Notice
This document has not been formally released by EPA and should not now
be construed to represent Agency policy. It is being circulated for
comment on its technical accuracy and policy implications.
STANDARDS SUPPORT AND ENVIRONMENTAL IMPACT STATEMENT
AN INVESTIGATION OF THE
BEST SYSTEMS OF EMISSION REDUCTION
FOR
ELECTRIC ARC FURNACES
IN
THE GRAY IRON FOUNDRY INDUSTRY
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards
Emission Standards and Engineering Division
Research Triangle Park, North Carolina 27711
Telephone: (919) 688-8146
-------
Notice
This document has not been formally released by EPA and should not now
be construed to represent Agency policy. It is being circulated for
comment on its technical accuracy and policy implications.
STANDARDS SUPPORT AND ENVIRONMENTAL IMPACT STATEMENT
AN INVESTIGATION OF THE
BEST SYSTEMS OF EMISSION REDUCTION
FOR
ELECTRIC ARC FURNACES
IN.
THE GRAY IRON FOUNDRY INDUSTRY
Principal Investigator
Naum T. Georgieff
Economic Investigator
F. L. Bunyard
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Air Quality Planning and Standards
Emission Standards and Engineering Division
Research Triangle Park, North Carolina 27711
Telephone: (919) 688-8146
October 1976
-------
TABLE OF CONTENTS
Chapter 1. Summary
(To be completed by the Standards Development Branch)
Chapter 2. Introduction
(To be completed by the Standards Development Branch)
Chapter 3. The Gray Iron Foundry Industry
(Electric Arc Furnaces) 3-1
3.1 General 3-1
3.1.1 Industry Growth 3-5
3.2 Foundry Operations and Emissions 3-7
3.2.1 Description of Process 3-7
3.2.2 Selection of Furnace 3-14
3.2.2.1 Types of Furnaces 3-14
3.2.2.1 Raw Materials Optimization 3-15
3.2.2.2 Energy Requirements 3-18
3.2.2.3 Metallurgical Specifications 3-18
3.2.2.4 Minimum Pollution 3-19
3.2.2.5 Space Requirements 3-19
3.2.2.6 Ease of Temperature Control 3-20
3.2.2.7 Operation and Maintenance 3-21
3.2.2.8 Conclusion 3-21
-------
3.2.3 Electric Arc Furnace Operation 3"21
3.2.3.1 Charging 3~22
3.2.3.2 Melting and Refining 3-25
3.2.3.3 Material Balances 3-28
3.2.3.4 Energy Considerations 3~29
3.2.3.5 Rate and Composition of Emissions . . . . *3-30
REFERENCES 3"38
Chapter 4. Emission Control Techniques 4-1
4.1 Capture Systems 4-1
4.1.1 Canopy Hoods 4-3
4.1,2 Roof Hoods 4-6
4.1.3 Side Draft Hoods 4-8
4.1.4 Direct Furnace Evacuation 4-8
4.1.5 Enclosures 4-10
4.2 Control Devices 4-12
4.2.1 Fabric Filters 4-12
4.2.2 Electrostatic Precipitator 4-13
4.2.3 Wet Scrubbers 4-14
4.3 Performance of Emission Control Systems 4-15
REFERENCES 4-28
Chapter 5. Modification and Reconstruction of Foundries .... 5-1
5.1 Provisions for Modification and Reconstruction 5-2
5.1.1 Modification 5_2
ii
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Page
5.1.2 Reconstruction 5-4
5.2 Applicability to Electric Arc Furnaces in
Gray Iron Foundries 5-4
5.2.1 Modification 5-4
5.2.2 Reconstruction 5-6
Chapter 6. Emission Control Systems 6-1
6.1 The Problem 6-1
6.2 Possible Solutions 6-2
6.2.1 Closed Charging System 6-2
6.2.2 Preheating 6-3
6.2.3 Hooded Charge Bucket 6-5
6.2.4 Enclosures 6-7
6.2.5 Waste Heat Recovery 6-11
6.2.6 Canopy Hoods 6-14
6.2.7 Degreasing 6-15
REFERENCES 6-16
Chapter 7. Environmental Impact 7-1
7 1 Introduction 7-1
7.1.2 Air Pollution Impact 7-1
7.1.3 State Air Regulations 7-5
7.2 Atmospheric Dispersion Modeling 7-10
7.2.1 Plant Characteristics 7-11
7.2.3 Meteorological Considerations 7-12
7.2.4 Results and Conclusions 7-17
-------
Page
. . • 7-21
las uc n,a ucj •
7.2.2.1 pH
7.2.2 Quality of Waste Water
. . . 7-22
7-?2
7.2.2.2 TOD ' "
7.2.2.3 Total Suspended Solids 7-24
7.2.3 Water Treatment 7"24
7.2.4 Conclusions 7"25
7.3 Solid Waste Disposal Impact 7-27
7.3.1 Quantity of Solid Waste 7-27
7.3.2 Composition of Solid Waste 7-30
7.3.3 Disposal • • 7-30
7.3.3.1 Pelletization, Use as Masonry Aggregate . . . 7-31
7.3.3.2 Fill and Aggregates 7-33
7.3.3.3 Safety Area Application 7-34
7.3.3.4 Foaming 7-35
7.3.3.5 Vitrification 7-35
7.3.3.6 Glazes and Polymer Fiber 7-35
7.3,3.7 Colorant and Agricultural Uses 7-36
7.3.3.8 Metal Extraction ..... 7-37
7.3.3.9 Present Disposal Techniques 7-37
7.3.4 Summary 7-37
7.4 Energy Impacts 7.39
7.4.1 Introduction 7.39
7.4.2 Process Energy Consumption 7.39
7.4.3 Emission Control Systems Energy Consumption 7-42
7.4.4 Conclusions 7_4g
iv
-------
7.6 Other Environmental Concerns . . 7-48
7.6.1 Irreversible and Irretrievable Commitment
of Resources 7-48
7.6.2 Environmental Impact of No Standards 7-50
REFERENCES 7-57
Chapter 8. Economic Impact 8-1
8.1 Industry Economic Profile 8-1
8.1.1 Introduction 8-1
8.1.2 Markets for Iron Castings 8-2
8.1.2.1 Principal Markets 8-2
8.1.2.2 Competition of foundries for markets .... 8-3
8.1.2.3 Competition from Substitutes 8-5
8.1.3 Prices 8-6
8.1.4 Balance of Trade for Iron Castings 8-7
8.2 Cost Analysis of Alternative Control Systems 8-10
8.2.1 New Facilities 8-10
8.2.1.1 Introduction 8-10
8.2.1.2 Model Plants 8-10
8.2.1.3 Control Technology Costs 8-11
8.2.1.4 Costs for State Regulations 8-15
8.3 Other Cost Considerations 8-15
8.4 Economic Impact of Alternative Control Systems 8-16
8.4.1 New Facilities 8-16
8.4.1.1 Introduction 8-16
8.4.1.2 Impact on Prices 8-17
8.4.1.3 Impact on Plant Profitability 8-22
-------
Page
8.4.1-4 Impact on Imports 8'25
8.5 Socio-Economic Impact 8"27
8.5.1 Introduction 8-27
8.5.2 Market Dislocations 8~28
8.5.3 Small Businesses 8~30
8.5.3 EPA Guidelines-Screening Inflationary Impacts . . . 8-31
REFERENCES S"33
Chapter 9. Technical Studies to Define Performance of
Best Systems of Emission Reduction 9-1
9.1 Selection of Source for Control 9-1
9.2 Selection of Pollutants and Affected Facilities 9-3
9.2.1 Pollutants 9-3
9.2.2 Affected Facilities 9-4
9.3 Selection of the Best System of Emission
Reduction Considering Cost 9-5
9.3.1 General 9-5
9.3.2 Canopy Hood 9-7
9.3.3 Enclosures 9-7
9.3.4 Hooded Charging Buckets 9-8
9.3.5 Pretreatment 9_9
9.3.5.1 Preheaters 9-9
9.3.5.2 Degreasing 9-9
9.3.5.3 Briquetting 9-10
9.3.5.4 Automated Charging Systems 9-10
9.3.6 Alternative Control Systems 9-12
9.3.7 Background g_]3
9.3.8 Data g_16
vi
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Page
REFERENCES 9-18
Appendix A. Evolution of the Selection of the Best System
of Emission Reduction A-l
Appendix C. Summary of Particulate and Gaseous
Emission Test Results C-l
Appendix D. Emission Measurement and Continuous Monitoring . . . D-l
Appendix E. Enforcement Aspects of the Recommended Standard . . . E-l
vn
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3. THE GRAY IRON FOUNDRY INDUSTRY
CELECTRIC ARC FURNACES)
3.1 GENERAL
Cast irons and steels are both solid solutions of iron and carbon and
various other alloying elements. Although there are many types of each,
the iron and steel families can be distinguished by their carbon content.
Irons typically contain two percent or greater and steels less than two per-
cent.
The gray iron foundry as here defined includes all foundries that pro-
duce primarily gray, white, ductile or malleable iron castings. This class-
ification is justified because most of the steps in the production of these
irons are identical. Regardless of the final product, the charging, melting
and refining proceed similarly as follows. Based on the chemical specifica-
tions of the desired product, select scrap is introduced or "charged" into
the furnace and melted. Samples of the homogenous melt are then analyzed to
verify the chemical composition. If the make-up of scrap does not yield a
melt that is within specification, the chemistry of the melt is easily
changed by the addition of small amounts of alloying metals or adjustment
of the carbon content.
Inspection of the Table 3.1 shows clearly that the chemical specifica-
tions for gray iron do not quite, but almost encase those of these other
irons, i.e., they are subsets of gray iron. Consequently, the melting and
3-1
-------
Table 3.1 RANGE OF COMPOSITIONS FOR TYPICAL CAST IRONS
Element
Carbon
Silicon
Manganese
Sulfur
Phosphorus
Gray Iron, %
2.5 -
1.0 -
0.25 -
0.02 -
0.05 -
4.0
3.0
1.0
0.25
1.0
White Iron, %
1.8 -
0.5 -
0.25 -
0.06 -
0.06 -
3.6
1.9
0.80
0.20
0.18
Malleable Iron
(cast white) , !
2.00
1.10
0.20
0.04
0.18
- 2.60
-1.60
-1.00
- 0.18
maximum
1 Ductile Iron, %
3.0
1.8
0.10
0.03
0.10
- 4.0
- 2.8
- 1.00
maximum
maximum
refining of a cast iron, which has more restrictive chemical properties than
gray cast iron, is for all practical purposes, merely preparation of a special-
ized type of gray. (One obvious difference in the chemistry of cast irons is
the magnesium content of ductile iron, however, since the "innoculation" of
the magnesium into the molten melt does not take place in the furnace, that
difference is academic insofar as the quantity and type of emissions from
the furnace are concerned.) The composition of the gases emitted by furnaces
producing gray, white, ductile or malleable iron is very similar since their
chemistries are similar. The slightly elevated temperature in production
of malleable iron (35°C) would not result in significantly higher nitrogen
oxide emissions and although sulfur is used in the production of malleable
iron, practically all is absorbed.1 The more significant source of any sulfur
dioxide in the emissions is the sulfur content of the electrodes and the oil
and grease in the scrap. These, of course, are not unique to any product.
Similarly, the amount or type of particulates emitted would not be expected
to vary significantly from charge material used to produce gray, white,
malleable or ductile iron.2 Consequently, characteristics of the particulate
3-2
-------
such as participate size, wettability, electric resistance properties,
agglomeration characteristics, etc., should be relatively consistent. This
rationale leads to the conclusion that an air pollution control device should
be similarly effective on emissions from all products. A review of emission
regulations in some foreign countries reveals that they also do not differen-
tiate between emissions from production of gray iron, white, malleable and
ductile iron.3
The gray, white, ductile and malleable iron foundries produced 18.12
million short tons of castings in 1973. Assuming an average yield of 60 per-
cent good castings, then the total weight of metal melted was 30.2 million
short tons. A production breakdown for 1973 by furnace type is shown in
Table 3.2.
TABLE 3.2 ESTIMATED AMOUNT OF IRON MELTED IN THE VARIOUS
TYPES OF FOUNDRY MELTING FURNACES PER YEAR
Estimated Production of Castings in Various Furnace Types
and Different Sizes of Foundries
barge Foundries
Type of
Mel ti ng
Furnace
Cupola
Induction
Arc
Air
Total
Percent^
48.0
2.5
14.9
0.3
65.7
Thousand
?SS>)
14,496
755
' 4,500
90
19,841
Medium-Size
Foundries
Percent^3'
21.7
3.8
1.6
1.4
28.5
Thousand
Short, x
Tonseb)
6,553
1,148
483
423
8,607
Small Foundries
Percent^3'
5.1
0.4
0.3
—
5,8
Thousand
&
1,540
121
91
__
1,752
All
Foundries
Thousand
Short
Tons
22,589
2,024
5,074
513
30,200
(a) Estimated percentage of total production, based on capacity and assumed daily
melting period.
(b) Estimated annual tonnage melted, based on 1973 production of 18.12 million short
tons of castings. At an estimated yield of good castings of 60 percent, then the
total weight of iron melted was 18.12/0.60 = 30.20 million short tons.
3-3
-------
Table 3.3 GRAY AND DUCTILE IRON FOUNDRIES IN
19734
Furnace type
Cupola
Channel induction
Coreless inducation
Arc
Air and reverberatory
Number of units
1804
4081
726 f
••J
371
159
Companies
1092
397
187
—
Capacity,
tons/hour
14,213
2,362
2,555
--
Data on employment,4 indicative of the typical sizes of foundry shops,
are shown below:
Employees Number of foundries
More than 250 166
50 to 249 595
10 to 49 534
Less than 10 178
Notice that most of the foundries employ between 10 and 249 people. Total
employment for the industry is 138,000. Although no data are available on
employment in foundries by furnace type, it is expected that generally the
larger foundries use electric arc furnaces or cupolas. Induction and
reverberatory furnaces are more typical of smaller foundries. Larger fur-
naces (10 to 15 tons per hour) are usually located in integrated machine
producting plants; very few furnaces produce more than 15 tons/hour. Smaller
furnaces, down to a fraction of a ton per hour, are located in plants that
produce a limited variety of products or small quantities of-speciality castings.
3-4
-------
Small plants operate their arc furnaces periodically; large foundries
usually in two shifts.
3.1.1 Industry Growth.
Shipments of ferrous castings were expected to increase to 20.5
million tons in 1975 or about 6 percent above the 19.4 million tons shipped
in 1974. However, the 1975 increase did not materialize due to a lack in
demand from the automobile industry and other major customers. The same
reference projected shipments of tonnage castings in 1974 would decline 2
percent from 1973, largely because of curtailment of automotive production
and materials shortages (Table 3-4).
Table 3.4 GRAY IRON CASTINGS DATA AND PROJECTIONS 7
(Thousands of Tons)
Industry 1973 1974 1975
Quantity
Gray, including ductile iron 17,072 16,560 13,400*
Malleable, including
pearlitic iron 1,030 965 825*
Total quantity shipped 18,102 17,525 14,425*
*Gray and Ductile Iron Founder's Society Incorporated estimates.
Gray iron castings shipments are expected to decline to 13.4 million
tons in 1975, about 19.5 percent below 1974 shipments and 21.5 percent below
1973, the previous peak year. Concurrently, inflation has caused the value
of gray iron castings shipments to rise tp an estimated $5.2 million in 1974
and will likely increase by an additional 7 percent to about $5.6 billion
in 1975.
3-5
-------
In 1974, gray iron castings accounted for 85 percent of total ferrous
castings shipments, and will probably maintain th/is share in 1975. Ship-
ments in 1974 were below those in 1973 because of reduced demand by the
automotive industry and reduced production caused by shortages of such raw
material as pig iron, coke, ferroalloys, sand, resins and certain chemicals.
Ductile iron castings constituted about 16 percent of total gray iron ship-
ments in 1974, about the same percentage as in 1973.
8
As of July, malleable iron casting shipments in 1975 have been 23 per-
cent lower than in 1974. The projection for the entire year of 1975 is
that shipments will be 20 percent lower than in 1974. For 1975-1980, growth
in the tonnage shipments of ferrous castings (including about 10 percent
q
steel castings) is expected to average about 3 percent annually. Although
demand for castings will continue to be subject to cyclical swings, shipments
should reach 23 million tons in 1980. Gray iron castings will continue as
the dominant segment of the industry, representing about 85 percent of total
castings shipments. The ferrous castings industry must continue to modernize
and expand its capacity to keep pace with the growing needs of consuming
industries.
The growth in numbers of new furnaces installed varies with the type
of furnace. Electric arc furnace installations have increased considerably
and constantly. This trend is substantiated by data supplied by Union
10
Carbide, the largest supplier for arc furnace electrodes C50 to 75 percent
of the market in the United States). In 1974, the company projected a 1974
increase of about 400 tons/hour in installed melted metal capacity for arc
furnaces producing gray iron. (This figure has not been confirmed.) It is
difficult to predict how many furnaces will be installed during the 5-year
period to produce the projected amount of gray iron. A good guess (assuming
3-6
-------
operating time of between 6000 and 7000 hours per year) is probably 6 to 7
furnaces per year.
Brown Boveri Corporation projected an increase for induction furnaces
of 370 tons per hour capacity per year. With an operating time of about
3000 hours per year, this capacity corresponds to about 80 new furnaces per
year. Induction furnace installations have increased faster than arc furnaces
because they are generally smaller and smaller foundries can operate them.
Although cupolas and arc furnaces are inherently suited for melting large
tonnages (15 tons/hour and above), induction furnaces are best suited for
production at below 3 tons/hour. For production between 3 and 15 tons/hour,
the choice of a furnace type (induction, arc, or cupola) depends on the specific
application. Neither government nor industry data are available to adequately
estimate the expected increase in cupola furnace installations. This lack of
data is due mainly to the fact that coke—one of the few materials used in
the cupola melting process of making gray, white, ductile and malleable iron
castings—in in short supply.
Despite all the claims of the manufacturers of arc and induction fur-
naces, it is difficult to predict which kind of melting furnace will receive
widest application in the gray iron casting industry. Apparently, based on
the tonnage of gray iron handled, the arc furnace will be favored, although
s
the number of such furnaces installed will be several times less than that
of induction furnaces. This depends, of course, on cost of local scrap.
3.2 FOUNDRY OPERATIONS AND EMISSIONS
3.2.1 Description of Process.
A number of distinct but strongly interconnected operations are carried
out at an iron foundry. All foundries utilize certain basic operations
3-7
-------
consisting of:
1. Storage and handling of raw material.
2. Melting.
3. Pouring into molds.
Other processes present in roost, but not all, foundries include:
1. Preparation of the molds to hold the molten iron.
2. Molding.
3. Sand preparation and handling.
4. Mold cooling and shakeout.
5. Casting cleaning, heat treating, and finishing.
6. Coremaking.
7. Pattern making.
A simplified, schematic flow diagram encompassing most of these processes
is presented in Figure 3.1.
Foundry processes can be separated into melting and non-melting activities.
The process flow diagram for the four major melting devices (cupola, electric
arc, induction, and reverberatory furnaces) are represented in Figure 3.2.
Castings are produced in a foundry through the injection or pouring
of liquid iron, steel, aluminum, bronze, or other metals into cavities of
a mold, which can be made of sand, metal, or ceramic. These metals are melted
mostly in cupola, electric or reverberatory type furnaces.
The mold is a form containing cavities into which the molten metal is
poured. To produce a casting using sand, a pattern is, made which conforms
to the external dimensions of the desired casting. The pattern is placed
in a box-like frame or flask, which is then filled with a sand and binder
mixture, in such, a way that when the mixture hardens, a parting line separates
3-8
-------
Co
i
ID
METALLICS
FLUKES
FINISHING
GAS AND
PARTICULATE
EMISSIONS
GAS AND
PARTICULATE
EMISSIONS
METAL
MELTING
ELECTRIC
ARC
SHIPPING
DUCTILE IRON
-rJ INNOCULATION
DUST
AND
GASES
CASTING
SHAKEOUT
RETURN
DUST SAND
COOLING AND
CLEANING
POURING
; SPILL
DUST SAND
CORE SAND
AND BINDER
MOLDING
CORE
MAKING
DUST
SAND
PREPARATION
Figure 3.1 Iron foundry process flow and emission sources.
-------
CO
I
POUR
Figure 3.2 Process flow diagram of iron foundry melting department.
-------
the mold into two halves. After removing the pattern from the two mold
halves, and inserting cores where needed, molten metal is poured into the
cavity vacated by the pattern. When the metal has solidified, the casting
is cleaned in a casting shakeout with subsequent abrasive (sandblasting)
cleaning and grinding. The casting now can be shipped to another industry
for machining and/or assembly in a final product.
The process flow is essentially the same for all foundries although
the type of furnace (melting practices) and their auxiliary operations may
vary somewhat. Figure 3-3 depicts the flow of foundry operations.
All types of furnaces which produce gray iron can use the same raw
materials; some, however, require pretreatment of the charge. For example,
a foundry may operate a "scrap receiving station" wherein the scrap is stored
and classified according to size. (This station may also be known as the
"bulk storage area.") Classified scrap is transferred into the "day bins,"
which contain the scrap for one day's operation of the foundry. Depending
on the components of the scrap and the type of furnace, some of the material
must have special pretreatment. For example, metal borings have to be at
least 10 percent or lower in oil content before they can be used in most
furnaces. This is done in the "cleaning station," where part of the oil is
removed by centrifugation or heating by chemical means. Cupola furnaces
are somewhat unique in that they require areas for storage of limestone and
coke. Foundries with induction furnaces often feature another station, the
"preheater," in which all the water and most of the oil are removed from the
charges to preclude the possibility of an explosion hazzard. Excess dirt is
also -removed. Electric arc furnaces and cupolas can use preheated charges
also, but this is seldom done because they are not susceptible to the same
hazzard. In various preheating processes, the objectives vary. The furnace
3-11
-------
RAW MATERIAL STORAGE
AND FURNACE CHARGE
MAKEUP
1
MELT
I
HOLD
CORE-
MAKING
MALLEABLE IRON ONLY
PRESS
STRAIGHTEN
DUCTILE AND
MALLEABLE
IRON ONLY
LADLE
ADDITIONS
LADLE
1
POUR
1
1
MAGNESIUM
TREATMENT
DUCTILE IRON ONLY
MOLD
1
SAND CONDITIONING
AND RECLAMATION
1
ANNEAL
SHAKEOUT
1
CLEAN
i
FINISH
HEAT
TREAT
SURFACE
COAT
i
SHIP
Figure 3.3 Flow diagram for gray, ductile, and malleable
iron process.
3-12
-------
charge may be heated to slightly above 93°C to remove water, 202 - 232°C to
burn some of the oil and dirt as well (as reduce the melting time in the
furnace) or 650°C for the purpose of saving reducing additional time from
the furnace cycle. The charges are made up at the "charge makeup stations."
The bucket receiving the charge is either placed on a weighing platform or a
scale is attached to the magnet used to lift the scrap into the bucket. In
this way the bucket is charged with proper quantities of materials and
additives. The charge is transferred to the furnaces and dropped into the
furnaces by opening the bottom of the bucket. Cupolas, on the other hand,
are charged via a skip hoist with special buckets or by other different
methods.
The material charged to an electric furnace is melted by heat provided by
electrical energy. The rate of heating can be directly controlled by adjust-
ment of current and voltage. An electric-arc furnace converts electrical
energy into heat by an arc discharge above or within the iron to be melted.
(the metal is heated and melted by the heat radiated from the arc and by
conduction and convection) whereas an induction furnace generates heat
through magnetic fields induced by electrical current. In the cupola heat
is generated by the combustion of coke. Control is achieved by manipulating
the ra+'o of coke to iron in the charge and adjusting the blast rate.
The charge in each furnace is heated until it reaches a certain tempera-
ture and the proper chemistry of the melt has been verified. The iron can
then be poured out of the furnace into large teeming ladles and then into
the molds.
Preparation of molds and cores and the handling of sand are common opera-
tions to each tyoe of foundry. When the molten metal in a mold has solidified,
the casting is cleaned by shaking and subsequently abrasively cleaned
3-13
-------
(sandblasted) and ground. The casting can then be shipped to another industry
for machining and/or assembly in a final product.
Each of the above operations contains equipment and processes capable
of producing atr pollutants in the form of fumes, gases, and particulates.
The major emissions are fine ferrous and nonferrous oxides and smoke from the
melting furnaces. Coarse particles are generated during grinding operations,
shaking, blasting, sand reclamation, etc.
3.2.2 Selection of Furnace.
Important factors which influence the foundry in choosing the type of
furnace are:
1. Ability to optimize raw materials.
2. Energy consumption.
3. Easy attainment of metallurgical specifications.
4. Minimum pollution [both within the work area and outside of the
shop).
5. Space requirements.
6. Ease of temperature control.
7. Maintenance.
Following is a description of the melting processes of primary importance in
gray iron production (cupolas, electric arc and induction furnaces) and their
capabilities and limitations. Other types of furnaces are also used, but
to a very minor extent.
3.2.2.1 Types of Furnaces
The cupola is a vertical, refractory-lined, cylindrical steel shell
that is charged at the top with, alternate Additions of metal, coke, and
fluxing materials. The iron is melted by burning the coke. Air is supplied
3-14
-------
through tuyeres near the bottom of the furnace. Some are built with..a thin
refractory and are cooled with a water jacket.
Heat is generated in an induction furnace by the changing electrical
flux created by an induction coil around the furnace shell. Channel and
coreless are two types of induction furnaces. They are used to melt, hold
or superheat gray iron.
In the electric arc furnace, the heat for melting is generated by the
radiated heat from the arc formed when an electric current passes through
the air gap between three triangularly arranged cylindrical graphite electrodes
which extend through holes in the roof of the furnace and the metal charge.
Two other types of furnaces, electric-resistance and indirect-arc, are
seldom used in iron foundries.
Gas and oil-fired reverbatory furnaces are reported to have low emission
12
levels. The flyash from pulverized coal-fired reverberatory furnaces can
result in significant emissions to the atmosphere if an air pollution control
device is not used.
3.2.2.1 Raw Materia]Optimization-
The raw materials used for production of gray iron are: metal, fluxes
and power in the form of electricity, coke or other fossil fuel.
The metallics are scrap metal, foundry returns, borings and either solid
or molten pig iron. Although open scrap yards are common, covered storage is
desirable, especially for induction furnaces which cannot tolerate moisture
in the feed.
It is most economical to use scrap materials in the as-received form.
Some preparation is necessary, however, for some kinds of melting furnaces.
Preparation of the scrap for example, may involve the fragmentation of large
3-15
-------
pieces, heating to remove moisture orsoil, preheating to reduce cycle time
in the furnace or briquetting of small pieces.
The electric arc furnaces is superior to the other furnaces because
it oossesses the ability to melt large pieces and borings. Scrap charged to
cupola and induction furnaces has to be cut to .size because of their smaller
cross sectional area at the potnt of charging.' Another important feature of the
electric furnace is its capability, because of the large open top, to receive
surplus molten ladle metal back, into the furnace. Qhyioiisly, if metal can
be reused in the molten state, less energy will be used than starting from
cold scrap.
The dirt, oil, grease, and water content of the scrap is of paramount
importance. Although arc furnaces and cupolas can accept dirty scrap,
induction furnaces cannot tolerate contaminants of oil and water because
of the explosion potential.
Swarf and borings from metal fabrication operations can be remelted
easily in electric arc furnaces, however, their low bulk density and high
oil content make them a less desirably raw material. Canistering and
briquetting are being explored as ways to increase the bulk density and
reduce the high oxidation losses experienced with direct injection. Because
they contain oil, swarf and borings are difficult to handle in an induction
furnace. Even if the oil content is reduced to 1.5 percent, there is some
splashing and a large amount of flame and smoke from an induction furnace
(.although the latter can be dealt with using a fume evacuation system). If
the oil-water content exceeds about 2 percent then the splashing, flame and
smoke present a hazard to operators near the furnace.
Although induction furnaces can melt any charge that will fit into the
crucible, additional preparation of the material is required:
3-16
-------
1. Because of an explosion hazard, the charge must be water free and
nearly oil free when charging into a liquid metal bath.
2. Dirt included with the charge will cause excess slag that accumu-
lates on the walls of the crucible. Since the induction furnace
heats through the walls, the slag reduces the heat transfer,
increases power demand and reduces melting rate.
In order to meet these requirements, the scrap charge to an induction fur-
nace must be, dried, cleaned and/or preheated in a special preheater which
is usually fired by gas or oil.
