Mg/hr
35
0.23
1.10
1.10
1.10
1.40
0.53
Average of iron and steel furnace removal efficiency.
Canopy hood operation for 15 percent of furnace operational time.
-------
thousand cfm of exhaust flow is required by fans in a typical hood collector-
baghouse control system. The electric arc furnace (EAF) typically consumes
about 500 kWh of electricity per ton melted in the foundry. Three control
options require equivalent exhaust flowrates, and thus, have comparable energy
requirements. Electrical energy required to operate side draft hoods, close
capture systems and close capture/ladle pit enclosure is approximately 3 to 5
percent of energy used in melting and refining, for each furnace size. Energy
requirements for the side draft/canopy hood combination, however, are much
greater, even though total particulate control efficiency is lower than two of
the less energy intensive options. A side draft/canopy hood on the small
furnace will use about 10 percent as much energy used in melting. For the large
furnace with side draft/canopy hoods, about 5 percent of energy used in melting
is necessary to operate control devices.
5.3 GENERATION AND DISPOSAL OF FURNACE DUST
5.3.1 Quantities of Dust Generated
Virtually all electric arc furnaces in ferrous foundries use baghouses
for collecting particulates from furnaces exhaust gas. An approximation of
total dust collected per year can be established based on emission factors;
tonnage of iron produced and baghouse efficiency, as developed in Sections 2
and 3. Electric arc furnace production capacity is about 3.6 million megagrams
(Mg) annually of finished castings and furnace utilization rate for 1976 was
73 percent of capacity. At an average emission rate of 8.3 kg/Mg (including
charging and tapping) for iron and steel foundries, and a typical particulate
removal efficiency of about 88 percent, total collected dust for 1976 is cal-
culated at about 28,000 megagrams (31,000 tons).
5-4
-------
Table 5-3 shows the quantities of dust requiring disposal which would be
collected by model foundries with existing control technology and also with
improved control of charging and tapping. Small foundries typically handle
about 38 megagrams/yr while large foundries must dispose of about 420 mega-
grams /yr. With improved control of charging and tapping emissions at model
plants, the quantities of collected dust would increase by only 10 percent, as
shown in Table 5-3.
5.3.2 Dust Handling
Improper handling and disposal of particulates collected from the EAF
can easily cause some entrainment of dust to the atmosphere. Current state
and federal regulations generally do not address this problem because the
importance of fugitive emission sources has only recently drawn much atten-
tion. While this is not a major problem, methods are available to minimize
entrainment problems.
Dust collected from the foundry is usually placed in landfills. Economic
recycling of these iron-bearing dusts has not been demonstrated. The most
effective method for handling dust i« a pelletizing operation which practically
eliminates entrainment problems. However, many foundries will probably
continue to handle loose dust, usually transporting it by truck to the disposal
site. Open bodied trucks should have a cover to place over the load, and
vehicle speed should be limited to avoid losses during transport. Alternatively,
dust from the baghouses (or ESP's) can be emptied into sealed bags or contain-
ers which would also serve to contain dusts at the disposal site. Still ano-
ther option is to produce a slurry by injecting water at some point of the dust
handling system.
5-5
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TABLE 5-3. QUANTITY OF DUST COLLECTED AT MODEL FOUNDRIES IN MEGAGRAMS PER YEAR
.Furnace size
Total particulate*
control effi- Small, Medium
Large
ciency, percent 3.6 Mg/hr 9.1 Mg/hr 22.7 Mg/hr
Melting and refining
by side draft hoods
Melting, refining, charg-
ing, tapping by close
capture system and ladle
pit enclosure
88
38
115
97.5
42
128
420
465
Control efficiencies averaged for iron and steel foundries.
-------
5.3.3 Pelletizing
Many foundries and steel mills are currently pelletizing collected furnace
dusts to facilitate efficient disposal. Dusts collected from the EAF are fine
in size and can easily be wetted and rolled into granular pellets. This
eliminates potential for dust reentrainment and improves ease of dust handling.
The most common pelletizer configurations are the inclined disk and cone-shaped
units. The units are fairly small and can often be installed such that pellets
fall directly into a truck. Dust free transfer from baghouse to pelletizer can
be accomplished with enclosed tank-type trucks or conveying through enclosed
transfer pipes.
5.3.4 Recyling Potential for Electric Arc Furnace Dust
Dusts collected from foundry EAF's contain significant amounts of iron
oxides, but there are currently no commercial processes for recovering this
material. Recycling and material recovery from steelmaking dusts is under
investigation in this country and abroad. A major technical problem in ferrous
recovery is contaminating elements, notably lead and zinc, which may be present
in high concentrations. Zinc and lead can damage the interior of a furnace,
and also contaminate the melt. Recovery of valuable zinc is one option under
investigation.
Metal recovery from furnace dusts is technically feasible, but several
problems are restricting use of available technology:
There is no single process available for recycling all types of
furnace residues at a single processing facility.
Most plants do not produce large enough quantities of
residues in one location to make investment in such
facilities feasible.
5-7
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5.3.5 Landfill Disposal
Dust collected from the EAF can be safely landfilled if appropriate pre-
cautions are taken. Care in disposal is necessary because, as shown in
Table 5-4, relatively high levels of trace elements including the toxic metals
lead, cadmium, and arsenic, are often present in foundry dust.2
Trace elements shown in Table 5-4 are present in EAF dusts as metal oxides
which are insoluble in pure water. However, most are slightly soluble in
acidic solutions and rainfall over many parts of the country is somewhat
acidic. Further, since little control can be exercised over the possibility
of chemical reactions occurring in the landfill, landfill site design must
preclude horizontal or vertical migration of these metals to surface or
groundwaters. The Safe Drinking Water Act of 1974 provides for protection
of potential drinking water supplies, and sets limits on concentration of
certain toxic metals. Where geo-hydrological conditions do not provide
reasonable protection against leaching of these elements, precautions such
as impervious liners should be taken to insure long-term protection of the
environment.
TABLE 5-4. TRACE METALLIC COMPONENTS OF BAGHOUSE HOPPER
DUST (ppm)2
Pb -
Cu -
Zn -
Na -
Ni -
K -
Sn -
10,000
8,000
5,000
3,000
1,500
5,000
300
Ti -
Li -
Cr -
Zr -
Ba -
Mo -
Cd -
300
300
200
200
200
150
100
As -
B -
V -
Co -
Sb -
Sr -
Ag -
100 Be - 1
50
50
50
50
30
10
5-8
-------
Disposal sites often require approval by the responsible state agency to
ensure that sites are environmentally sound. This will become more common as
states comply with the Resource Conservation and Recovery Act of 1976 which
specifically addresses disposal of solid and potentially hazardous wastes.
When disposal is to a municipal landfill, dust must be segregated from
municipal refuse. As organic matter decomposes, acidic conditions develop and
could dissolve portions of trace metals in the dust, developing potential for
leachate contamination of nearby waters.
Several features can be designed into a landfill to ensure safe disposal
of wastes, mitigating potential for contamination of ground and surface waters
and the atmosphere. General criteria to be considered are:
Location away from excessive slopes and flood-plains.
Location in areas of low population, low land value and
low ground-water contamination potential.
No hydraulic or subsurface connection should exist with
standing or flowing surface or ground waters.
The base of the landfill should be located a sufficient
distance above the high water table to prevent leachate
movement to aquifers. Use of clay or plastic liners may
be necessary.
Diversion ditches should be constructed around the site to
intercept surface waters, thus reducing infiltration and
runoff from the site.
Dusts should be covered daily with earthfill and compacted
to avoid reintroduction into the atmosphere, and reduce
infiltration of rainwater.
If an electrostatic precipitator (ESP) was used to control furnace emis-
sions, dust would be collected in a dry form and disposal considerations
discussed above for baghouse-collected dusts would also apply to the ESP-
collected dusts.
5-9
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5.4 DISPOSAL OF SCRUBBER WASTEWATER AND SLUDGE
Wet scrubbers are generally not used in the United States for control of
EAF furnace emissions from foundries. In fact, a review of the Penton Publish-
ing Company's 1974 listing of iron foundries shows fabric filters were used
exclusively.3 In situations where scrubbers could be used, scrubber wastewater
should be contained in a settling pond and recirculated. Protection of ground-
waters and surface waters is essential, and landfill disposal requirements of
dry dusts also apply here.
5.5 EFFECT OF EMISSION CONTROL ON PLANT NOISE
Noise control is rapidly gaining attention due to OSHA regulations for
in-plant personnel exposure and EPA restrictions on permissible noise levels
at the plant boundry. Fans which power baghouses or other control devices are
one noise source at the foundry. Proper design and installation of fans can
significantly reduce noise levels from these sources. However, it is much
easier to design a quiet fan than to retrofit an existing noisy fan for noise.
reduction. Inclusion of the following equipment and design parameters have
been suggested to significantly dampen external fan noise.^J5
Fan silencer
Fan casing heavy enough to reduce transmission of noise
Seals between casing and rotating shaft that do not allow
escape of fan's internal noise
Expansion joints acoustically treated and designed to be
as far removed from the fan as feasible
Duct walls to and from the fan heavy enough or acoustically
treated to retain fan noise
Fan mounted on appropriate vibration damping pads
If necessary, a vibration analysis should be conducted, con-
sidering radial and thrust vibration amplitudes, dynamic
balance, foundation resonance, and so on.
5-10
-------
While fan noise can be substantial if not properly controlled, such
noise is often insignificant compared to furnace noise which is radiated to
the surrounding countryside. Noise from a large electric arc furnace during
meltdown is caused by electrode arcing, and is directly proportional to the
area of small furnace openings. Fortunately, effective control of air pollu-
tion from the furnace dictates closing of most openings in the furnace, and
this tends to reduce noise escaping the furnace shell. Openings which should
be investigated both as a noise source and an air pollution source are:
Slag door
Fourth hole slip joint
Roof ring gap
Electrode holes
Air pollution control significantly reduces furnace noise if a furnace
enclosure is used. Here, the entire furnace is enclosed, isolating the fur-
nace from the melt shop and creating a barrier to furnace noise.
5-11
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REFERENCES
1. Managing and Disposing of Residues from Environmental Control Facilities
in the Steel Industry. EPA-600/2-76-267, U.S. Environmental Protection
Agency, Office of Energy, Minerals and Industry, Research Triangle Park,
North Carolina, October 1976.
2. Georgieff, N. T. Emission Standards and Engineering Division, Office of
Air Quality Planning and Standards, U.S. Environmental Protection Agency.
Memo to GCA/Technology Division, April 1978.
3. Penton Computer Print-Out of Gray Iron Foundries in the United States.
The Penton Publishing Company, Cleveland, Ohio. March 1974.
4. Knipe, H.F. Controlling Fan Noise. Iron and Steel Engineer, 40(8):55.
August 1976.
5. Molecey, T.C. Noise Control and the Electric Arc Furnace Shop. Electric
Furnace Proceedings, American Society of Steel and Petroleum Engineers.
1975.
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6.0 COMPLIANCE TEST METHODS AND MONITORING TECHNIQUES
This section discusses sampling and monitoring methods which are applicable
to both new and existing sources.
6.1 MEASURING PARTICULATE EMISSIONS
6.1.1 Standard Approach - EPA Reference Method 5
For gray iron and steel foundries using the electric arc furnace (EAF),
particulate emissions can normally be measured using EPA Method 5, and visible
emissions can be determined with Method 9. Both of these reference methods
should be conducted in accordance with the provisions in Appendix A of 40 CFR,
Part 60. When sampling a positive pressure baghouse with no distinct exhaust
stack, special provisions must be included as described in the next section.
When sampling high efficiency control devices such as the fabric filters'
typically used on foundries, a relatively small amount of particulate is
captured by the Method 5 sampling filters because of low mass concentrations
in the exhaust stream. Accurate recovery of the sample from the sampling train
and weighing of the recovered samples requires collection of at least 50 mg of
particulate to insure an accuracy of ± 10 percent. Thus, EPA suggests that a
minimum volume of 9.0 dsm3 (320 dscf) be drawn through the sampling train when
Method 5 is applied to foundries.1 Sampling trains which collect large sample
volumes and conform to Method 5 specifications, are commercially available.
Depending on the sampling train selected, a reduction in sampling time and thus
the cost of testing can often be realized.
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6.1.2 Special Techniques for Positive Pressure Baghouses
A positive pressure type baghouse is often favored over the negative
pressure type for new installations on EAF's because of significantly lower
installation costs and ease of identifying and replacing broken bags. However,
unlike negative pressure (pull-through) baghouses, positive pressure systems
do not ordinarily have distinct exhaust stacks. Rather, the positive pressure
baghouse often discharges cleaned gas through a series of louvers, vents or
short, "stub" stacks located above each compartment. Consequently, these sys-
tems cannot always be sampled in strict accordance with criteria of EPA
Method 5 which were developed to measure emissions from a single stack.
EPA requires operators of positive pressure baghouses at source cate-
gories that are subject to new source performance standards to develop sampling
procedures for demonstrating compliance. If sampling procedures acceptable to
EPA cannot be developed, exhaust Rases must be collected from each compartment,
and directed to a single stack which can then be sampled by Method 5. To avoid
this procedure, EPA and others have recommended modifications to Method 5 which
should allow development of an acceptable sampling procedure.1'2
Since positive pressure baghouses discharge to the atmosphere through mul-
tiple compartments and vents, sampling each discharge point would be costly
and time-consuming. If each compartment is in equivalent condition, with simi-
lar operating parameters, an acceptable procedure is to sample a randomly se-
lected, representative number of compartments or subareas. The representative
selection of compartment(s) can be based on analysis of baghouse design and
estimation of air flow distribution through the baghouse.
Standard Method 5 equipment has been used with pressurized baghouses when
the systems discharge through short, stub stacks. Because of the low effluent
6-2
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mass concentrations resulting from high efficiency baghouses, the duration of
the sampling period is usually extended to about 3 hours to collect enough
mass for the sample filters. To estimate emissions, individual points may be
sampled by traversing or by simultaneous sampling at several points. Measure-
ment of flow velocity through stubstacks can ordinarily be accomplished by
standard equipment.
Without stub stacks, a problem often encountered In using Method 5 for
positive pressure baghouses is the inability of standard sampling equipment
to measure low exhaust velocities (about 2 m/s) encountered in the roof moni-
tor exhaust vents. Method 5 requires isokinetic sampling, that is, maintain-
ing air velocities drawn through the sampling probe equal to the velocity of
the exhaust stream, to assure representative collection of particles. Since
Method 5 sampling equipment cannot measure low flow rates, isokinetic sampling
cannot be maintained.
One acceptable solution to this problem is to measure the average flow
rate prior to sampling, using instruments capable of low velocity measurements.
The Method 5 sampling equipment can then be preset to sample at this flow rate.
This average sampling rate can then be used for the duration of the sampling
period.
Another alternative is to sample emissions at subisokinetic rates, which
Involves withdrawing the sample with Method 5 equipment at a rate lower than
the exhaust stream velocity. EPA data has Indicated that for particles with
aerodynamic diameters less than 5 microns, typical of EAF dusts, and for
sampling of low velocity streams, an insignificant error should result when
the isokinetic requirements of Method 5 are not observed. Under these condi-
tions any errors that do occur result in a positive bias.
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While Method 5 has been used with some success on pressure baghouses,
several state agencies have developed sampling procedures using hi-vol sam-
plers.3"5 The hi-vols are used to measure concentrations within several com-
partments or may be drawn across a horizontal cross-section of roof monitors
or exhaust vents. Inherent limitations on the accuracy of this method have
not been quantified, but it'is believed that judicious use of hi-vols can give
a reasonable estimate of emissions.
6.2 VISIBLE EMISSION MONITORS
Visible emission monitors are based on a light source and receiver (trans-
missometer) installed in the exhaust stack of the air pollution control device.
Output from the monitor is ordinarily connected to a pen recorder which provides
a continuous record of relative opacity of the exhaust gas. Thus, an increase
in recorded opacity indicates a decrease in performance of the emission control
device. Performance standards for monitors have been promulgated by EPA and
are published in the Federal Register, October 6, 1975. (Appendix B of
40 CFR Part 60).
Continuous monitors can be installed in the exhaust stack of negative
pressure (pull-through) baghouses. However, some of the newer baghouses
installed on EAF's are the positive pressure type which have no distinct stack,
but discharge through a series of vents or short stacks sbove each individual
compartment. For this type of baghouse, continuous monitoring can be accom-
plished by either:
internal monitoring of several representative compartments
with conventional, continuous monitors, or
use of recently developed instruments capable of monitoring
long distances to measure opacity over the length of
several compartments, or over the top of the baghouse,
immediately above the discharge vents.
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However, such devices are fairly costly to install and maintain, and require-
ments for continuous monitors should be carefully evaluated.
6.3 VISIBLE EMISSIONS FROM FOUNDRY ROOF MONITORS
At foundries where charging and tapping are poorly controlled,
fugitive emissions generally escape to the atmosphere through vents in the
roof, called "monitors". Emissions from roof monitors cannot be measured with
transmissometers because such emissions are not uniform and vary widely in
duration and magnitude. Many foundries have a number of monitors or roof fans
through which fugitive emissions from the furnace may escape. Evaluation of
roof monitor emissions not amenable to continuous monitoring devices must
therefore be conducted by trained smoke observers, in accordance with EPA
Reference Method 9.
6-5
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REFERENCES
1. Georgieff, N.T. Emission Standards and Engineering Division, OAQPS.
U.S. Environmental Protection Agency. Private Communication to GCA/
Technology Division. September 1977.
2. Background Information for Standards of Performance Electric Submerged
Arc Furnaces for Production of Ferroalloys. Volume 3: Supplemental
Information. Environmental Protection Agency, Research Triangle Park,
N.C. EPA-450/2-74-018-C. April 1976.
3. Mr. Achinger, Assistant Director. Wayne County Air Pollution Control,
Detroit, Michigan. Private Communication with GCA/Technology Division.
March 23, 1977.
4. Mr. Andrews. Wayne County Air Pollution Control, Detroit, Michigan.
Private Communication with GCA/Technology Division. March 24, 1977.
5. Mr. Nlm. Allegheny County Air Pollution Control. Pennsylvania.
Private Communication with GCA/Technology Division. March 21, 1977.
6-6
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7.0 ENFORCEMENT ASPECTS
7.1 INTRODUCTION
This section summarizes the type of data required to enforce various types
of standards applicable to iron and steel foundries. Basically, there are
four types of formats in which standards can be written:
Limits on concentration of pollutants emitted
Mass limits
Opacity limits
Equipment specifications and operating practices
7.2 CONCENTRATION LIMITS
Concentration limits on exhaust gas, commonly expressed as grains/dry
standard cubic foot or mg/dry cubic meter, are used widely. Enforcement
requires the use of a field sampling crew and field testing equipment which is
expensive and time consuming. In the case of particulate sampling, the method
required is EPA Reference Method 5. In using Method 5, difficulties can arise
from the low flow rates which accompany large area discharges typical of
positive pressure baghouses which are often installed on new foundries. This
often hinders isokinetic sampling which can cause errors in sample collection.
In some cases EPA has required new sources to provide a stack or well-defined
exit to positive pressure baghouse such that emissions can be properly measured
by Reference Method 5. Although there are currently no standard procedures
for measuring emissions from positive pressure baghouses, several EPA publica-
tions address procedures which have been used.1'2
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These involve construction of a "quasi stack" and also procedures to measure
emissions from roof monitors of positive pressure baghouses. Because concen-
tration limits also imply the presence of a well-defined exit stack or duct
for emissions which are not available in many foundries, concentration limits
are often difficult to define.
One disadvantage of concentration limits is that they do not account for
lower mass emissions which would result from systems with lower flow rates.
That is, since the total mass emitted is the product of concentration and
flow rate, systems which minimize exhaust flow rate, while meeting a concen-
tration standard, will have lower total emissions than systems not minimizing
flows. A concentration standard does not recognize benefits of minimizing
exhaust flow rates. An advantage to concentration limits, however, is that
they can be inexpensively screened using opacity observations. The correlation
between opacity and mass concentration can be used to indicate situations
where more detailed testing is required.
7.3 MASS LIMITS
Emission standards may also be based on the maximum mass of emissions
relative to either production rate (kg particulate/Mg of metal produced) or
furnace capacity (kg particulate/Mg of metal charged). The units for these
two methods differ, since the production rate is affected by the operating
conditions (length of heat), while the furnace capacity is independent of this
factor.
The data required to enforce a mass standard would still require a field
test to measure the mass of emitted particulates. These measurements are
analogous to those for concentration standards.
7-2
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Required process Information is the furnace capacity and the times when a
cycle starts and ends (which can easily be obtained from plant logs). The
capacity of a single furnace is determined by averaging the tons of steel
produced for all cycles which contribute to the particulate sample obtained
during a performance test.
7.4 OPACITY LIMITS
Particulate emissions can also be regulated solely in terms of opacity
limits, as is currently done with baghouses in most states. Opacity regu-
lations can be readily enforced using EPA smoke inspectors trained in accordance
with Reference Method 9. Difficulties sometimes arise, however, because of
plume thickness. Continuous opacity monitors are now available to record con-
trol device performance, and can provide help in enforcing opacity standards.
In some cases, it may be difficult for a specific plant to meet an opacity
regulation because of conditions or problems peculiar to that specific plant.
In this case, EPA may grant or establish an opacity standard for the particular
plant, with approval of the EPA Administrator.3
7.5 EQUIPMENT STANDARDS
Standards could also be written in a form that specifies the type of con-
trol equipment to be used. For instance, a standard might be set for EAF's which
required foundries to install and operate a control system consisting of a
canopy hood in combination with direct furnace evacuation. However, a problem
arises here with determining whether a proposed piece of control equipment
will, in fact, provide adequate emission control. This potential problem is
well illustrated by the canopy hood. Proper design depends entirely on the
specific foundry and the physical configuration of the foundry roof, wall
openings, cross-drafts, etc. It is usually difficult to predict collection
7-3
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efficiency of such a canopy, and in certain shops, the canopy may only provide
very low collection of fume.
Monitoring a standard of this type is easy, and in practice, this seems
to be the type of standard that many local pollution control agencies actually
apply to existing facilities. Inspectors generally check to see that the bag-
houses and evacuation systems are installed and functioning properly.
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REFERENCES
1. Kolnsberg, H.J., et al. Technical Manual for the Measurement of Fugitive
Emissions. Quasi-Stack Sampling Method for Industrial Fugitive Emissions.
EPA Publication. EPA 600/2-76-089C. May 1976.
2. Kenson, L.E. Technical Manual for the Measurment of Fugitive Emissions.
Roof Monitor Sampling Method for Industrial Fugitive Emissions. EPA
Publication. EPA-600/2-76-089B. May 1976.
3. Code of Federal Regulations, 40, Part 60. Standards of Performance for
New Stationary Sources, Subpart A. General Provisions, Paragraph 60.11.
Compliance with Standards and Maintenance Requirements, Subparagraph e2.
July 1, 1977.
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8.0 REGULATORY OPTIONS FOR CONTROL OF ELECTRIC ARC FURNACES AT
IRON AND STEEL FOUNDRIES
8.1 SUMMARY OF CONTROL TECHNOLOGY OPTIONS FOR IRON AND STEEL FURNACES
There are essentially three levels of control which one can attain for the
electric arc furnace: control of melting only; control of melting and charging;
and control of melting, charging and tapping. Summarized below are the pre-
ferred technologies for meeting these three levels of control; the ranges of
costs and control efficiencies; the energy requirements; and the quantity of
solid waste generated. The implications of each control option with respect to
formats for writing emission regulations are also discussed.
8.1.1. Control of Melting Emissions Only
Melting (and refining) emissions account for about 90 percent of total
emissions from the EAF, with charging and tapping accounting for the remainder.
Side draft hoods and fabric filtration are currently the most common technique
for controlling melting emissions at iron and smaller steel foundries. For
larger steel furnaces, direct shell evacuation can be used, which reduces
both the flowrate required to evacuate the furnace and the size of the ac-
companying fabric filter unit.
8.1.1.1 Control of Iron Furnaces - Side Draft Hoods Plus Fabric Filter
Side draft hoods typically collect 90 to 99 percent of melting and re-
fining emissions; usually the dust-laden air stream is cleaned in a fabric
filter. A well-designed side draft hood can collect about 99 percent of
melting and refining emissions, resulting in a net control of 87 percent of
8-1
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total furnace emissions as discussed in Section 3.7. (Charging and tapping,
which account for 10 percent of total emissions, are not controlled by side
draft hoods.) Energy to operate side draft exhaust fans ranges from 3 to 5 per-
cent of total energy required for melting scrap in the large- and small-sized
model plants, respectively, as indicated on page 5-2. Quantity of dust col-
lected by the fabric filter ranges from 38 megagrams annually for the small
(3.6 Mg/hr) furnace to about 420 megagrams annually for the large (22.7 Mg/hr)
furnace. Total annual costs (capital charges and operation cost) for the side
draft hood plus baghouse system for new iron furnaces range from $43,000 for one
small 3.6 Mg/hr furnace to $168,000 for a large 22.7 Mg/hr furnace (see Sec-
tion 4). Retrofitting side-draft hoods on iron furnaces normally presents few
problems, and the annual cost for retrofitted side-draft hoods is generally
equal to that encountered in new installations. (This control option also ap-
plies to small steel furnaces as they cannot use the direct evacuation systems
described below.)
8.1.1.2 Control of Steel Furnaces; Direct Evacuation Plus Fabric Filter
Melting emissions from medium- and large-sized steel furnaces can be ef-
fectively controlled by a direct evacuation roof tap which requires only about
25 percent of the exhaust flow rate used by side draft hoods. The reduced flow
rate results In smaller-sized duct work and a smaller baghouse, thus reducing
control costs. For the medium (9.1 Mg/hr) and large (22.7 Mg/hr) steel furnaces,
annual control costs are $28,000 and $61,000, respectively, which are less
than one-half the costs of side draft hoods for the same furnaces. Retrofit
costs for direct evacuation plus a baghouse are normally equal to costs of new
Installations. This control option cannot, however, be applied to Iron furnaces
as the chemistry of the Iron bath Is adversely affected by direct evacuation.
Small steel furnaces also cannot use direct evacuation for melting emission
control because of difficulties in precisely controlling exhaust flow rate.
8-2
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Capture efficiency for direct evacuation is equal to side draft hoods;
i.e., 90 to 99 percent of melting and refining emissions. The quality of
dust collected by the baghouse may be slightly greater for the steel furnace,
compared to iron because emissions are slightly greater. Energy requirements
for operating direct evacuation systems are about one-third of those for side
draft hoods because of reduced exhaust volume.
8.1.1.3 Regulatory Formats for Control of Melting Emissions
A regulation for control of melting emissions of the EAF must first ensure
that fumes are properly evacuated at the furnace, then secondly ensure that ef-
ficient gas cleaning is accomplished. Regulatory options are (1) mass or con-
centration limits for the outlet of a gas cleaning device (which requires sam-
pling of emissions), (2) opacity limits (which do not require sampling), and
(3) an equipment specification (which also does not require sampling).
Effective capture of furnace emissions by side draft hoods, or direct
evacuation relies on maintaining an adequate exhaust flowrate through the
furnace evacuation system. With the fabric filter gas cleaning device, out-
let particulate concentrations tend to be insensitive to the inlet concentra-
tion. Because of this characteristic, a greater exhaust flowrate (i.e., side
draft hoods) will result in greater net mass emissions even though the mass
concentration is low. A mass emission standard, therefore, must be chosen to
provide the operator with enough flexibility to maintain high enough exhaust
flowrates for good capture of furnace emissions. A concentration standard
would provide this flexibility. Baghouses can typically reduce furnace exhaust
concentrations to 12.0 mg/dsm3, as indicated in Section 3.6. An opacity stan-
dard, in addition, would be effective for evaluating baghouse performance since
a well-designed and operated baghouse should exhibit an opacity of zero or only
8-3
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a few percent. For melting emissions which are controlled by side draft hoods
and baghouse, EPA test data presented in Section 3.6 and Appendix A shows that
maximum opacity at the baghouse stack is normally less than 10 percent for iron
furnaces and normally less than 5 percent for steel. There may be exceptions
to these norms during injection of carbon black at iron foundries, and in ex-
treme cases, during oxygen lancing at steel foundries. An opacity standard could
also be applied to fugitive emissions escaping the fume collectors, except that
supporting data is not generally available for setting such a standard.
An equipment standard can also be adapted for controlling melting emissions
since control technology is well developed and accepted by the industry. An
equipment standard should specify type of equipment (e.g., side draft hoods for
iron or steel, or direct evacuation for steel) and design parameters necessary
to ensure effective particulate evacuation and removals. For example, an equip-
ment standard might specify baghouse parameters such as air-to-cloth ratio
(which is normally low, 2 or 3 to 1) as well as the flowrates necessary for ef-
fective particle capture. Exhaust flowrates summarized on page 4-3 are used by
newer foundries. These flowrates are on the order of 100 percent greater than
those used by some older evacuation systems (refer to Section 3.6 and Appendix A
which summarizes test data from furnaces). Flowrates lower than those shown on
page 4-3 can still provide effective evacuation of melting emissions. Higher
flows are more common today mainly in response to OSHA requirements.
8.1.2 CONTROL OF MELTING AND CHARGING
Together, melting and charging emissions account for about 90 percent of
particulate emissions from the EAF. The most practical options for controlling
these emissions are the side draft hood (direct evacuation in the case of
steel) plus use of clean scrap, and the close capture hood systems; in both
cases, a baghouse is used for gas cleaning.
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8.1.2.1 Control of Melting and Charging at Iron Furnaces
Of the two options for controlling melting and charging emissions from
iron foundries, the close capture hoods are most efficient, providing total
particulate removals of 96 percent. (It should be noted that this estimate
is based on limited data, see page 3-29.) The side draft hood combined with
scrap cleaning using a preheater will control about 92 percent of total furnace
emissions (refer to page 3-53). In terms of annual costs, close capture hoods
are somewhat less expensive. For a new small model plant (3.6 Mg/hr), the
annualized cost for close capture hoods is $50,000 compared to $66,000 for the
side draft/preheater option. For a new large model plant (22.7 Mg/hr), close
capture hoods and side draft/preheater annual costs are $192,000 and $254,000,
respectively (refer to Section 4). Retrofitting a preheater may be difficult
due to structural limitations. This is also true for close capture hoods,
where costs of a retrofit may be substantially increased above costs for new
installations. Fuel availability (usually natural gas) can also be a problem.
As mentioned earlier in Section 3, the use of a charge preheater may reduce
net melting energy requirements by about 15 percent. Both control options use
about the same energy for control of melting, and only a small additional amount
is used by the close capture design for charging control. Collected dust
quantity is almost identical to that collected by systems discussed above in
Section 8.1.1 since charging emissions represent only an additional 5 percent
of total furnace emissions. When establishing a regulation for melting and
charging, it must be recognized that controlled charging emissions will usually
be difficult to distinguish from melting emissions due to their intermittent
nature. It would, therefore, be difficult to establish and enforce a mass or
concentration standard for charging emissions. An opacity standard could be
8-5
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applied to charging emissions from a control device only for systems with one
baghouse per operating furnace. The opacity standard would, however, be ap-
plicable to emissions which escaped collection by the close capture hoods, and
especially applicable to emissions from charging of preheated scrap. For un-
controlled charging emissions which escape foundry roof vents, EPA data (see
Appendix A and Section 3.6) indicates maximum opacities are typically 10 per-
cent for 3 minutes. However, it will sometimes be difficult to distinguish
charging emissions from other foundry emissions escaping through the same roof
vent. Use of an equipment standard would avoid problems with enforcing mass
or concentration standards. However, retrofit of close capture hoods or even
preheaters for charging control may often be limited because of space restric-
tions. These problems will be of minor importance for new foundries.
An equipment standard for melting and charging control should specify cer-
tain items. For close capture hoods, the necessary exhaust flowrate, (12.9 m3/
sec for a 3.6 Mg/hr furnace, ranging to 50 m3/sec for 22.7 Mg/hr furnace, see
page 4-3), method of diversion of exhaust to charging hoods and actual size or
shape of hoods should be specified (see Section 3.3.4). For the preheater
option, control of emissions can be addressed by specifying evacuation to an
afterburner or specifying the use of preheaters with built-in secondary com-
bustion chambers.
8.1.2.2 Control of Melting and Charging at Steel Foundries
Control options for melting and charging at steel foundries differ from
those discussed above for iron foundries only in that direct evacuation is
substituted for side draft foods for medium- and large-sized furnaces. Total
particulate removal efficiency for preheaters combined with direct evacuation
and a baghouse is about 93 percent (refer to page 3-53), a level also
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achievable by close capture hoods installed on steel furnaces. Annualized
costs for close capture hoods at steel foundries are the same as those dis-
cussed above for iron. Sometimes a briquetter is used at steel foundries in-
stead of a preheater; costs are still greater than for close capture hoods,
even though gas volumes are reduced with direct evacuation. Annualized costs
for direct evacuation/briquetter are about $93,000 and $372,000, respectively,
for the small and large model foundries while close capture costs are about
$49,000 and $192,000, respectively. As in the case of iron foundries, the
cost of retrofitting these control options may be substantially increased
if extensive structural modifications must be made. In terms of energy con-
sumption, direct evacuation only requires about 1 percent of energy used for
furnace operation - less than energy requirements of side draft hoods on iron
foundries; energy use by the briquetter is not available. Generation of col-
lected dusts will be about 5 percent greater than dust generation with melting
control only.
Comments relative to the format of emission standards presented in Sec-
tions 8.1.1.3 and 8.1.2.1 also apply here, except that for uncontrolled charg-
ing emissions which escape through foundry roof vents, EPA test data in Appen-
dix A shows maximum opacities are typically 20 percent for 3 minutes for steel
(compared with 10 percent for 3 minutes with iron).
8.1.3 Control of Melting, Charging and Tapping
The last level of control includes tapping as well as melting and charging
emissions. Tapping emissions account for an estimated 5 percent of total
furnace emissions. Three basic techniques for total control of melting, charg-
ing and tapping emissions were identified in Section 3 as:
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Canopy hoods coupled with side draft hoods (iron) or direct
evacuation (steel).
Total furnace enclosure.
Close capture hoods with a ladle pit enclosure.
In all of the above cases, a baghouse is usually used for gas cleaning.
8.1.3.1 Control of Melting, Charging and Tapping at Iron Foundries
Of the three control options, canopy hoods have been employed at foundries
which currently control charging and tapping. The close capture/ladle pit en-
closure system has not been used to date at foundries. However, several found-
ries use close capture hoods, and a patented ladle pit enclosure is operating
at a large steel-making EAF. The total furnace enclosure concept is in opera-
tion at only one domestic steel-making EAF facility and has not been used in
iron foundries to date.
Canopy hoods combined with side draft hoods typically provide 95 percent
removal of all furnace emissions, while the close capture hood/ladle enclosure
system is somewhat more efficient at 97.5 percent. Total enclosure systems are
expected to be at least as efficient as the close capture hood/ladle enclosure
system, if not more so (refer to Section 3.7). Canopy hood efficiency is ad-
versely affected by crossdrafts in the shop and may, in some cases, provide
substantially less than the 80 percent collection of charging and tapping emis-
sions. Collection efficiency of the close capture/ladle enclosure is not sub-
ject to this problem, although the 80 percent efficiency claimed by the manu-
facturer for collecting charging emissions could be reduced when very dirty
scrap is used. Adequate data is not available for a proper assessment.
8-8
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When comparing costs and energy requirements for the close capture/ladle
enclosure and side draft/canopy hood options, the canopy hood appears in an un-
favorable light. For a small (new) model furnace, annualized costs for close
capture/ladle enclosures are $58,000 compared to $246,000 for the side draft/
canopy hoods. For the large model furnace, the canopy hood option is 100 per-
cent more costly than for the close capture/ladle enclosure. Costs of retro-
fitting the close capture/ladle enclosure system are approximately 5 to 10 per-
cent greater than costs of a new installation. For the canopy hood option,
however, retrofit costs are approximately 30 percent greater than new installa-
tions (see Section 4.0). Energy requirements, as presented in Section 5.0, are
about 100 percent greater for the canopy hood option than for close capture/
ladle enclosures with respect to the small model furnace, and about 30 percent
greater for the large model furnace.
Annualized costs and energy requirements for the total furnace enclosure
have not been assessed due to the lack of operating data. However, capital
costs are expected to be greater for the enclosure compared to other options,
while operating costs (including energy requirements) should be between those
estimated for close capture/ladle enclosures and side draft/canopy hoods.
The quantity of dust collected by each of the above three options would
be approximately equal, corresponding to the uncontrolled emission factor for i
iron production (7.0 kg/Mg of iron charged for melting and refining emissions
and 0.7 kg/Mg for charging and tapping).
Regulatory formats based on concentration or mass standards could be applied
to effluents from the baghouse which cleans the combined charging, tapping and
melting emissions. It would be difficult, if not impossible to set a standard
specifically for charging and/or tapping because of the difficulty in identify-
ing and measuring these specific emissions at the baghouse. An opacity standard
8-9
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would be useful to ensure proper baghouse operation, and particularly useful in
evaluating fugitive emissions which escape collection by the furnace evacuation
systems. EPA visible emission data for uncontrolled tapping emissions which
escape foundry roof vents, as presented In Section 3.6 and Appendix A, show
that opacity is normally less than 20 percent for 3 minutes, with no alloys
added to the ladle, and normally less than 40 percent for 3 minutes with alloy
addition to the ladle.
An equipment standard specifying either close capture/ladle enclosures
or total furnace enclosure could be used for new shops which could be designed
to accommodate these devices. For retrofitted shops, space and furnace opera-
tional characteristics will usually preclude retrofit of the total enclosure.
Space limitations at some foundries may also hinder Installation of the close
capture/ladle enclosure design. Installation of canopy hoods are not usually
subject to as severe space limitations, although foundry roof areas must some-
times be extensively modified.
An equipment standard should specify the design parameters which affect
particulate collection efficiency. For example, efficiency of the canopy
hoods depends on the size of the hood, distance between the hood and the furnace,
relative diameter and thermal uplift of the furnace, and presence of cross
drafts In the shop. Since each foundry Is different, it would be difficult to
quantitatively specify these parameters In an equipment standard for canopy
hoods. Exhaust ventilation rates, however, have a significant Impact on canopy
efficiency and typical flowrates are summarized on page 4-3. For the close
capture/ladle enclosure design for control of melting, charging, and tapping,
the equipment specification should contain the Items already discussed In
Section 8.1.2.1, namely exhaust flowrates (page 4-3), diversion of flow to
charging hood of ladle enclosure, and perhaps, geometric design of the hoods.
8-10
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8.1.3.2 Control of Melting, Charging and Tapping at Steel Foundries
The above discussion (8.1.3.1) pertaining to the iron foundries also ap-
plies to steel foundries with minor exceptions as noted below.
The close capture/ladle enclosure and total furnace enclosure options are
identical for iron and steel foundries, the only difference being a somewhat
greater quantity of dust collected for steel (emission factors are 7.0 kg/Mg of
iron and 8.0 kg/Mg of steel, plus 10 percent for charging and tapping). Annu-
alized costs for canopy hoods/direct evacuation system at medium and large
steel furnaces are slightly lower than canopy hoods/side draft hoods on iron
furnaces because of reduced gas volumes necessary for control of melting emis-
sions with direct evacuation. Similarly, energy requirements are slightly
lower for this option at steel foundries. Costs and energy use of the canopy
hoods themselves are equal for iron and steel furnaces.
Comments in Section 8.1.3.1 concerning regulatory formats for total control
of iron furnaces also apply to these options identified for steel foundries.
The only difference would be those aspects concerning use of direct evacuation
for melting control at steel furnaces, relative to side draft hoods used for
melting control at iron furnaces. These aspects were discussed in Section 8.1.1
which discusses control of melting emissions only.
8.2 FORMAT OF REGULATIONS FOR THE ELECTRIC ARC FURNACE AT IRON AND STEEL
FOUNDRIES
Regulations may be based on one of four available formats:
mass limitations (kg/hour of particulate, or kg/Mg of iron
or steel produced)
concentration limitations (usually mg/dry standard cubic
meter - mg/dsm3)
8-11
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opacity limitations
equipment specifications requiring the installation and proper
operation of certain types of control equipment.
Mass discharge standards commonly used in state regulations for processes
such as the EAF expressly limit total mass of particulate discharged, based on
process weight rates. However, many New Source Performance Standards (NSPS)
promulgated by EPA for other industries are written in terms of exhaust con-
centration achievable by best demonstrated control technology and do not
directly limit total mass discharge. In practice, opacity standards are often
used by state regulatory agencies as a major enforcement tool, because viola-
tions can be easily and quickly determined. This is generally true of both
furnace emission stacks and fugitive emissions from charging and tapping.
Equipment standards are not usually written into a regulation, but are often
implied, as stringent regulations can often be met only with certain types of
control equipment. Each of the above regulatory formats is applicable to the
EAF and has certain advantages and disadvantages which influence the effective-
ness of reducing particulate emissions and also enforcement of the standard.
8.2.1 Concentration Limitations
A concentration limitation is often applied to baghouses which tend to be
insensitive to inlet concentrations and produce a fairly consistent effluent
concentration. This type of standard is desirable as it does not restrict
volume of air withdrawn through furnace evacuation systems, allowing flexibility
in capture flow rates maintained at the furnace. However, concentration limits
do not restrict the total mass discharged from the baghouse.
The concentration standard (and also mass standards) cannot generally be
applied to just charging and tapping, since these emissions are intermittent .
8-12
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and of a short duration. Accurate sampling of collected and controlled charging
and tapping emissions is almost impossible, and it may also be difficult to
identify charging and tapping emissions from other furnace operations.
Enforcing a concentration standard requires sampling of control device
exhaust streams which is sometimes difficult. Sampling procedures are not
standardized for the positive pressure baghouse, sometimes installed on EAF's, be-
cause of multiple discharge points and low exhaust flow rates. Measuring low
exhaust concentrations from the very efficient fabric filter requires long
sampling times to ensure collection of adequate sample weight. Sampling pro-
cedures, in general, must also consider the variation of fume concentration
during furnace operation cycles. However, enforcement of concentration stan-
dards can frequently be supplemented by opacity readings because of the general
relationship between concentration and visible emissions from the EAF. A pro-
perly designed and well operated baghouse is capable of an effluent concentra-
tion of 12 mg/dsm3 (0.0052 gr/dscf) based on EPA test data summarized in
Section 3.6.