The charge must contain some additive if only to adjust the chemistry
of the iron. In electric arc furnaces, these additives amount to a fraction
of the total charge, but in cupolas the amount of lime and coke charged is
substantial. The flux, which has to be stored and handled, also becomes an
air pollution problem because it is emitted along with exhaust gases. In
addition to all these ingredients to the charge in a cupola, a large amount
of air must be provided for the combustion of coke.
The kind and size of charge materials play a strong role in the selection
of melting equipment.
The metallic charge to a cupola can be all-steel, but this limits the
maximum melt rate because more coke is required to supply the needed carbon
to the melt. In induction and electric arc melting, carburization of steel
is more attractive because more efficient and denser carbonaceous materials
can be used tp raise the.carbon 1 eye/Is., Therefore, in places where most of
the scrap is steel, cupolas would be the least desirable melter, depending on
other economical factors.
In addition, because of the splashing hazzard of the molten steel In an
induction furnace, only the electric arc furnace can accept charges of very
large pieces of scrap metal. Electric arc furnaces, therefore, are better
3-17
-------
suited to the melting of different kinds of scrap than cupolas and induction
furnaces.
3.2.2.2 Energy Requirements
Cupolas, at 40 percent are less efficient than either electric arc
(65 percent) or induction [75 percent) furnaces. Electric furnaces have
the disadvantage that they are less economical in regions where electric
power is expensive.
Cupolas require about 1810 Btu to produce 1 pound of iron against 850
Btu for electric arc furnaces. Perhaps of equal importance, however, is the
source of energy required by the different types of furnaces. The cost of
both electric power and coke has gone up in recent years. In addition, good
metallurgical coke for foundry use is not easy to obtain. These factors
would seem to suggest electric melting will gain the economic upper hand.
But this, too, depends on availability of electric power and coke in specific
13
localities. (Interestingly, several years ago, the opinion was expressed
that if electric current prices were reduced by 50 percent, the cupolas would
become obsolete.) The energy required also depends on the kind of scrap
available, and the product. Steel scrap requires more energy to melt than
iron. In the case of the cupola, any "additional" coke required to provide
incremental heat reduces the amount of scrap that can be charged and thereby
lowers production rates.
Induction furnaces, in addition to electric energy, might need gas or
oil to fuel preheaters if the charge material is wet, oily or dirty.
3.2.2.3 Metallurgical Specifications
The chemistry adjustments necessary on a specific gray iron furnace
charge also influence the choice of furnace type. Adjustments are more
3-18
-------
difficult in a cupola or an induction furnace than in an electric arc furnace.
For this reason, corrections of the chemistry of melts from these furnaces
are often made in the transfer ladle or in an electrically heated holding
furnace. This is still less efficient than making similar changes in the arc
furnace.
Electric arc furnaces do not contaminate the melt. Cupolas, on the
other hand, may impart sulfur into the iron from the coke used for heating
the furnace. Moreover, the yield in electric arc furnaces is somewhat higher
since less oxidation of the iron occurs because unlike cuoolas, no air is
blown through the charge.
3.2.2.4 Minimum Pollution
Cupola furnaces, because of the attendant combustion of coke produce
greater volumes of gaseous emissions than do other iron-melting systems.
Therefore, the cost of installing, operating, and maintaining the larger
air-pollution-control equipment is a major disadvantage of this melting
method over electric arc furnaces which also require control equipment
deoending on the cupola design.
Melting by induction furnaces might require air-pollution-control
equipment depending on the cleanliness of the scrap. Some pollution-control
equipment 's required on the preheater if one is used. This control device would be
relatively inexpensive.
3.2.2.5 Space Requirements
Space requirements are substantially lower for operation of electric arc
furnaces than for cupolas. Cupolas need storage areas for coke and fluxes,
which demand quite a bit of space. Whereas the operation of an electric arc
furnace can be adjusted to the needs of the pouring department of the foundry,
the cupola must be operated continuously to meet such requirements. Cupolas
use a forehearth, which is arranged for separation of slag and intermittent
3-19
-------
tapping. The main function of the forehearth is the temporary storage of
metal, which increases the space requirements for a cupola.
3.2.2.6 Ease of Temperature Control
The temperature control is much easier in electric furnaces than in a
cupola because tfie coke burning rate is not easy to adjust.
3.2.2.7 Operation and Maintenance
Electric arc furnaces are usually manned by one operator on a 8-hour
shift. The^inakeup of the charge and the transfer of molten metal to holding
furnaces or to the molding department is the duty of the overhead crane
operator, who can service several furnaces. Similarly, induction furnaces,
need only two operators; in fact, very often one furnace operator can monitor
two furnaces. Cupolas need more operating personnel--one furnace operator,
one overhead crane operator, and two operators for handling the coke and
fluxes. Operators number for all furnaces depends on their size and operation.
Maintenance on the refractory lining is easier in the case of electric
arc furnaces because the larger diameter-to-height ratio make it easier for
craftsmen to work compared to the small diameter deep cupolas. Refractory
repairs can be done by hand or by mechanical means such as a fettling machine
that allows for rapid and even application of the refractory materials.
A desirable feature of any foundry operation is the consistent delivery
of molten metal to the molding line at a constant temperature. This is
especially important when the holding furnace is bypassed, and the molten
iron is transferred directly to the molding department. This constant
temperature is more easily achieved on am electric furnace than on a cupola.
3-20
-------
3.2.2.8 Conclusion
The selection of one roe!ting process over another depends on the
particular circumstances within a given foundry as well as its geographical
location with respect to raw materials and energy sources. In addition, the
present economic conditions with regard to cost and availability of energy
make it difficult to predict which type of melting equipment will prevail.
Examination of recent trends in the industry is also of little help. For
example, the malleable iron industry, which has been the most cost-conscious
segment over the last few years, recently has been the leader in converting
to electric melting and holding furnaces. On the other hand, the trend toward
electric arc melting for foundries in the 5- to 25-ton/hour capacity range
has been reduced (and may even have been reversed) by the development of new
charge equipment for cupolas which permitted a reduction in the size of the
charge door. This decreased the size requirement of the air pollution control
equipment and, hence, its cost. Expectations of higher productivity for
electric arc furnaces using ultra high power (UHP) in the gray iron industry
have not been realized. To what extent this will affect future projects will
depend, again, on the availability of power production.
3.2.3 Electric Arc Furnace Operation.
Emphasis in this section is on the operation of the electric arc furnace
because it is the main pollutant source requiring air pollutant standards in
an electric arc furnace foundry. Other emission sources, in addition to the
electric arc furnace, are present. These sources are discussed in Chapter 6.
Electric arc furnaces are refractory lined, cylindrical vessels made of
heavy welded steel plates. The three electrodes, made of graphite, are
nounted on a superstructure above the furnace and can be lowered and lifted
3-21
-------
through holes in the furnace roof. With the electrodes lifted, the
furnace roof can be swung aside to permit the charge materials to be
dropped into the furnace (top charged). Additional alloying agents, when
required, are added through the side or slag door of the furnace. Top
charging of materials is most economical because a furnace can be charged
to the brim within a few minutes. (Some smaller or older furnaces are
charged through side doors).
Gray iron foudries using electric arc furnaces as melters consist of
the electric furnace itself, scrap storage area, scrap weighing stations,
molten metal and slag transfer ladles and hot metal holding furnaces.
Holding furnaces normally are of the induction type; arc furnaces are rarely
used. Heavy-duty cranes are used to transfer the materials from one point
to another within the shop. Scrap is charged by drop-bottom bucket carried
by the crane.
The production of gray iron in an electric arc furnace is a batch process
where cycles or "heats" range from 60 minutes to several hours depending on
the size of the charge and the power input to the furnace. Each cycle normally
consists of charging and melting (melt down of the charge and refining) opera-
tions and tapping. An overall diagram outlining the emissions from electric
arc furnace operations is presented in Figure 3-2.
3.2.3.1 Charging -
The scrap is loaded into the charge bucket with an electromagnet suspended
from a crane. The bucket stands on a scale or a scale car in the scrap makeup
area. The weight of materials are displayed electronically on a dial that is
clearly visible to the crane operator. Dust emissions from filling the
bucket are often controlled by venting them into the control device which serves
the electric arc furnace.
3-22
-------
PARTICIPATE
HC VAPORS
CO
SOOT
PARTICULATE
HC VAPORS
CO
SOOT
PARTICIPATE
co
r\s
co
CHARGING
HEATING
POURING
Figure ff-k. Emissions from the various cycles of electric-arc furnace operation
-------
The charge to an electric arc furnace producing gray iron consists
of steel scrap, foundry returns, and additives such as carbon raiser,
manganense and silicon. (Carbon raiser is pure carbon in the form of graphite
or coke breeze used to increase the carbon content of iron.) Foundry returns
include sprues, end gates, risers, defective castings and borings from machining
operations. The drop-bottom bucket is charged in layers. (Loose charge such
as turnings and borings in excess of 20% is normally avoided because it
increases the power consumption, electrode consumption, and melting time-
all costly items). The normal cycle of an electric arc furnace is primarily
composed of charging, heating, and tapping operations. The material charged
to an electric arc furnace in a gray iron foundry typically has the following
... 14-16
composition:
50 to 60 percent iron (approximately 80 percent casting returns
and 20 percent cast iron turnings.)
37 to 45 percent- steel (approximately 70 to 100 percent steel
shreds 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
0.2 percent FeMn
Heating for a typical ultra high power electric arc furnace lasts about 70
2 4
minutes. ' The temperature of the molten iron when tapped, usually ranges
from 2500 to 2700°F. 17~2°
Normally, the furnace is charged only once with the full charge, and
backcharging (additional charge) is usually not practiced. (If the carbon
level is too high, however, some steel can then be added through the slag door
oreferably clean, dry, heavy pieces that will drop to the bottom of the molten
gray iron bath). After charging is complete, the roof is rotated back into
position and lowered on the furnace. A very small gap may remain between the
roof and the bezel ring of the furnace.
3-24
-------
During charging of a hot electric arc furnace, emissions result from
the (1) vaporization and partial combustion of a portion of the oil introduced
with any borings, turnings, and chips which are contained in the charge and
(2) the liberation of sand particles which are introduced into the furnace
on the surface of casting returns. Emissions are essentially made up of
particulate materials, carbon monoxide, hydrocarbon vapors, and soot.
3.2.3.2 Melting and Refining -
Melting and refining is achieved with the heat supplied through arcs
formed between the electrodes of the furnace and the metallic charge. Elec-
trodes may be moved either manually or automatically. Hand control is used
to activate switches that start the positioning equipment to lower the elec-
trodes, or bring them up to "full lift". The electrodes extend into the
furnace through water-cooled roof cooling glands on the roof. The controls
are automated to maintain the arc at optimum current by activating the electrode
motor(s) to adjust the position of the electrodes as necessary. The electrode
consumption varies from 9 to 20 Ibs/ton of gray iron produced. Many factors
contribute to electrode consumption; no systematic study of the complex
interactions involved has been published. Their consumption is a source of
hydrocarbon, carbon monoxide, carbon dioxide and sulfur dioxide emissions.
The "lectric current supply may be controlled automatically or by hand.
The furnace is powered by a step-down transformer which brings down the voltage
from 6-30 kilovolts to 80-320 volts. This varies with primary line voltage
available and size of furnace transformer. The transformer may have anywhere
from 3 to 33 taps on the low voltage side for better control of electric supply
and heat conditions of the furnace. The power is first passed through the
high voltage transformer, then via a selected tap among the number of taps
off the primary coil of the transformer. The voltage levels applied to the
furnace are governed by the size of the furnace, phase of the furnace cycle,
metal temperature, and other factors.
3-25
-------
The maximum power available to the plant is often limited by the supplier
or controlled by the owner primarily because the high price of peak power.
This makes it mandatory that the power be used in the most effective manner.
A "demand limiter" is used to electronically convert the power (kilowatts)
coming into the foundry into a signal if the rate of consumption is higher
than the present level. Automatically, the electrodes on the last furnace lift
(in case of several furnaces), the breaker is opened, the transformer tap
is changed down one, the breaker is closed and the electrodes lowered to melt
again. If consumption in the foundry is still too great, the demand limiter
will repeat the cycle again and again until either the furnace is shut off
or a point is reached where power consumption is at the desired rate or
slightly less. When the electrodes go through this cycle to reduce power, it is
"shedding power" or a "shed" in the industry vernacular. When a predetermined
point is reached as power again becomes available, the cycle is repeated, in
reverse, and the tap is raised back toward the original setting.
The melt-down begins by striking an arc through the electrodes using
often the highest voltage tap in the transformer. After the scrap has melted,
the metal bath surface becomes completely flat, that is, with no incompletely
nelted pieces floating in the molten material. The bath temperature is about
1370°C. During the next period, the furnace is fed from another tap while
the bath is superheated. In some foundries, a spectrometer sample is then taken
for a silicon analysis. When the desired final temperature is reached, the pool
is skimmed to remove the slag.
Slagging, which is usually performed with the power off, is normally carried
out once per heat (only rarely does one have two slags). The furnace is tilted
about 10 degrees. A couple of shovels of sand are thrown on the threshold of
the slagging door to prevent the slag from,sticking. The slag is then withdrawn
manually with wooden paddles to fall into the slag pit.
3-26
-------
After slagging is complete, the power is restored at a lower tap for
15 to 30 minutes to superheat and refine the melt. During this time, the
furnace chemistry and bath temperature are checked and adjusted if necessary.
These two operations last only a couple of minutes. During melting operations
(meltdown, slagging, and refining), emissions result from: (1) the vaporization
of iron, (2} the vaporization and partial combustion of any oil not driven off
during charging, (3) the combustion of a fraction of the additives introduced
with the charge, and (4) the combustion of a portion of the carbon electrodes.
Melting cycle emissions are mainly composed of particulate in the form of
metallic and mineral oxides, carbon monoxide, hydrocarbon vapors and soot.
Carbon level, the key to producing gray iron, can be increased by adding
carbon "raiser" to the charge. The quantity added depends on the charge
makeup, the desired grade of iron and the type of carbon raiser. For example,
the higher the amount of carbon in foundry returns, the less carbon raiser
needed. The initial silicon level also will depend on the silicon level in the
charge. If too low, the silicon can be adjusted in the electric arc furnace, in
the transfer ladle or in the holding furnace, which is not recommended since
the slag damages the refractory.
As soon as the proper chemistry and metallurgy is reached, the furnace
is prepared for tapping. The temperature at which the gray iron is tapped
from the furnace is about 1535°C for nodular and 1480°C for gray iron.
The tapping is done with the power off and electrodes lifted. During
tapping, the furnace with roof in place, may be tilted by as much as 45
degrees. The ladle receiving the molten material is large enough to receive
the entire content of the furnace. Soarks and fumes, which are entirely molten
iron particles, are generated along the trajectory of the flowinq material as
3-27
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it falls from the spout to the ladle. Abundant sparks are generated during
this transfer of the material although there is often a hood over the pouring
spout of the furnace. These sparks are oxidized and a large portion of them
become aerosol particulate.21 However, if any soarks are carried into the upper
levels of the melting shop, it is as an invisible aerosol because nothing
was noted during the plant visits.
There are many possible circumstances that may delay the operation of
an electric arc furnace. "Sheds", that is, cutting off the power to the elec-
trodes, might not be considered an unusual operating delay since they take
place so very frequently. Delays that might be considered upsets, however,
are: lack of room in the holding furnaces or on the molding floor, thus
delaying the tapping of the electric furnace; waiting for the crane; failure
of the electrode lifting mechanism; electrodes not arcing properly; and an
inoperative furnace roof which cannot be opened or closed. Such delays
may result in emission levels very slightly greater than normal.
3.2.3.3 Material Balances -
The yield of an electric arc furnace is rather high, producing about
94-98 percent gray iron from a typical charge. About 0.65 - 0.75 percent of
the charge escapes as dust, and the remainder is lost in the slag.
3-28
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3.2.3.4 Energy Considerations
Only electric energy (unless some preheating of the charge is carried
out) is used in electric arc furnace operations. The largest portion of the
energy is consumed for melting and refining of the charge, but some is used
for driving pumps, cranes, building evacuation equipment, air pollution
control equipment, etc.
Between 450 and 625 kilowatt hours Own) of energy are consumed by
the furnace per ton of metal melted, depending jnainly upon the quantity of
borings added to the charge and the final temperature. The lower figure
corresponds to a quantity of borings representing about 10 percent of the
charge makeup; the higher figure relates to a charge with well over 50
percent of uncompressed borings.
Energy can also be spent in a pretreating process such as centrifuging
out excessive oil from borings, or by drying and/or preheating the scrap.
It is desirable to have as little oil in the scrap as possible. Borings
are a special problem because their large surface will contain a lot of oil.
Borings can be centrifuged to reduce their oil content to about 2 percent
by weight.
If the charge is preheated to drive out superficial water, it is heated
to 93°C. (Energy spent for this purpose does not improve the operating
efficiency of the furnace.) However, if the drying process is carried out at
202 - 232°C, not only will the water be driven out but some oil which adheres
to the scrap will be also burned out. Scrap preheated to this temperature
saves about 35- kw.h/ton of gray iron produced. With 650°C preheat, known
as "full preheating," energy consumption i,s reduced by about 125 kwh/ton of
22
gray iron theoretically.
3-29
-------
Preheating burns off the oil and some other contaminants so that
substantially less furaes are generated during charging. It also results
in less slag, which helps protect the lining of the furnace. Preheating,
therefore, results not only in energy sayings but also in air pollution
reduction at the furnace and extended life of the furnace lining. The
oreheater itself is a source of pollution. The lower gas volumes, however,
make it less expensive for an owner to control than to attempt to recapture
charging emissions from an open furnace.
3.2.3.5 Rate and Composition of Emissions-
Wide variations have been reported in the emission rates from iron
foundries. These may be attributable to the following factors; type of
furnace process, furnace size, quality of scrap, cleanliness of scrap,
rormulation of charge, melt-down rate, and pouring temperature.
The effect of the type of furnace process, size and power rating were
discussed earlier in this chapter,
The quality of scrap charged has a strong effect on emissions because
the inclusion of large quantities of lower-boiling nonferrous metallic
impurities in the melt will inevitably lead to high concentrations of oxides
o* these metals in the fume. The cleanliness of the scrap likewise is an
iinportant factor as discussed earlier.
The significance of these aboye factors is clearly shown by Coulter 23
who performed several tests under identical operating conditions except for
differences in cleanliness and quality of the scrap charged. The amount of
fume emitted per ton of metal melted increased 1QQ percent when dirty, sub-
quality scrap was used. This trend was substantiated by Kane and Sloan.24
Their tests, although marred by a malfunction, showed an increase of over
3-30
-------
40 percent in the amount of fume released per ton of metal processed when
poorer scrap was charged to the furnace, (The actual increase was greater
than 40 percent because fumes evolved during a full quarter of the melting
cycle were lost because of a defective collecting thimble.)
The fume emission rate and the chemical composition of the fume appear
to be a function of the phase of the melting cycle (i.e., melt down, refin-
ing, etc.). Temperature of the molten bath also has an important effect on
emissions.
Table 3.6 on the following page shows the composition of metal fume
25
produced during an entire melting cycle.
EPA analyzed a sample obtained from the bottom hopper from a fabric
filter. Table 3.5 presents the results.
Table 3.5 *
Component Weight percent
Ferrous oxide - FeO 8.75
Ferric oxide - Fe203 41.2
Silicon oxide - Si02 34.9
Magnesium cxide - MgO 5.0
Aluminum oxide - AlgC^ 4.7
Manganese oxide - Mn02 8.0
Calcium oxide - CaO 1-4
The same sample was also analyzed for metallic components. Listed below
are components and th.eir concentration in parts per mi 11 ion (ppm). Table
3.7 shows the results.
* This table does not agree with Table 3.6, since it is a different
sample, analyzed by another laboratory.
3-31
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Table 3.6 CHEMICAL ANALYSIS OF PARTICULATE EMISSIONS
FROM AN ELECTRIC ARC FURNACE
Proportion of Total Participate
Constituent
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
Loss on ignition
Ash
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
8.87
91.93
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
3.1
96.9
(weight percent)
Foundry C
75-85
10
1
2
0.5
0.5
0.8
0.3
0.01
0.03
0.02
0.01
0.02
0.01
0
100
3-32
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Table 3.7 METALLIC COMPONENTS OF HOPPER DUST (ppm)
Pb - 10,000 Ti - 300 As - 100 Be - 1
Cu - 8,000 Li - 300 B - 50 Mn - High, See Table 3.5
Zn - 5,000 Cr - 200 V - 50 Fe - High, See Table 3.5
Na - 3,000 Zr - 200 Co - 50 Si - High, See Table 3.5
N1 - "1.500 Ba - 200 Sb - 50 Mg - High, See Table 3.5
K - 5,000 Mo - 150 Sr - 30 Ca - High, See Table 3.5
Sn - 300 Cd - 100 Ag - 10
The sample was analyzed for water soluble sulfate to evaluate whether there
would be a water pollution problem if a scrubber were used and to determine
the possible Teachability from a disposal site. The water soluble sulfate is
very low, only 0.13 percent. Carbon was also surprisingly low, about 1.10 percent.
Particulate emissions from electric arc furnaces in gray iron foundries
are very fine in size, Often, about 80 percent of the dust is smaller than 5
microns. The following Table (3.8) shows the size distribution of these samples.
TABLE 3.8 PARTICLE-SIZE DISTRIBUTION FOR PARTICULATE
EMISSIONS FROM THREE ELECTRIC-ARC-FURNACE
INSTALLATIONS
Particle Size,
micrometers
Less than I
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
Cumulative Percent by
indicated Particle
Foundry B
8
54
80
89 .
93 .
96
99
Weight for
Diameter
Foundry C
18
61
84
91
94
96
99
3-33
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The bulk density of the dust collected in a fabric filter is 40.5
Ib/ft. The resistivity of the dust at 93.5°C is 6.0 X 1011 ohm-centimeters
o 9 26
and at 316 C, 2.8 X 10 ohm-centimeters.
The data shows a wide variety of substances to be contained in the dust,
but silicon dioxide (SiOJ and iron oxides are the most abundant. Silicon
dioxide (in either amorphous or crystaline form) causes silicosis and oxides
if iron, siderosis. The large concentration of silicon dioxide in the
particulate emission make is essential that pood control be required of
emissions from electric arc furnaces in iron foundries.
In electric arc furnaces during a furnace cycle, both particulate and
gaseous emissions are evolved. The rate of participate emissions varies
considerably during the furnace cycle. The maximum generation of dust occurs
during the following periods:' the starting of a heat; during charging; when the
material around the walls caves into the center of the furnace; during meltdown,
and when the arc is reestablished after an interruption.
Particulate emission factors reported in the literature for uncontrolled
emissions during the charging, tapping, and melting phases of electric arc
furnace operation in gray iron foundries show large variations. Levels
ranging from 4 to 40 pounds of dust per ton of iron produced have been
27 28
reported. J Discussions between EPA and manufacturers of gray iron
on the quantity of particulates collected by control devices suggest that
the emission factor may be more than 20 pounds per ton. These variations
are primarily attributable to the cleanness of the scrap and the foundry
returns. Foundries that process relatively clean scrap and returns have
lower emission factors.
3-34
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The emission factor for uncontrolled emissions durinq the melting
phase of furnace operation is important for the sizing of hoppers for dust
control devices, screw conveyors, and other dust handling facilities.
For example, hoppers on small baghouses that shake only once per heat
must be sized to accommodate all the dust generated during the entire
furnace heat. Designers use even higher emission factors than 20 pounds
30
per ton of iron. The charging/tapping emission factor is an important
parameter for determining the impact on air quality around multiple furnace
shops since, on a mass basis, emissions during these phases of operation
exceed by many times the emissions from efficient control devices during
the melting phase.
It is difficult to quantitatively determine the emissions durinq charging
and tapping of gray iron electric arc furnaces. Emissions generated during
charging and tapping are usually evacuated through roof fans or louvers,
and discharged directly into the atmosphere. No standardized techniques
have been developed for measurement of these emissions. In the steel
production industry, charging and tapping emissions from one electric arc
furnace have been quantified by monitoring the dust collected in two different
control devices. One control device collected emissions during charging,
backcharginy, and tapping by means of building evacuation. The other control
device collected emissions during the melting operation by means of a
fourth-hole furnace evacuation system. The results showed that about 10 percent
of the emissions were generated during charging, backcharging, and tapping.
No data on charging/tapping emissions has been found by EPA from contacts
with manufacturers and operators of gray iron electric arc furnaces.
3-35
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With no serious crosswinds In the furnace bay area, about 90 to 100
percent of the fumes from a steel mill electric arc furnace during charging
32
are evacuated through the roof of the enclosing building. Under less
favorable conditions, up to 30 percent drifts into the adjacent foundry
bays and settles on equipment within the building. With strong winds
outside the melting shop and the large doors in the building fully open,
fumes can be blown away from the furnace in various directions. The
dispersion of emissions in the furnace bay area of a gray iron foundry
is similar. Consequently, low opacity readings on roof fans or louvers
are not necessarily indicators of minimal charging/tapping emissions in
the foundry.
In the first two drafts of this document (November 1975 and May 1976),
the charging/tapping emission factor was taken for calculation purposes
to be equal to the one for arc furnaces that produce steel, namely 10 percent
of the total emission factor or 1.5 pounds per ton or iron. However, the
operating conditions in the steel industry on which this factor was based
do not always apply for gray iron furnaces. For example, gray iron electric
arc furnaces are not usually backcharged. Also, tapping emissions from
steel electric arc furnaces are very pronounced, based on visual observations.
The main factor that affects the formation of iron oxide smoke during tapping
of steel in ladles without allowing is the very high temperature of the
molten steel. Transfer of gray iron from the furnace into ladles, also with
no additives in the ladle, produces negligible emissions. This may be
explained by the fact that the tapping temperature of gray iron is about
200°C lower than the tapping temperature for steel. Alloying in the ladle
3-36
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contributes to iron oxide and silicon oxide smoke generation. Emissions
are similar for steel and gray iron furnaces if there are additives in the
ladle.
Taking these facts into consideration, it is reasonable to assume that
the charging/tapping emission factor for gray iron electric arc furnaces
without alloying in the ladle is lower than for steel electric arc furnaces.
It has been argued that for steel electric arc furnaces the emissions
33
are divided approximately equally between charging and tapping. The plume
from ladles during tapping of electric arc furnaces that produce steel
appears much denser than the plume during charging, even if rather dirty
scrap is charged. This indicates that the emission factor for charging
34
may be less than that for tapping.
Therefore, the best available estimate of uncontrolled charging and
tapping emissions from gray iron electric arc furnaces is 5 percent of
the total uncontrolled emissions. In cases where alloying in the ladle
is carried out, the best available estimate is 10 percent of the total
uncontrolled emissions.
3-37
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REFERENCES FOR CHAPTER 3
1. Letter from Mr. Price Burgess of Hayes-Albion Corp., Albion Malleable
Division, of May 17, 1974 to N. T. Georgieff, EPA.
2. Letters from Mr. W. 0. Ferguson of Gray and Ductile Iron Founders' Society
Inc., of May 29, 1974 and October 14, 1975 to N. T. Georgieff, EPA.
3. Personal communication of N. T. Georgieff, EPA, with Prof. Dr. Weber,
Technical University, Essen, Germany.
4. Screening Study on cupolas and electric furnaces in gray iron foundries
to U. S. EPA, August 15, 1975 by Battelle Columbus Laboratories.
5. Industrial Heating, February 1975, Special Issue, page 25.
6. Op. cit, Reference 5.
7. Op. cit, Reference 5.
8. Personal communication of N. T. Georgieff, EPA, with Mr. Clayton Strizaker,
Malleable Founders Society, Rocky River, Ohio, October 1975.
9. Op. cit, Reference 5.
10. Personal communication of N. T. Georgieff, EPA, with Union Carbide Corp.,
New York, Arc Furnace Dept., Mr. Fred G. Bailine, and data supplied by
him to EPA in May 1974.
11. Personal communication of N. T. Georgieff, EPA, with Mr. Aref Hakki,
Brown Boveri Corp., New Brunswick, New Jersey, April 1974.
12. Miller, W., Philadelphia, Penn., "Gray Iron Foundries without Cupolas:
Emission Reduction and Operating Experience", presented at the Third
International Clean Air Congress, Dusseldorf 1973.
13. Murray, R. W., "Foundry Melting: Cupola vs. Induction vs. Arc, Iron Age,
May 11, 1967.