8.2.2 Mass Standards
Unlike a concentration standard, a mass discharge standard limits the total
amount of particulate emitted from the baghouse. Stringent mass standards may
provide an incentive to an operator to restrict air flow through the fume con-
trol equipment to the minimum necessary for effective capture of furnace emis-
sions to maintain compliance. This is often an undesirable situation because
reduced exhaust flow can result in Inefficient fume capture at the furnace, in-
creasing uncontrolled fugitive emissions. Consequently, a stringent mass dis-
charge standard must be designed to allow the furnace operator flexibility in
maintaining an exhaust flow rate most effective for a particular shop.
8-13
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Enforcing a mass standard requires sampling which involves difficulties
in measuring low exhaust concentrations, analogous to sampling for concentration.
Unlike concentration standards, mass standards are based on plant production
rates which must be accurately obtained from the plant.
8.2.3 Cjpacity Standards for Melting and Charging and Tapping Emissions
Opacity standards can be enforced quite easily and frequently by trained
smoke observers, and this is a strong advantage compared to concentration or
mass limits which require actual sampling of emissions. An opacity standard
is the only type which can be used to evaluate fugitive emissions which result
from a poorly operating melting, charging or tapping evacuation system. This
is an important advantage because a furnace evacuation system could be collect-
ing only a small portion of furnace emissions, while still meeting mass emission
standards as measured as the outlet of the fabric filter glass cleaning device.
Another advantage of an opacity standard is that it could be written to
allow for the higher emission rate which occurs immediately after charging
and during alloying. However, enforcement may present problems. If opacity
is read outside the foundry above roof vents, charging emissions may be un-
distinguishable from other fugitive shop emissions escaping through the same
roof vent. The opacity standard could be written to be applicable to emis-
sions as they leave the furnace, prior to exiting through roof monitors. This,
however, may cause enforcement problems, as such emissions to the internal
foundry atmosphere are not normally considered within the realm of air pollution.
One common criticism of an opacity standard is the somewhat subjective
nature of smoke reading. However, a properly operating baghouse should exhibit
an opacity of zero, or only a few percent. It is thus fairly easy to observe
whether the. control system is functioning properly.
8-14
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Opacity standards alone are not generally considered to be quantitative
enough to evaluate performance of a sophisticated and highly efficient control
system. However, they have several important features which account for their
frequent use by state agencies. Enforcement is easy since violations are
easily recorded by one trained observer in a short amount of time. Determining
compliance does not require advance notification and preparation at the plant,
and compliance can often be determined from outside plant grounds. Thus, both
costs and manpower requirements are drastically lower for enforcing opacity
standards compared to concentration and mass standards. EPA visible emission
data for several foundries was reported in Section 3.6 and Appendix A. For
baghouse emissions, the maximum opacity generally reported for iron furnaces
is below 10 percent, and for steel furnaces, below 5 percent. For fugitive
emissions escaping foundry roof vents, charging of iron furnaces generally
showed maximum roof vent opacities below 10 percent, for 3 minutes. While
tapping iron, with no alloys added to the ladle, maximum opacities were be-
low 20 percent for 3 minutes. For steel furnaces, data developed from large
steel mill EAF's showed charging emissions below 20 percent (3 minutes) and
tapping emissions below 40 percent (for 3 minutes) at the roof monitor.
8.2.4 Equipment Standards for Melting Emissions
To avoid difficulties inherent with sampling Demissions, regulations could
simply require installation of specific control equipment. An equipment stan-
dard must be written in a manner which avoids potential retrofit problems.
For example, structural or operational constraints may prohibit use of certain
control techniques. An example would be lack of physical space around a fur-
nace for a close-capture hood or furnace enclosure.
Enforcement of an equipment standard for melting emissions would be quite
easy as the standard would specify the required type of control. The design
8-15
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and types of melting control systems are well established, and level of per-
formance achievable is quite clear. Certain parameters must be included in the
equipment standard, as discussed in this section and in Section 3.0. The
regulatory agency would, however, need to evaluate engineering plans for a pro-
posed control device and determine whether the design is adequate. This may
place a burden on some agencies.
8.3 SUMMARY OF REGULATORY CONTROL OPTIONS
Table 8-1 summarizes control options for new medium-sized (9.1 Mg/hr)
model iron furnaces and indicates particulate removal efficiency, total an-
nualized costs and energy requirements, as developed in preceding sections.
Table 8-2 summarizes control options and other data for new steel furnaces
(9.1 Mg/hr). For retrofitted furnaces, annual costs tend to increase slightly
(see Section 4.0) while particulate removal efficiency and energy requirements
are equal to new installations. For small and large model plants, total par-
ticulate efficiency is equal to that shown in the tables for medium plants,
while annual emissions change in proportion to furnace size and annual operating
time. Total annualized costs and energy requirements for other furnace sizes
increase or decrease from those shown for medium furnaces, roughly in propor-
tion to the relative furnace sizes (see Section 4.0).
As shown in Tables 8-1 and 8-2, control of melting emission provides 87 to
89 percent control of total furnace emissions; this can be achieved by side
draft hoods or direct evacuation plus baghouses. This results in annual emis-
sions of 16.1 megagrams for steel and 17.5 megagrams for iron furnaces. Energy
requirements and costs are substantially less for the direct evacuation system,
but this can only be used on steel furnaces.
8-16
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Table 8-1. SUMMARY OF REGULATORY OPTIONS FOR A NEW MODEL 9.1 Mg/hr FURNACE PRODUCING IRON
oo
i
Control option
Melting Emissions
1. Side draft hood plus baghouse
Melting and Charging
1. Side draft hood plus
clean scrap plus baghouse
2. Close capture system
plus baghouse
Melting, Charging and Tapping
1. Side draft and canopy
hoods plus baghouse
2. Close capture system,
ladle pit enclosure
plus baghouse
3. Total furnace enclosure
plus baghouse
Total
particulate removal
efficiency
(percent)
87
92
96
95
97
99
Annual! zed
costs for
new plants
(103 $/yr)
70
103
80
272
94
N/A
Energy requirement
(105 kWh/yr)
0.30
0.30f
0.30
0.54
0.30
N/A
Annual
emissions
(Mg/yr)
17.5
10.7
5.4
6.7
3.4
1.3
Annualized costs include amortized capital costs, operation costs and maintenance cost.
Does not account for potential savings in melting energy requirements resulting from charging of
hot scrap.
-------
Table 8-2. SUMMARY OF REGULATORY OPTIONS FOR A NEW, MODEL 9.1 Mg/hr, FURNACE PRODUCING STEEL
oo
I
oo
Total Annualized ._ ..
Control option particulate removal costs for Energy requirement A^nu^1
efficiency new plants 106 kWh/yr) emissions
(percent) (103 $/yr) (Mg/yr)
Melting Emissions
1. Direct evacuation plus baghouse 89
Melting and Charging
1. Direct evacuation plus clean 93
scrap plus baghouse
2. Close capture system 93
plus baghouse
Melting, Charging and Tapping
1. Direct evacuation plus 97
canopy hoods plus baghouse
2. Close capture system plus ladle 97
pit enclosure
3. Total furnace enclosure 99
28 0.10 16.1
61 O.llf 10.8
80 0.30 10.8
288 0.36 4.6
94 0.30 3.8
N/A N/A 1.5
Annualized costs include amortized capital costs, operation costs and maintenance costs.
Does not account for potential energy savings resulting from charging of hot scrap.
-------
For control of melting and charging, either the close capture system can
be used (for both iron and steel) or scrap preheaters in conjunction with side
draft hoods (iron) or direct evacuation (steel). For iron furnaces, the close
capture system is less expensive than preheaters with side draft hoods, and
also provides improved collection of all furnace emissions (96 percent versus
92 percent for side draft hoods with preheater). For steel furnaces, however,
the preheater with direct evacuation is less expensive than close capture hoods
because exhaust flows from direct evacuation are considerably less than for
close capture hoods.
For control of melting, charging and tapping, data is only available for
two options: (i) canopy hoods with side draft hoods (iron) or direct evacua-
tion (steel) and (ii) close capture hoods with ladle pit enclosure. The
close capture/ladle enclosure system is more efficient (97.5 percent total
particulate removal, versus 95 percent for the canopy hood option) and also
less costly to operate, by a factor of three or four.
The total furnace enclosure is probably more efficient in particulate re-
duction potential, but data for assessing this option is not readily available.
Capital and operation costs are likely to be greater for the enclosure than
the close capture option, but less than the canopy hood option.
8-19
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APPENDIX A
EMISSION TEST DATA FOR FABRIC FILTERS AT
IRON AND STEEL ELECTRIC ARC FOUNDRIES
This appendix presents emission test data for iron and steel electric
arc furnaces which was summarized previously in Section 3. Section A.I shows
results of particulate and gaseous sampling and opacity observations conducted
by EPA at four iron foundries, and data from two other foundries. Section A.2
presents results of other available data for steel foundry particulate emis-
sions, and Section A. 3 shows opacity observations made by EPA at two steel-
producing foundries.
A.I PARTICULATE EMISSION LEVELS AND OPACITY FROM FABRIC FILTERS AT IRON
ELECTRIC ARC FURNACES
The following discussion summarizes results of emission sampling con-
ducted on baghouses installed on electric arc furnaces at six different gray
iron foundries. Analyses were conducted for both particulate and gaseous
pollutants. The concentration of particulate emissions was measured by EPA
Method 5 as outlined in the Federal Register, December 31, 1971. Each test
consisted of sampling in the baghouse exhaust stack, downstream of the baghouse
and exhaust fans.
Plant A has three arc furnaces of 13.6 to 14.5 megagrams (15 to 16 tons)
melting capacity each. This is a new foundry and the design of the arc fur-
nace and pollution control equipment were based on experience obtained at
Plant B, another foundry operated by the same company. A "heat" encompasses
A-l
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the time from the beginning of charging to the end of the tapping of molten
metal. Two automatically-shaken (for cleaning purposes) baghouses provide
for gas cleaning. Two furnaces are exhausted to one baghouse while the third
furnace is controlled by the other baghouse. The furnaces are equipped with
side draft hoods and also hoods above the pouring spout and the slag door.
All three hoods are connected to a common take-off box which is under suction
from the centrifugal fan at the baghouse. Overhead roof fans and monitors
ventilate the furnace scrap bay areas and also withdraw a small amount of air
from adjacent areas. An inlet duct (1.5 meters in diameter) about 13 meters
(43 feet) above each furnace is manifolded to the main furnace exhaust duct
which leads to the baghouse. These inlet ducts are not canopy type hoods but
are open end pipes which extend down from the roof area towards each furnace,
and are used during charging and tapping of the furnace. Being just an open
end duct, and not a complete canopy-type hood, complete control of charging
and tapping is not provided, especially during the time of pronounced cross-
drafts. The baghouse which was sampled controls two furnaces. The Dacron
filter bags withstand a maximum temperature of 135°C (275°F), and the air-to-
cloth ratio is 2.54:1. The baghouse inlet and outlet were,sampled for par-
ticulates (by EPA Method 5), carbon monoxide (using a nondispersive infrared
(NDIR) analyzer), hydrocarbons (using a Beckman Hydrocarbon Analyzer), sulfur
dioxide (by EPA Reference Method 6), and nitrogen oxides (by EPA Reference
Method 7). Both furnaces were performing at design capacity during the tests,
and the emission control system appeared to be operating well. Measurements
of flow rate averaged 77.0 dry standard cubic meters per minute per megagram
of iron produced (2490 dscf/m/ton of iron). Each sample period commenced
with the beginning of a heat cycle on one of the furnaces and continued for
A-2
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approximately 3 hours. Generally, the furnaces were on a staggered schedule.
An average heat lasted about 70 minutes, and the sampling period encompassed
two full heats on each furnace.
Detailed results of the tests are part of this appendix, Tables A-l
and A-2. Average partlculate loadings, determined from the four samples,
were 8.7, 8.0, 6.4 and 12.0 mg/dscm (0.0038, 0.0035, 0.0028, and 0.0054 grains
per dry standard cubic foot, gr/dscf), for an average of 8.9 mg/dscm
(0.0039 gr/dscf).
Concurrent with baghouse sampling, visible emission data were obtained
for the baghouse stack and for the roof monitor above the furnaces. The
highest opacity (6-minute average) observed from the baghouse stack during
the nearly 15 hours that readings were taken was 10 percent. The opacity was
zero about 80 percent of the time. At the roof monitor, the maximum 6-minute
average opacity was 10.0 percent, but the opacity was zero about 90 percent
of the entire period of scrutiny. The detailed results of the visible emis-
sion readings are presented in this appendix in Tables A-12 through A-19.
Plant B is a new foundry with four electric arc furnaces of 11 to 12 mega-
grams, 12 to 13 tons melting capacity per heat, each. Particulate emissions
from each pair of furnaces are controlled by a common fabric filter dust col-
lector. The furnaces are equipped with side draft hoods and also hoods above
the pouring spouts and slag doors. All these hoods are connected to a take-
off box which is under suction via the automatically-shaked baghouse by a
centrifugal fan. The fan withdraws an average of 97 dscm/m/Mg of iron
(3,117 dscf/m/t of iron). The Dacron filter bags withstand a maximum tem-
perature of 135°C (275°F). The air-to-cloth is 2.26. Roof fans and moni-
tors ventilate the furnace and scrap bay areas, also withdrawing small amounts
of air along from adjacent foundry areas. The same analyses were carried out
A-3
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at this plant as In Plant A, except only on the outlet of the control device.
The two furnaces tested as well as the other two were performing at design ca-
pacity and the dust control system was operating normally. The furnaces are
on a staggered schedule. The sampling cycle was begun at the beginning of a
heat at one furnace, and continued for approximately 3 hours. The average
heat lasted about 70 minutes, and sampling covered two full heats on each
furnace. Detailed sampling results are presented in this appendix as Table A-3.
The average particulate loadings from the three samples were 15.1, 8.7, and
8.7 mg/dscm, averaging 11.0 mg/dscm (0.0066, 0.0038 and 0.0038 gr/dscf for an
average of 0.0048 gr/dscf).
Concurrent with baghouse sampling, visible emissions data were obtained
for the stack of the baghouse and also the roof monitor vent above the fur-
naces. The maximum 6-minute average opacity at the baghouse stack was 11.5
percent, although opacity at the stack was zero about 80 percent of the time.
At the roof monitor, the maximum 6-minute average opacity was less than 1 per-
cent and the opacity was zero more than 98 percent of the time. Detailed
results of visible emission readings are presented in this appendix in
Tables A-20 through A-25.
Plant C has two furnaces which produce up to 7 megagram (8 tons) of gray
iron each, per heat. Each arc furnace is controlled by a separate fabric
filter dust collector, and both furnaces and collectors are retrofits. The
furnaces are equipped with roof type hoods and also hoods above the pouring
spout and slag door which are connected to individual take-off boxes
(57.4 dscm/m/Mg of iron, or 1855 dscf/m/ton). The Orion filter bags withstand
a maximum temperature of 105 C (225 F), and the air-to-cloth ratio is 2.83.
Both furnaces were operating during the tests, and the dust control system
A-4
-------
was operating normally. Furnace production during each test varied, namely,
7, 6 and 4.5 megagrams (8, 7 and 5 tons) per heat, for each of the three
sampling periods. Roof fans and monitors ventilate the furnace and scrap bay
areas, withdrawing small amounts of air from adjacent areas and exhaust directly
to the atmosphere.
Particulate, carbon monoxide, hydrocarbons and sulfur and nitrogen oxides
were measured on the stack of one of the dust control devices, downstream of
the fan and fabric filter. Each sample was collected over a 1.5 hour period
in a manner analogous to previously described sampling. Sampling periods
coincided with the beginning of a furnace heat cycle and were finished prior
to the end of the heat cycle. An average furnace heat lasted about 90 minutes.
The average particulate emissions for the three tests were 36.5, 43.0, 65.4
mg/dscm, averaging 48 mg/dscm (0.01599, 0.01877, and 0.02858 gr/dscf averaging
0.02106 gr/dscf). These results are presented in Table A-4. Emissions at
facility C are higher than at the other facilities probably due to two reasons:
1. The collector is manually shaked, and therefore cleaned at irregular
intervals and subject to overcleaning. Overcleaning results in a poor filter
cake buildup, reduced collection efficiency, and higher emissions.
2. Injection of carbon raiser to the molten bath is carried out via a
lance by means of compressed air. Only about 60 to 85 percent of the carbon
is dissolved in the metal or retained in the slag, and some carbon escapes the
furnace to the baghouse. Due to the very small particle size, only some of
the carbon particles are collected in the baghouse.
Visible emissions data were also obtained during sampling periods, for
the baghouse exhaust stack and the roof monitor vent above the furnace. The
maximum 6-minute average opacity at the stack was 30 percent, but occasional
A-5
-------
peaks of up to 80 percent were observed for short periods (several seconds
only). At the roof monitor, opacity was zero over 98 percent of the time,
but the maximum 6-minute average was 32.5 percent. The much higher opacity
of emissions from this plant are a consequence of the two somewhat unique
characteristics of this particular foundry., the carbon black injection,
and manual shaking of the baghouse. Detailed results of the visible emissions
readings are presented in this appendix in Tables A-26 through A-31.
Plant D has one furnace which produces 5.4 megagrams (6 tons) of gray
iron per heat. The arc furnace is surrounded on three sides by two walls and
the transformer room wall, so that fumes from charging and upset conditions
(gas puffs escaping through the electrodes holes or other furnace openings)
are directed upward to a ventilation fan located above the furnace. Thus,
fugitive emissions from the furnace are emitted to the atmosphere in greater
concentrations than at the other foundries tested in this program. In the
previous foundries, the furnaces were located in large open bay areas, con-
sequently, furnaces were subject to crossdrafts and drift at times sidewards
instead of upwards. The furnace is retrofitted with a side draft hood and hoods
above the pouring spout and slag door. The gaseous discharge rate to the fabric
filter control device averaged 96.4 dscm/m/Mg of iron (3,100 dscf/m/t of iron).
The Dacron filter bags withstand a maximum temperature of 135°C (275°F). The
air-to-cloth ratio is 2.61. The first test was run only for 1 hour; i.e., only
during one heat. However, the next two tests were extended over two heats to
capture a greater quantity of dust on the sampling filters. Each test was
started at the beginning of two consecutive heats and continued for 1 hour dur-
ing each heat. An average furnace heat lasted about 70 minutes, and the fur-
nace operated at design capacity. Particulate measurements were made at both
A-6
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the inlet and outlet of the collector. The three measurements showed particu-
late concentrations of 18.1, 3.1 and 6.3 mg/dscm, averaging 10.5 mg/dscm
(0.00792, 0.00137, and 0.002768 gr/dscf for an average of 0.0046 gr/dscf) at
the baghouse outlet. The detailed results of the tests are in Tables A-5 and
A-6 of this appendix.
Concurrent with sampling of the baghouse, visible emissions data was
obtained for the baghouse exhaust stack and the roof monitor vent above the
furnace. Opacity at the stack was zero about 98 percent of the time, and the
highest 6-minute average opacity was 5.0 percent. On the first sampling
period, opacity at the foundry roof vent was zero, 100 percent of the time,
but reached a maximum 6-minute average of 7.5 percent on a subsequent test.
A summary of visible emission data for charging and tapping and fugitive emis-
sions, and also baghouse emissions, is presented in this appendix in
Tables A-32 through A-38.
Plant E operates one electric arc furnace capable of producing either
12.5 megagrams (14 tons) per heat or 6 megagrams/hr (7 tons/hour) of gray iron.
Particulate emissions from the furnace are controlled by a fabric filter dust
collector. The furnace is equipped with side draft hoods and hoods above the
pouring spout and slag door. Roof fans and monitors, discharging directly to
the atmosphere, ventilate the furnace bay area. Emissions were sampled at the
stack on the baghouse outlet where the flow rate was 86.9 dscm/m/Mg of iron
(2810 dscf/m/ton). The bags are made of Dacron and withstand a maximum tem-
perature of 135 C (275 F). The air-to-cloth ratio is 3.1. Average particu-
late loadings, as determined by the three samples, were 12.8, 23.3, 13.5
mg/dscm, averaging 16.5 mg/dscm (0.0056, 0.0102, and 0.0059 gr/dscf, averaging
0.0072). These data are presented in Table A-7.
A-7
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During these tests, sampling periods were selected to coincide with
different times of the heat cycle - the first test was started when the heat
was begun; the second test was started 1 hour after the furnace was started;
the third test was started 1.5 hours after the furnace was started. The in-
tegration of all three tests should provide a good average because a heat on
this furnace lasts about 2.5 to 3 hours.
Visible emission observations were taken only for the stack of the dust
collector. Opacity was not evaluated in accordance with standard methods,
but rather by frequent spot checks which showed a maximum opacity of 5 percent
from the baghouse.
Plant F has two electric arc furnaces of 13.5 to 15.3 megagrams (15 to
17 tons) melting capacity per hour each (27 to 32 megagrams per heat). One
baghouse serves the two gray iron producing arc furnaces, two induction
holding furnaces and one duplexing arc furnace. The volume withdrawn from
each gray iron furnace is 74 dscm/s (157,000 acfm) at 135 C (275 F). Sampling
was conducted at the stack outlet of the collector. The furnaces are equipped
with side draft hoods, hoods above the pouring and slag doors, and also a
direct furnace evacuation tap. All hoods are connected to a takeoff box which
is under suction via the baghouse by a centrifugal fan. The direct furnace
evacuation system is only in operation for 20 to 25 minutes at the beginning
of the melt until the oil from the scrap charge is burned off. (These fur-
naces melt scrap consisting of 40 percent by weight of borings and turnings
which contain up to 10 percent oil). Roof fans and monitors which exhaust
directly to the atmosphere ventilate the furnace bay area and adjacent aisles.
Sampling was conducted for 2 hours with a test method similar to EPA's Method 5
which meets most of the EPA criteria. In these tests, the sampling period was
A-8
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not selected to coincide with the beginning of a heat cycle on one of the
furnaces. Generally, the furnaces are on a staggered schedule.
The highest particulate concentration during these tests was 10.3 mg/dscm
(0.0045 gr/dscf). Most of the time, emissions were around 3.2 mg/dscm
(0.0014 gr/dscf). The lowest level measured was 1.6 mg/dscm (0.0007 gr/dscf),
while the average of 15 measurements was 3.2 mg/dscm (0.0014 gr/dscf). The
bags are made of Nomex and withstand a maximum temperature of 204 C (400 F).
The data summary of these tests is not available.
Carbon monoxide levels were tested during the EPA tests on four of the
foundries, and the data is presented in Tables A-8 through A-ll. During all
tests, emissions were continuously monitored with a.nondispersive infrared
analyzer. The sampling location was downstream of the furnace, at the fan,
where the temperature is far below the 700 C above which pyrophoric conditions
exist. Measurements began during charging and continued until the tap was
complete.
At Plant A, carbon monoxide ranged from 33 to 275 ppm with an average
(based on three tests) of 95 ppm. The overall hourly emission rates which
were measured are rather uniform, the highest differing from the lowest by
about 16 percent. The average level, based on three tests, is 0.62 kg/hr per
Mg/hr (1.26 Ib/hr per ton) of melting capacity.
At Plant B, carbon monoxide ranged from 14 to 142 ppm with an average
(based on three tests) of 73 ppm. The overall hourly emissions vary somewhat,
the highest differing from the lowest by about 33 percent. The average level
of carbon monoxide, based on three tests, is 0.52 kg/hr per Mg/hr of furnace
capacity (1.03 Ib/hr per ton per hour).
A-9
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At Plant C, carbon monoxide ranged from 10 to 425 ppm, with an average
(based on three tests) of 121 ppm. The overall hourly emissions also vary,
the highest differing from the lowest by about 44 percent. The average level
of carbon monoxide, based on three tests, is 0.73 kg/hr per Mg/hr (1.45 Ib/hr
per ton per hour).
At Plant D, carbon monoxide ranged from 0 to 435 ppm with an average
(based on three tests) of 104 ppm. The highest measurement differs from the
lowest by about 60 percent. The average level of carbon monoxide, based on
three tests, is 0.45 kg/hr per Mg/hr (0.775 Ib/hr per ton per hour).
During these tests, emissions of sulfur dioxide, hydrocarbons, and nitrogen
oxides were also measured. Because no control techniques exist for any of
these pollutants (including carbon monoxide) on electric arc furnaces, these
measurements are not discussed further. Detailed data on these readings are
also reported in Tables A-8 through A-ll.
A.2 PARTICULATE EMISSION LEVELS FROM FABRIC FILTERS AT STEEL ELECTRIC ARC
FURNACES
Several steel foundries and air pollution control agencies in the U.S.
and abroad were contacted to obtain emission test data. These data are pre-
sented in Table A-39 (metric units) and repeated in Table A-40 (English units).
Plant A operates a 27.2 Mg (30 short tons) capacity basic electric arc
furnace with single slag. Furnace emissions are evacuated by a side draft
hood, and the control device is a fabric filter with an air-to-cloth ratio
of 2.5:1. The fabric filter is shaken once per heat, at the end of the furnace
heat. The baghouse was designed for 95,000 dscm/hr (80,400 acfm); however,
it operates at 81,300 dscm/hr (68,800 acfm). The installation was acceptance
tested in February 1969, using the ASME Method. Each test lasted 60 minutes,
A-10
-------
whereas a typical furnace heat with oxygen lancing lasts about 2 hours. Each
of the four sampling periods encompassed the time of highest particulate
emissions, during oxygen lancing. The following outlet loadings were recorded
in the four different tests: 9.17 mg/dscm (0.004 gr/dscf); 5.73 mg/dscm
(0.0025 gr/dscf); 6.87 mg/dscm (0.003 gr/dscf); and 36.68 mg/dscm (0.016
gr/dscf). The average outlet loadings were 14.58 mg/dscm (0.0064 gr/dscf).2
Plant B operates a 29.92 Mg (33 short tons) capacity basic electric arc
furnace with single slag. A side draft hood collects emissions which are
exhausted to a fabric filter with an air-to-cloth ratio of 2.5.1. The bag-
house was designed for 115,700 dscm/hr (98,000 acfm), but operates at
95,000 dscm/hr (77,000 acfm). The installation was acceptance tested in
February 1969, using the ASME Method. Each test lasted 60 minutes, whereas a
typical furnace heat with oxygen lancing lasts about 2 hours. Each sampling
period included the oxygen lancing operation. The following outlet loadings
were recorded in two different tests: 4.6 mg/dscm (0.002 gr/dscf) and 6.87
mg/dscm (0.003 gr/dscf). The average outlet loadings amount to 5.73 mg/dscm
(0.002 gr/dscf).2
Plant C operates a 33.2 Mg (36.5 short tons) capacity basic electric arc
furnace with single slag. Furnace gases are evacuated by direct shell evacua-
tion to a baghouse which handles 43,800 dscm/hr (29,550 acfm). Dacron bags
operate at an air-to-cloth ratio of 2. A typical furnace heat with oxygen lanc-
ing lasts about 3 to 4 hours, depending on the availability of electrical energy.
The tests were carried out using EPA Method 5. The first test encompassed the
backcharging and the total test time was 80 minutes. The second test was con-
ducted near the middle of a 5-hour heat, and the total time for the second test
was also 80 minutes. The third test, of 30 minutes duration, was conducted
A-ll
-------
after backcharging, but prior to oxygen lancing. The following outlet loadings
were recorded in the three different tests: 5.73 mg/dscm (0.00225 gr/dscf);
2.8 mg/dscm (0.001223 gr/dscf); and 8.71 mg/dscm (0.0038 gr/dscf). The average
outlet loadings amount to 5.74 mg/dscm (0.0025 gr/dscf).6
Plant D operates a 20 to 22 Mg (22 to 24.2 short tons) capacity basic
electric arc furnace with single slag. Furnace gases are also evacuated by
direct shell evacuation to a fabric filter which treats about 28,000 to
30,000 dscm/hr (16,478 to 17,655 dscfm). Emission sampling tests were con-
ducted at both the inlet and the outlet of the baghouse. Outlet loadings
range between 6 and 20 Mg/dscm (0.0026 to 0.0087 gr/dscf). The average out-
let loading of 14 tests was 7 mg/dscm (0.003 gr/dscf).7 The highest loadings
were experienced during oxygen lancing. A normal heat for this furnace lasts
2-1/2 hours.
Plant E has two furnaces, one producing 7 Mg (7.7 short tons) per heat
and the other 4 Mg per heat (4.4 short tons). The gas volume for the first
furnace is 16,000 dscm/hr (9416 dscfm), and for the second is 12,000 dscm/hr
(7,062 dscfm). Furnace exhausts are combined and treated in a single fabric
filter. The outlet temperature is 70 to 80°C (183 to 200°F). Inlet and
outlet loadings were taken during tests; outlet lo.adings ranged between
1 mg/dscm (0.0026 gr/dscf) and 4 mg/dscm (0.00174 gr/dscf).7
The two test results for Plants D and E originate from Germany and were
conducted with the VDI particulate test method, which is not identical to
EPA Method 5. Based on previous tests carried out in Germany on municipal
incinerators, EPA Method 5 collected 30 percent more dust from the cleaned
gas stream. The German test results are very similar to the ones obtained
from steel electric arc furnaces in this country if this correction is applied.
A-12
-------
Plant F operates one basic arc furnace producing 27.27 Mg (30 short
tons) per heat, with single slag. Direct shell evacuation directs emissions
to a fabric filter. The installation was acceptance tested in May 1973,
using EPA Method 5. The gas volume is 174,390 dscm/hr (102,628 dscfm), with
temperature of the outlet gas stream of 49 C (88 F). The tests were run
during two consecutive heats, the first handling 28.4 Mg (31.2 short tons) and
the second 28.2 Mg (31 short tons) of scrap and additives. The following
concentrations were measured: inlet, 68.6 mg/dscm (0.0295 gr/dscf); outlet,
6.63 mg/dscm (0.0029 gr/dscf).8 The entire test lasted 4 hours, since 2 hours
are needed to complete each heat.
German sources report that the average outlet loadings from baghouses on
arc furnaces in the steel foundry industry average 1.0 mg/cm (0.00043 gr/dscf).
The temperature of the gases is not indicated, but assuming 100 C (212 F) at the
fabric filter inlet and outlet, emissions will be about 35 percent higher when
expressed at standard conditions. Direct shell evacuation is used on these
furnaces, and the data applies only to melting and refining emissions.
Another German company reports that for about 30 fabric filters installed
in their own plants, and other companies also producing steel castings (mostly
with direct shell evacuation), the outlet loadings ranged between 2 mg and
20 mg/dscm (0.00087 and 0.0087 gr/dscf, respectively). Higher emissions were
experienced on charges that contained large amounts of swarf.3
A French company that has built many control devices for steel electric
arc furnaces for general steel production, and which has pioneered some of
today's techniques in control of fumes from arc furnaces, was also contacted.
The company reports that emissions on steel arc furnaces, similar in size to
those used for steel castings, range between 5 and 15 mg/dscm (0.00217 and
A-13
-------
0.0065 gr/dscf), and that there are no visible emissions at the stack of the
control devices. The higher loadings occur at older installations.^
Emissions from well-controlled (fabric filters) electric arc furnaces in
steel foundries in Italy, are reported to range between 4 to 12 mg/dscm
(0.00174 to 0.00522 gr/dscf).5 Both the Italian and the French methods for
measuring emissions is identical to the German VDI method.
A.3 OPACITY OBSERVATIONS AT STEEL FOUNDRIES
In addition to the above data supplied by plants and suppliers of control
devices, it is reported that no visible emissions are detectable at the stack
during normal operations, including oxygen lancing periods. Two of the plants
were observed by EPA personnel. Plume opacity readings were taken at faci-
lities B and C, according to EPA Method 9, and are reported in Tables A-41
through A-47.
The available opacity data point to two conclusions. The opacity at the
stack of arc furnaces processing steel for castings is lower than opacity
observed on arc furnaces producing iron. The opacity at the stack for
steel producing furnaces seldom exceeds 5 percent, and then only for very
short periods. This is due to the fact that raising the carbon level for
gray iron calls for introduction of black carbon into the molten bath.
Absorption of this carbon is not complete, ranging between 60 to 95 percent.
Large amounts of the fine black carbon particles escape collection in the
control device and produce an opaque plume. Pitch dark plumes have been
observed on gray iron furnaces due to unabsorbed carbon raiser.
With respect to fugitive emissions from the foundry roof, steel foundry
electric furnaces have higher opacity than gray iron foundry arc furnaces
unless backcharging and tapping emissions are controlled.
A-14
-------
The highest 6-minute average opacity recorded due to fugitive emissions
at roof fans or monitors on steel-casting furnaces is about 16 percent at one
plant and about 10 percent on another. Opacity is highest during tapping,
followed by backcharging and then charging. Observed opacities are lower
than for arc furnaces in the steel-making industry which control fugitive
emissions. The main reason for these differences is the size of the furnaces;
steel mill furnaces are much larger than foundry steel furnaces. Conse-
quently, larger quantities of fugitive emissions are generated during furnace
operation.
The high opacity levels shown in Tables A-42 and A-43 are due to the fact
that at this plant they shake the bags once between heats. Following shaking
a certain time is required for a filter cake to build up and allow efficient
filtering. During this time, some emissions might escape and cause a visible
plume. Inspection of the bags 1 week after the visit of the EPA engineers
found that 3 to 4 bags had cracks. Due to the fact that during the rest of
the time the opacity was below 5 percent, the higher opacity levels can be
explained by excessive emissions from oxygen lancing and dislodging of scrap
adhering to the walls.
A-15
-------
TABLE A-l
FACILITY A (Ua&house Inlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity - tons
Flow Kate - ACFM
Flow Sfate - DSCFM
Flow rate - DSCFM/ton of
furnace capacity
Temperature - °F
Water Vapor - Vol. %
C02 - Vol. % dry
02 - Vol. % dry
CO - Vol % dry
Parti cul ate Eitri ss i ons
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hour
Total catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hour
1
6/19/74
210
15.5
95431
72783
2347
188
2.b
0.3
19.7
0.2766
0.2132
172.5
6.28
0.2960
0.2281
185
5.96
2
6/19/74
210
15.5
85721
65721
2120
185
3.1
0.3 .
1935
REPORTED
0.3415
0.2626
190.7
7.b <
0.3690
0.2837
206
6.64
3
6/20/74
210
15.5
90990
76069
2453
189
1.5
0.3
19.5
ELSEWHERE
0.3201
0.2491
192J2
7.0
0.3250
0.2529
195
6.3
Averagi
210
15.5
90714
69343
2236
187
2.4
0.3
19.9
0.3127
0.2146
185.1
6.84
0.3300
0.2549
195
6.3
A-16
-------
TABLE A-2
FACILITY A (Baghouse Outlet)
Summary of Results
Rim Number
Date
Test Time - Minutes
Total Furnace Capacity
- tons
Flow rate - ACFM
Flew rate - DSCFM
Flow rate - DSCFM/ton of
furnace capacity
Temperature - °F
Water vapor - Vol. %
C02 - Vol. % dry
02 - Vol. % dry
CO - Vol. % dry
Participate Emissions
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hour
Total catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton /hour
1
6/18/74
210
15.5
96674
79992
2570
183
212
0.0038
0.0029
2.44
0.089
0.0072
0.0056
4.62
0,167
2
6/19/74
210
115.5
99797
79331
2550
174
1.5
0.0035
0.0028
2.38
0.087
0.0057
0.0045
3.89
0.142
3
6/19/74
210
15.5
98140
76140
2460
185
2,4
SAME AS
0.0028
0.0022
1.83
0.067
0.0044
0.0034
2.87
0.105
4
6/20/74
240
15.5
100111
76985
2475
188
2.9
INLET
0.0054
0.0042
3.56
0.128
0.0073
0.0056
4.83
0.177
Average
217
15.5
99349
77465
2490
182'
2.3
0.0039
0.0031
2.59
0.094
0.0058
0.0045-,
4.05
0.146
A-17
-------
TABLE A-3
FACILITY B (Baghouse Outlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity -
- tons
Flow rate - ACFM
Flow rate - DSCFM
Flow rate - DSCFM/ ton of
furnace capacity
Temperature - °F
Water vapor - Vol. %
C02 - Vol. % dry
02 - Vol. % dry
CO - Vol. % dry
Particulate Emissions
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
Total catch
gr/DSCF
GR/ACF
Ib/hr
'ib/hr per ton/hr
1
6/8/74
215
12.5
85212
65973
2615
197
3.0
0.3
19.3
0.0066
0.0051
3.72
0..174
0.0109
0.0084
6.17
0.288
2
6/9/74
219
12.5
86454
69611
2790
171
2.8
0.2
20.0
REPORTED
0.0038
0.0031
2.26
0.1057
0.0004
0.0052
3.81
0.178
3
6/9/74
214
12.5
84818
65508
2662
195
3.2
0.2
20.0
ELSEWHERE
0.0038
0.0029
2.11
0.098
0.0050
0.0039
2.83
0.134
Averag*
216
12.5
85495
67031
2680
188
3.0
0.234
19.75
0.0048
0.0037
2.71
0.126
0.0074
0.0058
4.27
0.20
A-18
-------
TABLE A-4
FACILITY C (baghouse Outlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity
- tons
Flow rate - ACFM
Flow rate - DSCFM
Flow rate - DSCFM/ ton of
furnace capacity
Temperature - °F
Water vapor - Vol . %
C02 - Vol. % dry
02 - Vol . % dry
CO - Vol . % dry
Particulate Emissions
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
Total catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
1
9/18/74
120
7
14771
12006
1720
184
0.7
0.7
20.6
0.01599
0.01988
2.03
0.58
0.02195
0.02701
2.96 .
0.84
2
9/18/74
78
5
15196
12317
2470
186
0.7
0.5
20.4
REPORTED
0.01877
0.02316
2.45
0.98
0.02643
0.03262
3.68
0.965
3
9/19/74
.120
8
14987
12463
1555
161
1.0
0.5
21.0
ELSEWHERE
0.02858
0.03437
3.67
0.9
0.0409
0.04926
5.58
1.6
Average
* 106
6.66
14985
12262
1855
177
0.8
0.6
20.7
0.02106
0.02574
2.71
0.82
0.02643
0.03630
4.07
1.15
A-19
-------
TABLE A-5
FACILITY D (Baghouse Inlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity -
Shop Effluent
Flow rate - ACFM
Flow rate - DSCFM
Flow r«te - DSCFM/ton
furnace capacity
Temperature - °F
Water vapor - Vol . %
COg - Vol. % dry
02 - Vol. % dry
CO - Vol. % dry
Parti cul ate Emissions
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
Total catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
1
10/1/74
60
tons 6
21783
1§166
of
3194
124.7
0.8
0.8
.19.7
0.0
.0.41254
0.36297
67.. 76
11.29
0.42624
0.37502
70.01
11,67
2
10/2/74
120
6
23855
15185
2531
123.5
0.1
3.9
17.7
0.0
0.28666
0.26126
58.60
11.37
0; 29368
0.26125
60.04
11. «5
3
10/3/74
120
6
22086
19387
3231
125.8
. 0.5
3.8
20.0
0.0
0.46288
0.40631
76.91
14.93
0.47761
0.41924
79.35
15.49
Average
100
6
. 22575
17913
2985
124.7
0.47
2.8
19.13
0.0
0.38736
0.34351
67.76
12.53
0.39918
0.35184
69.80
12.93
£-20 _
-------
TABLE A-6
FACILITY D (Baghouse Outlet)
Sunmary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity -
Shop Effluent
Flow rate - ACFM
Flow rate -. DSCFM
Flow rate - DSCFM/ton
furnace capacity
Temperature - °F
Water vapor - Vol . %
C02 - Vol . % dry
02 - Vol . % iir}.
CO - Vol . % dry
Participate Emissions
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
Total catch
gr/DSCF
.gr/ACF
Ib/hr
Ib/hr per ton/hr
1
10/1/74
60
tons 6
16790
15185
of 2520
112.1
0.8
0.8
19.7
0.0
0.00792
0.00717
1.03
Q.2
0.02353
0.02128
3.06
0.51
2
10/2/74
120
6
21758
20037
3380
107.0
0.0
3.9
17.7
0.0
0.00127
0.00117
0.22
0.04?
0.00319
0.00294
0.55
0.063
3
10/3/74
120
. 6
18061
20486
3420
125.3
0.2
3.8
20.0
0.0
0.00268
0.00237
0.42
0.082
0.00502
0.00443
0.78
0.076
Average
100
6
18870
18569
3100
114.8
0.3
2.8
19.1
0.0
0.00462
0.00357
0.593
0.108
0.01058
0.00955
1.463
0.213
A-21
-------
TABLE A-7
FACILITY E (Baghouse Outlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity
- tons
Flow rate - ACFM
Flow rate - OSCFH
Flow rate - DSCFM/ton of
furnace capacity
Temperature - °F
Water vapor - Vol. %
C02 - Vol. % dry
02 - Vol. % dry
CO - Vol. % dry
Participate Emissions
Probe and filter catch
gr/OSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
1
5/6/74
60
15
53500
54118
3600
106
0.083
20.7
0.0
0.0056
0.00483
2.04
0.292
2
5/7/74
60
15
47500
39857
2600
126
0.47
NOT RECORDED
20.5
0.1
0.010184
0.001596
3.27
0.46
3
5/7/74
60
15
48100
40642
2710
128
0.47
20.45
0.1
0.005935
0.000890
1.93
0.286
Average
60
15
49700
42205
2990
120
0.341
20.55
0.1
0.00723
0.00243
2.41
0.3462
A-22
-------
TABLE A-8
Gaseous Emission Data
Facility A
Suronary of Results.