14. Op. cit, Reference 1.
15. Op. cit, Reference 2.
16. Op. cit, Reference 3.
17. Op. cit, Reference 1.
18. Op. cit, Reference 2.
19. Op. cit, Reference 3.
20. Op. cit, Reference 4.
-------
21. Op. cit, Reference 1.
22. James, A. I. GKN Birwelco (Usfc-lsidel Ltd., Developments in electric furnace
plant and operation. Crucible induction furnace melting plant at Sulzer
Bros., 1973 British Cast Iron Association Meeting, Oct. 3-5, 1972, University
of Keele.
23. Coulter, R. S., "Smoke, Dust, Fumes Closely Controlled in Electric Furnaces",
The Iron Age, 173, pp. 107-10, Jan. 14, 1954.
24. Kane, J. M. and Sloan, R. V., "Fume Control - Electric Melting Furnaces",
American Foundryman, 18, No. 5, 33-5, Nov. 1950.
25. System analysis of Emissions and Emissions Control in the Iron Foundry
Industry, Feb. 1971, A. T. Kearney & Co., Inc. APCO-DPCE.
26. Analysis carried out by EPA from the hopper of a dust collector servicing
a gray iron producing electric arc furnace.
27. Air Pollution Emissions and Control Technology-Iron and Steel Foundries
Report, prepared for Environmental Canada, Air Pollution Control Directorate,
March 1975, by Hatch Associates, Ltd., Toronto, Ontario.
28. System Analysis of Emissions and Emissions Control in the Iron Foundry
Industry, Volume II - Exhibits; Exhibit VI-16, by A. T. Kearney and
Company, Inc., February 1971.
29. Georgieff, N. T., EPA Trip Report of May 7, 1974, on Findings At General
Motors Pontiac Division, at Pontiac, Michigan.
30. Private communications between Lectromelt Corporation, Pittsburgh, Pennsylvania,
and N. T. Georgieff, June 1975.
31. Letter from Goodwin, D. R., dated November 25, 1974, to G. T. Helms, P. E.,
Acting Director, Air Programs Office, Region IV, Information on Electric
Arc Furnaces.
32. Flux, J. H., Containment of Melting Shop Roof Emissions in Electric Arc
Furnace Practice; Iron and Steelmaking (Quarterly), 1974, Number 3, Page 123.
33. Discussions between N. T. Georgieff, EPA, and A. R. Trenholm, EPA.
34. Memo of N. T. Georgieff, EPA, to files, September 1976.
-------
4. EMISSION CONTROL TECHNIQUES
4.1 CAPTURE SYSTEMS
Control of air pollution from most metallurgical furnaces (and gray
iron is no exception) is a consequence of the efficiency of two completely
separate operations:
1. capture or containment of the exhaust gas stream from the furnace
which contains contaminants and
2. removal of contaminants from this exhaust gas stream.
Capture itself poses two separate problems:
1. Capture of emissions during charging and tapping.
2. Capture of emissions during melting and refining of the gray iron.
The control of emissions during charging as well as during normal operations
of electric arc furnaces has progressed in several stages. In the early
days, hot air and emissions were allowed to rise to the roof of the shop
where they- were vented through louvres or fans into the atmosphere.
Although these procedures indeed cleared the melting shop of emissions (and
heat), they merely transferred the fumes outside and resulted in complaints
from the surrounding communities. To be effective, the fans which were used
were large, hence expensive. In an effort to reduce the exhaust volume
required and permit less expensive fans, trusses were boxed in with baffles
directly above the furnace. This was progress, as it did reduce the required
exhaust volume; of course, the amount of dust discharged remained unchanged
and was still objectionable.
4-1
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The next phase of evolution was the installation of small canopy hoods
above the furnaces and a relatively inefficient control device to remove
pollutants from the hot gases. The gas volume was still large which
necessitated large, high volume collectors. These were expensive, so few
systems of this early design were installed. Canopy hoods also did not
solve the problem of in-plant air pollution entirely. Strong drafts within
the building caused by open doors disturb the flow pattern of the gases from.
the furnace causing some emissions to bypass the hood and drift to the roof
area. These occasionally work downward toward the floor too rapidly for the
ventilation exhaust fans to remove. Under such conditions, the overhead
crane operator's vision is sometimes impaired. This can result in dangerous
operating conditions in all parts of the electric furnace bay area.
Subsequent attempts have been made to reduce exhaust volumes as much as
possible by mounting hoods closer to the furnace or by directly evacuating
the furnace itself (direct furnace evacuation system). Although this
historical movement of the hoods closer to and indeed mounted on the furnace
roof has reduced the volume of air which must be captured and cleansed, it
has one major shortcoming. Since most present generation furnaces are charged
by overhead cranes, the furnace roof-mounted capture device is rendered
ineffective during charging when the furnace roof is rotated to the open
position. Unfortunately, this is the very time when instantaneous emissions
may be a maximum.
There appear to be four approaches an operator may use to minimize his
problems in capturing emissions from the furnace,
1. Install a canopy-type hood (.to be operated only during charging
and tapping operations) in conjunction with a second capture system
designed to contain emissions during normal operation.
4-2
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2. Install a closed charging system that negates the necessity of
removing the furnace lid during the charging operation.
3. Install a pretreatment system which removes those impurities,
primarily oil and grease, which are responsible for most of the
emissions during the charging operation.
4. Completely encase the furnace with a shroud-type hood.
Presented below is a discussion of the characteristics of the type of hoods
now used by the industry.
4-1.1 Canopy Hoods
To minimize the adverse effect of cross currents within a furnace shop,
a canopy hood should be mounted as close to the furnace as possible to pick
up the fumes generated during charging and tapping. Such an arrangement will
minimize the air volume which must be cleaned, hence the size of the control
device and the power requirements will also be minimal. Canopy hoods may
be suspended as a separate unit above the furnace, or the roof of the building
can be modified to serve as a hood (see Figure 4.1 and 4.la).
Obviously, when installing a canopy hood, consideration must be given
to interference with the overhead cranes and the normal movement of the
electrodes. For this reason, the clearance between the hood face and the
furnace often ranges from 7 to 14 meters. If a canopy is to function properly,
a rather large amount of air must be drawn in to assure complete capture of
the furnace fumes. Even so, rising gases are often prevented from entering
the hood due to deflection caused by the crane and its charging bucket.
Excessive cross drafts within the building and large fluctuations in emissions
that sometimes exceed the capacity of the hood also cause a great deal of
dust to bypass the hood. In order to "recapture" this dust, canopy hoods
4-3
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200° C
Quenching Chamber
60° C
I
1
73° C
Figure 4.1 Canopy hood combined with direct shell evacuation.
-------
ELECTRIC-ARC
FURNACE,
Figure 4.la Canopy hood utilizing the building roof as part of
the hood combined with direct shell evacuation.
-------
often contain "scavenger openings" near the roof of the building which permit
any fume that bypasses the flood and collects in the upper portion of the
building to gradually be induced into the hood. This technique is more
effective in winter than in summer, because monitors in the roof are some-
times opened in summer to ventilate the building, hence the fume escapes the
building before it can be aspirated into the 'hood.
To improve their efficiency, canopy hoods are sometimes divided into
sections. Damper valves are used to maximize the draft in the portion of
the hood directly above the point of greatest emissions during the charging,
tapping, or slagging operation.
The volume of air inherent in the use of a canopy hood requires large-
sized pollution control equipment and greater power to capture and remove
pollutants. Consequently, more economical control methods continue to be
sought.
4.1.2 Roof Hoods
In the roof hood evacuation system (Figure 4.2) the hood which is
mounted directly on the furnace roof, maintains an indraft through the
annuli between the electrodes and the openings in the furnace's roof.
Overhead hoods mounted on the lintels above the pouring spout and slagging
doors are connected to the roof hood system. This successful and economically
attractive concept has the additional advantage that it also muffles the
noise of the furnace. The disadvantages are the difficulty of performing
maintenance of the roof. Hinged flaps mounted on the side or on the top of
the hood can help alleviate this shortcoming and allow for inspection of the
roof and electrode ports. Many electric arc furnaces in both the steel and
gray iron industries use this type of control system.
4-6
-------
-fa.
I
^w
Fi'gure 4.2 Roof hood.
-------
4.1.3 Side Draft Hoods
The side draft hood (Figure 4.3) is also mounted on the furnace roof.
It has one side open for the electrode arms so that their travel is not
restricted. The hood traps fumes escaping from the furnace and draws them
into the exhaust duct. Hoods may be mounted above the slagging door and
pouring spout to connect back to the same exhaust duct.
This hood collects the fumes after they have escaped from the furnace
via the electrode holes. Most of the furnace roof is left clear to permit
easy access for maintenance of cooling glands and electrodes. This hood
does require larger exhaust volumes than do roof hoods. This larger gas
volume helps reduce the temperature to the control device. Moreover, there
is no need to induce extra air to assure complete burning of the carbon
monoxide.
4.1.4 Direct Furnace^Evacuation
Direct furnace evacuation (Figure 4.3), also known as "fourth hole
evacuation" requires another hole in the, furnace roof beyond the three
required for electrodes. Mounted above .this ventilation hole is an elbow
which is connected via duct work to the exhaust fan which withdraws gases
from beneath the furnace roof. The elbow must be designed to withstand the
heat of the molten bath, i.e., water cooled, high alloy stainless or
refractory lined. The elbow is often not bolted to the exhaust duct.
Rather a gap is maintained between the flange of the elbow and the off-take
to permit aspiration of air which both oxidizes the explosive carbon monoxide-
rich stream to harmless carbon dioxide and reduces the temperature of the
exhaust gases to protect the air pollution control equipment.
This evacuation system provides good fume control and minimizes both
the space required on the furnace roof and the gas volume which must be
4-8
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f. V:-;:
. *
SIDE DRAFT
-o-
DIRECT EVACUATION-FOURTH HOLE
Figure 4.3 Side Draft and Direct Evacuation Hoods.
4-9
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withdrawn. Disadvantages are th.at the ingr.es.sion of air to the furnace,
although minimal, cools the slag, makes control of the temperature difficult,
and reduces the carbon level in the melt through formation of carbon monoxide.
Because the amount of draft necessary to capture emissions varies during
different phases of the operating cycle, the amount of draft can be adjusted.
Any of the above mentioned furnace hood systems can do an effective
job in evacuating the furnace emissions during melt-down and refining of the
gray iron. These systems alone, however, cannot preclude emissions during
charging or tapping.
4.1.5 Enclosures
The concurrent impetus of improvements in the control of air pollution
and rapidly increasing cost of power have resulted in renewed interest in
separate enclosures for each furnace. These are not dissimilar from those
used by Germany during the early 1940's to shield the red furnace fumes from
aerial observation. One such system consists of an enclosure Figure 4.4
constructed mainly of corrugated sheet metal which completely encases the
furnace. Electrically operated doors permit the crane to deliver the
charge bucket to the furnace. At the top of the enclosure, charging
emissions are contained by an air-curtain directed across the openings
through which the cables from the crane enter.
The volume of air which must be removed from this system is estimated
at only 30 to 40 percent of that which would be required for good control
with a more conventional method of canopy hoods or building evacuation
(i.e. only 90,000 ACFM for a 17 foot diameter furnace and 30,000 for an 11
foot.) This design has a secondary benefit in that it also abates some of
the noise around a furnace.
4-10
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Figure 4.4 Completely Enclosed Furnace.
4-11
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A second system also now under construction has a corrugated metal
shroud on four sides mounted about 8 feet above floor level which extends
to a point beneath the crane. Open along one side to permit entrance of
the bucket, this enclosure contains the emissions, shields against cross
drafts within the shop and directs them towards a conventional canopy hood
above the crane-way.
Both enclosure systems will contain both charging and tapping emissions
since in one case the tapping takes place within the enclosure and the second
has an auxiliary tapping hood system to augment the benefit of the enclosure.
The first domestic installation of each of these two systems is scheduled
to startup during the second quarter of 1976.
4.2 CONTROL DEVICES
Following evacuation of the fumes by one of the hood systems, a dust
cleaning device must be used to treat the gases before they are discharged
to the atmosphere. Because of the small size of the dust particles only
three types of dust collectors have been generally accepted as being suitable:
1. Fabric filters
2. Electrostatic precipitators
3. High efficiency wet scrubbers
4.2.1 Fabric Filters
The most common collection device used on electric arc furnaces with
the capture systems described above is the fabric filter. There are two
general types, one has an open top or "monitor", the second a stack through
which the gas is discharged. Fabric filters depend on a filter media to
remove the dust from the gas. The devices are simple to operate and come
in many designs, sizes and shapes, differing primarily in the characteristics
4-12
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of the filter media (woven or felted glass, Dacron or Orion) and th.e method
of removing the dust from the fabric (.reverse air pulse, mechanical shaking,
or reverse air flow). Fabric filters have a very high efficiency, even for
the submicron metallic oxide fume from electric arc furnaces and are not
greatly affected by fluctuating operating condition. Typical differential
operating pressure for fabric filters is in the range of 10 to 20 centimeters
of water gauge. Maximum operating temperatures are about 260°C for glass
fabric and about 136°C for the more conventional synthetic fabric filter.
4-2-2 Electrostatic Precipitator
The electrostatic precipitator, another type of collection device,
operates by routing the gases through a high voltage field to impart an
electrical charge to the dust particules which are subsequently trapped on
the collecting electrodes or plates of opposite polarity. The dust particles
are removed from the collecting electrodes by water or mechanical vibration.
On "wet" precipitators, dust is removed by flushing the collecting plates;
on "dry" precipitators, dust is dislodged by "rapping" (shaking) the collecting
plates.
Electrostatic precipitators have a relatively high efficiency for
micron-size particles and a very low resistance to the flow of the gas
stream, but their successful operation is strongly dependent on the
resistivity characteristics of the dust. (Dust from foundries must be
wetted with water to decrease the resistivity to an acceptable range.)
Because of their high initial cost electrostatic precipitators have been
rarely used in North America, but haye been more widely accepted In Europe
for cleaning gases from foundry furnaces. This is due primarily to the fact
that Europeans have been more energy conscious. The increasingly high
4-13
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energy costs i,n America may Influence the future domestic trend. The
successful application of electrostatic preci.pitators on emissions from
basic oxygen furnaces argues for their installation on electric arc furnaces
also. The space requirements of both preclpitators and fabric collectors
are almost the same.
4.2.3 Viet Scrubbers
Although none were found controlling electric arc furnaces, high-energy
wet scrubbers find wide application in other parts of the ferrous metal
industry. The characteristics of emissions from basic oxygen furnaces (BOF's)
and steel electric arc furnaces (EAF's) are very similar to those from the
arc furnace in the iron foundry. In the steel industry venturi scrubbers
are widely used to control BOFs and EAFs. Where space is at premium and
wet dust disposal facilities can be made available, this control technology
is worth investigating in the iron foundry industry as well. In addition
to particulate, scrubbers (and wet electrostatic precipitators) might also
remove some of the sulfur dioxide from the effluent gases.
The operating principle is to wet the gas stream to cool it and reduce
the volume, then remove the wetted dust from the gas. In order to be
effective, these scrubbers must have a relatively high energy penalty on
the exhaust gas stream, i.e. 100 to 150 centimeters of water gauge.
Scrubbers require water; therefore, a satisfactory system must also adequately
deal with any associated water pollution and sludge disposal problems. To
their advantage, scrubbers, which are normally venturi type, have low space
requirements and can be readily installed if water treatment facilities are
present or constructed.
It is conceivable that the mass emission rate from a venturi scrubber
could be less than a filter collector because of the lower gas volume which
4-14
-------
might be processed. The level of mass emissions achieved for a fabric filter
is directly proportional to the air flow rate. (One investigator reports
that a "fabric filter might well operate with the same outlet concentration
when the inlet loading changed tenfold. ) At present, foundries reduce
the temperature of hot exhaust gases to a level not detrimental to the
filter fabric by diluting with ambient air.
Since the mass emission rate is the product of the discharge concentration
and the gas flow rate, the dilution air actually increases the mass discharge
rate. Gas streams controlled by scrubbers are cooled by water injection.
This minimizes the final volume of gas. The gas volume from a scrubber would
be at least 50 percent lower than from a fabric filter or electrostatic
precipitator applied to the same type of capture system.
4.3 PERFORMANCE OF EMISSION,CONTROL SYSTEMS
The following discussions summarize the analytical results of emission
samples taken from several control devices installed on electric arc furnaces
producing iron. The data pertain to emissions of both particulate and gas.
Figure 4,5 presents the results of measurements of the concentration
of particulate emissions as measured by method 5 which EPA obtained for the
development of standards. Each test consisted of three or four samples
collected at a single point at fabric filter collectors with single stacks.
Figure 4.6 presents the results of the same measurements in pounds per hour
per ton/hour. In both figures, all of the data for each plant
are grouped in one vertical data bar. Each data point represents
a separate sample collected by traversing the sampling plane.
Plant A has two electric arc furnaces of 15 to 16 tons melting capacity
per heat each. (A "heat" encompass the time from the beginning of the charging
4-15
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0.030
0.025
0.020
0.015
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to 0.01599
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average
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Figure 4.5 Particulate Emissions from electric
arc furnaces in gray iron foundries.
4-16
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0.120 _
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0.171
0.100
0.090
0.080
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O EPA test methods
C other test methods
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PLANTS
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A B C D
Figure 4.6 Particulate Emissions from electric
arc furnaces in gray iron foundries.
4-17
-------
to the end of the tapping of the molten material.) Particulate emissions
from the two furnaces are controlled by a single fabric filter dust collector.
Samples were collected at the inlet and discharge of the filter.
The two furnaces are equipped with side draft hoods as well as hoods
above the pouring spout and the slag door. All three hoods are connected
to a common take-off box which is under suction via the baghouse by a
centrifugal fan. Overhead roof fans and monitors ventilate, not
only the furnace and scrap bay areas, but also withdraw a small amount of
air from adjacent areas. An inlet duct above each furnace is manifolded to
the main duct which leads from the furnace area to the collector. These
inlet ducts should not be confused with a canopy type hood; they are merely
open pipes which extend down towards each furnace. Emissions from both
furnaces are controlled by the one dust collector from which samples were taken.
Measurements of flow rate averaged 2,490 dry standard cubic feet per minute
per ton of product (dscf/m/t). As shown in the figure 4.5, average particulate
loading results determined from the four samples were 0.0038, 0.0035, 0.0028
and 0.0054 grain per dry standard cubic foot (gr/dscf) for an average of
0.0039 gr/dscf.
The mass rate, i.e., particulate emissions in pounds per hour averages
2.59; the four individual test results were 2.44, 2.38, 1.83, and 3.56 oounds
per hour. Using as a denominator the hourly tonnage, the amount of particulates
per ton averages about 0.094 pounds per hour per ton per hour.
Figure 4.5 shows the dust caught by the probe and filter during the four
tests. Each sample commenced with, the beginning of a heat cycle on one of
the furnaces and continued for approximately 3 hours. Generally, the furnaces
were on a staggered schedule. During the tests, an average heat lasted about
70 minutes; therefore, the sampling period encompassed two full heats on each
furnace.
4-18
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Simultaneously, visible emission data were obtained for the stack of the
dust collector and roof monitor aboye the furnaces. The highest opacity (6
minute average) observed from the dust collector stack during the nearly 15
hours that readings were taken was 10 percent with the opacity at zero about
80 percent of the time. At the roof monitor, the maximum 6 minute average
opacity was 10.1 percent but the opacity was zero about 90 percent of the
entire period of scrutiny.
Plant B has two electric arc furnaces of 12 to 13 tons melting capacity
per heat each. Particulate emissions from the two furnaces are controlled by
a common fabric filter dust collector. Measurements were made on the stack
downstream from the fan and fabric filter. The furnaces are equipped with
side draft hoods as well as hoods above the pouring spouts and slag doors. All
these hoods are connected to a take-off box which is under suction via the bag-
house by a centrifugal fan which pumped an average of 3,117 dscf/m/t. Roof fans
and monitors ventilate the furnace and scrap bay areas and also withdraw small
amounts of air from adjacent areas. As shown in the Figure 4.5,
particulate loading results from the three samples were 0.0066, 0.0038 and
0.0038 gr/dscf for an average of 0.0048 gr/dscf.
The mass rate, i.e. particulate emissions in pounds per hour, averages
2.71 Ibs/hr. The amount of particulates averages about 0.126 pounds per hour per
ton per hour. Each sample commenced with the beqinninq of a heat cycle on one of
the furnaces and continued over approximately three hours. The average heat
again lasted about 70 minutes, with two full heats covered on each furnace.
Simultaneously, visible emissions data were obtained for the stack of the
dust collector and the roof monitor vent above the furnace. The maximum 6 minute
average opacity at the dust collector stack was 11.5 percent although the opacity
at the stack was zero about 80 percent of the time. At the monitor, the maximum
4-19
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6 minute average opacity was less than 1 percent and the opacity was zero more
than 98 percent of the time.
Plant C has two furnaces which produce up to 8 tons of gray iron each
per heat. Each arc furnace is controlled by a separate fabric filter dust
collector. The furnaces are equipped with roof type hoods as well as hoods
above the pouring spout and slag door. These hoods for each furnace are
connected to individual take-off boxes which are under suction via the separate
baghouses by centrifugal fans each pumping an average of 1,855 dscf/m/t. Roof
fans and monitors which ventilate the furnace and scrap bay areas also withdraw
small amounts of air from adjacent areas and exhaust directly to the outside.
Measurements were made on the stack of one of the dust control devices at
a location downstream of the fan and fabric filter. Each sample was collected
over a 1.5 hour period. The sampling periods coincided with the beginning of
a heat cycle of the furnace and were finished prior to the end of the heat
*
cycle. An average furnace heat lasted about 90 minutes. As shown in Figure
4.5, results determined by the three samples were 0.01599, 0.01877, and 0.02858
gr/dscf for a combined average of 0.02106 gr/dscf.
The mass rate of particulate emissions in pounds per hour averaged 2.71.
The amount of particulates per ton of production averaged about 0.82 pounds
per hour per ton per hour.
Visible emission data were also obtained simultaneously for the stack
of the dust collector and the roof monitor vent above the furnace. The maximum
6 minute average opacity at the stack was 30- percent but occasional peaks of
up to 80 percent were observed for short periods (several seconds only). At the
monitor, the 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 appear to be a consequence of two major things. First, this was the
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onlv plant that inject carbon raiser for final carbon adjustment by blowing
finely divided graphite beneath the surface of the melt. (The bulk is by the
bag). Secondly, only this plant cleaned the fabric filter during operation of
the furnace.
Plant D has one furnace which produces 6 tons of gray iron per heat. The
arc furnace is surrounded on three sides by two walls and the transformer so
that the fumes during charging and upset conditions (gas puffs escaping through
the electrodes holes or oth.er furnace openings) are funnelled upward and dis-
charged by the ventilation fan located above the furnace directly to the
atmosphere. The furnace is equipped with a side draft hood as well as hoods
above the pouring spout and slag door. The gaseous discharge rate to the conr
trol device averaged 3,100 dscf/m/t. The first test was run only for one 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 train filters.
* t
Each of these tests was started at the beginning of two consecutive heats and
continued for one hour during each heat. An average furnace heat lasted about
70 minutes. Particulate measurements were made at both the inlet and outlet of
the collector. As shown in Figure 4.5, the three measurements resulted in
particulate concentrations of 0.00792, 0.00137, and 0.002768 cir/dscf for an average
of 0.0046 gr/dscf at the baghouse outlet.
The mass rate, i.e. particulate emissions in pounds per hour, averaged
0.593, based on results of the three tests. The amount of particulates per
ton of production averaged about Q.I08 pounds per hour per ton per hour.
Simultaneously, visible emission data was also obtained for the dust
collector stack and the roof monitor vent above the furnace. Based on all three
tests, the 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 test, the
opacity was zero at the vent 100 percent of the time, but it reached a maximum
6 minute average of 7.5 percent on a subsequent test.
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Plant E had one electric arc furnace producing 14 tons per heat.
Participate emissions from the furnace were controlled by a fabric
filter dust collector. The furnace is equipped with side draft hoods as well
as hoods above the pouring spout and slag door. Roof fans and monitors discharg-
ing directly to the outside ventilate the furnace bay area. The emissions were
sampled at the stack on the outlet of the collector where the flow rate was
2,810 dscf/m/t. As shown in Figure 5.1 average particulate loading results
determined by the three samples were 0.0056, 0.0102, and 0.0059 gr/dscf, for an
average of 0.0072. The mass rate, i.e., particulate emissions in pounds per
hour averaged 2.41. The amount of particulates per ton averaged about 0.3462
pounds per hour per ton per hour.
During these tests the 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
integration of all three tests should provide a good average because a heat
on this furnace lasts about 2.5 to 3 hours.
Visible emission information was gathered only for the stack of the dust
collector. The determination of the opacity measurements was not performed in
accordance with standard methods, but rather by frequent spot checks. They
showed the opacity of the emissions to be a maximum of 5 percent.
Plant F has two electric arc furnaces of 15 to 17 tons melting capacity
per hour each (30 to 35 tons per heat). This facility has a fabric filter dust
collector serving the two gray iron producing arc furnaces, two induction hold-
ing furnaces and one duplexing arc furnace. The volume withdrawn from each
gray iron producing arc furnace is 157,000 actual cubic feet per rotnote at 275°F.
The tests were carried out at the stack, at the outlet of the collector. The fur-
naces are equipped with side draft hoods and direct furnace evacuation as well as
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hoods above the pouring and slag doors. AH hoods are connected to a take-
off box Khich is under suction via the b.aghouse by a centrifugal fan. Roof
fans and monitors exhausting directly to the atmosphere ventilate the furnace
bay area and adjacent aisles. 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 furnaces melt scrap consisting of 40
percent by weight of borings and turnings which contain up to 10 percent oil.)
Figure 4.5 shows the concentration of dust measured by the sampling train down-
stream of the control device and the fan. Each sample was collected for two
hours with a test method similar to EPA's method 5 which meets most of the EPA
criteria. In this test, the sampling period was 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 loading level during these tests was 0.0045 gr/dscf.
Most of the time the emission levels were around 0.0014 gr/dscf. The lowest level
measured was 0.0007 gr/dscf. The combined average of the measurements, 15 in all,
carried out by 7 different laboratories is 0.0014 gr/dscf.
As shown in Figure 4.5, the average loading is 0.0012 grains per dry standard
cubic foot of gas. The mass particulate emissions rate in pounds per hour was
1.62. Us-'ng as a denominator the tonnage, the amount of particulates per ton
averages, to about 0.1078 Ibs/hour per ton per hour,
Control of particulate emissions from fabric filters has been
guaranteed by manufacturers at levels as low as. 0.004 gr/dscf on collectors
to be installed in steel alloy shops. The guarantee applied if the inlet
loading to the fabric was below 0.3 gr/ds_cf. Above this level, the
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gurantees specify 99 percent efficiency. Because operating conditions on
gray iron furnaces are similar to steel producing furnaces and because the
dust is somewhat coarser, it is expected that levels of outlet loadings as
low as 0.004 gr/dscf could be achieved. Similar and even better results
were obtained during EPA testing of several collectors of the fabric filter
type.
Although we were unable to identify any electric arc furnaces producing
gray iron which are controlled by high energy scrubbers during this investiga-
tion of the domestic industry, several references obtained from American and
foreign sources provide insight into levels of performance which might be
expected.
The emissions from an electric arc furnace in a foundry are not totally
dissimilar from those from a similar furnace which produces steel. Since
the dust particles from the foundry are somewhat coarser due to lower opera-
ting temperatures and shorter heats, they should actually be less difficult
to remove.
Based on literature references, scrubbers should have no difficulty
achieving levels of 0.01 to 0.02 gr/dscf with an attendant energy loss of
50 inches of water gage. In addition to removing particulate, venturi
scrubbers can remove up to 80 percent of any attendant trace concentrations
of sulfur dioxide. This high removal efficiency is possible since the
level of sulfur dioxide in the effluent gases is very low, about 10 ppm.
Similarly, data from the literature indicates discharge loadings from
electrostatic precipitators on electric arc furnaces in steel mills on the
order of 0.0025 gr/dscf.
Even when these gases are cleaned by wet methods, they should first be
cooled while still at higher temperatures by addition of air to oxidize
4-24
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carbon monoxide as much as possible. Water cooling is not recommended
because of formation of explosive oxyhydrogen gas, which ignites with explo-
sive effect.
Figure 4.7 presents the carbon monoxide data collected during the testing
of four plants. During all tests, the 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. Emissions were measured during
charging and sampled from the time charging began until the tap was complete.