Run Number
Date
Carbon Monoxide Emissions
Average ppm (by volume)
Ib/hr
i
Ib/hr per ton per hour
Nitroqen Oxides (as N02) Emissions
Average ppm tby volume)
Ib/hr
Ib/hr per ton per hour
Hydrocarbon (as CH,) Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
Sulfur Dioxide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
1
6/19/74
95
34.93
1.27
3.37
1.87
0.068
7.4
1.554
0.056
4.86
3.78
0.137
2
6/19/74
88
31.38
1.14
1.59
0.851
0.031
7.8
1.588
0.058
5.26
3.93
0.144
3
6/20/74
104
37.13
1.36
2.48
1.36
0.0495
7.6
1.566
Q.057
4.40
3.32
0.1P.1
Average
-
95
34.61
1.26
2.48
1.36
0.0395
7.6
1.566
0.057
4.84
3.68
0.134
A-23
-------
TABLE A-9
Facility B '
Summary of Result
Run Number
Date
Carbon Monoxide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
Nitrogen Oxides (as NOo) Emissions
Average ppm by volume
Ib/hr
Ib/hr per ton per hour
Hydrocarbon (as CH4) Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
Sulfur Dioxide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
1
6/8/74
75
22.4
1.04
3.24
1.34
0.062
8.6
1.47
0.068
2.88
1.86
0.086
2
6/9/74
84
26.5
1.24
52.14
25.0 .
1.162
9.6
1.73
0.08
0.66
0.45
0.02
3
6/9/74
59
17.6
0.82
11.5
1.96
0.09
1.37
0.88
0.040
Average
-
73
22.2
1.03
27.1
13.2
0.612
9>9±
1.72
0.079
1.64
1.06
0.049
A-24
-------
TABLE A-10
Facility C
Summary of Results
Run Number
Date
Carbon Monoxide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
Nitrogen Oxides .(as N02) Emissions
Average ppm (by volume
Ib/hr
Ib/hr per ton per hour '
Hydrocarbons (Total) Emissions ..
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
Sulfur 0-1'oKide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
1
9/18/74
137
5.15
1.47
8.95
0.754
0.214
5.6
0.180
0.0515
14.1
1.655
0.47
2
9/18/74
88.25
3.4
1.36
9.57
0.818
0.218
17.6
2.091
0.55
3
9/19/74
138.5
6.07
1.52
9.97
0.861
0.23
17.3
2.082
0.54
Average
-
121.25
4.873
1.45
8.50
0.811
0.22
5.0
0.180
0.0515
16.3
1.943
0.52
A-25
-------
TABLE A-ll
Facility Q
Summary of Results
Run Number
Date
Carbon Monoxide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
Nitrogen Oxides (as NO?) Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton of furnace capacity
Hydrocarbon (as CH,) Emissions
Average ppm (by volume)
Ib/hr
1 b/hr per ton per hour
Sulfur Dioxide Emissions
Average ppm (by volume)
Ib/hr
Ib/hr per ton per hour
1
10/1/74
107
4.805
0.933
&
2.88
0.604
0.117
1.7
0.245
0.047
2
10/2/74
143
5.166
1.00
tf *"*
7.3
1.487
0.289
2.5
0.492
0.095
3
.10/3/74
60
2.03
0.394
«tf ^
>V*"
10.85
2.23
0.433
17.7
3.16
0.613
Average
-
103
4.00
0.775
&
7.01
1.44
0.279
7.3
1.29
0.248
A-26
-------
TABLE A-12
FACILITY A-
Summary of Visible Emissions
uate: June 18, 1974
Type of Plcint: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Stack
Height of Point of Discharge: 40 Feet
Description of Background: Black Building
Description of Sky: Clear
Hind Direction: North
Color of Plume: Brown
Duration of Observation: 4 Hours, 15 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: 100
Ftct
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point: North
Wind Velocity: 10 to 15 mph
Detached Plume: No
. SUMMARY OF AVERAGE OPACITY
TfiSe"
"Opacity
TTmF
Opacity
Set Number Start End Sum Average Set Number Start
End
Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
10:45
10:50
10:56
10:02
11:08
11:14
11:26
11:32
11:44
11:50
12:02
12:08
12:14
12:20
12:26
12:32
12:38
12:44
12:50
12:56
10:50
10:56
11:02
11:08
11:14
11:20
11:32
11:38
11:50
11:56
12: OB
12:19
12:20
12:26
12:32
12:38
12:44
12:50
12:56
1:02
0
0
0
0
0
80
120
120
20
10
0
0
0
100
65
15
100
85
80
5
0
0
0
0
0
3.35
5
5
0.836
0.418
0
0
0
4.18
2.7
0.627
4.18
3.5
3.35
0.21
*
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
:02
:08
:14
:20
:26
:32
:38
:44
:50
:56
2:02
2:08
2:14
2:20
2:26
2:32
2:38
2:44
2:50
2:56
:08
:14
:20
:26
:32
:38
:44
:50
:56
2:02
2:08
2:14
2:20
2:26
2:32
2:38
2:44
2:50
2:56
3:02
0
0
30
210
165
240
170
5
40
5
5
5
55
85
- 0
0
90
95
105
0
0
0
1.25
8.77
6.45
10.90
7.1
0.21
1.66
0.21
0.21
0.21
2.39
3.5
0
0
3.75
3.95
4.36
0
Sketch Showing How Opacity Varied With Time:
2 3
10
10
5
0
Time, hours
A-27
-------
TABLE A-13
FACILITY A
Summary of Visible Emissions
uate: June 18, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Roof Vents
Height of Point of Discharge: 3 Feet
Description of Background: Sky
Description of Sky: Sunny Blue Sky
Wind Direction: North
Color of Plume: Brown
Duration of Observation: 4 Hours
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: 24
Feet
Height of Observation Point: 60 Feet
Direction of Observer from Discharge Point:
East of Roof Fan
Wind Velocity: 10 to 15 mph
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
TimeOpacity
Set NumberStartEndSum
Time'
Opacity
Average Set Number Start
End
Sum" Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
10:50
11:56
11:02
11:08
11:14
11:20
11:26
11:32
11:38
11:44
11:50
11:56
12:02
12:08
12:14
12:20
12:26
12:32
12:38
12:44
10:56
11:02
11:08
11:14
11:20
11:26
11:32
11:38
11:44
11:50
11:56
12:02
12:08
12:14
12:20
12:26
12:32
12:38
12:44
12:50
75
35
5
0
0
0
0
0
0
0
90
55
110
55
0
150
10
30
0
95
3.13
1.46
0.21
0
0
0
0
0
0
0
3.75
2.39
4.58
2.39
0
6.24
0.418
1.25
0
3.95
' 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
12:50
12:56
1:02
1:08
.1:14
1:20
1:26
1:32
1:38
1:44
1:50
1:56
2:02
2:08
2:14
2:20
2:26
2:32
2:38
2:44
12:56
1:02
1:08
1:14
1:20
1:26
1:32
1:38
1:44
1:50
1:56
2:02
2:08
2:14
2:20
2:26
2:32
2:38
2:44
2:50
o
45
5
0
260
30
45
0
195
25
0
0
0
85
135
no
0
0
245
75
0
1.875
0.21
0
10.08
1.25
1.87
0
8.1
1.14
0
0
0
3.5
5.63
4.58
0
0
10.02
3.13.
Sketch Snowing How Opacity Varied With Time:
2 3
10-
io-
1
r-nJL-Lj-L
i
Time, hours
A-28
-------
TABLE A-14
FACILITY A
Summary of Visible Emissions
ime: June 19, 1974
Type of Pidnt: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Stack
Height of Point of Discharge: 40 Feet
Distance from Observer to Discharge Point: 100
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
North
Description of Background: Dirk Gray Side of Building
Description of Sky: Clear
Wind Direction: Calm
Color of Plume: Brown
Duration of Observation: 3 Hours, 25 Minutes
SUMMARY OF AVERAGE OPACITY
Wind Velocity: Not Recorded
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Opacity
Time
Opaci ty
Set Number Start End
Sum
Average Set Number Start End Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
10:00
10:06
10:12
10:18
10:24
10:30
10:36
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11:24
11:30
11:36
11:42
11:48
11:54
10:06
10:12
10:18
10:24
10:30
10:36
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11:24
11:30
11:36
11:42
11:48
11:54
12:00
0
5
0
10
80
90
45
50
0
80
95.
65
15
40
45
0
10
45
120
55
0
0.21
0.
0.417
3.33
3.75
1.875
2.1
0
3.33
3.97
2.7
0.625
1.67
1.87
0
0.417
1.87
5
2.29
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
12:00
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
1:18
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
1:18
1:24
115
125
135
65
95
35
10
0
5
5
5
5
5
5
4.78
5.22
5.63
2.7
3.6
1.46
0.417
0
0.21
0.21
0.21
0.21
0.21
0.21
Sketch Showing How Opacity Varied With Time:
2 3
I
a
o
10
5
0
10
5
0
1 Time, hours
A-29
-------
TABLE A-15
FACILITY A
Summary of Visible Emissions
uate: June 19. 1974
Typ-i of Plant: Gray Iron Foundry
Type of Discharge: Roof Vent
Location of Discharge: Over Fumice No. 2
Height of Point of Discharge: 3 Feet
Description of Background: Sky
Description of Sky: Cloudy, Bright Sun
Wind Direction: Not Recorded
Color of Plume: Brown
Duration of Observation: 3 Hours, 18 Minutes
SUW4ARY OF AVERASE OPACITY
Distance from Observer to Discharge Point: 24
Feet
Height of Observation Point: 60 Feet
Direction of Observer from Discharge Point:
Sun in the Back of Observer
Wind Velocity: Not Recorded
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Stt Number
1
2
3
4
5
6
7
8
9
10
11
11
13
14
IS
16
17
18
19
20
Start
10:00
10:06
10:12
10:18
10:24
10:30
10:36
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11:24
11:30
11:36
11:42
11:48
11:54
End
10:06
10:12
10:18
10:24
10:30
10:36
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11:24
11:30
11:36
11:42
11:48
11:54
12:00
'Opacity ' ""
Sum
70
15
0
0
40
60
0
0
0
0
60
10
20
0
0
60
0
0
0
35
Average
2.9
0.625
0
0
1.66
2.5
0
0
0
0
2.5
0.417
0.83
0
0
2.5
0
0
0
1.46
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
12:00
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
End
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
1:18
Opaci ty
Sum
0
0
0
20
50
0
0
0
0
0
0
0
55
Average
0
0
0
0.417
2.1
0
0
0
0
0
0
0
2.29
Sketch Snowing How Opacity Varied With Tine:
2 1 i-
i
f.
10
s
0
10
5
0
JL
Time, hours
A-30
-------
TABLE A-16
FACILITY A
Summary of Visible Emissions
Date: June 19, 1975
Typ2 of Plant: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Stack
Height of Point of Discharge: 40 Feet
Distance from Observer to Discharge Point; 100
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
North
Description of Background: Dark Gray Side of Building
Description of Sky: Cloudy and Sunny (after 6:30 p.m.)
Wind Direction: Not Recorded Wind Velocity: Not Recorded
Color of Plume: Brown Detached Plume: No
Duration of Observation: 3 Hours, 58 Minutes
SUMMARY OF AVERAGE OPACITY . SUMMARY OF AVERAGE OPACITY
Time
Opacity
Time
Opaci ty
Set Number Start End Sum Average Set Number Start
End
Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
U
15
16
17
18
19
20
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:04
5:10
5:16
5:22
5:28
5:34
5:40
5:46
5:52
5:58
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:04
5:10
5:16
5:22
5:28
5:34
5:40
5:46
5:52
5:58
6:04
0
5
15
20
0
50
90
130
120
120
60
15
5
5
5
10
95
110
140
125
0
0.21
0.627
0.83
0
2.1
3.73
5.42
5
5
2.5
0.62
0.21
0.21
0.21
0.21
4
4.6
5.8
5
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
6:04
6:10
6:16
6:22
6:28
6:34
6:40
6:46
6:52
6:58
7:04
7:10
7:16
7:22
7:28
7:34
7:40
7:46
7:52
7:58
6:10
6:16
6:22
6:28
6:34
6:40
6:46
6:52
6:58
7:04
7:10
7:16
7:22
7:28
7:34
7:40
7:46
7:52
7:58
8:04
35
15
45
90
60
65
0
35
0
90
120
125
100
5
0
25
75
55
5
1.46
0.625
1.875
3.73
2.5
2.71
0
1.76
0
3.73
5
5.22
9.17
0.21
0
1.04
3;13
2.3
0.21
Sketch Showing How Opacity Varied With Time:
2 3
10
5
It
§ 10
1 T1M, hours
A-31
-------
TABLE A-17
Distance from Observer to Discharge Point: 24
Feet
Height of Observation Point: 60 Feet
Direction of Observer from Discharge Point:
East of Roof Fan
FACILITY A
Summary of Visible Emissions
uatc: June 19, 1974
Typs of F'unt: Gray Iron Foundry
Type of Discharge: Roof Vent
Location of Discharge: Over Furnace No. 2
Height of Point of Discharge: 3 Feet
Description of Background: Sky
Description of Sky: Cloudy, Rainy to Partly Cloudy
Wind Direction: Not Recorded Wind Velocity: Not Recorded
Color of Plume: Brown Detached Plume: No
Duration of Observation: 4 Hours
SUMMARY OF AVERAGE OPACITY SUMMARY OF AVERAGE OPACITY
Opacity' "
Sum Average
0
0
0
0
0
0
0
0
0
0
0
0
0
65 2.6
0
0
0
0
0
0
Sketch Showing How Opacity Varied With Time:
2 3
10
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:09
5:10
5:16
5:22
5:28
5:34
*:40
5:46
5:52
5:58
End
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:04
5:10
5:16
5:22
5:28
5:34
5:40
5:46
5:50-
5:58
6:04
Opacity
Sum
0
0
0
20
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Average
0
0
0
0.8
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Ti
Start
6:04
6:10
6:16
6:22
' 6:23
6:39
6:40
6:46
6:52
6:58
7:04
7:10
7:16
7:22
7:28
7:34
7:40
7:46
7:52
7:58
me "
"End
6:10
6:16
6:22
6:28
6:34
6:40
6:46
6:52
6:58
7:04
7:10
7:16
7:22
7:28
7:34
7:40
7:46
7:52
7:58
8:04
o 10
s-
5
T
T
_n
1 TIM, hours
A-32
-------
TABLE A-18
FACILITY A
Summary of Visible Emissions
Date: June 20, 1974
Type of Plant: 'ray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Height of Point of Discharge: 80 ft.
Description of Background: Hark Gray Side of t Recorded Wind Velocity: 15 moh
Color of Plume: Brown Detached Plume: No
Duration of Observation:
SUMMARY OF AVERAGE OPACITY SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point:100 ft.,
40 ft. ahove observer
Height of Observation Point: Ground level
Direction of Observer from Discharge Point:North
Time
Opacity
Time
Opacity
Set Number Start End Sum Average Set Number Start End Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 -
9:20
9:26
9:32
9:38
9:44
9:50
9:5fi
10:02
10:38
10:14
10:20
13:26
10:32
10:38
13:44
10:50
10:56
10:02
11:08
11:14
9:26
9:32
9:38
9:44
9:50
9:56
10:02
10:08
10:14
10:20
10:26
10:32
13:38
10:44
10:50
10:56
11:02
11:03
11:14
11:20
0
0
0
0
0
15
0
0
0
0
0
0
0
0
0
0
0
n
10
40
0
0
0
0
0
2.92
0
0
4.37
0
0
0
1.25
0
0
1.45
0.417
1.25
0
0.84
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
11
11
11
11
11
1.1
11
12
12
12
12
12
12
:20
:26
:32
:38
:44
:SO
:5S
:02
:08
:14
:ZO
:26
:32
11:26
11:32
11:38
11:44
II:1?)
11:56
12:02
12:08
12:14
12:20
12:26
12:32
12:38
120
125
50
60
ISO
55
15
5
0
' 0
9
0
0
5
5
2
5
6
2
6
0
0
0
0
0
0
.13
.OR
.2S
.I"
.27
.»!
Sketch Showing How Opacity Varied With Time:
J 1"' ^
10
+*
I 5
10
JL
Time, hours
A-33
-------
TABLE A-19
FACILITY A
Summary of Visible Emissions
uate: June 20, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Roof Vent
Location of Discharge: Over Furnace No. 2
Height of Point of Discharge: 3 Feet
Description of Background: Sky
Description of Sky: Sunny with Haze
Wind Direction: Not Recorded
Color of Plume: Brown
Duration of Observation: 3 Hours,. 18 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: 24
Feet
Height of Observation Point: 60 Feet
Direction of Observer from Discharge Point:
East of the Vent
Wind Velocity: 15 mph
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
9:20
9:26
9:32
9:38
9:44
9:50
9:56
10:02
10:08
10:14
10:20
10:26
10:32
10:38
10:44
10:50
10:56
11:02
11:08
11:14
End
9:26
9:32
9:38
9:44
9:50
9:56
10:02
10:08
10:14
10:20
10:26
10:32
10:38
10:44
10:50
10:56
11:02
11:08
11:14
11:20
Opacity
Sum
0
0
0
0
0
70
0
0
105
0
0
0
30
0
0
35
10
30
0
20
Average
0
0
0
0
0.21
2.92
0
0
4.37
0
0
0
1.25
0
0
1.45
0.417
1.25
0
0.84
Set Number
' 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
11:20
11:26
11:32
11:38
11:44
11:50
11:56
12:02
12:08
12:14
12:20
12:26
12:32
End
11:26
11:32
11:38
11:44
11:50
11:56
12:02
12:08
12:14
12:20
12:26
12:32
12:38
Opaci ty
Sum
80
0
0
0
5
50
0
20
0
0
55
5
100
Average
3.34
0
0
0
0.21
2.08
0
0.84
0
0
2.3
0.21
4.17
Sketch Showing How Opacity Varied With Time:
10-
n_H
I
Time, hours
A-34
-------
TABLE A-20
FACILITY B
Summary of Visible Emissions
uate: 'July 8, 1974
Type of Pi tint: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Height of Point of Discharge: 50 Feet
Distance from Observer to Discharge Point: 125
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South-East
Description of Background: Gray Buildings and Equipment
Description of Sky: Sunny, Scattered Clouds, Blue Sky, Humid, 95°F
Hind Direction: Calm Wind Velocity: Not Recorded
Color of Plume: Brown Detached Plume: No
Duration of Observation: 3 Hours, 40 Minutes
SUMMARY OF AVERAGE OPACITY SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
:20
:27
:33
:45
:52
1:57
2:03
2:08
2:14
2:20
2:26
2:32
2:38
2:44
2:50
2:56
3:02
3:08
3:14
3:21
End
1:26
1:32
1:39
1:51
1:56
2:02
2:08
2:14
2:20
2:26
2:32
2:38
2:44
2:50
2:56
3:02
3:08
3:14
3:20
3:26
Opacity
Sum
0
0
0
0
55
10
0
85
30
65
25
0
0
0
0
0
0
0
45
50
Average
0
0
0
6
2.2
0.41
0
3.54
1.25
2.7
1.04
0
0
0
0
0
0
0
1.88
0.21
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
3:26
3:32 '
3:37
3:42
3:46
3:52
3:58
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
End
3:32
3:36
3:42
3:46
3:52
3:58
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:04
Opacity
Sum
25
35
0
30
10
0
0
0
115
130
50
55
65
195
45
0
0
Average
1.0
1.46
0
1.25
0.417
0
0
0
3.83
5.42
2.08
2.29
2.7
6.05
1.875
0
0
Sketch Showing How Opacity Varied With Time:
1
25
20
10
5
0
Tint, hours
A-35
-------
TABLE A-21
FACILITY B
Summary of Visible Emissions
oate: July 8, 1974
Typ-. of F'ldnt: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Roof Vent
Distance from Observer to Discharge Point: 30
Feet
Height of Observation Point: At Vent Level
Height of Point of Discharge: 3 Feet Above
Roof
Description of Background: Sky
Description of Sky: Scattered Clouds
Hind Direction: Calm
Color of Plume: Brown
Direction of Observer from Discharge Point:
30 Feet South of Discharge Point
Hind Velocity:
Detached Plume:
Duration of Observation: 3 Hours, 40 Minutes
SUMMARY OF AVERAGE OPACITY
Not Recorded
No
SUMMARY OF AVERAGE OPACITY
Set Number
!
2
3
4
5
7
Time
Opacity
Start End
:20 :'
:26 :
:32 :
:38 :
:44 :
:50 1:
:56 2:
8 2:02 2:
'9 2:08 2:
10 2:14 2:
11 2:20 2:
12 2:26 2:
13 2:32 2:
14 2:38 2:
15 2:44 2:
16 2:50 2:
17 2:56 3:
18 3:02 3:
19 3:08 3:
20 3:14 3:
26
32
38
44
50
56
02
08
14
20
26
32
38
44
50
56
02
08
14
20
Sum
0
0
0
0
20
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Average
0
0
0
0
0.835
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
3:20
3:
3:
3:
3:
3:
3:
4:
4:
4:
4:
4:
4:
4:
4:
4:
26
32
38
44
50
56
02
08
14
20
26
32
38
44
50
4:56
5:02
End
3:
3:
3:
3:
3:
3:
4:
4:
4:
4:
4:
4:
4:
4:
4:
4:
5:
5:
26
32
38
44
50
56
02
08
14
20
26
32
38
44
50
56
02
08
Opaci ty
Sum
0
0
0
20
20
0
0
0
5
5
5
5
5
0
15
0
0
0
Average
0
0
0
0.83
0.83
0
0
0
0.2
0.2
0.2
0.2
0.2
0
0.62
0
0
0
Sketch Showing How Opacity Varied With Time:
25
+*
§ 20
"i 10
5
0
2 3
Tine, hours
A-36
-------
TABLE A-22
FACILITY B
Summary of Visible Emissions
uate: July 9, 1974
Tyi.-j of Plant: Gray Iron Foundry
Type of Discharge: Partlculates
Location of Discharge: Stack
Height of Point of Discharge: 50 Feet
Distance from Observer to Discharge Point: 125
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South-East
Description of Background: Gray Buildings and Equipment
Description of Sky: Clear
Wind Direction: Calm
Color of Plume: Brown
Duration of Observation: 3 Hours, 36 Minutes
SUMMARY OF AVERAGE OPACITY
Wind Velocity: Not Recorded
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
7:55
8:01
8:07
8:13
8:19
8:26
8:32
8:38
8:44
8:50
8:56
9:02
9:08
9:14
9:20
9:26
9:32
9:38
9:44
9:50
End
8i01
8:07
8:13
8:19
8:25
8:32
8:38
8:44
8:50
8:56
9:02
9:08
9:14
9:20
9:26
9:32
9:38
9:44 .