U Plant A the carbon monoxide ranged from 33 to 275 ppm with an average
(based on three tests) of 95 ppm. The overall hourly emissions are rather
uniform, the highest differing from the lowest by about 16 percent. The same
applies, of course, for the pound of carbon monoxide. The average level,
based on three tests' is 1.26 Ib/hr per ton per hnur,
At Plant B the carbon monoxide ranged from 14 to 142 ppm with an average
(based on three tests) of 73 ppm. The overall hourly emissions are somewhat
different, the highest differing from the lowest by about 33 percent. The
same applies, of course, for the pound of carbon monoxide per hour per ton
of furnace production. The average level of carbon monoxide, based on three
tests is 1.03 Ib/hr per ton per hour.
At Plant C the carbon monoxide ranged from 10 to 425 ppm with an average
(based on three tests) of 121 ppm. The overall hourly emissions are some-
what different, the highest differing from the lowest by about 44 percent.
The same applies, of course, for the pound of carbon monoxide per hour per
ton of furnace production. The average level of carbon monoxide, based on
three tests is 1.45 Ib/hr per ton per hour.
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2.Or-
cS
UJ
Q C
>-i O
X -M
O --
•z. i-
l.i
Q
* I
i!
, n
1.0
o
CQ
0
0.5
H3H
I !
y
PLANT
B
Figure 4.7 Carbon Monoxide Emissions from electric
arc furnaces in gray iron foundries.
4-26
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At Plant D the carbon monoxide ranged from 0 to 435 ppm with, an average
Cbased on three tests) of 104 ppm. The overall hourly emissions are
somewhat different, the highest differing from the lowest by about 60 percent.
The same applies, of course, for the pound of carbon monoxide per hour per
ton of furnace production. The average level of carbon monoxide, based on
three tests is 0.775 Ib/hr per ton per hour.
During these same tests, measurements were taken on emissions of sulfur
dioxide, hydrocarbons, and nitrogen oxides. Because no control techniques
exist for any of these pollutants (including carbon monoxide) on electric
arc furnaces, the readings obtained during the tests are not discussed in
this chapter. Detailed data on these readings are reported in Appendix C.
Some sulfur dioxide will be removed, however, if venturi scrubbers are used
as control devices.
Fugitive emissions from around the furnace can be reduced with canopy
hoods. Of course, pretreatment of the scrap nearly eliminates the major
"fugitive emissions", those during charging. Proper layout of the foundry
melting shop and related foundry areas help reduce fugitive emissions; for
example, streamlined and short transfer distances in hot metal ladles, move-
ments and scrap bins in relation to charge make-up stations, etc. can be of
substantional help.
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REFERENCES FOR CHAPTER 4
1) Beach, G. H., "The Stack Test - Final Proof of Non-Pollution," in
Proceedings of the Specialty Conference On: The User and Fabric
Filtration Equipment. October 14-16, 1973, sponsored by the Air
Pollution Control Association, p. 35.
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5. MODIFICATION AND RECONSTRUCTION OF FOUNDRIES
In accordance with Section 111 of the Clean Air Act, as amended in
1970 and 1974, standards of performance shall be established for new
sources within a stationary source category which "... may contribute
significantly to air pollution ...." Standards apply to operations or
apparatus (facilities) within a stationary source, selected as "affected
facilities," that is facilities for which applicable standards of performance
have been promulgated and the construction or modification of which commenced
after proposal of the standards.
On , 1975, EPA promulgated amendments to the general
provisions of 40 CFR Part 60 including additions and revisions to clarify
the modification provision and to add a reconstruction provision. Under these
provisions, 40 CFR 60.14 and 60.15 respectively, an "existing facility" may
become subject to standards of performance if it is deemed to have been
modified or reconstructed. An "existing facility" defined in 40 CFR 60.2
(aa), is an apparatus of the type for which a standard of performance is
promulgated and the construction or modification of which was commenced before
the date of proposal of that standard. The following discussion examines
the applicability of these provisions to electric arc furnaces in gray iron
foundries and details conditions under which existing facilities could be-
come subject to standards of performance. It is important to stress that,
because standards of performance apply to affected facilities which, combined
5-1
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with existing and other facilities, comprise a stationary source, the addition
of an affected facility to a stationary source through any mechanism—new
construction, modification or reconstruction—does not make the entire
stationary source subject to standards of performance, but rather only the
added affected facility.
5.1 PROVISIONS FOR MODIFICATION AND RECONSTRUCTION
5.1.1 Modification.
It is important that these provisions be fully understood prior to
investigating their applicability.
Section 60.14a defines modification as follows:
"Except as provided under paragraphs (d), (e), and (f)
of this section, any physical or operational changes to an
existing facility which result in an increase in emission
rate to the atmosphere of any pollutant to which a standard
applies shall be a modification. Upon modification, an exist-
ing facility shall become an affected facility for each
pollutant to which a standard applies and for which there is
an increase in the*" emission rate."
Paragraph (b) clarifies what constitutes an increase in emissions (in
kilograms per hour) and the methods for determining the increase including
the use of emission factors, material balances, continuous monitoring
systems, and manual emission tests. Paragraph (c) affirms that the addition
of an affected facility to a stationary source does not make any other facility
within that source subject to standards of performance. Paragraph (f)
simply provides for superseding any conflicting provisions.
The exception in paragraph (d) of section 60.14 allows for an existing
facility to undergo a physical or operational change that results in an
increase in the emission rate of any pollutant to which a standard applies,
but not be deemed a modification, provided the owner or operator can demon-
strate to the Administrator's satisfaction (by any of the procedures
5-2
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prescribed under paragraph (b) of section 60.14) that the total emission rate
of that pollutant from all facilities within the stationary source has not
increased.
This may be accomplished by decreasing the emission rate from other
facilities within the stationary source, to which reference, equivalent or
alternative methods of sampling and analysis can be applied, to compensate
for emission rate increases resulting from physical or operational changes
to an existing facility. The required reduction in emission rate may be
accomplished through the installation or improvement of a control system or
through physical or operational changes to facilities including reducing
the production of a facility or closing a facility.
(
In addition, an owner or operator may completely and permanently close
any facility within the stationary source to prevent an increase in the total
emission rate from occuring regardless of whether reference, equivalent or
alternative test methods can be applied, if it can be clearly demonstrated
(by any of the procedures prescribed under paragraph (b) of section 60.14)
that the emission rate reduction resulting from such closure offsets any
increase.
Paragraph (e) of section 60.14 lists certain physical or operational
changes that will not be considered as modifications, irrespective of any
change in the emission rate. These changes include:
(1) Routine maintenance, repair, and replacement.
(2) An increase in the production rate not requiring a capital
expenditure as defined in section 60.2 (bb).
(3) An increase in the hours of operation.
(4) Use of an alternative fuel or raw material if prior
to proposal of the standard, the existing facility was
designed to accommodate that alternate fuel or raw material.
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(5) The addition or use of any system or device whose primary
function is the reduction of air pollutants, except when
an emission control system is removed or replaced by a
system considered to be less environmentally beneficial.
5.1.2 Reconstruction.
Section 60.15 regarding reconstruction states:
"An existing facility shall be considered an affected
facility by the Administrator upon reconstruction through the
replacement of substantially all of the existing facility's
components irrespective of any change of emission rate. The
owner or operator may request the Administrator to determine
whether the proposed reconstruction Involves replacement of
substantially all of the existing facility's components based
on the capital of all new construction and other technical and
economic considerations."
The purpose of this provision is to ensure that an owner or operator
does not perpetuate an existing facility by replacing all but vestigial
components—support structures, frames, housings, etc.--rather than totally
replacing it in order to avoid subjugation to applicable standards of
performance. As noted, upon request EPA will determine if the proposed
replacement of an existing facility's components constitutes reconstruc-
tion.
5.2 APPLICABILITY TO ELECTRIC ARC FURNACES IN GRAY IRON FOUNDRIES
5.2.1 Modification.
As indicated in Chapters 3 and 4, the particulate emissions from an
electric arc furnace are extremely diverse and consequently a variety of
evacuation and control methods and techniques can be used. In view of this,
it should be noted that compensatory emission reduction allowed under para-
graph (d) of section 60.14 must be accomplished by upgrading an existing
control system, by adding a new control system, or by making physical or
operational changes on facilities within the source that are amenable to
5-4
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conventional emission test methods so that the owner or operator can demon-
strate by emission tests that no net increase in emissions has occurred.
Emission measurements will be required to verify the absence of an increase
in emissions unless the compensatory emission reduction resulted from a
operational change such as reducing the production capacity or shutting down
a piece of process equipment to which an acceptable emission factor is
applicable.
In addition to the above exemptions, the following physical or opera-
tional changes will not be considered as modifications irrespective of any
change in the emission rate:
I. Changes determined to be routine maintenance, repair, or
replacement. This will include the replacement or refurbishing
of equipment elements subject to high abrasion and impact to high
consumption such as refractories and electrodes.
2. An increase in the production rate if that increase can
be accomplished without a capital expenditure which exceeds
the guidelines provided in 40 CFR .
3. An increase in the hours of operation.
4. Use of an alternative raw material if the existing facility was
designed to accommodate such material. (Because electric arc
furnaces are designed to accommodate a variety of types of
charge, any change in raw material feed, other than an increase in
the oil content of the scrap, is expected to be inconsequential.)
5. The addition or use of any air pollution control system except when
a system is removed or replaced with a system considered to be
less environmentally beneficial.
5-5
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6. The relocation or change in ownership of an existing facility. It
should be noted, however, that the purchase and installation of a
used piece of equipment at a stationary source to either expand
capacity or replace existing capacity would be considered new con-
struction and thus subject to standards of performance.
The impact of the modification provision on existing electric arc furnaces
in gray iron foundries should be slight.
5.2.2 Reconstruction.
The reconstruction provision is applicable only where an existing facility
is so extensively rebuilt that it is virtually identical to an entirely newly
constructed facility. An action which could be construed as reconstruction
of an electric arc furnace is the replacement or extensive refurbishment of
the furnace and power supply. The replacement of components subject to high
abrasion and severe wear such as refractory surfaces and electrodes should be
exempt and considered routine.
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6. EMISSION CONTROL SYSTEMS
6.1 THE PROBLEM
Entrained particulates in the exhaust gases from an electric arc
furnace can be removed with any of the conventional methods i.e.,
fabric filtration, electrostatic precipitation and wet scrubbing.
The primary difficulty in the control of air pollutants from furnaces
ts the containing of these exhaust gases in order to direct them to
the control device. Equipment which is most effective in containing
the emissions during melting and refining operations is mounted
directly on the roof of the furnace. (It is axiomatic that the
closer the capture device is to the source of the emissions the lower
the volume of air which is entrained into the system. Since the
capital and operating costs of the fan and control device are directly
related to the volume of gas, there is economic merit in a closely
mounted hood.)
Unfortunately, all domestic furnaces rotate the furnace lid to
the side in order to introduce the charge. This renders the close-
mounted evacuation systems such as the side draft, direct furnace
evacuation and roof hoods ineffectual during the period of maximum
instantaneous emissions. The bulk of those emissions are the result
of foreign matter. Furnace charges often contain from 10 to 40 percent
6-1
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metal borings. Borings can contain oil at levels up to 10 percent.
(Although they are rarely fed at greater than a level of 10 percent).
Some oil adheres to other scrap components as well. Charged into
a hot furnace, up to 20 percent of the oil (plus some dust from
the returns) is burned and rises as dirty gases to the roof.
The emissions from a 5-ton per heat furnace with a charge
containing 1 percent oil amount to over 20 pounds of soot, dust,
hydrocarbons, carbon monoxide, etc. Uncontrolled, these emissions
would reach the atmosphere as fugitive pollutants through roof
ventilation fans, monitors, and open doors. Some might settle on the
equipment. Such emissions are generated within a very short time -
seldom longer than 2 to 3 minutes.
6.2 POSSIBLE SOLUTIONS
There are a number of ways that these "charging emissions" can
be reduced. The order of the list below is not significant.
6.2.1 Closed Charging System
An automated charging system could be used which does not require
the furnace roof to be removed. Demonstration projects of this type
have been conducted on electric arc furnaces but we know of no
domestic commercial furnace with such a system. It would require a
pretreatment system that properly sizes the scrap so that it will
flow from a charge bin through a charging chute into the furnace.
Charging chutes have been used on steel electric arc furnaces, dumping
the charge through a door or via a special opening on the same
2 3
elbow through which the furnace is evacuated. * The advantage of this
6-2
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type of charging Is that the furnace's roof remains in position,
thereby permitting the melting ventilation system to remain in
operation during charging. This eliminates the need for any other
capture system entirely. Such charging, however, is possible only
with scrap which has been shredded to 7 to 10 centimeters maximum
in any direction. Charging via chutes merits consideration by the
gray iron producing industry which uses electric arc furnaces.
Although fragmented scrap is necessary, its cost may be moderate
compared to the other charging techniques when the cost of a canopy
hood is taken into account.
An improvement on this system has been used in Italy for three
years. The system is described in section 6.2.5.
6.2.2 Preheating
The charge materials can be preheated, a practice very common
for induction furnaces and practiced to a limited extent with
electric arc furnaces. Preheating also generates emissions, but the
4
control system it requires is much smaller than would be required
on a companion furnace. The particulate matter from a preheater also
tends to be more coarse in size, hence, easier to collect.
Preheating of the metallic charge also offers economic
advantages:
One is that preheating the charge to 760°C supplies theoretically 38
percent of the energy necessary to melt and refine the charge.
Preheaters are fossil fuel fired, hence, cheaper to operate than
electric furnaces. This represents a saving to the operator.
6-3
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Although, preheaters will burn the oil and a lot of other "dirt"
off the charge at lower temperature, having installed a preheater,
it is usually to the operator's advantage to have "full" preheating.
Besides direct monetary savings in power, an equally important
advantage is that the production rate of a furnace is increased at
least 25 percent, or conversely, one can install a smaller
(hence cheaper) furnace to achieve a given output. Furthermore,
with a preheater, the scrap storage area does not need to be covered
since the preheater will remove any water. This too represents a
definite monetary savings. Finally, since the volume of the exhaust
gas is reduced from that of a furnace, the mass emission rate
is lower for a select control device. Incidentally, preheating
is standard practice on induction furnace unless dry and oil-free
scrap is available. Since moisture or oil in the scrap can cause
the molten metal to splash from a furnace (an extremely hazardous
event, as many induction furnace operators can testify) and the
availability of clean scrap is limited, the installation of preheaters
is mandatory. The most important reason for installation of
preheater to process scrap for induction melting is safety, and
consequently, many companies will install such devices regardless
of the quality of scrap delivered to their foundries. Electric
arc furnaces are not subject to the same safety hazard.
Another pretreatment practice is processing metallized iron pellets.6
One foundry has replaced 20 percent of its metal charge to a cupola
with metallized pellets because of a lack of other raw materials
6-4
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necessary for gray Iron production. The results are being evaluated
and indications are tfiat pellets can be successfully used in gray
iron production. Since pellets are relatively clean feed, they result
in reduced emissions.
6.2.3 Hooded Charge Bucket
Still another approach, that merits mentioning is the hooded
scrap bucket. With this system, tfie charging bucket, which has a
cover and a lateral duct, rests on the furnace during a charge. When
in position, the lateral duct connects the bucket to the furnace's gas
cleaning device during the time the charge is dumped (cascaded) into
the furnace. The fumes produced by contact of the scrap with the hot
furnace are withdrawn through the charge bucket into the lateral duct
and collected in the furnace dust collector. This charging method
is expected to substantially reduce emissions during charging
although some emissions will spread into the furnace bay areas during
the interval between removal of the bucket and the swinging back of
the roof. The systems have been offered to companies operating an
electric arc furnace, but so far none has been installed. See Figure 6.1
Hoods for the control of charging emissions that may be attached
to the scrap charging bucket itself or suspended from the crane are
Q
being studied in other countries. In operating position, the hood
is aligned with the exhaust duct. Consequently, the hood could be
also connected to the furnace gas collection system. During the
first few seconds of the charging operation, the crane with attached
scrap charging bucket and hood exhaust system remains above the
furnace with the furnace roof swung out of the way, during which
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TO CONTROL DEVICE
COVER
CTl
I
COOLING
Figure 6.1 Scrap charging emission control.
-------
time the bulk, of the waste gases escapes. The escaping gases are
withdrawn into the hood. Both hood techniques have the disadvantage
that they cannot handle emission during tapping. Several tapping
control systems have been suggested. For example, a hood can be
located directly above the ladle as shown in figure 6.2, This
hood is connected to the primary gas cleaning system. One such
system being installed in the U.S. is scheduled to start up in early
g
1976. Another technique is shown in figure 6.3. Air supplied by
powerful blowers entrains the aerosols formed during tapping and
introduces them into a hood connected to the primary gas cleaning
system. Another ladle tapping system is shown in figure 6.4.
All these ladle systems are linked to the conventional furnace
dust control system, (side draft or direct shell evacuation) so that the
pollution problems can be solved at minimal cost, rendering a canopy
hood and its associated equipment unnecessary.
6.2.4 Enclosures
Another and very promising way to contain (confine) air pollution
from electric arc furnaces during charging and tapping is by means of
an enclosure around the furnace. One type acts as a chimney to
direct charging and tapping fumes up to a canopy hood. (This design
has a secondary benefit in that it also abates some of the noise from
the furnace.) Although this concept requires a canopy hood, which in
turn means relatively high gas volumes, it has merit because both
charging and tapping take place beneath the enclosure and can be
contained.
6-7
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I
00
Figure 6.2 Tapping hood above ladle.
-------
S
CM
en
\
to
DUCT TO CONTROL
DEVICE
J-—T'-B /
^-4^ I' \
i i^-.iS1 i
BFI1066
Figure 6.3 Air curtain over tapping ladle.
-------
DAMPER
TO CONTROL DEVICE
Figure 6.4 Ladle tapping emission control.
-------
A second design features a totally enclosed corrugated sheet
metal building which, surrounds the furnace and its tapping stations.
Instead of furnace evacuation and canopy hoods Cor, for that matter,
building evacuation), the new design evacuation system features
electrically operated doors through which the crane can move the
charge bucket in and out of the shroud enclosure. See figure 6,5.
At the top where the crane cables extend through the roof,
emissions are precluded by a curtain of air. Gases generated
during charging and melting are withdrawn at the top of the hood.
Emissions generated during tapping are withdrawn through a special
duct whose opening is located above the tapping station which is
within the enclosure. The design appears very attractive and requires
substantially lower gas volumes than would a conventional canopy hood.
No problems are anticipated with heat stress to operators or excessive
heating-up of the furnaces due to the confinement of the furnace.
The emission volume for a 16 foot diameter electric arc furnace which
melts 60 tons with two charges is 80,000 actual cubic feet per
minute.
6.2.5 Waste Heat Recovery
Another pretreatment technique, uses the sensible heat of the
1 p.
waste gases from the furnace to preheat the scrap prior to charging.
The waste is vented up through an inclined rotary kiln or drum. The
charge material is fed continuously down through the kiln into the
furnace. Figure 6.6 shows the principle of the installation. A
full scale unit on a steel furnace has been in operation for three
years in Italy. The technique is applicable to mixed scrap of light
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Figure 6.5 Completely enclosed furnace.
6-12
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I
Co
Figure 6.6 Waste heat scrap per heating.
-------
weight, to shredded scrap, and to sponge iron. Preheat temperature
of 1000°C has been reported. No oxidation problems of the ch.arge
have been experienced in the kiln. All indications are that scrap
preheating is an economical technique which can be applied in the
foundry industry. Although- economic data are available from Europe,
this technique is not evaluated as to its economic impact in this
study. The environmental impact is similar to that of a conventional
preheater, except that no heat losses whatever are encountered.
6.2.6 Canopy Hoods
The canopy hood is a hood located high above the furnace for
the purpose of collecting emissions during charging, tapping and
upset conditions. While evacuating the fumes the canopy hood also
reduces the heat load within the furnace bay area. The canopy hood
can be suspended from the roof or parts of the building roof can
be modified to form the housing of the hood. Since these hoods
must not restrict the movement of the crane which charges raw
materials to the furnaces, they must allow 30 to 40 feet of clear
area immediately above the furnace. Canopy hoods are sometimes
divided into sections in an attempt to improve their efficiency.
Dampers are used to. maximize draft directly above the point of
greatest emissions during subsequent charging, tapping or slagging
operations.
One drawback of the canopy hood is the high air volume necessary
to capture the fumes they are intended to collect. One advantage
of the large air volume is the innate protection it provides the
fabric filter collector against the effect of unusually hot gusts
of exhaust gas that would damage the fabric.
6-14
-------
Canopy hoods, due to the high volume of gas they need to be
effective, are expensive to operate, especially on single furnaces.
Multiple furnace installations are more economical because they can
use one collector with proper dampers for maximizing the flow rate
above the furnace generating the largest amount of emissions.
6.2.7 Degreasing
Degreasing is a technique which has traditionally used to remove
oil and grease from more valuable scrap such as brass, bronze, copper,
etc. Experiments using these same techniques for degreasing
turnings made of steel and scrap iron (some times supplemented by
ultrasonics) have deomonstrated the technological feasibility of the
process although no such commercial installation is known to exist.
6.2.8 Conclusions
Charging emissions are appreciable, and methods for controlling
these emissions should be further developed. The most promising way is
the waste heat recovery pretreatment technique. However, the impact of
providing a supply of uniform scrap has not yet been evaluated for U. S.
conditions. The waste heat preheater can handle swarf and stampings
without oxidation. Also, this technique has the advantage of using a
fourth hole for evacuation of the furnace off-gases, which produces the
lowest gas volume and the smallest control device. Only one of the
conventional type preheaters evaluated in chapter 8 can handle swarf,
at lower Quantities as charged to the waste heat preheater.
The completely enclosed furnace technique will soon be in
operation (sometime in May 1976).
6-15
-------
HEFP.KPTTCF," rO?.. CHAT? PR 6
1} Personal coii^anication between T':r. A. IPiccla, of
Pennsylvania Pnrir.perin", and IT. T. Qeor^ieff, "^PA
2; SevryMlLOv, T~. et 2.! , General ""etalurrry , page 123
3} Personal concunioation oetween ''!r. je^har-rl , of
3au:;.co, Pssen, 3-errsny and IT. T. Georgieff, "PA
etter fror.. 7.r. "^cn ?or--~i"ur?,t , Yenetto., Inc., to
T. T. 3-^orgieff, PPA, iato; Pov TS, 1ST"
^ ! ^ " ' '*"" P i ^W '~' 'CO *> TS "•'' i 3 i ''1 *% •' "*" "t ^
^r-"1 TCT "3>-"No 1 i-!1"?? q^.;^-;;-.^ .^^crf ~i^,~v 'c^r^-1^-
~J L',.*. //t; X -Ji ^_ i.. _. j'l-Oi j.6j._ j
hN; T<=f4-p-p -^v.,-.- T'v, p "nr^- T o-j-on ^ t n T* m a^.ov~- -~.-"-r
w , __J vj V> \j O i j. ^, O.j 1 * 1 L * ._' -JI j.j.A'»iO L»UA. -L. O W -!-•.• -L • 7 • -J— f ^_ «^ J_ •
dcted Oct. 3, 1S73
6-16
-------
12) united States Patent "eu.r.etiruei] er, To. 3/45,5-5,
Feo. 2S, 1S72
13} lleurnan, 5. et al, lS;r75 - C.I.T. ?To. ^, Le proc^i
32"-3i"asa d1Elaboration de 1'acier
k •-•- u c- _4_ 9 j. .-'.'_i c "."• .?• —-"'- l:.—'_l"
T?,,.. ^ r^ ^,,., ir " ^4. .-. 'u i ., ^ ,q TT J, c1 p r.
~: £_> 4- :.
^ ^ >j .•_
"^ f^ p ,
-------
7. ENVIRONMENTAL IMPACT
7.1 INTRODUCTION
The air pollution impact and the other environmental consequences of
the alternative systems of emission reduction presented in Chapter 6 are
discussed in this section. The emission sources for which these
alternative systems pertain are off-gases from electric arc furnaces used
in gray iron foundries. The environmental impact resulting from emissions
during the melting phase of the furnace operation and the disposal of the
collected dust is considered. In other words, the impact of charging and
tapping emissions is considered, however, the impact of pretreatment
techniques on charging emissions are not considered. A comparison is made
between the emissions from the systems required to meet State regulations for
these sources and the emissions from demonstrated systems that were tested
by EPA. Both beneficial and adverse impacts which may be directly or
indirectly attributed to the operation of these alternative systems are
assessed.
7.1.2 AIR POLLUTION IMPACT
In Chapter 4, three different types of control devices for electric arc
furnace off-gases are discussed. These are the baghouse, electrostatic
precipitator, and the venturi water scrubber. Each of these devices is
designed primarily to control particulate emissions and each can be designed
to reduce the emission levels from the arc furnace off-gas to 0.0052 gr/DSCF.
One of the alternatives for reducing emissions from electric arc
furnaces in gray iron foundries is a system consisting of a side-draft hood
in combination with a fabric filter. This system is identified in the
following text of this document as alternative No..l. Information other
7-1
-------
than emission tests, discussed in Chapter 4, which, indicate that high
efficiency electrostatic precipitators and water venturi scrubbers can
achieve the same outlet grain loadings as the fabric filter.
All three control devices can be used in combination with any one of
the particulate containment methods described in Chapter 6: side-draft
type hood, roof type hood, and direct shell evacuation. The most often
used is the side-draft type hood.
The quantities of air pollutants emitted from typical uncontrolled
electric arc furnaces in gray iron foundries (during melting) amount to
about 13.8 Ibs per ton of molten material. This amount depends strongly
on the quality of the scrap charged into the furnace. Somewhat lower levels
of uncontrolled meltina emissions were recoHed durina EPA tests at two
facilities. Obviously the environmental impact would be great if such
emissions should remain uncontrolled.
Based on field test data, Table 7-1 presents pollutant loadings upstream
of fabric filters applied to gray iron foundry electric arc furnaces. In
three EPA field tests, fumes emitted from the furnace were evacuated by
side-draft hoods. In the fourth by a roof hood. Fourth hole evacuation or
canopy hooding systems were not tested due to the fact that such systems are
rarely applied to electric-arc furnaces in gray iron foundries. Flow rates
on fourth hole evacuation are about one-quarter the flow on side-draft hoods ;
pollutant loadings for fourth hole systems would be on the order of four
times greater than those presented in Table 7-1.
Using field test pollutant loading data (Table 7-1) in conjunction with
side-draft hood volume flow rates (Appendix A), electric-arc furnace pollutant
emission rates, shown in Table 7-2 were calculated. These uncontrolled
7-2
-------
Table 7-1., TYPICAL CONCENTRATIONS UPSTREAM OF A FABRIC FILTER
APPLIED TO GRAY IRON FOUNDRY ELECTRIC-ARC
FURNACES EMPLOYING SIDE DRAFT HOODING SYSTEliS
Pollutant
Particulate
Hydrocarbons
(as CH^)
Carbon
monoxide
Sulfur dioxide
Range of averages3
0.33-0.40 gr/DSCF
7.8-67.4 ppm
73-115 ppm
1.6-16.3 ppm
Average loading value
0.36 gr/DSCF
23.3 ppm
94 ppra
7 . 5 ppm
3These ranges were developed from the averages of results from
emission test programs conducted at four separate sites.
bAverage values were calculated by taking the mean of the averages
of results from emission test programs conducted at four separate
*• - 1_ ** *m
sites.
7-3
-------
•Table 7-2 PREDICTED EMISSION RATES FROM VARIOUS CAPACITY
UNCONTROLLED ELECTRIC-ARC FURNACES UTILIZING
ADJUSTED DATA FROM EPA TEST RESULTS
Arc-furnace heating cycle capacity, tons/hr
10
20
50
Emission control status
'Particulate emission rate Ib/hr
Uncontrolled 69.0
Controlled by
alternative No. 1 0.35
Controlled by
most stringent
state regulation (N.J.) 2.3
Typical state
regulations:
a) existing foundries __.1_.2
b) new processes 6.0
138
0.7
4.6
19.2
8.7
276
1.4
9.24
30.5
12.5
690
3.5
2.31
44.6
20.5
7-4
-------
emission rates are slightly lower than the values of 13.8 and 9.2 pounds
1 p
per ton cited in the literature. This is possibly due to the fact that
the scrap melted in the electric arc furnaces that were measured during
the aforementioned field test survey was reasonably clean. To be
conservative, we have chosen to use the uncontrolled particulate emission
rate of 13.8 pounds per ton during this impact assessment. For comparison
purposes Table 7-2 contains controlled emission rates by the New Jersey
State regulations and by typical State regulations on existing and new
foundries. The California State regulation requires compliance with
ambient air quality data.
7.1.3 State Air Regulations
A summary of state air pollution regulations for foundries is presented
in Appendix D. An estimate of the impact of state regulations can be
obtained by looking at the regulations of a small number of crucial states.
The major portion of the gray iron doundries that employ electric-arc
furnaces are located in the east north central and Pacific regions of the
United States. The east north central region if composed of Illinois,
Indiana, Michigan, Ohio and Wisconsin. The Pacific region is made up of
California, Oregon and Washington. Table 7-3 presents the existing foundry
air pollution regulations for these states and for the state of New Jersey
o
which has the most stringent air regulations. Based on an inlet mass
emission rate of 13.8 (Ib/ton of charge) and using 70 minutes as an average
heating cycle, Table 7-2 was formulated. A comparison of Tables 7-2 and 7-3
readily shows that uncontrolled arc-furnace emissions would exceed state
i
regulations in all cases. Employment of not every efficient emission
control devices would present state regulations from being exceeded in all
7-5
-------
Table 7- 3 EXISTING FOUNDRY AIR POLLUTION REGULATIONS FOR STATES IN THE EAST
NORTH CENTRAL AND PACIFIC REGIONS OF THE U.S.*
State
California
(1973)
UllnoU
(197.J)
Indian*
(1973)
Kichlcan
(1974)
Ohio
(1972)
Oregon
(1972)
Washington
(1972)
Paniculate collation limitation (Ib/r.r)
baaed on Indicated process weight (toau/hr)
5 tona/hr 10 tona/hr 20 tona/hr SO tona/hr
Sons specifically for foundries
Must csct asbltr.c-nir quality standards
Small foundries
16.6) 25.10
Existing foundries*
12.0 19.2 ' 30.5 44.6
1*£W prcce^acs
6.0 3.7 12.5 20.5
Existing foundries
16.6) 24 36 ~ 52.6
Nov foundries
12.0 19.2 30.5 44.6
Snail cupolas
24
Other cupolu
4.6 5.8 7.0 17.A
Industrial processes
12.0 19.2 30.5 . 44.6 "
Manufacturing processes
10.0 16.2 28.3 44.6
*
General processes:
Existing
0.20 gr/ECKc
4.1 8.2 16.4 41.0
Kaw after 7/1/75
0.10 gr/SC7
2.0S 4.1 8.2 20.5
Kaxlmiin effluent
concentration or
specified treatment
for carbon nonoxidc
Cupola R.-isea burc.cd with
an &fccr:aurncr to ICSM
than 200 ppai corrected 'to
50 percent CKCSSU air.
Cupolac v(th a welt rate
ot loaa .than 5 tono/hr
cxclu^c^.
For proccseoa lacgar than
10 tons/hr, an after-
burner muse be uaed.
Burned at 1300°? for 0.3
seconds in a direct flaca
afterburner.
Meet acbleat air quality
standards.
Kaxlaua sulfur
dioxide concentration
for any coabusclon
process
2000 ppa
Forauld for proccsa
operation ausc ba
net.
Existing sources: 2000 ppa
Now sources: 500 ppa
Moat ambient air quality
standards.
Opacity regulations
No oorc ch.in Rlnp.li'euin
no. 2 or 40 pcrce.ic opacity.
No more than 30 percent
opacity ur.d up to 60 per-
cent opacity for 3 olnuces
of any 60 alnute cpan.
Not more than 40 percent ops-
city for up to 15 alnuto la
any 24 hours.
No more than 20 percent opacity snu
up to 40 pcrccnc opacity for
3 minutes ii\ aay 60 muu.-tc* not c&crs
than 3 clraos In 24 hour*.
No more than Rlnp.lctun no. 1 or
20 percent opacity and no more than
Ringlccvin no. 3 or 60 percent opacity
for 3 ninutcs oi any 60 olnutei.
No more th.in 40 portent opacity and
up to 40 percent opacity for
3 minutes in 1 hour.
Special areas not more than 20 per-
cent opacity nnd up to 20 percent
opacity for 3 minutes In 2 hours.
Existing sources, not core than 40
percent opacity and greater than
40 percent opacity for 15 olnut«s
in 8 hours.
New sources, not more than 20 per-
cent opacity snd greater than 20 par-
cunt opacity for 15 cOautes la
8 hours.
I
01
-------
Table 7- 3 (continued).
EXISTING FOUNDRY AIR POLLUTION REGULATIONS FOR STATES IN THE EAST
NORTH CENTRAL AND PACIFIC REGIONS OF THE U.S.5
State
Wisconsin
•<1»73)
Kcv Jersey
(1972)
?«r:iculatc emission limitation (Ib/hr)
based on indicate.! proccas uclghc (tona/hr)
S tona/hr 10 cona/hr • 20 tona/hr SO cona/hi
Cupolas .
0.45 Ib dust/ 1000 Ib gas
5.23 10.10 20.92 52.3
Manufacturing processes (baaed on 0.02 gr/SCF)
0.41
Maximum effluent
concentration or
specified treatment
for carbon munoxidc
Burn at 1300°? for at least
0.3 second u in a direct
flame afterburner.
Maximum sulfur
dldxldc concentration
for any combustion
process
Meet aablcnt air
quality standards.
.2000 ppa by volume.
Opacity regulation*
Maximum of 40 percent opacity.
Maximum of 20 percent opacity
and not more than 20 percent
for 3 minutes in 30 ainutea.
E - 4.10 P°-6?
t - 55.0 P0'11 - 40.
*P < 30 tona/hr
F > 30 tons/hr
Michigan specifies: 5 tons/hr - 0.4 Ib particulate/1000 Ib gas
10 tons/hr - 0.25 Ib partlculatc/1000 Ib gns
20 tor.s/hr or over - 0.15 Ib particulatc/1000 Ib gas.
laied on 2.324 Ib gas/ton of iron oetlcd. the indicated particulate In pounds
per hour was calculated.
cThe tabulated values were calculated aa follows: average volusc of undiluted top gas par
ton of iron melted was estimated to be 28,765 acf. The aUou.ible emission of 0.20
grain/act - 28,765 x 0.20 - 5,753 grains/ton - 7.000 grains/lb - 0.32 Ib/ton of iron
eeltcd. Then 0.82 Ib/ton x number of tons/hr°- Ib/hr.
tabulated valuaa were calculated as followa: tha average undiluted cupola-top-gas
discharge is 2.324 Ib/Coo ol iron Belted. Then 0.45- Ib dust x 2.324/1000 - 1,046 Ib
aWt par toa of iroa swlted. Tilting 1,04& Ib/coa x aucber of tons/hr - Ib/hr.
-------
the states considered. New Jersey and California regulations would be
met if control by alternative No. 1 was used.
The state regulations would not be exceeded if less effective control
devices than alternative No. 1 were used. Even one of the most stringent
state regulation, the New Jersey standard of 0.02 gr/scf, is about four
times higher than the level achievable with alternative No. 1 which is
based on EPA test work. If properly designed fabric filters, electrostatic
precipitators, or venturi scrubbers were used, this would, of course,
prevent state regulations from being exceeded even if the devices are
allowed to deteriorate, for example, due to poor maintenance of equipment.
To comply with the new source performance standards, operators would be
forced to maintain the control devices in proper operating conditions.
Lower efficiency control devices such as medium energy scrubbers can be
used to meet state standards. No such control devices were located in
6
the United States, but, there are some abroad. The same reference
discusses wet electrostatic precipitators meeting the New Jersey standards,
0.02 gr/dscf, equal to about 45 mg/dsm . Such electrostatic precipitators
are undersized, i.e., they operate at higher velocity or do not apply the
proper voltage level.
The beneficial impact of alternative No. 1 can be also expressed based
on the achievable level of opacity. The typical state regulations limit
visible emissions for new installations to a maximum of 20 percent opacity
CRingelmann Number 1) except for 3 minutes per hour and not to exceed 40
percent opacity (Ringelmann Number 2) at any time. The achievable opacity
under alternative No. 1 at the control device stack is much more restrictive.
Particulate matter can also be generated during disposal of the dust
7-8
-------
collected by air pollution control devices. The impact of these emissions
is minimal if good housekeeping practices are maintained. The disposal
of the dust can he carried out be pelletizing it or transporting and
idsposing of it in closed containers.
7-9
-------
7.2 ATMOSPHERIC DISPERSION MODELING
An analysis, as presented below, was carried out to assess the
level of ambient concentrations which result from emissions from electric
arc furnaces in gray iron foundries. Discussed are also the ambient
concentrations which will result from adopting the most restrictive state
standards, namely the ones on particulates. Emissions from these sources
include particulate matter and carbon monoxide (CO). For the purpose of
this study, all pollutants are assumed to display the dispersion behavior
of non-reactive gases. The modeling considered estimates over 1-hour and
8-hour averaging periods for CO and 24-hour and annual estimates for
particulates. The estimated pollutant concentrations are based on the
application of state-of-the-art modeling techniques, which implies reliability
of the estimates to within about a factor of two.
The three prototype gray iron foundries examined (within the three cases)
are: 4 tons/hour, 10 tons/hour, and 20 tons/hour. The configurations and
emission characteristics of these plants were provided by the Industrial
Studies Branch (ESED), OAQPS, EPA.
The following assumptions were applied in the analytical approach:
(1) There are no significant seasonal or hourly variations in emission
rates for these plants.
(2) These plants are located in flat or gently rolling terrain. In
restrictive terrain, however, the dispersion of effluents could
be more impaired, resulting in higher ambient concentration levels.
(3) The meteorological regime is unfavorable to the dispersion of effluents.
The effect of this is to introduce an element of conservatism into
the analysis.
7-10
-------
7.2.1 Plant Characteristics
1. An unfavorable feature of the three prototype foundries is the
stack height, which is not sufficiently taller than the surrounding
structures, thereby promoting aerodynamic complications which can
seriously interfere with the rise of the effluent plume.
2. In all three cases modeled here, the maximum air quality impacts are
associated with aerodynamic downwash, a condition in which the pollutant
plume is brought down to ground level in the wake of the plant building.
Due to the extremely short stacks (Table 7-4), relative to the height
of the plant building, downwash was computed to occur at reasonably
moderate values of wind speed.
3. Another feature of the plant design is that the shop roof fans and
the control rlevice are sufficiently close together (Table 4) to permit
their collocation for purposes of dispersion estimation.
7.2.2 The Dispersion Model
The dispersion model used to analyze these foundries is the single
source model (JMHCRD-1) developed by the Meteorology Laboratory, EPA.
The meteorological data input to the model consists of hourly
observations made during the year 1964 from the station at Oklahoma City,
Oklahoma. The choice of a meteorological site for analysis of electric
arc furnace in gray iron foundries is explained in 7.2.3.
The model is programed to use a previously determined set of
dispersion conditions derived from the basic meteorological data for
each hour of the given year. The calculations simulate the interaction
between the plant characteristics and these dispersion conditions to
produce a dispersion pattern for each hour. These computations are
7-11
-------
performed for each of 180 receptors for any number of hours. In the
case of electric arc furnaces in gray iron foundries> the averaging
periods of interest are 1 hour and 8 Kours for CO and 24 hours and
annual for particulates.
The prototype gray iron foundries were modeled with the
aerodynamic-effects version of the JMHCRD-1. Aerodynamic effects
(downwash and retardation) were found to be responsible for the
maximum pollutant concentrations.
7.2.3 Meteorological Considerations
Preliminary analyses indicated that, for the electric arc furnaces
in gray iron foundries, critical meteorological conditions (i.e., those
giving rise to maximum short-term impact) generally consist of a
combination of stable atmospheric conditions and moderate windspeed.
If such conditions occur frequently at a given location, especially if
they can be combined with a high directional bias in the wind, then
longer-term impacts (e.g., 24 hours and annual) will also tend to be high.
Siting factors for new gray iron foundries indicate that these
facilities will be located in urban areas and subject to urban influences on
atmospheric dispersion properties. These urban factors are principally
the "heat island" effect and enhanced turbulence due to greater roughness
from numerous buildings. The joint effect on dispersion is to eliminate
stable atmospheric conditions and to produce lower ambient concentration
levels. This is accomplished in the computer modeling by utilizing an
urban/industrial option which, substitutes neutral conditions for all
stable cases. Consequently, the "worst case" meteorological condition
will arise under moderate wind/neutral conditions. The climatological
7-12
-------
conditions at Oklahoma City satisfy both the requirement-,of a high
frequency of moderate winds and a high, directional hi as in the wind
direction. Therefore, this station was selected as the "worst case"
location for analysis of prototype gray iron foundries.
Related to the choice of plant location is the selection of source-
receptor distances. Preliminary analysis indicated that the prototype
plants exert their maximum impact relatively close to themselves. The
JMHCRD-1 program permits the pre-selection of five (5) distances. In
light of the preliminary analysis, these were specified as 0.3, 1.0, 1.5,
2.0, and 3.0 kilometers and may be viewed as the radii of concentric
circles around the plant. Receptors are placed along each 10° of
azimuth, thus accounting for the 180-receptor grid.
7-13
-------
TABLE 7-4
EMISSION SOURCE CHARACTERISTICS OF PROTOTYPE GRAY IRON FOUNDRIES
f
4 tons/hour-furnace
hood
10 tons/hour-furnace
hood
20 tons/hour-furnace
hood
Control Device Effluent
Emission
Rate
Parti cul ate/
Carbon
Monoxide
Grams/sec
0.069/0.58
0.17/1.5
0.34/2.9
Effluent Properties
Volume Velocity
m /sec m/sec
7.6 18
19 18
38 18
Temp.
°K
403
403
403
Stack
Height
Above
Ground
m
11
11
11
Stack
Di ameter
m
0.74
1.17
1.65
Shop Roof Fan Effluent (each fan)
Emission
Rate
Parti cul ate/
Carbon
Monoxide,
Grams/sec
0.075/0.064
0. 5625/0. 16b
1.25/0.32b
Effluent Properties
Volume Velocity Temp.
m/sec m/sec K
14 18 311
14 18 - 311
14 18 311
Stack
Height
Above
Ground
m
12
12
12
Stack
Height
Above
Shop
Roof
m
1
1
1
Stack
D1 ameter
m
0.96
0.96
0.96
Number
of
Fans
1
3a
3a
a One fan is located directly above the furnace and the other two are each 30 feet away on opposite sides.
Emission rate particalate, grams/sec per fan
7-14
-------
TABLE 7-5
ESTIMATED MAXIMUM GROUND-LEVEL CARBON MONOXIDE AND PARTICULATE
CONCENTRATIONS DUE TO EMISSIONS FROM MODEL GRAY IRON
FOUNDRIES (ALTERNATIVE NO. 1)
Averaging
Period
1 hour
8 hours
24 hours
Annual
Furnace Size
Tons/hr
5
10
20
5
10
20
5
10
20
5
10
20
co 3
(mg/m )
0.19
0.39
0.68
0.11
0.27
0.49
—
—
—
—
—
w w «
Parti culates
(M
-------
TABLE 7-6
ESTIMATED MAXIMUM GROUND-LEVEL PARTICULATE CONCENTRATIONS
BASED ON OUTLET CONCENTRATION OF 0.02
Averaging Case
Period Number
24 hours 1
2
3
Annual 1
2
3
Parti cu-iates
/ i \
75
182
361
17
37
74
Distance to Maximum
(km)
0.3
0.3
0.3
0.3
0.3
0.3
The above results indicate clearly that the primary air and
secondary ambient air standards cannot be met if the outlet gas
concentration is 0.02 gr/scf. This standard is based on standard
cubic feet, wet basis, and not on the volume of dry gas. However,
this should have little influence on the calculations, since electric
arc furnace gases have very low humidity.
7-16
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7.2.4 Results and Conclusions
The maximum estimated ambient concentrations for the various
averaging oeriods are shown in Tables 7-5 and 7-6. The CO concentrations
are far below the Federal air quality standards regardless of the furnace
size. The CO values shown in Table 7-5 apply also for the case when the
particulate outlet concentration is 0.02 gr/scf, since CO emissions are
the same as those used for evaluation of the data in Table 7-5.
The estimated ambient particulate concentrations for 24-hour
periods for the two larger furnaces are close to the maximum allowable
values, and the largest furnace exceeds the 24-hour primary air quality
standards. The 24-hour secondary standard is exceeded by the two
largest size furnaces. The annual ambient concentrations resulting from
emissions from the largest furnace (20 tons per hour) are very close to
the secondary standards.
The 24-hour primary ambient standard based on an outlet concentration
of 0.02 gr/scf including the shop roof emissions as for the calculations
in Table 7-6 cannot be met by the largest furnace and the secondary
cannot be met by both larger furnaces. The annual primary ambient emission
standard can be met by all three furnace sizes, however, the secondary
standard cannot be met by the largest furnace.
In evaluating the estimated concentrations, it should be emphasized
that the plant configurations are very unfavorable. The configurations
are similar to plants which were tested by EPA. The low stack heights and
the closeness of the stacks to the building contributes to aerodynamic
downwash. The distance for which the data were calculated is short, 300 meters,
but still allows for more accurate calculations.
7-17
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Concentrations closer to the plant are higher than the ones
tabulated, but such distances would probably be well within the
plant boundary. At a distance of 500 meters from the stack, the
concentrations are 50 percent less the values at 300 meters. At
these distances the secondary 24-hour standard for the plant that
discharge 0.02 gr/scf is still exceeded. The calculated concen-
trations, in both cases can be reduced to be in compliance with the
ambient quality standards if the stack height is increased within
the limits of good engineering practice.
7.3 WATER POLLUTION IMPACT
7.3.1 Volume of Wastewater
The waste water generated by the use of ahigh-energy venturi
scrubber comes from the exhaust or "blowdown" from the scrubber's
own "recycle system. Since electric-arc furnaces used in gray iron
foundries are similar to those used in the steel industry, we
have computed effluent volumes from the EPA recommended water
recycle rate and blowdown rate for scrubbers utilized on electric-
arc furnaces in the steel making industry. The operation of what
EPA considers a "tight system" calls for a recycle rate of 661
gallons per ton of product with a 7.5 percent blowdown, or 50
gallons of blowdown per ton of product,8 thus 50 gallons per ton
of gray iron manufactured.
7-18
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Although this water discharge rate may be substantially less than cur-
rently operating plants, it is stated by EPA that plants utilizing this
water rate are presently operating properly, and this rate has been used
to set standards for the steelmaking industry.
7.3.2 Quality of Waste Water
The use of high energy venturi scrubbers for air pollution control on
electric-arc furnaces results in waterborne wastes. Potential pollutants
contained in the waste water are listed in Table 7-7.
Table 7-7. CATEGORIES OF POLLUTANTS WHICH MIGHT BE FOUND IN AN
ELECTRIC-ARC FURNACE SCRUBBER SYSTEM EFFLUENT
Acidity
Alkalinity
Carbon and its compounds
Color
Fluorides
"Hardness"
Heat (temperatures above ambient)
Iron and compounds
Lead and. compounds
Mercury and compounds
Nitrogen and compounds
Oil and grease
Phosphorous compounds
Silica
Sulfur compounds
Solids (suspended and dissolved)
Total oxygen demand
7-19
-------
The quantity and chemical composition of dissolved solids are of poten-
tial concern when evaluating the quality of the scrubber effluent. Toxic
metals like lead and mercury will have an adverse environmental impact upon
the receiving body of water.
To determine whether any of the pollutants listed in Table 7-7 could
appear in sufficiently high concentrations to require reduction through
wastewater treatment, one would first consider the chemical composition of
the materials used in the process. Generally, the type of scrap and flux
utilized in gray iron foundry electric-arc furnaces will not generate suf-
ficient dissolved metals or anions to be of any concern.
The effluent limitations promulgated by EPA for effluent from scrub-
bers on steel making electric-arc furnaces currently only consider total
suspended solids and pH (alkalinity, acidity) when application of the best
Q
practicable control technology is to be utilized. The scrubber effluent
from an electric-arc furnace in a gray iron foundry should be very similar,
so we can also neglect the majority of the pollutants listed in Table 7-7.
Of the potential pollutants listed in Table 7-7 only oil and grease, pH,
suspended solids, and total oxygen demand (TOD) would be likely to occur
in sufficiently high concentrations to need treatment.
7.3.2.1 pH - The pH of the scrubber effluent should be similar for both
gray iron and steel electric-arc furnace scrubbers, and have similar emis-
sion factors for effluents, as they utilize similar raw materials. It is
not anticipated that treatment for pH will be required.
7.3.2.2 TOD - Only oil and grease, and hence "total organic carbon" (TOC),
are potentially higher for the gray iron electric-arc furnace than in the
steel making electric-arc furnace. This potential difference can be attributed
,7-20
-------
to the difference in the type of scrap charged to the furnaces. Steel
producing electric-arc furnaces are typically charged with plate-punchings,
crop ends, plate shearings, and alloy and carbon steel. The charge in a
gray iron electric-arc furnace can contain borings, turnings, and chips
which are heavily contaminated with cutting oils. These oils can be picked
up by the scrubber as soot if their combustion is incomplete during the heat.
These partially combusted oils, once in the scrubber water, will con-
tribute to the total oxygen demand, both biological and chemical. No data
are available indicating the BOD (biological oxygen demand) or the TOD
(total oxygen demand) in a scrubber effluent from an electric-arc furnace,
but a useful approximation can be derived from the total carbon content of
the particulate. For a total carbon content of from 0.5 to 7 percent in
the particulate, it can be calculated that if up to 10 percent of the
carbon is soluble, the total carbon content of the waste water will be from
18 to 250 mg/liter. This range is from an essentially negligible concen-
tration to a concentration as high as found in typical municipal sewage.
The solubility of the smoke and soot in the scrubber effluent would
probably be closer to 1 percent than 10 percent since these compounds are
generally insoluble in water. At 1 percent solubility, even the worst case
corresponds to only 25 mg/liter of carbon or TOD, essentially negligible for
discharge to typical receiving bodies.
The presence of high levels of oils and grease in the scrap charged to
electric-arc and other types of furnaces creates a deleterious effect upon
the furnace operation in general, and especially the air pollution control
equipment. To avoid the problems associated with high oil content scrap,
7-21
-------
foundries are imposing increasingly stringent specifications for the
acceptable level of oil permissible in scrap. This has resulted in more
pretreatment and cleaning of scrap by the suppliers. Therefore, the
likelihood of oil being found in scrubber effluent from electric-arc furn-
aces is diminishing.
It is thus unlikely that the scrubber wastewater effluent would require
any TOG reduction. If an electric-arc furnace were consistently charged
with very oily scrap such as turnings from machining operations, then the
scrubber effluent might contain sufficient oily matter to require the use
of an oil skimmer as part of the water treatment facility.
7.3 2.3 Total Suspended Solids - Total suspended solids from the scrubber
effluent would be generated at approximately the rate of particulate genera-
tion multiplied times the scrubber efficiency. Using the results from
Section II, 13.8 pounds of particulate is produced per ton of gray iron
charged to the furnace. At a scrubber efficiency of 99.7 percent, there
would be 13.76 Ib of solids collected per ton of gray iron melted.
Using the EPA recommended water circulation rate (661 gal/ton) and blow-
11
down rate (50 gal/ton) for an electric-arc furnace used for steelmaking,
the total suspended solids were determined to be 35,700 mg/liter in the
blowdown.
7.3,3 WATER TREATMENT
The blowdown can be treated for removal of suspended solids using a.
classifier followed by a clarifier and/or a magnetic flocculator. This
system is recommended by EPA for use on the scrubber effluent from steel-
making electric-arc furnaces and is capable of reducing the suspended solids
to 50 mg/liter. 12
7-22
-------
The blowdown from the scrubber is sent to a classifier from which solids
are continuously removed using a moving trowel or screw conveyor. These
solids are collected and conventionally trucked to a landfill for disposal.
The liquid effluent from the classifier is sent to a clarifier which
utilizes polyelectrolytes to promote chemical coagulation. Sludge is
drawn off from the bottom of the clarification tank and is vacuum filtered.
The dewatered sludge, is disposed of with the classifier solids and the
water is recycled back into the clarifier.
If further solids reduction is required, the water effluent from the
clarifier can be discharged to a magnetic flocculation tank where the
remaining suspended solids are subjected to magnetic collection forces.
This step is not likely to be required when chemical coagulation is utilized.
The effluent from the clarifier or magnetic flocculator is the final
treated effluent and would then be discharged to some receiving body of
water. This system is capable of removal of suspended solids at greater
13
than 99.8 percent efficiency. Waterborne solids would thus be < 0.03 Ib
per ton of gray iron produced. Figure 7-1 is a simple schematic diagram
of the proposed treatment system.
7.3.4 CONCLUSIONS
The use of a high energy venturi scrubber on an electric-arc furnace
would result in an effluent creation of 50 gal/ton of waste water if operated
prudently. This waste water will be the blowdown from the scrubber recycle
system. Available data indicates that this scrubber blowdown would have a
pH of approximately 8.0, a total organic carbon content (TOC) of less than
25 mg/liter, and a total suspended solids content of nearly 36,000 ing/liter.
7-23
-------
RECOVERED METAL
I
r\i
-F*
PROCESS
SLOWDOWNS I
FROM >—--J
PROCESS
DUMP
BOX I
POLY
ELECTROLYTE
WASTE WATER
T"1^H
^
CLARIFIER
r-L.
00
1 1
1
1 I ~*
i
, FLOCCULATOR
i v
RECEIVING
BODY
_L_ j
I VACUUM U«. i
i FILTER I
L__—„-_—i
SOLIDS TO
DISPOSAL
Figure 7-1. Proposed scrubber wastewater treatment system
-------
Waste water of this quality would only require that the level of
total suspended solids be lowered before it could be discharged to a re-
ceiving stream. Water treatment for removal of suspended solids is straight-
forward and technically well established. Utilization of EPA's defined
"best practicable control technology currently available" will reduce the
level of total suspended solids in the 50 gal/ton blowdown by greater than
14
99.8 percent to 50 mg/liter.
The use of this treatment will result in approximately 15 Ib/ton of
solids requiring disposal. These solids will be contained in a high solids
sludge which would contain up to 60 percent solids, depending upon the
amount of dewatering applied. Disposal of this nearly insignificant quality
of sludge will pose no adverse environmental impact which would not have
been previously imposed upon the disposal site if the particulates were
from another air pollution control system. The sludge will be essentially
the same as the particulate generated and would require disposal regardless
of the air pollution control technique employed. Secondly, compared to the
quantity of slag requiring disposal, the quantity of particulate requiring
disposal is insignificant.
7.4 SOLID WASTE DISPOSAL IMPACT
7.4-1 Quantity of Solid Waste
When scrubbers, precipitators or fabric filters are used to control
emissions from electric-arc furnaces in gray iron foundries, solid wastes
will be generated.
The quantities of solid wastes that would be produced by the emission
control devices mentioned above can be calculated based on an emission rate
of 13.8 pounds of particulate per ton or iron melted and the respective
7-25
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emission control efficiencies. Based on Table 7-8 , an ESP would generate
13. 73 pounds of solid waste per ton of iron melted while a baghouse would
generate 13.73 pounds per ton. Venturi scrubbers also produce solid waste
(13.76 pounds per ton based on Table 7-8 . The solid waste from a venturi
is in the form of dewatered sludge, commonly resulting from a settling pond
or lagoon. The disposal techniques which will be discussed here may also
be applied to dry dewatered scrubber sludge assuming its chemical composi-
tion and properties are similar to those for dry.waste from an ESP and
baghouse.
Table 7-8. SOLID WASTE GENERATION FOR DIFFERENT CONTROL
SYSTEMS' 5,16,17, T8» J 9
Control system
Electrostatic
precipitator
Venturi scrubber
Filter baghouse
Furnace
emission rate,
lb/ton
13.8
13.8
13.8
Efficiency,
%
98.5
99.7
99.5
Solid waste
generation,
lb/ton
13.59
13.76
13.73
The quantity of solid waste generated with present control techniques
have been calculated based on information from Table 7-9. From this table
one can assume 57 percent of these foundries have emission control equipment.
(The size distribution of these furnaces are assumed to be representative
of the industry as a whole). Since the majority of the control equipment
is fabric filters, we have used the solid waste generation factor for a
baghouse from Table 7-8 (13.71 pounds per ton). The total amount of cast
iron produced in 1973 from electric-arc furnaces in gray iron foundries was
20 fi
2.32 million short tons. Based on this, approximately 18.16 x 10 pounds
7-26
-------
of solid waste was collected by emission control systems for the year 1973.