9:50
9:56
Opacity
Sum
25
15
30
30
55
0
10
15
135
130
110
70
0
0
45
0
0
5
5
25
Average
1
0.625
1.25
1.25
2.29
0
0.41
0.625
5.63
5.42
4.5
0
0
1.875
0
0
6.20
0.20
1.0
Set Number
' 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
9:56
10:02
10:08
10:14
10:20
10:26
10:32
10:38
10:44
10:50
10:56
11:02
11:08
11:14
11:20
11:26
11:32
End
10:02
10:08
10:14
10:20
10:26
10:32
10:38
10:44
10:50
10:56
11:02
11:08
11:14
11:20
11:26
11:32
11:36
Opacity
Sum
10
0
0
0
0
25
10
10
0
0
0
0
0
0
10
5
0
Average
0.417
0
0
0
0
1.0
0.417
0.417
0
0 -
0
0
0
0
0.417
0.20
0
Sketch Showing How Opacity Varied With Time:
25
4-*
2 20
. 15
S 10
° 5
0
2 3
Time, hours
A-37
-------
TABLE A-23
FACILITY B
Summary of Visible Emissions
lute: July 9, 1974
Typt of Fidnt: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Roof Vent
Height of Point of Discharge: 3 Feet
Above Roof
Description of Background: Sky
Description of Sky: Scattered Clouds
Wind Direction: Calm
Color of Plume: Brown
Distance from Observer to Discharge Point:
Height of Observation Point:
Direction of Observer from Discharge Point:
30 Feet South of Discharge Point
Wind Velocity: Not Recorded
Detached Plume: No
Duration of Observation: 3 Hours, 36 Minutes
SUMMARY OF AVERAGE OPACITY
SUMMARY OF AVERAGE OPACITY
Time
Opacity
Time
Opacity
End
Set Number Start End
Sum
Average Set Number Start
Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
8:00
8:06
8:12
8:18
8:24
8:30
8:36
8:42
8:48
8:54
9:00
9:06
9:12
9:18
9:24
9:30
9:36
9:42
9:48
9:54
8:06
8:12
8:18
8:24
8:30
8:36
8:42
8:48
8:54
9:00
9:06
9:12
9:18
9:24
9:30
9:36
9:42
9:48
9:54
10:00
0
0
0
0
0
0
0
0
0
0
0
0
15
0
0
0
15
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.625
0
0
0
0.625
0
0
0
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
10:00
10:10
10:16
10:22
T0:28
10:34
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11:24
11:30
11:36
10:10
10:16
10:22
10:28
10:34
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11:24
11:30
11:36
11:40
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sketch Showing How Opacity Varied With Time:
25
20
15
10
5
0
2 3
Tim, hours
A-38
-------
TABLE A-24
FACILITY B
Summary of Visible Emissions
uate: July 9, 1974
Type of Fliint: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Height of Point of Discharge: 50 Feet
Distance from Observer to Discharge Point: 125
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South-East
Description of Background: Gray Buildings and Equipment
Description of Sky: Clear
Wind Direction: Calm
Color of Plume: Brown
Duration of Observation: 3 Hours, 40 Minutes
SUMMARY OF AVERAGE OPACITY
Wind Velocity: Not Recorded
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Opacity
Time
Opacity
Set Number Start End Sum Average Set Number Start End Sum Average
1 :20
2 :26
3 :32
4 :38
5 :44
6 :50
7 :56
8 2:02
9 2:08
10 2:14
11 2:20
12 2:26
13 2:32
14 2:38
15 2:44
16 2:50
17 2:56
18 3:02
19 3:08
20 3:14
:26 5
:32 0
:38 0
:44 0
:50 60
:56 0
2:02 0
2:08 0
2:14 0
2:20 0
2:26 0
2:32 27-
2:38 0
2:44 85
2:50 95
2:56 5
3:02 0
3:08 0
3:14 0
3:20 10
0.20
0
0
0
2.5
0
0
0
0
0
0
1.125
0
3.53
4.00
0.2
0
0
0
0.417
21
22
23
24
25
26
27
28 t
29
30
31
32
33
34
35
36
37
38
39
40
3:20
3:26
3:32
3:38
3:44
3:50
3:56
1:02
:08
:14
:20
:26
:32
:38
:44
:50
3:26
3:32
3:38
3:44
3:50
3:56
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
4:50
4:56
75
25
0
0
105
150
85
0
0
125
180
150
90
120
275
225
3.12
1.0
0
0
4.28
6.25
3.51
0
0
5.22
7.5
6.27
3.73
5
11.45
9.38
Sketch Showing How Opacity Varied With Time:
Tine, hours
A-39
-------
TABLE A-25
FACILITY 8
Summary of Visible Emissions
uate: July 9, 1974
Typ-.- of Plant: Gray Iron Foundry
Type of Discharge: Partlculates
Location of Discharge: Roof Vent
Height of Point of Discharge: 3 Feet
Above Roof
Description of Background: Sky
Description of Sky: Clear
Wind Direction: Calm
Color of Plume: Brown
Duration of Observation: 3 Hours, 30 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: 30
Feet
Height of Observation Point: At Vent Level
Direction of Observer from Discharge Point:
30 Feet South of Discharge Point
Wind Velocity: Not Recorded
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
1:30
1:36
1:42
1:48
1:54
2:00
2:06
2:12
2:18
2:24
2:30
2:36
2:42
2:48
2:54
3:00
3:06
3:12
3:18
3:24
End
1:36
1:42
1:48
1:54
2:00
2:06
2:12
2:18
2:24
2:30
2:36
2:42
2:48
2:54
3:00
3:06
3:12
3:18
3:24
3:30
Opacity
Sum
0
0
0
0
0
0
0
0
0
0
0
0'
0
0
0
0
0
0
0
0
Average
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
3:30
3:36
3:42
3:48
3:54
4': 00
4:06
4:12
4:18
4:30
4:36
4:42
4:48
4:54
5:00
End
3:36
3:42
3:48
3:54
4:00
4:06
4:12
4:18
4:28
4:36
4:42
4:48
4:54
5:00
5:06
Opacity
Sum
0
0
55
0
0
0
0
0
0
0
0
30
0
0
0
Average
0
0
0.23
0
0
0
0
0
0
0
0
0.124
0
0
0
Sketch Showing How Opacity Varied With Time:
25
«
8 20
*16
5
S 10
° 5
0
2 3
T1mt, hours
A-40
-------
TABLE A-26
FACILITY C
Summary of Visible Emissions
: Sept. 18. 1974
Typ-: of Plant: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Distance from Observer to Discharge Point: 20 feet
Height of Observation Point: Even with stacktop
Height of Point of Discharge: 15 feet above Direction of Observer from Discharge Point:
flat roof R00ff N.W. of stack
Description of Background: Sky
Description of Sky: 100% overcast
Wind Direction: N.W. Wind Velocity: 0-5
Color of Plume: brown Detached Plume: no
Duration of Observation: 2 Hours, 7 Minutes
SUMMARY OF AVERAGE OPACITY
SUMMARY OF AVERAGE OPACITY
Time
Opacity
Time
Opac i ty
Set Number Start End Sum Average Set Number Start End Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
11:30
11:36
11:42
11:48
11:54
12:00
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
1:18
1:24
11:36
11:42
11:48
11:54
12:00
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
1:18
1:24
1:30
330
95
5
30
10
15
0
45
120
T85
235
145
165
140
40
90
35
20
0
40
13.25 '
4.0
0.2
1.25
0.417
0.625
0
1.87
5.0
7.7
9.8
6.0
6.87
5.85
1.66
3.76
1.46
0.835
0
1.67
21 1:30 1:36 65 2.7
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Time:
20
&
. 15
2?
°
T1«*. hours
A-41
-------
TABLE A-27
FACILITY C
Summjry of Visible Emissions
uato: Sept. 18. 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Height of Point of Discharge: 15 feet
Description of Background: Sky
Description of Sky: 100% overcast
Wind Direction: N.W.
Color of Plume: brown
Duration of Observation: 2 Hours, 7 Minutes
Distance from Observer to Discharge Point: 30 feet
Height of Observation Point: Even with stack top
Direction of Observer from Discharge Point:
North-West of Stack
Wind Velocity: 0-5 mph
Detached Plume: no
SUMMARY OF AVERAGE
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
IS
16
17
18
19
20
Start
11:30
11:36
11:42
11:48
11:54
12:00
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
1:06
1:12
1:18
1-24
End
11:36
11:42
11:48
11:54
12:00
12:06
12:12
12:18
12:24
12:30
12:36
12:42
12:48
12:54
1:00
:06
:12
:18
:24
:30
OPACITY
Opacity
Sum
200
130
0
20
0
0
0
40
120
235.
200
150
150
120
25
90
15
15
5
50
Average
10.82
5.42
0
0.83
0
0
0
1.66
' 5.0
9.8
8.34
6.27
6.27
5.0
1.0
3.75
0.625
0.625
0.208
2.08
SUMMARY OF AVERAGE OPACITY
Time Opacity
Set Number Start End Sum Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Time:
25
+>
§ 20
Time, hours
A-42
-------
TABLE A-28
FACILITY C
Sumnary of Visible Emissions
uate: Sept. 18, 1974
Tyf2 of Plant: Gray Iron foundry
Type of Discharge: Participates Distance from Observer to Discharge Point: 20 feet
Location of Discharge: stack Height of Observation Point: Even with stack top
Height of Point of Discharge: 15 feet »bove Direction of Observer from Discharge Point:
flat roof Roof N w_ of stack
Description of Background: Sky
Description of Sky: 95% overcast
Wind Direction: N.W. Wind Velocity: 0-5 mph
Color of Plume: Brown Detached Plume: no
Duration of Observation: One Hour. 23 Minutes
SUMMARY OF AVERAGE OPACITY . SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
2:00
2:06
2:12
2:18
2:24
2:30
2:36
2:42
2:48
2:59
3:12
3:18
3:24
End
2:06
2:12
2:18
2:24
2:30
2:36
2:42
2:48
2:59
3:00
3:18
3:24
3:30
Opacity
Sum
505
45
70
15
5
105
30
125
0
140
160
175
160
Average
21
1.8
2.92
0.625
0.2
4.4
1.25
5.21
0
13.15
6.66
7.3
6.67
Time Opacity
Set Number Start End Sum Average
' 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Tin
25
*>
| 20
. 15
$
"5 10
5-
5
0 -
Tim, hours
A-43
-------
TABLE A-29
FACILITY C
Summary of Visible Emissions
uate: Sept. 18, 1974
Type of Flont: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Height of Point of Discharge: 15 feet
Description of Background: Sky
Description of Sky: 95% overcast
Wind Direction: N. W.
Color of Plume: brown
Distance from Observer to Discharge Point: 30 feet
Height of Observation Point, even with stack top
Direction of Observer from Discharge Point:
30 feet NW of stack
Hind Velocity: 0-5 mph
Detached Plume: no
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
2:00
2:00
2:12
2:18
2:24
2:30
2:36
2:42
2:48
2:59
2:30
3:06
3:12
3:18
End
2:06
2:12
2:18
2:24
2:30
2:36
2:42
2:48
2:54
3:00
3:06
3:12
3:18
3:24
Opacity
Sum
505
35
70
25
0
85
20
90
0
95.
305
60
115
165
Average
21
14.6
29.2
1.0
0
3.54
8.36
3.74
0
3.96
12.7
2.5
4.8
6.87
SUMMARY OF AVERAGE OPACITY
Time Opacity
Set Number Start End Sum Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Time:
25
| 20
£
£ 15
"o 10
o.
o
5
0
Time, hours
A-44
-------
TABLE A-30
FACILITY C
Summary of Visible Emissions
uate: Sept. 19. 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Distance from Observer to Discharge Point: 30 feet
Height of Observation Point: 20 feet above
basis of stack
Height of Point of Discharge: 15 feet above Direction of Observer from Discharge Point:
flat roof 30 feet Roof, east of stack
Description of Background: Clear and Sunny
Description of Sky: South East
Wind Direction: brown wind Velocity: 0-5 mph
Color of Plume: 2 hours 18 minutes Detached Plume: no
Duration of Observation: 2 Hours, 12 Minutes
SUMMARY OF AVERAGE OPACITY . SUWARY OF AVERAGE OPACITY
Time
Opacity
Time
Opacity
Set Number Start End Sum Average Set Number Start End Sum Average
1 8:
30
2 8:36
3 8:42
4 8:48
5 8:54
6 9:00
7 9:06
8 9:12
9 9:18
10 9:24
11 9:30
12 9:36
13 9:42
14 9:48
15 9:54
16 10:00
17 10:06
18 10:12
19 10:18
20 10:24
Sketch Showing How
25
§20
g.
.15
|io
. 5
-
__
-
~
-
8:
8:
8:
8:
9:
9:
9:
9:
9:
9:
9:
9:
9:
9:
10:
10:
10:
10:
10:
10:
36
42
48
54
00
06
12
18
24
30
36
42
48
54
00
06
12
18
24
30
Opacity
290
5
0
0
0
0
40
40
80
5
60
50
75
20
80
315
310
730
135
10
Varied
r~~
12.1
0.2
0
0
0
0
1.65
1.65
3.3
0.2
2.5
2.08
3.13
0.83
3.33
13.12
12.8!
32.5
5.63
0.416
With Time:
J~~i_ri-j
,
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
r-l_T
10:30 10:36 25 1.05
10:36 10:42 15 0.627
10:42 10:48 0 0
1
_
-
-
,
35
30
TlM, hours
A-45
-------
TABLE A-31
FACILITY C
Summary of Visible emissions
uate: Sept. 19, 1974
Type of Pidric: Gray Iron Foundry
Type of Discharge: Participates
Location of Discharge: Stack
Height of Point of Discharge: 15 feet
Description of Background: Sky
Description of Sky: Clear and Sunny
Wind Direction: South East
Color of Plume: brown
Duration of Observation: 2 Hours, 12 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point:30 feet
Height of Observation Point: even with base of
stack
Direction of Observer from Discharge Point:
30 feet east of stack
Wind Velocity: o-5 mph
Detached Plume: no
SUMMARY OF AVERAGE OPACITY
Opacity
Time
Opacity
Set Number Start End Sum Average Set Number Start End Sum Average
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
8:30
8:36
8:42
8:48
8:54
9:00
9:06
9:12
9:18
9:24
9:30
9:42
9:48
9:54
10:00
10:06
10:12
10:18
10.24
10:30
8:36
8:42
8:48
8:54
9:00
9:06
9:12
9:18
9:24
9:30
9:36
9:48
9:54
10:00
10:06
10:12
10:18
10:24
10:30
10:36
245
0
0
0
0
35
15
60
0
40
70 '
55
20
75
335
500
530
140
5
5
10.2
0
0
0
0
1.45
6.25
2.5
0
1.66
2.91
2.39
0.837
3.11
12.96
20.08
22.1
23.3
0
0
21 10:36 10:42 0
22 10:42 10:48 0
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
0
0
Sketch Snowing How Opacity Varied With Time:
25
20
15
10
5
0
T1mt, hours
A-46
-------
TABLE A-32
FACILITY D
Sumniiiry ot Visible Emissions
uate: October 1, 1974
Type of Pldnt: Gray Iron Foundry
Type of Discharge: Dust
Location of Discharge: Baghouse Outlet
Height of Point of Discharge: 20 Feet
Description of Background: Sky
Description of Sky: Overcast
Hind Direction: East
Color of Plume: White
Duration of Observation: 87 Minutes
Distance from Observer to Discharge Point: 50
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South
Wind Velocity: 3 to 5
Detached Plume: No
SUMMARY OF AVERAGE
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
3:20
3:26
3:32
3:38
3:44
3:50
3:56
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
End
3:26-
3:32
3:38
3:44
3:50
3:56
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
4:47
OPACITY
Opacity
Sum
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Average
0
0
0.
0
0
0
0
0
0
0
0
0
0
0
0
SUMMARY OF AVERAGE OPACITY
Time Opacity
Set Number Start End Sum Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35 .
36
37
38
39
40
Sketch Showing How Opacity Varied With Time:
25
§ 20
. 15
Tine, hours
A-47
-------
TABLE A-33
FACILITY D
Summary of Visible Emissions
Udtu: October 1, 1974
Type of F'unL: Gray Iron Foundry
Type of-Discharge: Furnace Roof Exhaust Distance from Observer to Discharge Point:
90 Feet
Location of Discharge: Furnace Roof Exhaust Height of Observation Point: Ground
Level
Height of Point of Discharge: 80 Feet Direction of Observer from Discharge Point:
South
Description of Background: Sky
Description of Sky: Overcast - partly cloudy
Wind Direction: East Wind Velocity: 3 to 5
Color of Plume: White Detached Plume: No
Duration of Observation: 120 Minutes
SUMMARY OF AVERAGE OPACITY . SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IS
19
20
Start
3:20
3:26
3:32
3:38
3:44
3:50
3:56
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
4:50
4:56
5:02
5:08
5:14
End
3i26
3:32
3:38
3:44
3:50
3:56
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
4:50
4:56
5:02
5:08
5:14
5:20
Opacity
Sum
120
120
120
120
120
120
120
120
175
120
120'
120
120
120
120
120
120
120
120
120
Average
5.0
5.0
5.0
5.'0
5.0
5.0
5.0
5.0
7.3
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
Time Opacity
Set Number Start End Sum Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Time:
25
?> 20
10
5
0
_n
Time, hours
A-48
-------
TABLE A-34
FACILITY 0
Summary of Visible Emissions
Date: October 2, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Dust
Location of Discharge: Baghouse Outlet
Height of Point of Discharge: 20 Feet
Description of Background: Sky
Description of Sky: Partly Cloudy
Wind Direction: South
Color of Plume: White
Duration of Observation: 210 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: 50
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South
Wind Velocity: 20 to 30
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Set Number Start
1 A.M. 9:25
2 9:31
3 9:37
4 9:55
5 10:01
6 10:07
7 10:13
8 10:15
9 10:21
10 10:27
11 10:39
12 P.M. 3:10
13 3:16
14 3:22
15 3:28
16 3:34
17 3:40
18 3:46
19 3:52
20 ' 3:58
Sketch Showing How
c
Z 5
-------
TABLE A-35
FACILITY D
Summary of Visible Emissions
bate: October 2, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Dust Distance from Observer to Discharge Point: 90
Feet
Location of Discharge: Furnace Roof Exhaust Height of Observation Point: Ground Level
Height of Point of Discharge: 80 Feet
Description of Background: sky
Description of Sky: clear, Scattered Clouds
Wind Direction: South
Color of Plume: White
Duration of Observation: 120 Minutes
SUMMARY OF AVERAGE OPACITY
Direction of Observer from Discharge Point:
South
Wind Velocity: 20 to 30
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time Opacity
Set Number Start End Sum
1 9:25 9:31 5
2 9:31 9:37 10
3 9:37 9:43 110
4 9:43 9:49 0
5 9:49 9:55 0
6 9:55 10:01 65
7 10:01 10:07 120
8 10:07 10:13 120
9 10:13 10:19 120
10 10:19 10:25 120
11 10:25 10:31 120
12 10:31 10:37 120
13 10:37 10:43 120
14 10:43 10:49 120
15 10:49 10:55 120
16 10:55 11:01 120
17 11:01 11:07 120
18 11:07 11:13 120
19 11:13 11:19 120
20 11:19 11:25 120
Sketch Snowing How Opacity Varied
25 .x
| 20 _
£
. 15 -
|,0-
5 -
0 mr* * i >
. . 1
Average
0.2
0.4
4.6
0
0
2.7
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
With Time:
1
Time Opacity
Set Number Start End Sum Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
,
1 1
Time, hours
A-50
-------
TABLE A-36 .
FACILIir D
Summary of Visible Emissions
Date: October 2, 1974
Type of Fldnt: Gray Iron Foundry
Type of Discharge: Dust Distance from Observer to Discharge Point: 90
Feet
Location of Discharge: Furnace Roof Exhaust ^ight of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South
Height of Point of Discharge: 80 Feet
Description of Background: Sky
Description of Sky: Clear, Scattered Clouds
Wind Direction: South Wind Velocity: 20 to 30
Color of Plume: White Detached Plume: No
Duration of Observation: 180 Minutes
SUMMARY OF AVERAGE OPACITY SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 '
Start
3:10
3:16
3:22
3:28
3:34
3:40
3:46
3:52
3:58
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:04
End
3:16
3:22
3:28
3:34
3:40
3:46
3:52
3:58
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
4:58
5:04
5:10
Opacity
Sum
120
120
120
120
120
120
120
120
120
120 .