We will also assume that this production rate held constant for 1974 and
1975, the general economic decline inhibiting growth.
Table 7-9. AIR POLLUTION CONTROL EQUIPMENT FORpELECTRIC-
ARC FURNACES IN GRAY IRON FOUNDRIES -
Total respondent foundries employing electric-arc
furnaces
Total foundries with air pollution controls
Type of control used
1. Fabric filter
2. Portable wet scrubber
42
24
20
4
Using the same numbers and assumptions, the quantity of solid waste that
would be generated if electric-arc furnaces were all controlled by fabric
filters would be 31.85 x 10 pounds per year. Table7-10 lists the in-
formation used in quantifying solid waste generation for electric-arc
furnaces. The difference between the baghouse solid waste generation factor
and that for the average of the other two control systems (13.68 pounds per
ton) is only 0.05 pounds per ton or approximately 0.36 percent. Because of
this small difference and also because of the fact that at present most
emission control equipment for electric-arc furnaces (Table 7-9 ) are bag-
houses, the use of the baghouse solid waste generation factor extrapolated
to the industry in general seems to be valid.
The solid waste generation rate for electric-arc furnaces in gray iron
foundries would increase if: (1) state and/or federal air pollution emission
codes become more strict, or (2) if the production capacity of the industry
increases.
7-27
-------
Table 7-10. SOLID WASTE GENERATION FROM ELECTRIC-ARC
FURNACES AT PRESENT LEVEL OF PRODUCTION
AND AT CONTROL AND AT TOTAL CONTROL
Factor
Foundries presently controlled, %
Waste generation factor for a baghouse,
Ib/ton
Cast iron production for 1973, million
short tons
Present solid waste generation rate,
Ib/year 1973
Solid waste generation rate with 100%
control, Ib/year
Value
57
13.73
2.32
18.16 x 10£
31.85 x 106
and Si02« There are also trace
7.4.2 Composition of Solid Waste
Typical chemical analysis of electric-arc furnace dust is given in
Chapter 3. The major oxides are Fe
elements that may act as fluxes and have an effect on the melting behavior
of the material. "
7.4.3 Disposal
If either of the three emission control systems are employed, air pol-
lution impacts are substantially reduced but solid waste disposal impacts
are increased. The removal and disposal techniques employed to handle
solid waste determine the magnitude of the impact this material has on
the environment.
A variety of disposal techniques exist which have potential application
to the electric-arc furnace dust. If foundry waste material can be marketed,
then producing foundries would find it economical to collect, transport, and
dispose of the resultant product. Alternatively, they would have to convert
it to a form more readily disposable, because as demonstrated in Chapter 3,
7-28
-------
the particulate emissions generated by electric-arc furnaces are fine.
Because of this, dust generation as a result of transport and handling could
readily be a problem. Pelletization is the easiest and most economical
method to minimize handling and to control the evolution of dust.
Several feasibility studies were done for utilization of electric-arc
furnace dust in gray iron foundries, and to develop viable utilization
techniques for the waste material. The uses considered were:
1. Bulk disposal
a. Masonry aggregate
b. Land and road fill
c. Soil and fill stabilization
2. Processed for recycling
a. Foamed building products and insulation
b. Vitrified products and fibers for insulation
c. Glazes for masonry products
d. Polymer fillers
e. Colorants
f. Agricultural applications
g. Ore for extraction of metallic values
3. Present techniques.
7-4.3.1 Different bulk disposal and recycling techniques were investigated
by the /-.mencan Foundrymen Society, the Bureau of Mines and others. Except
for the disposal in land fills of dust, loose or pelletized, none of the
techniques have been applied and the ones which were fired following laboratory
investigations did not meet the expectations and were discontinued.
7.4.3.2 Present Disposal Techniques - At the present time, gray iron
foundries commonly dispose of arc furnace dust via landfilling or use a
roadfill. Of the four foundries contacted, tested by EPA, all use sanitary
landfill as a means of disposal. No recycling techniques were mentioned as
7-29
-------
an alternate to the current bulk disposal method. All the foundries con-
tacted mentioned that they had no problems (complaints from the public or
government agencies) in regards to their disposal practices. Though, land-
filling and use as roadflll have been found acceptable, this should not
discourage the other potentially beneficial uses of the effluent from
recycling even though more research in these areas is required.
7.4 .4 Summary
From the feasibility studies performed, it can be said that arc furnace
dust has no good potential for recycling. The dust is fine and can be
easily pelletized. Pelletization makes the handling, disposal, or processing
of this dust easier and more efficient. Crushing strength measurements
show that arc furnace dust forms dense strong pellets which would be
usable as aggregate in masonry products. These pellets might be used in
grog for structural clay products (i.e., brick, tile, and pipe.) The
high iron content of the effluent indicate that the pellets might be
recycled in a meltdown furnace. Before this application of the solid waste
is initiated, it must be supported by more studies.
7.5 ENERGY IMPACTS
7,5.1 Introduction
This section contains a comparison of the energy consumed by uncon-
trolled and controlled electric-arc furnaces. Emission control system
energy consumptions were extrapolated to estimate one impact on increasing
U. S. energy demands based on industry growth projections.
7-30
-------
7.5 ENERGY IMPACTS
7.5.1 Introduction
This section contains a comparison of the energy consumed by uncon-
trolled and controlled electric-arc furnaces. Emission control system
energy consumptions were extrapolated to estimate one impact on increasing
U.S. energy demands based on industry growth projections.
7.5.2 Process Energy Consumption
Electric-arc furnaces require a large amount of electrical energy to
produce gray iron. Electrodes supplied with sufficient electrical energy
in a transformer and differential top lines create the arc necessary to melt
and refine charged materials. Melting and refining occur as the heat from
the arc is transmitted to the solid charge and molten iron. The process
heat required can be controlled quite effectively by monitoring process
operations.
The quantity of electrical energy consumed (kWh) per ton of iron melted
is relatively constant for all gray iron foundries employing electric-arc
furnaces with 10 to 20 percent of swarf. Table 7-11 presents the electrical
energy consumed by electric-arc furnaces of varying capacity. Based on this
table (491 kWh/ton iron melted) and the total charge for 1973 (2.32 million
short tons were melted in electric-arc furnaces) we estimate 1139.12 x 10
23
kWh of electricity were consumed by electric-arc furnaces in 1973. (Does
not include emission control equipment power consumption.) We have assumed
no industrial growth from 1973 to 1975; therefore, 1139.12 x 106 kWh are
expected to be consumed by electric-arc furnaces in gray iron foundries for
1975.
7-31
-------
Table 7-11. ELECTRICAL ENERGY CONSUMPTION FOR ELECTRIC-ARC
FURNACES OF VARYING CAPACITY^4'"'^'
Source and furnace capacity,
tons
Paxton Mitchell, Omaha
Nebraska - 6 ton
Gleason Works, Rochester
New York - 8 ton
tf
J. Deere Co., Waterloo
Iowa - 15 ton
J. Deere Co., Moline
Illinois - 20 ton
Approx .
charge, tonsa
6
5
7 6-2/3 avg.
8
15
11
12 12 avg.
13
Approx.
total kWha
2904
3216
7200
6252
Avg.
kWh/tona
484
480
480
521
avg 491
Averages are based on best approximation of charge weight and total
kWh used per charge. The average kWh per ton of iron melted" are taken
over the course of 1 year.
7-32
-------
One may have expected a decrease in kWh consumed per ton of iron melted
as furnace capacity increases but from this table it can be seen that no
correlation of this kind exists. Variations in kWh/ton of iron melted are
affected more noticeably by operating procedures and charge composition.
There are two major variations in the operation of the arc furnace which
significantly influence the amount of electricity required.
The first charge of the day the furnace is cold and requires a certain
amount of energy to heat the inner shell of the furnace. A second charge
immediately following the first will require less energy to melt an equiva-
lent amount of tonnage (30 to 40 kWh/ton less on the second heat than the
first for a furnace with 8 tons capacity), while a third charge will require
even less energy than the second (10 to 15 kWh less on third heat than
27
second). This decrease in kWh/ton iron melted assumes that the furnace
is already hot while loads two and three are being charged, therefore the
extra energy required to heat the furnace for the initial cycle decreases
during subsequent cycles. A second foundry shows the same results for a
6 ton charge into a cold furnace: approximately 500 kWh/ton were consumed
28
while the same charge into a hot furnace used only 467 kWh/ton.
A second cause of variation in power consumption per ton of charge is
due to operation at less than full furnace capacity and is illustrated by
Table 7-11. More power is consumed per ton where the percent capacity used
decreases. This may be attributed to the theory of arc melting (i.e., the
charge is melted from the arc by radiant heat.) This source of power
consumption variations is primarily dependent on individual foundry operating
practices.
7-33
-------
A small foundry not operating a furnace at its maximum design capa-
city and/or only running one shift per day (one or two heats per shift)
may experience greater energy costs per ton of iron melted than a larger
furnace operating two or three shifts per day at maximum furnace capacity.
To reduce power consumption, foundries should operate furnaces at or near
maximum capacity and run heats as close together as possible. Another
method for reducing electric-arc furnace energy consumption is by using
computer controls. A saving of 15 percent in melting power costs for tv/o
electric-arc furnaces has been achieved by New York Air Brake with the
29
installation of a computerized electric power demand control system.
The system governs two 7.5 tons per hour arc furnaces that produce about
150 tons on a two-shift schedule.
7.5. 3 Emission Control Systems Energy Consumption
The quantity of electrical energy required to operate each of the emis-
sion control systems depends mainly on the type of ventilation system used.
As the ventilation rate of the system increases, the energy consumed by
the control device also increases. Of the three systems considered, Venturi
scrubbers operate under a relatively high pressure drop and therefore con-
sume the greatest amount of electrical energy per acfm. Fabric filters
demand the least amount of electrical power per acfm of the three systems.
Although power consumption is affected by the ventilation system employed,
control systems collection efficiency heed not be.
Table 7- 12 presents the energy requirements per acfm of effluent treated
for each of the three control systems. By using Table 7-12 |n conjunction
with the flow rates presented in Appendix A, a determination of the kilowatt hours
per ton of iron for the various emission control systems was made (Table 7-13) .
7-34
-------
Table 7-12. POWER REQUIRED FOR ALTERNATIVE EMISSION
CONTROL SYSTEMS 32,33,34,35,36
System
High energy
venturi scrubber
High voltage ESP
Fabric filter
kW/acfm
0.0196
0.00414
0.00235
kW/106 acfm
19,000
4,140
2,350
Table 7-13. COMPARISON OF ENERGY CONSUMPTION FOR THE ALTERNATIVE
EMISSION CONTROL DEVICES 37,38-41,42,43
High energy venturi scrubber
Side draft hood, fan 185°F
at fan,
Fourth hole, fan 180°F
at fan
Fourth hole, fan 105°F
at fan
High voltage ESP
Side draft hood, fan 18.5°F
at fan
Fourth hole, fan 700°F
at fan
Fourth hole, fan 200°F
at fan
Fabric filter
Side draft hood, fan 185°F
at fan
kW/acfm
0.0196
0.0196
0.0196
0.00414
0.00414
0.00414
0.00235
acfm/ ton
2500
755
670
2500
1370
780
2500
Energy consumption3
ratios based on
fabric filter energy
requirements
8.33
2.52
2.23
1.76
0.96
0.55
1.0
Calculation of the energy consumption ratios were based on a cycle time
of 70 minutes.
Table 7-13 lists the energy consumption ratios for the three emission
control systems considered in this study. Energy consumption ratios for
each control system are for the same service (i.e., on equivalent process
7-35
-------
rates). High energy venturi scrubbers require the greatest amount of
electrical energy while a high voltage electrostatic precipitator employing
fourth hole ventilation consumes the least amount of electrical energy
when treating an equivalent process weight rate. A fabric filter requires
less electrical energy than both a high energy venturi scrubber and a high
voltage ESP employing a side-draft hooding system. The flow rates used to
calculate the energy consumption ratios are based on flow rates developed
in Appendix A. The remainder of this section will deal primarily with
energy consumption for fabric filters. The reasons for concentrating on
fabric filters are as follows: (1) baghouses offer high overall efficiency
at a reasonable power cost; (2) baghouses seem to be the most likely of the
three emission control devices for future control of the iron industry;
44
(3) based on the A,T. Kearney study of the iron foundry industry, most
electric-arc furnaces presently using emission control equipment employ a
baghouse.
Table 7-14 lists the energy required per year to operate uncontrolled
and controlled electric arc furnaces under a variety of conditions. The
table was prepared based on information developed in Appendix C. The emis-
sion control system considered was a fabric filter. The fabric filter
energy factor (6.86 kWh/ton) was the only one used to quantify energy
consumption on a yearly basis.
A comparison of the energy consumed for uncontrolled versus controlled
sources can be made by referring to data previously presented. Table 7-14
lists the energy consumption for various operating conditions. Under pre-
sent conditions a total of 1148.18 x 10 kWh per year are consumed by
electric-arc furnaces in gray iron foundries. By determining the total
7-36
-------
energy for 1975, assuming all sources are uncontrolled, and the total with
100 percent control a difference of 15.90 x 10 kWh per year is obtained.
This would be the present annual demand for energy per year for emission
control equipment if all sources were controlled. Based on 57 percent
control, the annual power requirement per year for the emission control
equipment is 9.06 x 10 kWh. The amount of energy consumed by the emission
control equipment (9.06 x 10 kWh) as compared to the total power consump-
tion at present (1148.18 x 10 ) is 0.79 percent with 100 percent control;
the percentage of the total annual energy consumption utilized by the
emission control equipment is 1.4. The difference in energy required for
57 percent and 100 percent control is 6.84 x 10 kWh. Going from 57 per-
cent to 100 percent control would result in an energy consumption increase
of only 0.60 percent. Based on energy per ton data, uncontrolled sources
consumed 491 kWh/ton. Emission control equipment requires 6.85 kWh/ton.
Table 7-14. COMPARISON OF ENERGY CONSUMED: CONTROLLED VERSUS
UNCONTROLLED SOURCES 46,47,48-50,51
Condition
Energy, kWh x 106 for 1975
Uncon,rolled at present, 43%
Controlled at present, 57%
Total at present
Present use by emission control equipment
Present use if all were uncontrolled
Present use if 100% controlled
Present use by emission control equipment
if 100% controlled
Used per ton
Controlled
Uncontrolled
Emission control equipment
489.82
658.36
1148.18
9.06
1139.12
1155.02
15.90
energy, kWh
497.85
491.00
6.85
7-37
-------
From this comparison the additional amount of energy required to oper-
ate the emission control equipment is extremely small if compared to the
energy consumed by uncontrolled electric-arc furnaces. .Therefore, the
energy demand of the control system should not have any appreciable impact
on the foundry industry when applying emission controls to previously un-
controlled furnaces.
By extrapolating the emission control systems energy consumption, an
estimate of their impact on increasing U.S. energy demands can be fore-
casted. Figure 7-2 shows the proposed annual energy increase when utilizing
baghouses. The reasons for using a baghouse were listed earlier in this
section. The same analysis could be performed for an ESP or venturi scrub-
ber. Figure 7-2 assumes an overall industry growth rate of 2 percent per
year and that electric-arc furnaces (linear approach) will be responsible
52
for 32 percent of the total product from gray iron foundries by 1980.
One graph assumes a linear approach to 100 percent control (baghouses) by
1980 while the second assumes percent control of the industry will remain
constant.
Based on these two graphs a maximum and minimum determination can be
made with respect to the quantity of energy consumed by the control device
for any given year.
For the year 1980 a maximum of 61.58 x 10 kWh (100 percent control)
and a minimum of 35.10 x 10 kWh (57 percent control) are. obtained from
Figure 7-2. Taking the upper limit and comparing it with the total energy
consumed by electric-arc furnaces (4475.67 x 10 kWh) one finds it accounts
for only 1.38 percent of the total. The result of this extrapolation
assumes 2 percent industrial growth rate per year, 32 percent of the gray
7-38
-------
ENERGY CONSUMED BY CONTROL EQUIP., PER
YEAR,(I06KWH) FOR ELECTRIC ARC FURNACES
IN GRAY IRON FOUNDRIES , EMPLOYING
BAGHOUSES
X
5
X
o
cr
UJ
£E
UJ
Q.
O
U)
2
Z
O
u
o:
IU
z
U)
65
60
55
50
45
40
35
30
25
20
15
10
5
A CONTROL OF INDUSTRY REMAINS
CONSTANT , 57 % ^
O CONTROL APPROACHES 100% /
BY I960 /
/
/
/
/
/*
/
/
/
/
/ ^
/ ^^
/ ^^
^r ^^^
^F ^^^^
/ A
s^S'^
/X*^*^
.^^
^^&^
*
-
i i i i i i
1975 1976 1977 1978 1979 1980
TIME (yrs)
Figure 7-2. Projected annual emission control
system energy consumption53,54
7-39
-------
iron melted in 1980 was by electric-arc furnaces, baghouses were the control
devices employed, control of the electric-arc furnace was 100 percent, and
that overall control efficiency of the baghouses are 99.5 percent. An equivalent
comparison may be done for ESP's and venturi scrubbers using Table 7-13 and
assuming the same industrial growth rate with 100 percent control.
7.5.4 Conclusions
The quantity of electric! energy (kWh/ton iron melted) required to
operate the alternative emission control systems considered in this study
is generally less than 1.5 percent of gray iron foundry electric-arc furnaces'
total energy consumption. The energy consumption impact resulting from imple-
mentation of the emission control systems is relatively small. Going from
no control to complete control only results in an increase for the industry
of 61.58 x 10 kWh (baghouse) or 1.4 percent for 1980. The energy impact of
the new source performance standards as compared to State regulated electric-
arc furnaces producing gray iron is even smaller than the 1.4 percent number
for 1980, since a smaller amount of energy is required for control devices
to comply with State standards. Based on this, the impact of the increase
in energy consumption on future U.S. energy demands would be very small.
Therefore, the energy impact resulting from use of emission control equipment
does not seem to be a valid argument against the implementation of these
devices. This doesn't include furnace cooling air nor air which one has to
heat in winter in a closed foundry because of dust collecting equipment.
7-40
-------
7.6 OTHER ENVIRONMENTAL CONCERNS
7.6.1 Irreversible and Irretrievable Commitment of Resources
This section is concerned with the irreversible natural resource com-
mitments arising from implementation of the alternative emission control
systems. Curtailing the range of future use of land and water resources
resulting from this action will be discussed.
When employing an ESP or baghouse, dry dust is generated and solid
waste disposal becomes a problem. When scrubbers are used, solid waste in
the form of dewatered sludge will probably result. If landfill-in* is used
as the solid waste disposal technique, an irreversible land commitment
might be required. The future usefulness of this land is dependent on the
quantity and characteristics (chemical and physical) of the solid waste
material being disposed of. If toxic materials are present, the land may
become unfit for agricultural and recreational use. Potentially toxic
materials present in the dust at quantities of up to 10 percent are NiO,
PbO, and ZnO. Since the content of the ash is relatively insoluble in
water the likelihood of these materials leaching out into the surrounding
area is remote. If the landfill site is clay lined, no irreversible im-
pacts on the land should result from leaching of the toxic materials.
Relative to the quantity of slag produced 0s" 5 percent of the charge weight
or 100 Ib/ton) the additional solid waste generated from employment of the
emission control equipment (13.8 Ib/ton generated) is small.
7-41
-------
If a venturi scrubber is employed as an emission control device the
blowdown waste water must be disposed of. Both the type of treatment
used and the wastewater disposal method may result in irretrievable and
irreversible natural resource commitments. Water treatment in the form of
ponding or lagooning will prevent alternate use of the land involved. The
properties of the material pumped into the pond or lagoon will have the
greatest effect in determining future alternative applications of the area.
In most cases, ponds or lagoons are permanent installations.
Disposal of the waste water can also result in an irreversible natural
resource commitment. The disposal of the treated blowdown could
have an irreversible impact on the water environment depending on the
disposal technique, temperature and the chemical properties of the effluent.
Foundries that might employ venturi scrubbers in the future and conform to
state or federal water quality codes should not present a problem. In areas
where water quality codes are not proposed or promulgated, degradation of
natural resources could result from unregulated waste water effluent
discharge.
Chemical analysis of hopper dust indicates it does not contain water
soluble toxic materials in concentrations that would be harmful. These
materials are sufficiently insoluble so that they are not considered a
health hazard, however more studies should be carried out to determine
if there is any potential for these substances to build up in ponds or
cr cc
lagoons to critical levels during a long term disposal application. C)»3D
Treatment of scrubber water prior to discharge could also present a pro-
blem since fine suspended solids will permeate inadequate waste water
treatment plants.
7-42
-------
140 h
i
-P>
CO
2O 30
PROCESS RATE (tons/hr)
VENTURI'
Figure 7-3.
Comparison of electric-arc furnace earticulate emissions (controlled and uncontrolled)
and existing state regulations 57,58-61,62
-------
1000
900
— 800
c •
o
£ 700
< 600
ce
2 500
CO
CO
ui
U
•400
300
200
100
0
i
10
20 30
PROCESS RATE (tons/hr )
40
50
Figure 7-4. Particulate emissions from uncontrolled electric-arc furnaces
-------
To assess national impacts, we will use both values. Figures 7-6 and
7-7 present an estimate of the annual particulate emissions that would result
from electric-arc furnaces in gray iron foundries at various degrees of emission
control. As part of the same figure, the solid waste generation that would
result at these various levels of particulate emission control is also
illustrated. We have assumed that virtually all the solids collected in a
venturi scrubber eventually becomes solid waste. If no emission control
measures were employed, the particulate emissions would total about 21,500
tons/year.
I/
A 70 minute heat cycle duration was assumed.
7-45
-------
100
•—»
I 90-
•»
*>
h.
a.
w 80-
bJ
U
^ 70-
60-
50 -i
i
u
o
UJ
u
i 30H
2 20H
K
(0
5 ,OH
10
20 30 40 SO 60 70
ELECTRIC-ARC FURNACE THRUPUT CAPACITY (tons/cycle)
i
80
90
'100
Figure 7-5.. Distribution of all types of electric-arc furnaces by throughput capacity
67
-------
PARTICULATE EMISSIONS (tons/year X IO"2)
VENTURI
WASH - •
CONN-•
ARKAN.FLA,-•
COL . ME.
ARIZ,IDA,ILL,-
IOWA.KAN,KEN,
tOUS.MONT,
NEB.NEV. |
N DAK.OHIO, j
fil , S.OAK,
S CAR.TENN,
VIR.
Ui
b
p
'o
UI
b
N
O
b
1 I •
' I r
p
c>
IO
10
SOLID WASTE EMISSIONS (tons year X KTZ )
Figure 7-6 .
Estimated annual U.S. particulate emissions for 4.3 ton/hr
electric-arc furnaces at various degrees of particulate
emission control
7-47
-------
PARTICUUATE EMISSIONS (tons/yeor X
VENTURI
ARIZ, IDAHO,- •
ILL, IOWA,
KAN.KEN,
LOUS, MONT,
NEB.NEV,
N. DAK, OHIO
R.I..S. DAK,
S.CAR.TENN,
VIR.
01
I I I I I I I I I I "I I I I III—I I I I I I
ARK,FLA, - •
COL, ME.
SOLID WASTE EMISSIONS (font/year X 10~2 )
Figure 7-7 .
Estimated annual U.S. particulate emissions for 9.6 ton/hr
electric-arc furnaces at various degrees of particulate
emission control
7-48
-------
7.6.2 Environmental Impact of No Standards
As discussed in Section 7-1, the existing state air pollution regula-
tions regarding foundry operations are listed in Appendix C. By employing
these regulations, we have made a graphic comparison between the maximum
allowable particulate emissions for a representative cross section of states
and particulate emissions that would be generated by both controlled and
uncontrolled electric-arc furnaces (Figures 7-3 and 7-4). As well as pre-
senting the two most frequently implemented state regulations, the most per-
missive and two of the most stringent state regulations are also presented.
New Jersey regulations are more strineent than any other state regulations
in the U.S., while Washington regulations are more stringent than any other
state having a high density of gray iron foundry electric-arc furnaces.
In order to project, on a national basis, the air and solid waste im-
pacts that would result if electric-arc furnaces were either totally un-
controlled or adhering to existing state air pollution regulations, a
typical arc furnace throughput rate must be estimated. The distribution
of all types of electric-arc furnaces by throughput capacity is presented
in Figure /-5. From this figure we estimate a mean electric-arc furnace
throughput capacity of 11.2 tons/cycle (9.6 tons/hr).— However, electric-
arc furnaces used exclusively in gray iron foundries typically have a
throughput capacity of 5 ton/cycle (4.3 tons/hr).
~ A 70 minute heat cycle duration was assumed.
7-49
-------
APPENDIX 7-A
EMISSION CONTROL SYSTEM FLOW RATES
Both side draft and fourth hole hooding systems were considered. It
has been reported that side draft hoods generate about four times the volume
CO
flow generated by a comparable fourth hole hooding system. Roof hoods
generate about 25 percent lower volume than the side draft hood.
Based on field test data, Figure A-l presents a plot of gas flow rate
versus charge size for electric-arc furnaces employing side draft hoods and
fabric filters.6^0"^ The KVA rating of the three furnaces corresponding to
the data points in Figure A-l are from 3000 to 14000 KVA. Figure A-2
presents typical flow rates for the control device, hooding system, gas
temperature combinations considered in this impact assessment. Gas
temperature downstream of the venturi scrubbers were used since this is
where fans //ould be located.
7-A-l
-------
100
90
80
2 70
x
60
I 50
o
o
40
30
20
10
0
KEY:
A ACFM (ACTUAL ft3/min )
O OSCFM (DRY STANDARD ft^min)
10 20
CHARGE SIZE, tons
30
Figure A-l. Stack gas flow rate versus charge size for side draft hooding system applied to electric-
arc furnace heating cycles'3-76
-------
10
o
X
UJ
<
o:
100
90
80
70
o~ 60
uf J
< S 50
o 40
i-
to
j 30
o 20
10
O
LEGEND:
FF : FABRIC FILTER
ESP'- ELECTROSTATIC PRECIPITATOR
VENTURI : VENTURI SCRUBBER
10
20
30
CHARGE SIZE .tons
Figure A-2. Stack gas flow rate versus charge size for electric-arc furnace heating cycles
•77,78-81
-------
APPENDIX 7-B
EMISSION CONTROL SYSTEM POWER CONSUMPTION
The brake horsepower requirements for the fan were calculated using
the following equation:
(C-l)
brake HP = °-000157 Q AP
n
where: Q = flow rate at fan (ACFM)
Ap = pressure drop across the system (in. w.g.)
n = fan efficiency = 0.60
The fan power consumption rates generated from Equation C-l are pre-
sented in Table C-l.
oo oy
Table B-1. FAN POWER CONSUMPTION RATES
Control device
Fabric filters
Electrostatic precipitators
Venturi scrubbers
System pressure drop
(in. w.g.)
12
2
100
Fan power
consumption rate
(kW/ACFM)
0.00235
0.000391
0.0196
The total power consumption for fabric filter and venturi scrubber emis-
sion control systems were equated to the fan power consumption rates for
these systems. Venturi scrubber pump power requirements were assumed to be
7-B-l
-------
negligible in comparison to the power requirements of the fan. System
power requirements for electrostatic precipitators must include the power
consumed by the corona charging and rapping section of the precipitator..
Based on personal communications with Research-Cottrell, the corona charg-
ing and rapping power requirements for an electrostatic precipitator ap-
plied to a gray iron cupola and operating at 99 percent efficiency would
88
be (0.00375 kW/ACFM). We have assumed that the power consumption of an
electrostatic system applied to a gray iron electric-arc furnace would be
the same. By summing this figure with fan power consumption, a total pre-
cipitator consumption of 0.00414 kW/ACFM was obtained.
7-B-2
-------
APPENDIX 7-C
89
SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
7-C-l
-------
Table C-l. SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
90
-vl
o
INJ
State
Alabama
(1973)
Alaska
(1972)
Arizona
(1973)
Arkansas
(1973)
California
(1973)
Colorado
(1973)
Connecticut
(1973)
Delaware
(1972)
District of
Columbia
(1973)
Florida
(1972)
Ceorgia
(1972)
Hawaii
(1972)
Participate (pounda per hour) baaed on
Indicated process weight in tons/hour
S tons/hour 10 tons/hour 20 tone/hour 50 tons/hour
(For foundries)
16.65 25.10 37.0 32.28°'c
44.47b.
-------
Table C-l, (continued). SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
i
o
State
Idaho
(1973)
IlllnoU
(1973)
Indian*
(1973)
Iowa
(1972)
Kansas
(1974)
Kentucy
(1972)
Louisiana
(1973)
Maryland
(1974)
Massachusetts
(1973)
Par tic ate (pounda per hour) based on
Indicated process weight In tons/hour
5 tons/hour 10 tons/hour 20 tone/hour SO tona/hour
(Industrial processes)
12.0 19.2 30.5 44.6
(Small foundries)
16.65 25.10
(Existing foundries)*1
12.0 19.2 30.5 44.6
(New processes)8
6.0 8.7 12.5 20.5
(Existing foundries)
16.65 24 36 52.6
(New foundries)"1
12.0 19.2 30.5 44.6
(Small existing foundries)
16.65 25.10 -
(Large or new foundries)
12.0 19.2 30.5 44.6
(New foundries)
12.0 19.2 30.5 44.6
(Process operations)
12.0 19.2 30.5 44.6
(Process operations)
12.0 19.2 30.5 44.6
(Arablent-alr-quallty standards)
(Amblent-air-quality standards)
Carbon monoxide;
maximum effluent or
specified treatment
(Amblcnt-alr-qualtty
standards)
Cupola gasoB burned with
an afterburner to less
than 200 ppm corrected
to 507. excess air.
Cupolas with a melt rate
of less than 5 tons/hour
excluded
(For processes)
Creator than 10 ton/hour
must use afterburner
-
Burn In a direct-flame
afterburner at 1300F
for at least 0.3 second
Burn In a direct-flame
afterburner at 1300F for
at least 0.3 second
(ambient- a tr-quallty
standards)
(Amblent-alr-quallty
standards)
(Amblent-alr-quallty
standards)
Sulfur dioxide;
maximum
effluent for
any combustion
process
-
2000 ppo
(Meet formula for process
operation)
500 ppm by volume
-
2000 ppm In Priority I
reglona
(Amblent-alr-quallty
standards)
-
.
-------
Table C-l (continued). SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
I
o
State
Michigan
(1974)
Minnesota
(1971)
Mississippi
(1972)
Missouri
(1972)
Montsna
(1974
Nebraska
Nevada
(1973)
Mew Hampshire
(1974)
Particulatc (pounds per hour) based on
Indicated process weight In tons/hour
5 tons/hour
10 tons/hour
20 tons/hour
50 tons/hour
24
4.6
(Small jobbing cupola)
(Other cupolas)11
5.8 7.0
17.4
(Cleaning equipment 857. efficient or 0.4 grain per scf gas)
(Calculated partlculatc)*-
8.2 16.4 32.8 82.0
12.0
(Manufacturing processes)
19.2 30.5
56.4
(Same as Minnesota)
(Cleaning equipment 85% efficient or 0.4 grain per scf
gas, whichever most stringent.) .
(Calculated partlculatc)
8.2 16.4 32.8 82.0
(Process operation)
12.0 19.2 30.5 44.6
(Process operation)
12.0 19.2 30.5 44.6
(Industrial sources)
12.0 19.2 30.5 44.6
14.85
12.0
(Ferrous foundries)
(Existing).)
23.62 . 31.46 53.29
(New)"
19.2 30.5 44.6
Carbon monoxide;
maximum effluent or
specified treatment
Burn all cupola top gases
at 1200F for 0.3 second
Burn all cupola top gasea
at 1200F for 0.3 second
Meet amblent-alr-quallty
standards
Meet amblent-alr-quallty
quality standards
Sulfur dioxide;
maximum
effluent for
any combustion
process
Existing process equipment
» 2000 ppm by volume.
New process equipment •
500 ppm by volume
(Combustion-unit standards)
Loss than 250 million
Btu/hr - 0.71 Ib SO- per
million Btu. Over 250
million Btu/hr - 0.105 Ib
SO2 per million Btu
Meet amblent-alr-quallty
standards
-------
Table C-l (continued). SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
St«te
New Jersey
(1972)
New Mexico
(at of Doc. 31,
1974)
New York
<1973)
Horth Carolina.
(1972)
Horth Dakota
(1972)
Ohio
(1972)
Oklahoma
(1972)
Oregon
(1972)
Particular (pounds per hour) based on
indicated process weight In tons/hour
5 tons /hour
10 tons/hour 20 tons/hour 50 tons/hour
t,
(Manufacturing processes) (based on 0.02 graln/scf gas)
0.41
0.82 1.64 4.1
(Manufacturing processes)
Fartlculate ™ 0.05 pound per million Btu heat input.
Participate less than 2-mlcromcter diameter • 0.02 pound
per million Btu heat Input ^
0.55
16.65
1.10 2.20 5.50
(Jobbing foundries)
25.10 37.0
or BOX collection efficiency, whichever ia least restrictive
10.8
16.65
12.0
12.0
12.0
16.65
12.0
10.0
(Production foundries)
17.0 27.0 50.0
(Existing jobbing foundries)
25.1 - d
(Production or new foundries)
19.2 30.5 44.6
(Industrial processes)
19.2 30.5 44.6
(Indus trial processes)
19.2 30.5 44.6
(Existing Jobbing foundries)
25.1 - d
(Production or new foundries)
19.2 30.5 44.6
(Manufacturing processes)
16.2 28.3 44.6
Carbon monoxide;
maximum effluent or
specified treatment
-
.
-
-
-
Burned at 1300F for 0.3
second in a direct-
flame afterburner
Removal of 937. of the
CO with an after-
burner
—
Sulfur dioxide;
maximum
effluent for
any combustion
process
2000 ppm by volume
(Manufacturing processes)
Not to exceed 1 Ib S02 per
million Btu heat input
Less than 50 grains of sul-
fur compounds (measured as
H2S) per 100 scf of gas
Existing; 2.3 SO, /ml 11 ton
Btu Input
New; 1.6 Ib SOj/mlllion
Btu input
Must meet amblent-air-qosllty
standards
. Existing; 2000 ppm
New: 500 ppm
Existing: meet amblent-air-
quality standards
New: 2.0 Ib per million Btu
-
I
o
I
en
-------
Table C-l (continued). SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
State
Pennsylvania
(1972)
Rhode Island
(1972)
South Corolla*
(1974)
South Dakota
(1973)
Tennessee
11913)
text*
(1974)
Ut.h
(1973)
Vermont
(1973)
Virginia
(1974)
Particulate (pounds per hour) based on
indicated process weight In tons/hour
5 tons/hour * 10 tons/hour 20 tons/hour SO tons/hour
(Process -- iron-foundry melting)"
12.26 10.34 13.83 20.32
(Process operation)
12.0 19.2 30.5 44.6
(Process operation)
12.0 19.2 30.5 44.6
(Process operation)
12.0 19.2 30. S 44.6
(Existing jobbing cupolas)
16.65 25.10
(Existing foundries)
12.0 19.2 30.5 44.6
(Hew after August 9. 1969)
9.7 15.0 23.0 32.4
(Manufacturing processes)"
15.2 30.1 59.7 78.1
(Manufacturing processes)
Maintain at least 85% efficiency of control*.
(Industrial processes)
10.0 16.19 28.3 40.0
(Process operation)
12.0 19.2 30.5 44.6
Carbon monoxide;
maximum effluent or
specified treatment
-
-
Must meet ambient-air
standards
-
-
Burn at 1300F for at
least 0.25 second in
a direct- flame after-
burner
-
-
Burn at 1300F for at
least 0.3 second in a
direct-flame after-
burner
Sulfur dioxide;
maximum
effluent for
any combustion
process
500 ppm
-
Must meet ambient-air
standards
3.0 Ib SO. per million Btu
heat Input
(After July 1, 1975)
Class 1A county 500 ppo
Class I or II county - 1000
ppm
Class III county - 2000 ppm
-
If potential is greater than
250 tons sulfur per year.
control to 807. efficiency
Use fuel that is less than
1.07. sulfur by. weight or
control to discharge no
more than 1.0% of fuel by
weight
2000 ppm by volume
o
I
en
-------
Table C-l (continued). SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
State
Washington
(1972)
W«st Virginia
(1971)
Wisconsin
(1973)
Wyoming
(1973)
Particular (pounds per hour) baaed on
Indicated process weight In tons/hour
5 tona/hour 10 tons/hour 20 tons /hour 50 tons/hour
(General Processed)
Existing
(0.20 grain per scf)p
4.1 8.2 16.4 41.0
New after July 1, 1975
(0.10 grain per set)
2.05 4.1 8.2 20.5
(Manufacturing processes)
Existing before July 1, 1970
19.0 26.0 36.0 54.0
New after July 1, 1970
10.0 16.0 28.0 33.0
(Cupolas)
(0.45 Ib dust/1000 Ib gas)4
(Process operation)
Existing before April 9, 1973°
9.73 14.99 22.29 , 32.24
New processes after April 9, 1973
12.0 19.2 30.5 44.6
Carbon monoxide;
maximum effluent or
specified treatment
Meet amblcnt-alr-quallty
standard*
Burn at 1300F for at
least 0.3 second In a
direct- flame after-
burner
Meet amblent-alr-quality
standards
Sulfur dioxide;
maxl urn
effluent for
any combustion
process
Meet amblent- 30 tons/hour E - 17.31 p'
In footnotes c, d, g, j, and o, but not m:
E " maximum partlculate emission permitted
,0.62
,,0.16
P • process weight par hour, In tons/hour, that Is, tons of Iron melted per hour In the case of foundries.
In pounds/hour.
P < 30 tons/hour E - 4.10
> 30 tons/hour E - 55.0 P - 40.
"Uncertain whether the code applies to foundries.
The average undiluted-top-gas discharge per cupola from 12 cupolas was 28,765 scf/ton of Iron melted. Thus, 28,765 i (359 ft3 per lb-mole/29 Ib/mole)
•2,324 Ib gas/ton of Iron x (0.8/1000) • 1.86 Ib partlculate/ton with no dilution.
-------
Table C-l (continued). SUMMARY OF STATE AIR-POLLUTION REGULATIONS FOR FOUNDRIES
8P <450 tons/hour E - 2.54 p°'534
> 450 tons/hour E - 24.8 P°'16.
specifies: 5 tons/hour - 0.5 Ib partlculatc/1000 Ib gas
10 Ions/hour - 0.25 Ib purticulate/1000 Ib gas
20 tons/hour or over - 0.15 Ib partlculatc/1000 Ib gas.
Based on 2324 Ib gas/ton of iron melted (see f), the indicated particulate in pounds per hour was calculated.
The volume of undiluted top gas per ton of iron was estimated to be 28,765 acf. 7,000 grains - 1 pound. Thus, 28,765 x 0.4 T 7,000 - 1.64 pound of
particulate per ton of iron processed. Then 1.64 Ib/ton x number of tons/hour ~ Ib/hour.
h < 30 tons/hour E - 5.05 P°*67
E - 66.0 ?0al - 48.
The tabulated values were calculated as follows: average volume of undiluted top gas per ton of iron was estimated to be 28,765 scf. The allowable
emission of 0.02 grain/scf - 28,765 x 0.02 - 575.3 grains/ton T 7,000 grains/lb - 0.082 Ib/ton of iron melted. Then 0.082 Ib/ton x number of tons/hour
• Ib/hour.
Calculated pnrticulate emission permitted in melting gray iron. Heat required to melt 1 ton of iron and superheat to 2700F - 1,096,000 Btu. Estimated
nalting efficiency - 50 percent. Total heat required - 2,192,000 Btu. 2.192 million Btu x 0.05 « 0.110 pound of particulate per ton of iron melted.
Then 0.110 Ib/ton x number of tons/hour • Ib/hour.
e - process weight per hour in pounds/hour,
K " emissions in pounds/hour
P < 100,000 E - 0.024 p°-665
P > 100,000 E " 39 p°-°82 . 50>
The values tabulated w e calculated from the equation A " 0.76 E ' , where A • allowable emission in Ib/hour, E • emission index « f x W Ib/hour,
F "process factor, and W " production rate in tons/hour. F " 150 for 5 tons/hour or less; F - 50 for more than 5 tons/hour.
°P < 20.tons/hour E - 3.12 p°'985
P > 20 tons/hour E - 25.4 P°'287.
^The tabulated values were calculated as follows: average volume of undiluted top gas per ton of iron melted was estimated to be 28,765 scf. The
allowable emission of 0.20 graln/scf • 28,765 x 0.20 • 5,753 grains/ton T 7,000 grains/lb - 0.82 Ib/ton of iron melted. Then 0.82 Ib/ton x number
of tons/hour * Ib/hour.
^Tho tabulated values were calculated aa follows: the average undiluted cupola-top-gas discharge is 2,324 Ib/ton of Iron melted (aee footnote f).
Then 0.45 Ib dust x 2,324/1,000 " 1.056 Ib dust per ton of Iron malted. Taking 1.046 Ib/ton x number of tons/hour - Ib/hour.
Reference
1. Draft Report on Cray Iron Foundries. Battalia. 1975.
-------
7.7 REFERENCES
1. Systems Analysts of Emissions and Emission Control in the. Iron Foundry
Industry, Vol. II - Exhibits. A. T. Kearney Co., prepared for the
U. S. Environmental Protection Agency, February 1971. APTD 0645.
2. Compilation of Air Pollutant Emission Factors, 2nd Edition, AP-42,
U. S. Environmental Protection Agency, July 1973.
3. Draft Report on Gray Iron Foundries, Battelle, 1975.
4. Op. cit, Reference 3.
5. Op. cit, Reference 3.
6. Schmidt, G. K., Staubbekaempfung in der Giesserei Industrie, pp. 350 and 362.
7. Op. cit, Reference 3.
8. Development Document for Effluent Limitations Guidelines and New Source
Performance Standards for the Steel Making Segment of the Iron and Steel
Manufacturing Point Source Category. U. S. Environmental Protection
Agency, June 1974. EPA-44Q/l-74-024-a.
9. Federal Register, Washington, D.C., June 28, 1974.
10. Personal Communication - Sam Young, N.U.S. Corp., Pittsburgh, PA, July 15, 1975.
11. Op. cit, Reference 8.
12. Op. cit, Reference 8.
13. Op. cit, Reference 8.
14. Op. cit, Reference 8.
15. Air Pollution Emission Test. The Gle^son Works, Rochester, N. Y.
U. S. Environmental Protection Agency, Officer of Air Quality Planning and
Standards, Emission Measurement Branch, Research Triangle Park, N.C. 1975.
16. Source Sampling Report, John Deere Tractor Works, East Moline, Illinois,
Gray Iron Electric-Arc Furnace, U.S. Environmental Protection Agency,
Office of Air Quality Planning and Standards, Emission Measurement Branch,
Research Triangle Park, N.C. 1975.
17. Source Sampling Report, John Deere Co. Plant, Waterloo, Iowa. U. S. Environmental
Protection Agency, Office of Air Quality Planning and Standards, Emission
Measurement Branch, Research. Triangle Park, N.C. 1975.
18. Source Sampling Report, Paxton-Mitchell Co., Omaha, Nebraska. U. S. Environmental
Protection Agency, Office of Air Quality Planning and Standards, Emission
Measurement Branch, Research Triangle Park, N.C. 1975.
-------
19. Participate Pollutant System Study, Vol. II, Fine Particulate Emissions,
Midwest Research, Institute, prepared for U. S. Environmental Protection
Agency, August 1971. APTD 0744.
20. Chapter 3, pp. 3-3, Table 3.2.
21. Thomas W. and W. Barbour. Foundry M&T. Computer Controls: Arc Melting
of Iron. June 1974.
22. Aleskin, E. Utilization of Waste By-Products. ITT Research Institute.
Chicago, 111. American Foundry Society, Transactions, p. 313-322. 1968.
23. Personal Communications, Hank Bencus, Gleason Works, Rochester, N.Y.,
July 1975.
24. Op. cit, Reference 16.
25. Op. cit, Reference 17.
26. Op. cit, Reference 18.
27. Op. cit, Reference 15.
28. Op. cit, Reference 18.
29. Op. cit, Reference 21.
30. Op. cit, Reference 15.
31. Op. cit, Reference 16.
32. Op. cit, Reference 17.
33. Op. cit, Reference 18.
34. Op. cit, Reference 8.
35. Falvay, Pat. Personal Communications, Ferrotech Corp. July 1975.
36. McCarthy, Bob. Personal Communication. Research-Cottrell. August.
37. Op. cit, Reference 8.
38. Op. cit, Reference 15.
39. Op. cit, Reference 16.
40. Op. cit, Reference 17.
41. Op. cit, Reference 18.
42. Op. cit, Reference 35.
-------
43. Op. cit, Reference 36.
44. Op. cit, Reference 1.
45. Air Pollution Aspects of the Gray Iron Foundry Industry, Vol. II,
A. T. Kearney Co., prepared for the U. S. Environmental Protection
Agency, February 1971. APTD 0806.
46. Op. cit, Reference 8.
47. Op. cit, Reference 3.
48. Op. cit, Reference 35.
49. Op. cit, Reference 36.
50. Economic Impact of Air Pollution Controls on Gray Iron Foundry Industry.
U. S. Department of Health, Education, and Welfare. Publication Number
AP-74- November 1970.
51. Personal Communications. Mr. Gaultier. American Foundryman's Society. 1975.
52. Op. cit, Reference 1.
53. Op. cit, Reference 23.
54. Op. cit, Reference 3.
55. Op, cit. Reference 22.
56. Op. cit, Reference 23.
57. Op. cit, Reference 3.
58. Op. cit, Reference 15.
59. Op. cit, Reference 16.
60. Op. cit, Reference 17.
61. Op. cit, Reference 18.
62. Op. cit, Reference 19.
63. Op. cit. Reference 15.
64. Op. cit, Reference 16.
65. Op. cit, Reference 17.
66. Op. cit, Reference 18.
67. Op. cit, Reference 51.
-------
68. Op. cit, Reference 8.
69. Op. cit, Reference 23.
70. Trip Report for Source Teats, at the John Deere Co. Plant In Waterloo, Iowa.
U. S. Environmental Protection Agency, Office of Air Quality Planning and
Standards. Research Triangle Park, N.C., December 3, 1974.
71. Trip Report for Emission Tests at John Deere Co.. Plant in Moline, Illinois.
U. S. Environmental Protection Agency, Office of Air Quality Planning and
Standards. Research Triangle Park, N.C., January 17, 1975.
72. Trip Report for Emissions Tests at the Paxton-Mitchell Company in Omaha,
Nebraska. U. S. Environmental Protection Agency, Office of Air Quality
Planning and Standards, Research. Triangle Park, N.C., December 30, 1974.
73. Op. cit, Reference 2.
74. Op. cit, Reference 3.
75. Op. cit, Reference 6.
76. Op. cit, Reference 8.
77. Op. cit, Reference 1.
78. Op. eit, Reference 6.
79. Op. cit, Reference 8.
80. Op. cit, Reference 9.
81. Op. cit, Reference 10.
82. Op. cit, Reference 1.
83. Op. cit, Reference 2.
84. Op. cit, Reference 3.
85. Op. cit, Reference 6.
86. Op. cit. Reference 8.
87. Op. cit, Reference 9.
88. Personal Communications, Harry Patronic, Carborundum Co., Pollution Control
Division, July 1975.
89. Op. cit, Reference 3.
90. Op. cit, Reference 1.
-------
8. Economic Imoact Analysis
8.1 INDUSTRY ECONOMIC PROFILE
8.1.1 Introduction
A brief description of industry structure of the iron foundry industry
was presented in Section 3. In that section, information was presented on
the number of plants, the number of companies, employment, and growth pro-
jections. To briefly summarize that section, the grey iron foundry industry
consists of some 1500 foundries, many of which are single foundry companies.
Some 400 of the 3000 furnaces are electric furnaces and this represents about
13 per cent of total melting capacity. Furnaces in general range
from less than 1 ton per hour to more than 50 tons per hour, but electric
arc furnaces are seldom greater than 15 tons per hour.
Almost half of the iron foundries are very small, employing less
than 50 people. Only 166 foundries employed more than 250 people in
1973. About 93 per cent of the industry would be classified as small businesses
by the Small Business Administration.
Metal castings is a huge industry, with annual "value added" in excess
of $6 billion per year; the metal casting industry ranks sixth among all
American manufacturing industries.
Metal casting is exceeded in "value added" only by (1) motor vehicles,
(2) steel industry, (3) aircraft and parts, (4) industrial chemicals, and
(5) communications equipment; in turn, the casting industry exceeds the
average industrial fabricated metal products, drugs and Pharmaceuticals,
to name a few big industries.
Overall, the market for iron castings is expected to grow about 3
per cent annually. According to information from a supplier of
8-1
-------
arc furnace electrodes, about 5 to 6 arc furnaces will be built
each year for the next five years. These furnaces will range in 2.5 TPH
to 25 TPH. These furnaces represent either additional melting capacity
or conversion of cupolas to arc furnace capacity. The same information
source indicated that the growth rate in arc furnace melting capacity
will be 8.6 per cent.
8.1.2 Markets for Iron Castings
8.1.2.1 Principal Markets
Markets for iron castings—gray, ductile, and malleable— are wide-
spread and include almost all phases of our economy. Large amounts of
iron castings are used in almost all types of equipment, including motor
vehicles, farm machinery, construction machinery, petroleum-production
and refining equipment, iron-and-steel-mill equipment, and many others,
and in the housing industry. No government or private agencies compile
statistics on current markets for iron castings. A complete breakdown
of the markets for gray and ductile iron castings was made by the Gray
and Ductile Iron Founders Society, Inc., in 1969-1970, based on 1965 data.
The latter data are presented in Tables 8-1 and 8-2.
In 1973, the gray iron-foundry industry shipped 14,851,670 short
2
tons of castings which is about the same as the 14,882,852 tons
(15,712,852 tons of gray and ductile, minus 830,000 tons of ductile iron)
shown in Tables 8-1 and 8-2 for 1965. Differences in the product mix
between the 1965 markets and present markets for gray iron are expected to
be small. For the last ten years, no appreciable growth has occurred in
gray iron.
8-2
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TABLE 8-1. PRINCIPAL MARKETS FOR GRAY AND DUCTILE IRON CASTINGS
(1965 Data)
SIC
Code
33122
16,17
3713,5,7
3522
3494
3531
3519
3561
33212
3541,2
34310
3433
3585
33214
3566
3621
3429
Industry Description
Ingot molds
Construction castings
Motor vehicles and parts
Farm machinery
Valves
Construction machinery
Internal -combustion engines (excl. auto.)
Pumps and compressors
Pressure pipe and fittings
Machine tools
Enameled sanitary ware
Heating equipment
Refrigerators and air conditioners
Cooking utensils
Mechanical -power-transmission equipment
Motors and generators
Hardware
All other
TOTAL
Consumption,
short tons
3,406,925
3,185,566
3,089,387
875,653
337,474
304,194
292,501
277,180
221 ,000
209,740
207,061
198,887
151,462
139,609
135,073
110,500
91,167
2,479,473
15,712,852
Source: Battelle Columbus Laboratories
8-3
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TABLE 8-2. PRINCIPAL MARKETS FOR DUCTILE IRON CASTINGS
(1965 Data)
src
Code
3717
33212
3522
3548
3561
3741
3519
3531
3566
3554
3621
3494
3541,2,5
3555
3585
Consumption,
Industry Description short tons
Motor vehicles- and parts
Ductile iron pipe
Farm machinery and equipment
Metal working machinery (excl. mach. tools)
Pumps, air and gas compressors
Locomotives and parts
Internal -combustion engines (NEC)
Construction machinery and equipment
Mechanical -power-transmission equipment
Paper- industry machinery, parts, and attachments
Motors and generators
Valves and pipe fittings (excl. plumbing)
Machine tools
Printing machinery and equipment
Refrig. and machy. (excl. household and air cond.)
All other
TOTAL
340,000
221 ,000
50,000
29,560
19,763
18,751
17,512
10,856
9,501
9,000
8,252
8,172
7,608
4,201
3,158
72,666
830,000
Source: Battelle Columbus Laboratories
8-4
-------
The amount of ductile Iron shipped in 1973 was 2,247,585 tons, or
almost three times the 830,000 tons shipped in 1965. The types of ductile
iron markets for 1974 are expected to be somewhat different from and greater
in number than the 1965 markets. However, the major markets would be
expected to continue to be (1) motor vehicles and parts and (2) ductile
iron pipe.
Information on malleable iron was obtained from the Malleable
3
Founders' Society. Malleable iron shipments in 1973 were 1,030,039
tons of castings. The breakdown of the markets is as follows:
SIC Code
3712,5,7
3531,2
35
3522
3742
Industry Description
Motor vehicles and parts
Construction and mining
Machinery, other
Agriculture
Railroad
Miscellaneous
Total (1973)
Percentage
75
5
6
4
2
8
100
short tons
772,529
51,502
61,802
41,202
20,601
82,403
1,030,039
(a) calculated from the percentage values provided by Malleable
Founders' Society
Malleable iron castings have not shown any appreciable growth in the last
ten years, in terms of physical output.
8.1.2.2 Competition of foundries for markets
Large foundries compete with other large foundries for about the
same markets. For example, large pipe foundries will compete with other
large pipe foundries for the pipe markets, large foundries that produce
8-5
-------
parts for motor vehicles will compete with other large foundries producing
similar castings, even though part of the large foundries are captive.
These very large foundries are generally fully automated and produce very
large numbers of similar parts. This repetitive production of large
numbers of castings with automated equipment permits the large foundries
to produce castings at a minimum cost per unit.
Medium-size foundries, those foundries that have melting rates
of 10 to 50 tons per hour, generally produce a wider range of casting
designs and make fewer of each design than do the large foundries. Most
medium-size foundries have some automated equipment and make large
numbers of some castings but seldom will make one casting design every
day. Medium-size foundries have a higher unit cost than do large
foundries and, therefore, they must charge more per part than do the
latter.
Very small foundries (those foundries that melt about 4 tons per
hour for less than 8 hours per day) must find markets that are unattractive
to medium-size or large foundries. These markets for very small jobbing
foundries include replacement parts where only a few castings are needed,
castings for customers that only need a few parts per month, and some very
low quality castings (for example, counter-weights or manhole covers)
where very little control is required. The very small foundry cannot
compete with medium-size or large foundries for the casting markets of
interest to the larger foundries.
A few very small foundries compete with other small foundries
for specialty markets, such as piano-plate castings or alloy-extrusion
augers. However, these small, specialty foundries generally are a part
of a captive operation and are not jobbing foundries.
8-6
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8.1.2.3 Competition from Substitutes.
The various types of iron castings (gray, ductile, and malleable)
frequently compete with each other, with steel and nonferrous castings,
steel weldments, powdered-metal parts, metal forgings and stampings,
and plastics for the same markets.
Malleable, gray, and ductile iron frequently compete with powdered-
metal pressed parts, steel stampings and forgings, non-ferrous die
castings, and infection-molded plastics for markets that involve small
parts. The material that can perform the desired service at lowest
overall cost generally is selected. The material of lowest initial
cost may or may not be the one selected. Not only must a part meet the
desired physical and mechanical properties, but differences in such
things as machinability, weldability, performance in service, service
life, and the cost of repairs, and downtime can have marked effects on
total cost during the life of the part.
For medium-size parts, gray and ductile iron generally compete
with each other and with steel castings and steel forgings. Frequently,
either gray iron or ductile iron is competitive with the other materials.
Sometimes, when only a few parts of a given design are required, weldments
are more economical to use than are castings.
Gray and ductile iron generally compete with each other and with
steel castings or steel weldments for use in large parts. For many
large parts, use of either gray or ductile iron castings will make the
part at lowest cost. Large forgings generally are not in competition
with castings, because the markets are somewhat different.
8-7
-------
Some castings, such as gray iron ingot molds, have no competition
whatsoever, because no other material will perform satisfactorily in
that application. However, ingot molds are being replaced by a change
in technology to the production of continuously cast slabs and billets.
Gray iron motor blocks have almost no competition. A few small motor
blocks are aluminum castings made in permanent molds.
The rapid growth of ductile iron is the result of its replacement
of steel castings in many applications and, to a lesser extent, replace-
ment of gray and malleable iron castings. Ductile iron soil pipe has
become very popular with municipalities, because, unlike gray iron,
ductile iron with its high ductility can withstand some shifting of the
soil without breaking, and because it has good resistance to soil
corrosion, being much superior to carbon steel in that respect.