120
120
150
140
120
165
150
120
120
120
Average
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
6.3
6.8
5.0
6.9
6.3
5.0
5.0
5.0
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Time
Start
5:10
5:16
5:22
5:28
5:34
5:40
5:46
5:52
5:58
6:04
End
5:16
5:22
5:28
5:34
5:40
5:46
5:52
5:58
6:04
6:10
Opacity
Sum
120
120
120
120
120
120
120
120
120
120
Average
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
Sketch Showing How Opacity Varied With Time:
2 . 3
10
10
5
0
T1m. hours
A-51
-------
TABLE A-37
FACILITY D
Summary of Visible Emission-;
iwte: October 3, 1974
Typt of Plant: Gray Iron Foundry
Type of Discharge: Dust
Location of Discharge: Baghouse Outlet
Height of Point of Discharge: 20 Feet
Description of Background: Sky
Description of Sky: Partly Cloudy
Wind Direction: Southwest
Color of Plume: White
Duration of Observation: 82 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: 50
Feet
Height of Observation Point: Ground Level
Direction of Observer from Discharge Point:
South
Wind Velocity: 20 to 35
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Start
9:18
9:24
9:30
9:36
9:42
9:48
9:54
10:00
10:06
10:12
10:18
10:24
10:29
10:52
. 10:58
End
9:24
9:30
9:36
9:42
9:48
9:54
10:00
10:06
10:12
10:18
10:24
10:29
10:52
10:58
11:03
Opacity
Sum
0
0
0
0
0
0
0
100
20
0
0
0
No
120
100
Average
0
0
0
0
0
0
0
4.2
0.8
0
0
0
Readings
5.0
5.0
Time Opacity
Set Number Start End Sum Avtrage
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Time:
&
25
20
10
£
5
Time, hours
A-52
-------
TABLE A-38
FACILIIY 0
Summary of Visible Emissions
Date: October 3. 1974
Type of Pldnt: Gray Iron Foundry
Type of Discharge: Dust Distance from Observer to Discharge Point: 90
Feet
Location of Discharge: Furnace Roof Exhaust Height of Observation Point:Ground Level
Height of Point of Discharge: 80 Feet
Description of Background: Sky
Description of Sky: Partly Cloudy
Wind Direction: Southwest
Color of Plume: White
Duration of Observation: 63 Minutes
SUMMARY OF AVERAGE OPACITY
Direction of Observer from Discharge Point:
South
Wind Velocity: 20 to 35
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Set Number Start
1 9:03
2 9:09
3 9:15
4 9:18
5 10:47
6 10:53
7 10:57
8 11:08
9 11:14
10 11:20
11 11:26
12 11:32
13 11:38
14 11:44
15
16
17
18
19
20 . -
Sketch Showing How
25
4-1
c
| 20
O.
- 15
if
'I 10
0
5
0
^
-^
Time
End
9:09
9:15
9:18
10:47
10:53
10:57
11:08
11:14
11:20
11:26
11:32
11:38
11:44
11:46
Opacity
Opacity
Sum
0
20
20
No
120
80
No
120
120
120
120
120
120
40
Average
0
0.8
1.7
Readings
5.0
5.0
Readi ngs
5.0
5.0
5.0
5.0
5.0
5.0
5.0
Time Opacity
Set Number Start End Sum Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Varied With Time:
t .
_ _ 1
'
f
1 1
Tint, hours
A-53
-------
TABLE A-39.' TEST RESULTS ON FABRIC FILTERS INSTALLED ON STEEL-PRODUCING ELECTRIC ARC FURNACES
f
Plant
A
B
C
D
E
F
German Sources
Ref. 3
French Sources
Ref. 4
Italian
Sources Ref. 5
5
Outlet Loadings
mg/dscm
9.17, 5.73
6.87. 36.68
4.58, 6.87
5.73, 2.8
8.71
6 to 20
14 tests, average
.003
1 - 4
6.63
2-20
5 to 15
4 to 12
Control device
Type
Fabric filter
Fabric filter
Fabric filter
.
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Furnace Capacity
Mg
27.2
29.92
33.18
20 - 22
Two furnaces
7 and 4
on one control
devi ce
30 31.2
two consequtive
heats,
not specified
8
not specified
Furnace heat duration
hrs
2
2
4
2.5
not specified
each 2 hours
test runs for
4 hours
not specified
not specified
not specified
Measuring
Method
ASHE
ASME
EPA 5
VOI
VDI
EPA 5
VDI
VDI
VDI
-------
TABLE A-40. TEST RESULTS ON.FABRIC FILTERS INSTALLED ON STEEL-PRODUCING ELECTRIC ARC FURNACES
Ul
en
Plant
A
B
C
0
E
f
German Sources
Ref. 3
French Sources
(tef. 4
Italian
Sources Ref. 5
Outlet Loadings
gr/dscf
0.004 0.0025
0.003 0.0064
0.002 0.003
0.00225 0.001223
0.0038
0.0026 0.0087
14 tests, .average
7
0.00043 0.00174
-
0.0029
0.00087 0.0087
0.00218 0.0065
0.00174 O.C0522
i
Control Device
Type
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Fabric filter
Furnace Capacity
short tons
30
33
36.5
22 - 24.2
Two furnaces
7.7 and 4.4
on one control
device
30 31.2
two consequtive
heats
not specified
8.8
not specified
Furnace heat duration
hrs
2
2
4
2.5
not specified
each 2 hours
test runs for
4 hours
not specified
not specified
not specified
Measuring
Method
ASME
ASWE
EPA S
VDI
VDI
EPA 5
VDI
VDI
VDI
-------
TABLE A-41
FACILITY B
Summary of Visible Emissions - Roof Vents
Heat No.
1206
1207
Process Condition
Charge
Back-charge
Tap
Charge
Back-charge
Tap
Six Minute Average
Start time
9:29
10:31
11:59
12:10
12:57
14:22
Vent A
1.2
8.1
12.9
1.9
5.6
8.3
Vent B
1.5
9.6
16.7
0.4
4.8
16.0
NOTE: No visible emissions were noted during the remainder of the two
heats observed.
Heat No. 1206 ft 1207 wer* ofostrvered on July 14, 1976.
A-56
-------
TABLE A-42
FACILITY B
SUMMARY OF VISIBLE EMISSIONS
Htat 11206
Otte: July 14. 1976
Type of Plint: Steel Foundry
Type of Discharge: Electric Arc Furnace
Location of Discharge: Btghouie Outlet
Height of Point of Discharge:*"10-'5 et*r*
Oetcrlptlon of Background: Sky
Description of Sky: varied - blue to overcast
Hind Direction:
Color of Plu«e: gray-white
Interference of Steam Plum:
Duration of Observation:
SUMMARY OF AVERAGE OPACITY
Distance tram Observer to Discharge Point:
Height of Observation Mint: ground level
Direction of Observer from Discharge Point:
Wind Velocity:
Detached Pluee:
SUMMARY OF AVERASE OPACITY
Set Nwber
2
3
4
5
6
7
8
9
10
11
12
13
14
IS
16
17
18
19
20
Time
Start End
:29
:35
:47
:53
:59
10:05
10:11
10:17
10:23
10:29
10:35
10:41
10:47
10:53
10:59
11:05
11:11
11:17
11:23
Opacity
Sun
5
5
20
0
15
0
85
96
145
545
290
55
0
' 10
65
60
155
150
130
190
Average
0.2
0.2
0.8
0.0
0.6
D.O
3.5
4.0
6.0
21.9
12.1
2.3
0.0
0.4
2.7
2.5
6.5
6.3
5.4
7.9
Set Nu
21
22
. 23
24
25
»
Tine
*tr Start End
11:29
11:35
11:41
11:47
11:53.
11:69
* Last set consists
Opacity
SIM
375
15
50
0
0
0
of 20
Average
1S.6
0.6
2.1
0.0
0.0
0.0
readings
Sketch Showing How Opacity Varied With Tine:
25
£ 20
X15
I
TIME, hem
A-57
-------
TABLE A-43
FACILITY B
SUMMARY OF VISIBLE EMISSIONS
Neat 11207
Date: July 14, 1976
Type of Plant: Steel Foundry
Typt of Dlschirge: Electric Arc Furnace
Location of Discharge: Baghouse Outlet
Height of Point of Discharge:*"510"15 meters
Description of Background: Sky
Description of Sky: varied - blue to overcast
Wind Direction:
Color of Plune: gray-white
Interference of Steam Plume:
Duration of Observation:
Distance from Observer to Discharge Point:
Height of Observation P61nt: ground level
Direction of Observer from Discharge Point:
Wind Velocity:
Detached Plune:
SUMMARY OF AVERAGE OPACITY
SUMMARY OF AVERAGE OPACITY
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Time
Start End
12:10
12:16
12:22
12:28
12:34
12:40
12:06
12:52
12:58
13:04
13:10
13:16
13:22
13:28
13:34
13:40
13:46
13:52
13:58
14:04
Opacity
Sum
90
30
90
40
25
100
135
75
20
0
0
0
75
45
50
3D
5
205
285
30
Average
3.8
1.2
3.8
1.7
1.0
4.2
5.6
3.1
0.8
0.0
0.0
0.0
3.1
1.9
2.1
1.2
0.2
8.5
11.9
1.2
Set Nuater
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Tint
Start
14:10
14:16
14:22
Last
Opacity
End Sun Averafa
0
0
14:28:30 0
0.0
0.0
0.0
data sit consists of
14 consecutive readings.
Sketch Showing How Opacity Varied With Tins:
25-
10
i
TIME, heurs
A-58
-------
TABLE A-44
FACIII1YB
SUMMARY OF VISIBLE EMISSIONS
Date: Sept. 28, 1976
Type of Plant: Steel Foundry Electric Arc Furnace
Type of Discharge: Stack
Location of Discharge: Bwhouse Outlet
Height of Point of Discharge: 10-15 neteri
Description of Background: Sky
Description of Sky: Partly cloudy
Wind Direction: Variable
Color of Plane:
Interference of Steam Plume: None
Duration of Observations minutes
Height of Observation P61flt: ground
Direction of Observer fro* Discharge Point:
south of stack
Wind Velocity: not recorded, but hloh
Detached Plwae: No
SUMMARY
Set Winter
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
OF AVERAGE
Tine
OPACITY
Opacity
Start End Average
10:05
10:11
10:17
10:23
10:29
10:35
10:41
10:47
10:53
10:59
11:05
11:11
11:17
11:23
11:29
11:35
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
SUMMARY OF AVERAGE OPACITY
T1aw Opacity
Set NMber Start End Average
'
Sketch Showing HIM Opacity Varied With TIM:
c
i
TINE, Hours
A-59
-------
Oite: July 22. 1976
Type of Plant: Steel Foundry
Type of Discharge: Electric Arc Furn.tce
Location of Discharge: Roof vents
Height of Point of Discharge: 9=25 inters
Description of Background: Building
Description of Sky: overcast
Wind Direction: variable
Color of Plume:
Interference of Steam Plume:
Duration of Observation:
SUMMARY OF AVERAGE OPACITY
TABLE A-45
FACILITY C
SUMMARY OF VISIBLE EMISSIONS
Hett * E1-32S5
Distance from Observer to Discharge Point:
0*45 Mters
Height of Observation P61nt:«10 "eters
Direction of Observer fron Discharge Point:
MJUst
Wind Velocity:
Detached Plume:
SUMMARY Of AVERAGE OPACITY
Time
Set Number . Start End
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
7:56
8:02
8
08
8:14
8:20
8:
26
8:32
8
8
8
8:
9:
9:
9:
9:
9:
9:
9:
9:
9:
38
44
50
56
02
08
14
20
26
32
38
44
50
Sketch Showing Now Opacity
25
gzo
I15
E10
i ;
_
-
-
P^
- _«*«--
1
1
Opacity
Sun
90
25
110
0
0
0
5
0
0
0
5
0
0
0
, 0
10
0
10
25
135
Varied
J
2
Average
3.
1
4.
0.
0.
0
0.
0.
0
0.
0.
0.
0.
0.
0.
0.
0.
0.
1.
5.
8
0
6
0
0
0
2
0
0
0
2
0
0
0
0
4
0
4
0
6
Set Number
21
22
. 23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
3B
39
40
Time Opacity
Start End Sum Av*raf»
9:56 5 0.2
10:02 5 0.2
10:08 0 0.0
10:14 0 0.0
10:20 0 0.0
10:26 25 1.0
10:32 120 5.0
10:38 165 6.9
10:44 35 1.5
10:50 0 0.0
10:56 0 0.0
11:02 85 3.5
11:08 0 0.0
11:14 235 9.8
11:20 11:26 0 0.0
With Time:
J\
TIME.
r
oJ
1
3
hours
n
I
1
4
1
A-60
-------
TABLE A-46
FACILITY C
SUMMARY, .or. vjsjBuyy ISSIOKS
Heat
Dite: July 21, 1976
Type of Flint: Steel Foundry Electric Arc Furnace
' Type of Discharge: Roof Vents
Location of Discharge: Roof of Building
Height of Point of Discharge:» 25 arters
Description of Background: Building _
Description of Sky: overcast
Wind Direction: variable
Color of PluBe:
Interference of Stem Pluae:
Duration of Observation:
SUWIARY OF AVERAGE OPACITY
Distance fro* Observer to Discharge Point:*'*5
Height of Observation P61nt:nlO Balers
Direction of Observer fron Discharge Point:
eihnt
Wind Velocity:
Detached Pluae:
SUMMARY OF AVERA6E OPACITY
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Tine
Start End
7:51
7:57
8:03 8:09
8:20
8:26
8:32
8:38
8:44
8:50
8:56 9:02
9:13 9:19
9:19
9:25
9:31
9:37
9:43
9:49 9:55
9:55
Ooaclty
Sum
30
0
0
0
0
0
0
30
0
10
20
180
165
115
40
210
115
Average
1.2
0.0
0.0
0.0
0.0
0.0
0.0
1.2
0.0
0.4
0.8
7.5
6.9
4.8
1.7
8.8
4.8
Tine Opacity
Set Nuaber Start End SIM Average
21
22
. 23
24
25
26
"
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing How Opacity Varied With Tine:
25
6 20
"i"
t 10
TIME, heun
A-61
-------
TABLE A-47
FACILITY C
SUMMARY OF VISIBLE EMISSIONS
Heat I E1-3251
Date: July 21. 1976
Type of Plant: Steel Foundry Electric Arc Furnace
Type of Discharge: Stack
Location of Discharge: Baghouse Outlet
Height of Point of Discharge:***" "*ters
Description of Background: sky
Description of Sky: overcast
Wind Direction: .
Color of Plume:
Interference of Steam Plume:
Duration of Observation:
Distance fro* Observer to Dlscha,
'Int:
Height of Observation Point; ground
Direction of Observer from Discharge Point:
**. Northeast
Wind Velocity:
Detached Plume:
SUMMARY
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
OF AVERAGE
Time
Start End
6:18
6:24
6:30
6:36
6:42
6:48
6:54
7:00
7:06
7:12
7:18
7:24
7:30
7:36
7:42
7:48
7:54
8:00
8:06
8:12
OPACITY
Opacity
Sun
0
0
15
80
0
0
0
0
0
0
0
10
. 55
0
0
0
0
0
0
0
Average
0.0
0.0
0,6
3.3
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.4
2.3
0.0
0.0
0.0
0.0
0.0
0.0
0.0
SUMMARY
OF AVERAGE
Time
Set Nunber Start End
21
22
. 23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
6:18
8:24
8:30
8:36
8:42
8:48
8:54
'9:00
9:06
9:12
9:18
9:24
9:30
9:36
9:42
9:48
9:54
OPACITY
Opacity
Sun
0
75
0
0
0
0
0
0
0
0
65
0
0
0
0
0
0
Average
0.0
3.1
0.0
0.0
0.0
0.0
0.0
0.0
O.D
0.0
2.7
0.0
0.0
0.0
0.0
0.0
0.0
Sketch Showing How Opacity Varied U1th Time:
25
£10
5 5
_L
2 3
TINE, hours
A-62
-------
References
1. Georgieff, N. T. Emission Standards and Engineering Division, Office of
Air Quality Planning and Standards (OAQPS), U.S. Environmental Protection
Agency. Private Communication to GCA/Technology Division. April 1978.
2. American Steel Foundries, Inc. Private Communication to Donald R. Goodwin,
Emission Standards and Engineering Division, OAQPS, U.S. Environmental
Protection Agency. June 18, 1976.
3. Remers, K., Direktor, Thyssen Rheinstahltechnik, Duesseldorf, Germany.
Private Communication to Emission Standards and Engineering Division,
OAQPS, U.S. Environmental Protection Agency. June 18, 1976. \
4. Berton, D. Air Industrie, .Courbevoie, France, Private Communication
to N.T. Georgieff, Emission Standards and Engineering Division, OAQPS,
U.S. Environmental Protection Agency. June 18, 1976.
5. Bozzetti, M. A., Air Industrie, S.P.A., Milan, Italy. Private Commu-
nications to N. T. Georgieff, Emission Standards and Engineering
Division, OAQPS, U.S. Environmental Protection Agency. March 4, 1976.
6. Allegheny County Health Department, Pittsburg, Pennsylvania. Source
Test of Baghouse on Steel Electric Arc Furnace at Bucyrus-Erie, Glassport,
Pennsylvania. May 1975.
7. Welzel, Ing. K., Landesanstalt fuer Immission und Bodenschultz des Landes
Nordrhein - Westfalien. Private Communication to N. T. Georgieff,
Emission Standards and Engineering Division, OAQPS, U.S. Environmental
Protection Agency. June -10, 1976.
8. Glenn, D., Buckeye Steel Casting Company, Columbus, Ohio. Private Commu-
nication to N. T. Georgieff, Emission Standards and Engineering Division,
OAQPS, U.S. Environmental Protection Agency.
9. Urban, G., Direktabsaugung & Reinigung der Rauchgase aus Electroefen,
Krupp's Technische Mitteilungen, Heft 10, 1963.
A-63
-------
APPENDIX B
DETAILED COST ANALYSIS FOR FURNACES PRODUCING
IRON CASTINGS
B-l
-------
68
TABLE B-l. SUMMARY OF CONTROL COSTS FOR 3.6 megagram/hour MODEL PLANT PRODUCING
GRAY IRON (SINGLE-FURNACE SHOP)
Evacuation System
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal efficiency, ';
Model New Facilities
Installed Capital ($)
Direct Operating Cost ($/yr)
Capital Charges ($/Yr)
Net Annual ized Costs (S/Yr)
Controlled Emissions (1000 Kg/Yr)
Cost Per Kg Controlled (S/Kg)
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs ($/Yr)
Capital Charges ($/Yr)
Net Annual ized Costs ($/Yr)
Controlled Emissions (1000 Kg/Yr)
Cost per Kg Controlled ($/Kg)
Side
Draft
Only
-
Baghouse
87
198,000
9,170
33,400
42,570
40.60
1.05
198,000
9,170
33,400
42,570
40.60
1.05
Side
Draft
Only
Scrubber
87
538,000
49,000
92,300
141,300
40.60
3.48
592,000
49,000
102,000
151,000
40.60
3.72
Side
Draft
Only
Clean Scrap
Baghouse,
PreheaterU)
92
292,300
16,200
50,100
66,300
42.82
1.55
232,300
16,200
50,100
66,300
42.82
1.55
Side
Draft
Only
Clean Scrap
! Baghouse ,7\
Briquetter
92
357,000
32,300
61 ,200
93,500
42.82
2.18
357,000
32,300
61,200
93,500
42.82
2.18
Close
Capture
System
-
Baghouse
96
236,0o63'
9,500
40,400
49,900
44.68
1.11
260,000
9,500
44,600
54,100
44.68
1.21
Close Capture System
+
Ladle Enclosure
--
Baghouse
97.5
280, OOo'4^
10,000
48,000
58,000
45.36
1.28
325,000
10,000
55,700
65,700
45.36
1.45
Canopy and
Side Draft
-
Baghouse
95
1,104,000
?6,800
139,000
2i5,800
-1.36
5.54
1 ,470,000
56,800
252,000
308,800
44.36
6.96
Capital cost of $94,300 and direct operating costs of 57000 - Reference 1, Section 4.
Capital cost of $159,000 and direct operating costs of $23,100 - Reference 6, Section 4.
^Includes purchase cost of 520,000 for special hoods to capture charging and melting emissions - Reference 5, Section 4.
^Includes purchase cost of 520,000 for special hoods (3) and $40,000 for hood and enclosure on tapping area - Reference 7,
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4
-------
TABLE B-2.
SUMMARY OF CONTROL COSTS FOR 7.3 megagram/hour MODEL PLANT PRODUCING
GRAY IRON (TWO-FURNACE SHOP)
Evacuation Systeir
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency %
Model New Facilities
Installed Capital ($)
Direct Operating Cost (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cqst Per Kg Controlled ($/Kg)
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs ($/yr)
Capital Charges (S/yr)
Ntt Annual ized Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg)
Side
Draft
Only
--
Baghouse
87
400,000
19,800
68,600
88,400
81.20
1.09
400,000
19,800
68,600
88,400
81.2
1.09
Side
Draft
Only
Scrubber
87
790,000
85,700
135,000
220,700
81.2
2.72
870,000
85,700
149,000
234,700
81.2
2.89
Side
Draft
Only
Clean
Scrap
Bayhouse ,,<
Pre-Heaterv '
92
517,000
33,800
88,700
123,000
85.6
1.44
517,000
33,800
88,700
123,000
85.6
1.44
Side
Draft
Only
Clean
Scrap
Baghouse ,?»
Briquetter^'
92
559,000
66,000
95,900 '
162,000
85.6
1.89
559,000
66,000
95,900
162,000
85.6
1.89
Close
Capture
System
Baghouse
96
476,000
20,600
81,600
102,000
89.5
1.14
524,000
20,600
89,900
110,500
89.5
1.23
Close Capture
System +
Ladle Enclosure
Baghouse
97.5
570,000
21 ,500
97,800
119,300
90.5
1.32
660,000
21,500
113,000
134,500
90.5
1.49
Canopy and
Side Draft
..
Baghouse
55
1,300,000
64,800
223,000
267,800
53.7
3.24
1 ,800,000
64,800
309,000
374,000
= 3.7
-.22
Capital cost of 5117,000 and direct operating cost of 314,000 - Reference 1, Section 4.
C«pit«l cost of 5159,000 and direct operating coit of $46,200 - Reference 6, Section 4.
w
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4.
-------
w
TABLE B-3. SUMMARY OF CONTROL COSTS FOR 9.1 megagram/hour MODEL PLANT PRODUCING
GRAY IRON (SINGLE-FURNACE SHOP)
Evacuation System
Process Constraint
"Control Device
Auxiliary Equipment
Pollutant Removal Efficiency %
Model New Facilities
Installed Capital (S)
Direct Operating Cost (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cost Per Kg Controlled (S/Kg)
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs S/yr)
Side
Side
Draft Draft
Only
..
Baghouse
87
317,000
15,450
54,400
69,900
121.8
0.57
317,000
Only
Scrubber
87
686,000
77,000
118,000
195,000
121.8
1.60
755,300
15,450 ! 77,000
54,400
69,900
Controlled Emissions (1000 Kg/yr} ' 121.8
Cost per Kg Controlled (S/Kg) 0.57
!
129,300
206,000
121.8
1.59
Side
Draft
Only
Clean
51 crap
Bsghuuse /,%
Pr.-Heater1 '
92
434,000
28,400
74,400
102,800
128.5
0.80
434,000
28,400
74,400
102,800
Side
Draft
Only
Clean
Scrap
Baghouse /,,
Briquetter^""-
92
476,000
124,000
81,600 '
205,600
128.5
1.60
476,000
124,000
81,600
205,600
I
128.5 128.5
0.80
Close
Capture
System
Baghouse
96
370,000
16,100
63,400
79,500
134.3
0.59
409,000
16,100
70,100
86,200
Close Capture
System +
Ladle Enclosure
Baghouse
i
Canopy ;nd
Side Drift
Bag hc.se
i
97.5
448,000
16,800
76,800
95
1,21C,000
6i,400
20E.300
93,600 272,400
136.1 13:. 1
0.69
520,000
16,800
89,200
106,000
134.3 ! 136.1
2.3S
1.6K.300
6MOO
276.300
34C.400
1 3: . '
1.60 ; 0.64 ; 0.78 ! -.=6
(i)
(2)
Capital cost of 5117,000 and direct operating cost of 513,000 - Reference I, Section 4.
Capital cost of 5159,000 and direct operating cost of 5108,000 - Reference 6, Section 4.
SOURCE OF BASIC COST INFORMATION: Reference 3, Section ,.
-------
Cd
Ln
TABLE B-4. SUMMARY OF CONTROL COSTS FOR 18.2 megagram/hour MODEL PLANT PRODUCING
GRAY IRON (TWO-FURNACE SHOP)
Evacuation System
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency 5!
Model New Facilities
Installed Capital (S)
Direct Operating Cost (S/yr)
Capital Charges (S/yr)
Net Annual 1zed Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cost Per Kg Controlled (S/Kg)
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs ($/yr)
Capital Charges ($/yr)
Net Annual ized Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg)
Side >
Draft
Only
Baghouse
87
587,000
.
29,000
101,000
130,000
243.6
0.54
587,000
29,000
101,000
130,000
243.6
0.54
Side
Draft
Only
._
Scrubber
87
1,003,000
139,000
172,000
311,000
243.6
1.28
1,103,000
139,000
189.000
328,000
243.6
1.35
Side
Draft
Only
Clean
Scrap
Baghouse /, v
Pre-Heater'
92
821 ,000
54,000
141,000
195,000
257.0
0.76
821 ,000
54,000
141 ,000
195,000
257.0
0.76 .
Side
Draft
Only
Clean
Scrap
Baghouse ,->
Briquetteru;
92
905,000
246,000
155,000 '
401,000
257.0
1.56
905,000
246,000
155,000
401,000
257.0
1.56
Close
Capture
System
Baghouse
96
698,000
30,100
120,000
150,300
268.6
0.56
768,000
30,100
132,000
162,000
268.6
0.60
Close Capture
System +
Ladle, Enclosure
...
Baghouse
97.5
830,000
31,400
142,000
173,400
272.2
0.64
960,000
31,400
165,000
196,400
272.2
0.72
Canopy and
Side Draft
--
Baghouse
95
1,620,000
91,200
278,000
369,200
266.2
1.39
2,160,000
91,200
370,000
461,200
2". 2
'..73
(1)
(2)
Capital cost of $243,000 and a direct operating cost of $26,000 - Reference 1, Section 4.
Capital coit of $318,000 and a direct operating cost of 8217,000 - Reference 6, Section 4.
SOURCE OF BASIC COST INFORMATICS: Reference 3, Section 4.
-------
TABLE B-5. SUMMARY OF CONTROL COSTS FOR 22.7 megagram/hour MODEL PLANT PRODUCING
GRAY IRON (SINGLE-FURNACE SHOP)
Evacuation System
Process Constraint
"Control Device
Auxiliary Equipment
Pollutant Removal Efficiency J
Model New Facilities
Installed Capital ($)
Direct Operating Cost ($/yr)
Capital Charges ($/yr)
Net Annual ized Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost Per Kg Controlled ($/Kg)
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs ($/yr)
Capital Charges ($/yr)
Net Annual ized Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg)
Side
Draft
Only
Baghouse
87
710,000
45,500
122,000
167,500
440.0
0.38
710,000
'45,500
122,000
167,500
' 440.0
0.38
Side
Draft
Only
-
Scrubber
87
1,140,000
223,000
196,000
419,000
440.0
0.95
1,260,000
223,000
216,000
439,000
440.0
1.00
Side
Draft
Only
Clean
Scrap
Bacjrouse /-,.
Pre-Heater ;
<<2
949,000
91 ,200
163,000
" 254,200
468.4
0.54
949,000
91,200
163,000
254,200
468.4
0.54
Side
Draft
Only
Clean
Scrap
Baghouse ,.^
Briquetter1 ;
92
1,028,000
306,500
176,000
482,500
468.4
1.03
1,028,000
306,500
176,000
482,000
468.4
1.03
Close
Capture
System
Baghouse
96
845,000
47,000
145,000
192,000
489.7
0.39
933 ,000
47,000
160,000
207,000
489.7
0.42
Close Capture
System +
Ladl» Enclosure
Baghouse
97.5
1,000,000
48 ,400
172,000
220,400
496.2
0.44
1,080,000
48,400
185,000
233,400
496.2
0.47
Canopy and
Side Draft
...
Baghouse
95
1,550,000
1 1 5 ,000
283,000
398,600
485.2
0.82
2,300,000
115,600
394,000
509,500
48E.2
1.05
t»
(1)
(2)
Capital cost of 5239,000 and direct operating costs of $45,700 - Reference 1, Section 4.
Capital cost of $318,000 and direct operating costs of $261,000 - Reference 6, Section 4.
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4.
-------
TABLE B-6. SUMMARY OF CONTROL COSTS FOR 45.4 megagram/hour MODEL PLANT PRODUCING
GRAY IRON (TWO-FURNACE SHOP)
Evacuation System
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency %
Model New Facilities
Installed Capital (S)
Direct Operating Cost (S/yr)
Capital Charges (S/yr)
Net Annual 1zed Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cpst Per Kg Controlled (S/Kg)
Model Existing Facilities
Installed Capital (S)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg)
Side
Draft
Only
Baghouse
87
1,293,000 .
89,000
222,000
311,000
880.0
' 0.35
1,293,000
89,000
222,000
311,000
' 880.0
0.35
Side
Draft
Only
Scrubber
87
1,660,000
418,000
285,000
703,000
880.0
0.80
1,800,000
418,000
309,000
727,000
880.0
0.83
Side
Draft
Only
Clean
Scrap
Baghouse /,%
Pre-Heaterv ''
92
1,770,000
. 180,000
304,000
484,000
936.8
0.52
1,770,000
180,000
304,000
484,000
936.8
0.52 '
Side
Draft
Only
Clean
Scrap
Baghouse ,?<,
Briquetteru'
92
1,930,000
611,000
331,000
942,000
936.8
1.00
1,930,000
611,000
331 ,000
942,000
936.8
1.00
Close
Capture
System
Baghouse
96
1,540,000
91,500
264,000
355,500
979.4
0.36
1,690,000
91,500
290,000
381 ,500
979.4
0.39
Close Capture
System +
Ladle Enclosure
--
Baghouse
97.5
1,830,000
94,400
314,000
408,400
992.4
0.41
2.120.000
94.400
364,000
458,400
992.4
0.46
Canopy and
Side Draft
Baghouse
95
2,650,000
201,000
454,000
655,000
970.4
0.67
3,530,000
201,000
605,000
806,000
970.4
0.83
w
Capital cost of 5478,000 and a direct operating cost of $91,400 - Reference 1, Section 4.
(1)
C«pit»l cost- of 5636,000 and a direct operating cost of $522,000 - Reference 6, Section 4.
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4.
-------
APPENDIX C
DETAILED COST ANALYSIS FOR FURNACES PRODUCING
STEEL CASTINGS
C-l
-------
TABLE C-l. SUMMARY OF CONTROL COSTS FOR 3,
STEEL CASTINGS (SINGLE-FURNACE
6 megagram/hour MODEL PLANT PRODUCING
SHOP).
Evacuation System
Process Constrain l
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency t
Model New Facilities
Installed Capital ($)
Direct Operating Cost (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 kg/yr)
Cost per Kg Controlled (S/Kg)
Side
Draft
Only
--
Baghojsf
83.5
198,000
9,170
33,400
42,570
41.66
1.02
198,000
9,170
33,400
42,570
41.65
1.C2
Side
Draft
Only
-
Scrubber
89. 5
538,000
49,000
92,300
141,300
41.66
3.39
592,000
49,000
102,000
151,000
-1.66
3.62
Side
Draft
Only
Clean Sc^ap
Baghouse /,
Briquetter1
93
357,000
32,300
61,200
93,500
43.25
2.16
357,000
32,300
61 ,200
93,500
43.25
2.16
Close
Capture
System
Baghouse
93
236,000
9,500
40,400
49,400
43.25
1.14
260,000
9,500
44,600
54,100
43.25
1.25
1 Close Capture
System +
Ladle Enclosure
-
Baghouse
97.5
280,000
10,000
43,000
58,000
45.36
1.28
325,000
10,000
55,700
65,700
45.36
1.45
Canopy and
Side Draft
--
Baghouse
97
1,104,000
56,800
189,000
245,800
45.15
5.44
1,470,000
56,800
252,000
308,800
45.15
6.84
n
10
'Capital cost of 5159,000 and direct operating cost of 523,100 - Refere-ce ^, Section
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4.
-------
n
U)
TABLE C-2. SUMMARY OF CONTROL COSTS FOR 7.3 megagram/hour MODEL PLANT PRODUCING
STEEL CASTINGS (TWO FURNACE SHOP)
Evacuation System
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency X
Model New Facilities
Installed Capital ($)
Direct Operating Cost ($/yr)
Capital Charges (S/yr)
Net Annuallzed Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled ($/Kg
Hodtl Existing Facilities
Installed Capital ($)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Net Annuallzed Costs (S/yr)
Controlled Emissions (1000 kg/yr)
Cost per Kg Controlled (S/Kg)
Side
Draft
Only
Baghouse
89.5
400,000
19,800
68,600
88,400
83.3
1.06
400,000
19,800
68,600
88,400
83.3
1.06
Side
Draft
Only
Scrubber
89.5
790,000.
85,700
135,000
220,700
83.3
2.65
870.000
85,700
149,000
234,700
B3.3
2.82
Side
Draft
Only
Clean Scrap
Saghouse /,
Briquetter
93
559,000
66,000
95,900
162,000
86.5
1.87
559,000
66,000
95.900
162,000
86.5
1.87
Close
Capture
System
Baghouse
93
476,000
20,600
81,600
102,000
86.5
1.18
524,000
20,600
89,900
110,500
86.5
1.28
Close Capture
System +
Ladle Enclosure
Baghouse
97.5
570,000
21,500
97,800
119,300
90.7
. 1.32
660,000
21,500
113,000
134,500
. 90.7
1.48
1 Capital cost of 5159,000 and direct operating cost of 846,200 - Reference ft. Section !>.
Canopy and
Side Draft
--
Baghouse
97
1,300,000
64.800
223,000
287,800
90.3
3.19
1,800.000
64,800
308,700
373,500
90.3
4.14
SOl'RCE OF BASIC COST ISFORMATIOS: Reference 3, Section 4.
-------
o
TABLE C-3. SUMMARY OF CONTROL COSTS FOR 9.1 megagram/hour MODEL PLANT PRODUCING
STEEL CASTINGS (SINGLE-FURNACE SHOP)
Capital cost of 5159,000 and direct operating cost of S108
SOL'RCE OF BASIC COST INFORMATION: Reference 3, Section 4
000 - Reference 6, Section 4.
Evacuation System
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency %
Model New Facilities
Installed Capital ($)
Direct Operating Cost (S/yr)
C*piti1 Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 kg/yr)
Cost per Kg Controlled (S/Kg)
Di rect
Evac.
Only
Baghouse
89.5
127,500
5,950
21,900
27,S5'0
125.0
0.22
127,500
5,950
21 ,900
27,850
125.0
0.22
Direct
Evac.
Only
Scrubber
89.5
382,000
33,500
65,500 '
99,000
125.0
0.79
420,000
33,500
72,000
105,500
125.0
0.84
Direct
Evac.
Only
Clean Scrap
Baghouse /,
Briquetter1
93
287,000
114,500
49,200
163,700
129.7
1.26
287,000
114,500
48.200
163,700
129.7
1.26
Close
Capture
System
--
Baghouse
93
370,000
16,100
63,400
79,500
129.7
0.61
409,000
16,100
70,100
86,200
129.7
0.66
Close Capture
System +
Ladle Enclosure
Baghouse
97.5
448,000
16,800
76,800
93,600
136.1
0.69
520,000
16,800
89,200
106,000
136.1
0.78
. (
Canopy and
Direct Evac.
--
Baghouse
97
1,210,000
64,800
233,000
287,800
135.4
2.13
1,610,000
64,800
309,000
374,000
135.4
2.76
-------
TABLE C-4. SUMMARY OF CONTROL COSTS FOR 18.2
STEEL CASTINGS (TWO-FURNACE SHOP)
megagram/hour MODEL PLANT PRODUCING
Evacuation System
Process Constraint
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency %
Model New Facilities
Installed Capital ($)
Direct Operating Cost ($/yr)
Capital Charges (S/yr)
Net Annual Ized Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled (S/Kg
Model Existing Facilities
Installed Capital (S)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Ntt Annual ized Costs (S/yr)
Controlled Emissions (1000 kg/yr)
Cost per Kg Controlled (S/Kg)
Direct
Evac.
Only
--
Baghouse
89.5
236,000
11,900
40,500
52,400
250.0
0.21
236,000
11,900
40,500
52,400
250.0
0.21
Direct
Evac.
Only
..
Scrubber
89.5
559,000
58,000
95,900
153,900
250.0
0.62
615,000
58,000
105,000
163,000
250.0
0.65
Di rect
Evac.
Only
Clean Scrap
Baghouse /,
Briquetter^
93
554,000
228,900
95,000
323,900
259.4
1.25
554,000
228,900
95,000
323,900
259.4
1.25
Close
Capture
System
--
Baghouse
93
698,000
30,100
120,000
150,100
259.4
0.58
768,000
30,000
132,000
162,000
259.4
0.62
Close Capture
System +
Ladle Enclosure
Baghouse
97.5
830,000
31 ,400
142,000
173,400
272.2
0.64
960,000
31 ,400
165,000
196,400
272.2
'0.72
Canopy and
Direct Evac.
-
Baghouse
97
1,362,000
74,400
234,000
308,400
270.8
1.14
1,820,000
74,400
312,000
386,000
270.8
1.43
(1)
Capital cost of 5318,000 and direct operating cost of 3217,000 - Reference 6. Section
SOURCE OF BASIC COST INFORMATIOX: Reference 3, Section 4.
-------
o
CX.
TABLE C-5. SUMMARY OF CONTROL COSTS FOR 22.7 megagram/hour MODEL PLANT PRODUCING
STEEL CASTINGS (SINGLE-FURNACE.SHOP)
Evacuation System
Direct
Evac.
Only
1
Process Constraint
-.
1
Control Device
Auxiliary Equipment
Pollutant Removal Efficiency *
Model New Facilities
Installed Capital ($)
Direct Operating Cost ($/yr)
Capital Charges (S/yr)
Met Annual ized Costs (S/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled ($/Kg
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs (S/yr)
Capital Charges (S/yr)
Net Annual ized Costs (S/yr)
Controlled Emissions (1000 kg/yr)
Cost per Kg Controlled (S/Kg)
Baghousa
89.5
236,000 .
15,800
45,100
60,900
455.6
0.14
236,000
15,800
45,100
60,900
455.6
0.14
Direct Direct
Evac. Evac.
Only | Only
Close
Capture
Systen
1
! Clean Scrap
1
Scrubber
89.5
608,000
83,700
104,300
188,000
455.6
0.42
669,100
83,700
114,700
198,400
455.6
0.44
Saghouse ,,
Briquetter^
93
554,000
276,800
95,000
Baghouse
93
845,000
47,000
145,000
371,800 i 192,000
i
473.0
0.78
554,000
276,800
95,000
371,800
473.0
0.41
933,000
47,000
160,000
207,000
473.0' i 473.0
Close Capture
System +
Ladle Enclosure
Baghouse
97.5
1,000,000
48,400
172,000
220,400
496.2
0.44
1,080,000
48,400
185,000
233,400
496.2
0.78 i 0.44 1 . 0.47
Canopy and
Direct Evac.
Baghouse
97
1,650,000
115,500
283,000
398,600
493.8
0.81
2,300,000
115, iOO
394,000
509,600
493.8
1.04
Capital cost of 5318,000 and direct operating cost of 3261,000 - Reference 6, Section i.
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4.
-------
o
TABLE C-6. SUMMARY OF CONTROL COSTS FOR 45.4 megagram/hour MODEL PLANT PRODUCING
STEEL CASTINGS (TWO-FURNACE SHOP)
Di rect
Evac .
Evacuation System , Only
Process Constraint
Direct Direct , Close , close Capture i .,
Evac. Evac. ; Capture System + Canopy and
Only . Only_ ; System ' Ladle Enclosure D1rect Evac-
j Clean Scrap
Control Device >' Baghouse Scrubber
Auxiliary Equipment .
Pollutant Removal Efficiency % 89.5 89.5
Model New Facilities
Installed Capital ($) 494,000 ' 890,000
Direct Operating Cost ($/yr)
Capital Charges ($/yr)
Net Annual ized Costs ($/yr)
Controlled Emissions (1000 Kg/yr)
Cost per Kg Controlled ($/Kg
Model Existing Facilities
Installed Capital ($)
Direct Operating Costs ($/yr)
Capital Charges ($/yr)
Net Annual! zed Costs ($/yr)
Controlled Emissions (1000 kg/yr)
Cost per Kg Controlled ($/Kg)
30,700
84,700
115,400
911.2
0.13
494,000
30,700
84,700
115,400
911.2
0.13
153,000
153,000 '
306,000
911.2
0.34
980,000
153,000
168,000
321,000
911.2
0.35
Baghouse /,
Sriquetter1 '
93
--
Saghouse
93
1
Baghouse
97.5
1,130,000 I 1,540,000 | 1,830,000
553,000
194,000
747,000
946.0
0.79
1,130,000
553,000
194.000
747,000
946.0
0.79
91 ,500
264,000
355,500
946.0
0.38
1,690,000
91 ,500
290,000
381 ,500
946.0
0.40
94,400
314.000
408,400
992.4
0.41
2,120,000 |
94,100
364,000
458,400
992.4
0.46
Baghouse
97
1,984,000
143,000
340,000
483,000
987.6
0.49
2,640,000
143.000
453,000
596.000
987.6
0.60
(1)
Capital cost of $636,000 and direct operating cost of $522,000 - Reference 6, Section k.
SOURCE OF BASIC COST INFORMATION: Reference 3, Section 4.
------- |