8.1.3 Prices
From 1967 to 1973, prices of castings have appeared to appreciate at
a higher rate than commodities in general. The trend in the Wholesale
Commodity Price Index (WPI) for iron castings from 100 in 1967 to an
estimated value of 143.7 in 1974 was definitely higher than the aggregate
Whole Commodity Price Index for the same time period. See Table 8-3. The
average value of all shipments has increased from $205 per ton in 1967
to $334 per ton in 1975. Total tonnage and value of shipments both
reached a high water mark in 1975.
The WPI caught up with castings' prices in 1974. However, shipments
also declined for that year (in terms of tonnages) from 1973. Apparently,
the recessionary impact in the auto industry had some influence on shipments
8-8
-------
TABLE 8-3. SHIPMENTS OF IRON CASTINGS, THEIR VALUE, AND THE PRICE INDEX FOR 1967 THROUGH 1972,
WITH PROJECTIONS THROUGH 1975
CO
<£»
Shipments, millions of tons
Gray and ductile iron
Malleable iron
Total cast iron
Total valtie^ , billion $
Average value, $/ton
$/1b
Wholesale Price. Index
(1967 = ioorc7
Iron castings
Average all commodities
1967
14.329
1.041
15.370
3.157
205
0.103
100
100
1970
13.945
0.852
14.797
3.546
240
0.120
116.5
110.4
1971
13.
0.
14.
3.
263
0.
128.
113.
839
882
721
868
132
1
9
1972
15.329
0.960
16.289
4.476
275
0.138
134.0
119.1
1973(a)
17
1
18
5
296
0
143
135
.072
.030
.102
.362
.148
.7
.5
1974(a)
16.560
0.965
17.525
5.755
328
0.164
159.2,.^
ice o\a/
1 OD.O
1975(a)
17.
1.
18.
6.
334
0.
162.
470
030
500
185
167
1
(a) Estimated by U.S. Bureau of Domestic Commerce (BDC).
(b) Includes interplant transfers.
(c) Statistical Abstracts of the United States, 1974, U.S. Department of Commerce, Social and
Economic Statistics Administration, Bureau of Census (July, 1974).
(d) July, 1974.
-------
and pricing for castings. The compound rate of price increase, based on
aggregate value of shipments, has been 6.9 percent yearly from 1967
to 1974; the WPI has been 6.5 percent for the same time period. .,
Meanwhile, carbon-steel forgings, a close substitute for iron castings
in many markets have appreciated in price at a rate of 4.30% over the
same time period. 4 Note in Table 8-4 that the equivalent prices of steel
forgings have been about twice those for iron castings.
While these data do reflect the absorption of compliance costs
for the SIP's and as such reflect the actual'competitive prices facing
new foundries in the future, historical data do suggest that demand for
iron castings appears to show some inelasticity relative to substitutes.
Hence, we might expect then future foundries'will have every reason to
push on increased costs of production at the expense of external producers,
such as steel forging furnaces. However, new foundries will have, to,
compete with existing iron casting foundries for any share of the casting
markets.
8.1.4 Balance of Trade for Iron Castings
Recently, the value of the combined exports of gray, ductile,
and malleable iron castings and of steel castings has been about
2 percent of the value of all domestic shipments of ferrous castings. §
The value of the imports of ferrous castings has been slightly less than
1 percent of the value of all domestic shipments of these materials
as is shown in the following tabulation:
8-10
-------
TABLE 8-4. COMPARATIVE PRICES FOR IRON CASTINGS
AND CARBON-STEEL FORCINGS
Average Price, dollars/lb
Year
Castings
Forgings
1967
1970
1971
1972
1973
Compounded rate of yearly
0.103
0.120
0.132
0.138
0.148
increases. 23%
0.209
0.229
0.250
0.262
0.270
4.36%
Source: U.S. Department of Commerce
8-11
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1967 1970 1971 1972 1973^ 1974(a) 1975^
Value of all/.x
shipments ^Dj 4,289 4,694 4,976 5,685 6,822 7,370 7,920
Value of. ex-
ports107 53 90 104 93 132 150 165
Exports, per-
cent of all
shipments 1.2 1.9 2.1 1.6 1.9 2.0 2.1
Value of/im-
ports w 18 30 29 37 48 63 70
Imports, per-
cent of all
shipments 0.4 0.6 0.6 0.7 0.7 0.9 0.9
(a) Estimated by Bureau of Domestic Commerce.
(b) Value in millions of dollars,
By 1980, the value of the imports of all types of ferrous castings is
expected to increase to about 110 million dollars, and the value of the
exports is expected to increase to about 235 million dollars.
The exportation and importation of ferrous castings at present are
small in volume and, therefore, have minor effects on the industry. The
balance of trade in this industry is not expected to change drastically
even if economic conditions or government controls increase the cost
of producing castings in the United States. Castings are mostly dif-
ferent from each other in from and complexity. Casting buyers often
visit the vendor to discuss the problems and arrange for sample castings
to be delivered. After the samples are delivered, the design may be
changed one or more times to improve the product in which the castings
are used. The frequent monitoring of the casting design, casting scrap,
a-32
-------
and the production of castings does not lend itself to long-distance
negotiations and personal visits.
Some castings such as pressure pipe, soil pipe, and malleable iron
pipe fittings, are fairly standard in design. However, differences in
size because of the metric versus English units of measure make international
trade difficult even for those items.
Many castings, such as motor blocks and heads, brake drums, and ingot
molds, are made in large numbers and could be a part of international trade.
However, castings of these types have not been standardized, and each
company demands individual designs. The freight on heavy ingot molds is
also a problem.
Under present conditions, long lead times of up to a year or more are
required between the placement of an order for castings and the receipt
of the first production castings. These slow deliveries are even slower
when castings must be shipped long distances, and this is another factor
that tends to discourage foreign trade. (Even when foundry production is
low, lead times of about 6 months are required.)
The various factors discussed above encourage a close geographical
location of casting producers and customers and tend to limit international
trade.
8-13
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8.2 COST ANALYSIS OF ALTERNATIVE CONTROL SYSTEMS
8.2.1 New Facilities
8.2.1.1 Introduction
This section discusses the construction of cost estimates for various
control systems in model plant foundries. The affected facility is the
electric arc furnace melting operation, which includes introduction of the
charge into the furnace and tapping of the fffofteffirofl. The determination
of incremental costs for the various control options exemplary of best emis-
sion control technology over SIP requirements for new sources is a most
important element in this section. The incremental costs are then analyzed
for their economic impact upon growth in the metal casting industry. There
are no significant sources of water-borne effluents of concern for foundries
utilizing electric furnaces. OSHA costs for health and safety requirements
are expected to have minimal impact in new foundries.
8.2.1.2 Model Plants
The economic analysis of best control technology will focus on the melting
of pig iron, scrap, briquettes and pellets in a direct arc furnace for the pur-
pose of producing a molten metal to be cast into ductile, grey, or malleable
iron. Model electric arc furnaces will be characterized by the following
melt rates: 4 ton-per-hour, 10 ton-per-hour, and 25 ton-per-hour. Table 8-5
presents the salient characteristics for model plants that will be used in the
cost and economic analysis. The face velocity of 200 feet-per-minute will
be the design parameter for estimating the ventilation rate for sizing the canopy
hood system further in this section. The yield of castings to melt is assumed
as 60 percent. The rejects, called foundry cast, are almost always recycled
as furnace charge. The charge composition is stated as the normal furnace
8-14
-------
operation. During discussion on degreasing and briquetting, there will be
mention of changing this composition mix in favor of processing cheaper raw
materials (i.e., more borings, turnings) as a way of minimizing emissions at
a reasonable cost.
The hours of operation which are based on simple eight-hour shifts are
assumed to cover 200 operation days for the 4 TPH furnace, 240 days for the
10 TPH furnace, and 360 days for the 25 TPH unit. Operating schedules are
very critical for the small plants in this analysis because capital costs
per ton are inversely related to the hours of operation.
8.2.1.3 Control Technology Costs
The control technology for this section includes basically two fabric
filter systems in various combinations with scrap processing methods. The
five control options to be considered in this analysis are stated as follows:
1) Canopy hood system - this fabric filter system is designed in such
a way that a canopy hood suspended some 20_ to 40_ feet above the furnace will
capture emissions during charging of scrap and provide cooling air for the
hot gases exhausted from the side draft hood during melting. There is no
scrap processing involved.
2) Si"1* draft hood only - this fabric filter system captures emissions
only during melting. Cooling is achieved either by water quenching or radiant
coolers. Again, there is no scrap processing involved.
3) Side draft hood plus scrap pre-heater - the scrap pre-heater cleans
the hydrocarbon emissions that would otherwise be emitted during charging.
The fabric filter system is the same as in (2).
4) Side draft hood plus scrap degreasing - similar to (3), this option
is a variant form of scrap processing to remove matter that would contribute
8-15
-------
to charging emissions. The degreaser is an automatic operated vapor
degreaser that cleans a uniform composite of scrap, such as engine blocks,
or smaller motors. The requirement of a uniform type of scrap is a
technical limitation for this control option.
5) Side draft hood plus briquettes - an alternative processing Option,
similar to (4) and (3), the briquettes provide a clean charge material.
Unlike the degreaser, this unit process borings and turnings into compressed,
compact briquettes. The briquetter may be the type that compresses oil from
the scrap (included in this analysis) or the type that employs a pre-heater
to burn hydrocarbons prior to briquetting. In addition to the latter technology,
two more techno!ogies--the BBC/BRUSA scrap treatment process and the Obenchain
ventilation design—have been excluded because there are emerging technologies
for which costs have not been established for American operations.
Control costs for fabric filter systems were developed by contract with
the Industrial Gas Cleaning Institute, Inc. (IGCI), a trade association of
manufacturers of gas cleaning equipment. Capital and operating costs for
the scrap processing units were obtained from the following sources:
o
a) Scrap pre-heater - Battelle Columbus Laboratories
b) Vapor Degreaser - Detrex Chemicals
c) Briquettes - Combustion Engineering
The capital costs developed for the controls are based on turnkey bids
for new systems on new plants. Items included in the costs are the materials
and labor in fabrication and erection of the flange-to-flange control hardware,
8-16
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induced draft fans, required ductwork, stack where appropriate, screw conveyor
for dust handling, storage, freight, sales, taxes, engineering, field supervision,
construction labor, fringe benefits, vendor's administrative overhead costs,
performance tests, and start-up costs. All capital costs have been indexed to
July 1975 via the Chemical Engineering Plant Index.
The annualized costs have been developed according to the following
assumptions. Capital charges have been calculated on the basis of 100 per
cent debt financing and recovery of capital by uniform periodic payments
(capital recovery factor). Economic life for all equipment is assumed as
15 years. Rate of interest for institutional lending to foundries is assumed
to be 12 percent, which is in accord with the risky type of small business
depicted by the usual independent foundry. The large captive foundries may
find rates at about 10 percent.
Electricity costs were calculated on the basis of 3 cents per kilo-
watthour for a relatively low volume - peak demand consumer such as a
foundry. Operational labor was assessed at $6 per man-hour, including
fringes.
Maintenance and repair costs were provided by the respective sources
providing tne capital costs. For example, Detrex states the following
approximations for their degreaser: maintenance and repair, about 6 hours
per 40 hour week; direct labor about 1 hour per day. Direct labor costs
appear to be a significant factor for the briquettes. The manufacturer
states that the direct labor costs are about $6 per ton of scrap processed.
In regard to fuel consumption, the scrap pre-heater is assumed to use
about 550,000 BTU to heat one ton of scrap to 1000°F to burn off oil and
greasy material in the scrap. The finished scrap, which will vary in
8-17
-------
temperature from 500° to 1000 F depending upon holding time before charge, will
reduce power consumption that would otherwise be needed to heat up cold scrap.
Battelle estimated a cost savings for the arc furnace of 96 cents per ton
scrap, which was based on a power savings of 110,000 BTU per ton charge of
pre-heated scrap.
A summary of control costs for the five technical options are presented in
Table 8-5. The assumptions used in deriving the operating costs for scrap
processing systems are presented in Table 8-6. These estimates were obtained
from respective vendors for the various processes.
The only credits allocated to the offsetting of costs in Table 8-5
are the reduced power consumption associated with pre-heating of scrap.
These are the only credits that can be uniformly applied to each individual
source employing this technique. Savings in the range of $9 to $20 per ton
for raw materials processed by the scrap pre-heater, degreaser or briquettes
can offset processing costs for these units. Probably the only process, or
let's say the best process, where real savings exist would be the briquetters.
Loose borings and turnings, which otherwise would be unsuitable as a furnace
charge, can provide up to 50 per cent of the furnace charge, instead 10 per
cent (see Table 8-7) in the form of briquettes. For this situation, the
calculated savings in the form of "scrap price differences" that would offset
processing costs are tabulated as follows:
Furnace TPH Scrap Price Difference (per ton)
4 $20
10 _ $15
25 $ 9
For example, the annualized control costs for the 4 TPH furnace in Table 8-6
will be reduced from $117,000 to $68,000 if a $20 per ton differential in
competiting scraps exists.
8-T8
-------
Table 8-5 Summary of Control Cost Options for Model Plants Part A
MODEL PLANT A - 4 TPH
Side Draft Side Draft Side Draft
MODEL PLANT B - 10 TPH
oo
Ventilation Rate, acfm
Capital Cost
a) Fabric Filter System
b) Pre-heater
c) Degreaser
d) Briquetter
Total Capital Cost
Annualized Costs
Capital Charges
Taxes, Insurance, Adm.
Electricity
Maintenance, Replacement Parts
Labor
Fuel
Solvent Consumption
Steam
Total Annualized Costs
Annualized Costs/Ton Product
Control Cost as a % of Price
(Price s $340)
Canopy
Hood
.165,000
$1,000,000
_
i
1 --
i
!'
$1,000,000
147,000
40,000
15,800
6,400
900
--
--
— •••
$210,000
$54.71
15.1
With
Pre-heater
27,400
$276,500
89,000
—
--
$365,500
53,700
14,600
2,900
2,700
4,500
1,500
--
—
$79,900
$20.81
6-1.
With
Degreasinq
27,400
$ 276,500
--
110,000
149,500
$386,500
56,700
15,500
3,000
4,000
2,100
—
2,000
2,100
$85,400
$22.24
6.5
tS 1 U^ L/l U 1 I
With
Briquettlnq
27,400
$276,500
__
__
••*«
$426,000
62,500
17,000
5,600
4,300
16,100
—
—
—
$105,500
$27.47
8.1
Side Draft
Only
27,400
$276,500
~»
*•••
--
$276,500
40,600
11,000
2,900
1,760
900
__
—
$57,200
$14.90
4.4
Canopy
Hood
197,000
$1,140,000
--
« —
—
$1,140,000
167,400
35,600
22,500
• 8,800
1,100
__
--
$245,000
$21,30
6-3
With
Pre-heater
42,500
$327,700
100,000
--
$427,700
62,800
17,100
5,400
4,000
6,300
4,500
--
$100,100
$8.69
2.6
With
Deqreasinq
42,000
$327,700
v>»
110,000
—
$337,700
49,600
13,500
5,600
5,100
2,300
_-
4,800
5,100
$86,000
$7.47
2.2
With
Briquettinq
42,500
$327,700
<•-
--
150,000
$477,700
70,100
19,100
33,200
22,100
47,300
—
-.
—
$191,800
$16.65
4.9
Side Draft
Only
42,500
$327,700
-_
--
_.
$327,700
48,100
13,100
5,400
2,900
1,100
-.
__
1
$70,600
$6.13
1 .8 -
-------
fable 8-5
Summary of Control Cost Options for Model Plants Part B
MODEL PLANT - 25 TPH
Side Draft Side Draft Side Draft
oc>
I
Control Option
Ventilation Rate, acfm
Capital Cost
a) Fabric Filter System
b Pre-heater
c Degreaser
d Briquetter
Total Capital Cost
Annual ized Costs
Capital Charges
Taxes, Insurance, Adm.
Electricity
Maintenance, Replacement Parts
Labor
Fuel
Solvent Consumption
Steam
Total Annual ized Costs
Annual ized Costs/Ton Product
Control Cost as a % of Price
Canopy
Hood
278,000
$1 ,430,000
—
^™«
-.,
$1,430,000
210,000
57,200
48,000
13,800
1,600
--
—
--
$330,600
$7.65
.2.3
With
Pre-heater
106,000
$825,000
225,000
--
— •
$1 ,050,000
154,000
42,000
26,500
14,400
18,800
16,900
—
--
$272,600
$6.31
1.8
With
Degreasing
106,000
$825,000
—
225,000
--
$1,050,000
154,000
42,000
26,800
15,400
3,800
—
12,000
12,800
$266,800
$6.18
1.8
With
Briquetting
106,000
$825,000
--
--
300,000
$1,125,000
165,200
45,000
55,500
39,000
175,000
—
-_
--
$479,700
$11.10
3.3-
Side Draft
Only
106,000
$825,000
—
—
—
$825,000
121,000
33,000
26,500
10,900
1,200
—
__
--
$192,600
$4.46
1.3
(Price = $340)
-------
Table 8-6. ASSUMPTIONS FOR CALCULATING OPERATING
COSTS ON SCRAP PROCESSING
1. Scrap Pre-Heater
a) Direct labor - use 3 man-hours per shift for 4 TPH plant;
5.5 man-hours for 10 TPH plant; and 8 man-hours for 25 TPH
plant
b) Fuel consumption - 4 gal per ton scrap at cost of 30<£ per
gallon
c) Power savings - 32 KWH/ton scrap based on 110,000 BTU per
ton scrap
d) Maintenance, 1 percent of investment for pre-heater unit.
2. Vapor Degreaser
a) Solvent consumption - 1.25 gal solvent per ton scrap.
Cost of solvent, $2 per gal. Assume degreaser has activated
charcoal carbon adsorber
b) Steam requirement is 40 boiler horse power for unit degreasing
4 ton per hour scrap. Steam costs are $2 per 1000 Ibs
c) Electricity requirement for 4 TPH degreaser is 3.5 KW
d) Labor, 1 hour per shift, maintenance labor, 6 hours/40 hour
period.
3. Briquetter
a) LaMr cost of $6 per ton scrap
b) Electricity cost of $1 per ton based on 3
-------
Table 8-7. MODEL PLANT CHARACTERISTICS FOR ELECTRIC FURNACE FOUNDRIES
Model A Model B Model C
Furnace diameter, ft. 8 11 17
Melting rate, TPH 4 10 25
Canopy hood face
velocity, fpm 200 200 200
Annual hours of
operation 1,600 1,920 2,880
Annual melt, tons 6,400 19,200 72,000
Annual casting produc-
tion, tons 3,840 11,520 43,200
Raw material charge, %
a) Foundry cast 40 40 40
b) Borings, turnings 5-10 5-10 5-10
c) Heavy, coarse,
sheet metal 50-55 50-55 50-55
8-22
-------
According to quotations published in American Metal Market for several
metropolitan centers in spring 1975, price differences between loose borings,
turnings and dirty heavy material were at least $15 per ton f.o.b. delivered
and often higher than $20 per ton.
8.2.1.4 Costs for State Regulations
The "side draft hood only" control option can be used to satisfy compliance
with typical process weight code, which is in most state regulations for the
4 TPH and 10 TPH furnace. Charging emissions would not cause these 2 furnace
sizes to violate the process weight code. Only emissions from melting would
be controlled. The 25 TPH furnace would be required to install a canopy
hood (or otherwise utilize clean scrap) to capture the charging emissions, as well
as to control melting emissions to achieve compliance. As far as it is known,
no state would require canopy hoods on any single furnace below the 25 TPH size.
According to this assumption, then the cost data in Table 8-5 show that
only the 4 TPH and the 10 TPH furnace are of interest. These are the only
two furnaces where there seems to be measurable incremental costs for best
control technology over state requirements. Table 8-8 shows the cost dif-
ferences for capital and annualized costs for best control technology versus
control requirements for state regulations,
8.3 OTHER COST CONSIDERATIONS
According to the Department of Labor's OSHA, worker safety costs for new
sources are substantially less for new sources than for existing sources. Much
of the OSHA requirements are related to proper ventilation of buildings to
prevent inhalation of toxic substances, adequate room for workers, and prevention
of noise. Existing operating plants are or should be in full compliance by now.
Therefore, the costs for health and safety equipment will have been absorbed by
the industry prior to promulgation of standards of performance for new sources on
prevention of air emissions.
8-23
-------
TABLE 8-8. SUMMARY OF INCREMENTAL COSTS FOR BEST CONTROL
TECHNOLOGY ABOVE STATE REGULATORY REQUIREMENTS
Canopy hood
Side-draft with
Pre-heater
Side-draft with
degreaser
Side-draft with
briquetter
Canopy hood
Side-draft with
pre-heater
Side-draft with
degreaser
Side-draft with
briquetter
Capital
Requirements
$723,000
88,500
110,000
150,000
$812,300
100,000
110,000
150,000
4 TPH
Annualized
Costs
$152,900
22,700
28,200
48,300
10 TPH
$174,800
29,500
15,400
121,200
Furnace
Annualized
Cost per
Ton
Product
$39.82
5.91
7.34
12.58
Furnace
$15.17
2.56
1.34
10.52
Control
Cost
% of
Price
12.1
1.8
2.2
3.8
4.6
0.8
0.4
3.2
NOTE: Above costs are the incremental costs over costs for "side draft
hood only" option.
8-24
-------
The American Foundryman Society is presently surveying its membership
for capital expenditures to achieve compliance with OSHA standards. Results
of the survey will not be available until after January 1976. When avail-
able, these costs will be reviewed and incorporated into the economic impact
analysis.
Electrostatic precipitators have not been analyzed in the economic chapter.
There are safety problems in regard to possible explosions due to excursions
in carbon monoxide emissions from the electric furnace. If electrostatic pre-
cipitators were considered as possible technology, the investment cost would
be comparable to costs for baghouses. However, the annualized costs would be
significantly less because electric power costs and maintenance costs would be
much lower than for baghouses.
Another area of environmental regulation for foundries is water effluents.
To date, no guidelines have been set for the industry. The EPA is investi-
gating the cost of best technology for waste treatment and the economic impact
of setting proposed effluent standards.
The major sources of water effluents are wet scrubbers used in controlling
pollutants from furnaces. Most of the scrubbers employed by the industry are
installed on cupolas. Almost all electric *rc furnaces employ bag houses.
Miscellaneous sources in the foundry also employ baghouses. The best technology
reviewed in this study will not be impacted by the forthcoming water effluent
guidelines.
8.4 ECONOMIC IMPACT OF ALTERNATIVE CONTROL SYSTEMS
8.4.1 New Facilities
8.4.1.1 Introduction
The purpose of this section is to analyze the costs of alternative
control systems in terms of their impact upon product prices, profitability
8-25
-------
and acquiring capital for new sources, balance of trade, product substitution,
and small businesses. The states presently have emission regulations that
apply to electric arc furnaces in foundries. To date, no Federal Standards
for water effluents have been promulgated for iron foundries. The only impact
anticipated from eventual regulations would be associated with the use of
scrubbers for cleansing stack gases. The technology described in Section 8.2
does not include wet systems. Similarly, OSHA costs for health and safety
requirements will not be expected to have an impact on new sources. Therefore,
the full impact of Federal standards facing arc furnaces would be incurred
with the incremental costs of required air controls more stringent than state
regulatory requirements. Therefore, the purpose of this section is to iden-
tify those control options which would impose additional financial constraints
on the foundry industry, above those imposed already by the states' emission
standards.
8.4.1.2 Impact on Prices
Aggregate prices and trends were discussed in Section 8.1. The section
indicated that current price of the average casting is about $340 per ton
and that prices have been rising generally faster than the wholesale price
index. Volumes of shipments have been increasing along with higher prices.
Such an observation indicates that the castings in the aggregate are price
inelastic to some extent for consumers of castings as measured against the
wholesale price index.
Pricing information on individual castings is simply unavailable. There
must be hundreds of types of castings produced ranging from large volumes
of standardized prices, such as automotive engine blocks down to the single
piece casting for a prototype on a R and D project.
8-26
-------
Product pricing is negotiated on a per piece basis, not on a cents per Ib.
basis, for good castings (i.e., the material the customer received, not the metal
poured). The unit price will be dependent upon the volume of an individual order,
the requirements for the core and mold, the desired precision and the quality of
the casting itself. For very unique castings, the price will be highly sensitive
to the cost in pattern, core, and mold preparation. For large production and
standardized molds and cores, the price of castings may not be much more than the
melting cost. Such is the case in assembly line production foundries, or captive
foundries.
Most foundries divide their operation into four basic production departments
and allocate costs along several basic cost centers: 1) melting, 2) molding,
3) core production, 4) cleaning, and 5) shipping. Materials, direct labor,
utilities, and equipment depreciation are allocated to each individual center.
Depreciation of buildings, taxes, insurance, workers fringe benefits, administra-
tive selling expenses are allocated as general overhead to the overall plants.
What this means is that when an individual customer negotiates with
a foundryman, the size of the order, if small, will be strongly influenced
by the cost of core and mold making. Much of the cost will be specialized
experience r* individual personnel to produce a casting more or less hand-
made according to specifications. On the other hand, large orders will be
influenced by melting cost, which is subject to often fluctuating prices
of raw material—pig iron, coke, and scrap. Mold and core making costs
will be low because of standardized patterns and automated machinery
capable of high outputs.
Large foundries, particularly captive operations, with standardized,
highly-mechanized production methods can operate only profitably with large
8-27
-------
volume of orders. They are capital intensive, requiring large investments
in core and mold making equipment automation equipment, and other production
equipment. Unit production costs are low on large scale production and
prices of castings reflecting economy of scale production may be on the order
of a few cents (i.e., 10 to 15 cents per pound basis.) On the other hand, limited
production foundries, small foundries, will be oriented toward custom or
specialty production, where cores and molds have to be frequently changed for
each new pattern. Depending on individual customer wants, production methods
may be manual or highly automated. Reflecting this wide range in production,
specialty castings can range from a matter of cents to several dollars on
a pound basis.
Because of the differences in production methods, large jobbing foundries
on the whole will compete with other large foundries. Similarly, small jobbing
**
foundries will compete with small foundries. This hypothesis then suggests a
rationale for comparing air pollution control costs in new sources facing Federal
Standards, with comparable-sized existing sources (i.e., a 4 TPH new source with
another 4 TPH source already in existence). The argument that the cost per ton
of a small operation is disadvantageous with the large producer holds only to
the extent that some specialty casting producers may have to compete with large
foundries for some orders, where the cost structure becomes marginal for the
large producer. Whether a plant is competitive depends on its control cost
relative to its competitors in the same markets. For this reason, the impact
of control costs for a particular model plant will be analyzed with respect
to the (same size) new plant that (in the absence of Federal Standards) would
comply with the state standards.
8-28
-------
All foundries in the industry will, or have, raised prices sufficiently to
pay for the costs associated with air pollution control facilities in compliance
with state regulatory requirements (SIP's). The 25 TPH furnace will be
the price leader for all others to follow. This is because each small foundry
will compete to some extent for certain types of order with a somewhat
larger foundry for some business. At least any limited competition in the
industry might be in the melting department, as all firms are faced with the
same prices for raw materials. Therefore, the 25 TPH furnace will maintain
capacity on the basis of 2880 operating hours and pass on the full costs
of air pollution control. The small furnaces (4 and 10 TPH) are assumed
to pass on the same per ton product control costs as the 25 TPH; cost
differences will be absorbed by the small foundry either by reduced
profits or marking up his specialty sector of business.
The decision tool then for determining the impact of control alter-
natives becomes the incremental cost for a specific alternative over a
state regulatory requirement for a model plant. The presence of 4 TPH
plants, even newer plants, in the industry suggests such operations are
economically viable. If the incremental costs are sufficiently small,
perhaps a $"• or $2 per ton, these costs prooably can be absorbed by marking
up specialty castings or increasing plant output by extending hours of
operation. If the cost differences are large then the plant owner may
not be able to effectively mark up his specialty markets or effectively
extend his schedule.
Referring to Table 8-8 and the discussion in 8.2, the only area of
discernible economic impact is with the small furnaces. After all, the
8-29
-------
25 TPH facility is assumed to be required to install the canopy hood to
comply with state regulations. In terms of unit control cost, the canopy
hood requirement does present a significant impact upon the small furnace.
For the 4 TPH furnace, the incremental cost is approximately $40 per ton
product or 12 per cent of average casting price. For the 10 TPH furnace,
the same canopy hood option costs an additional $15 per ton, or 5 per cent
of selling price, more than the side-draft hood option which is acceptable
in complying with state regulations. In the judgment of EPA, these incre-
mental costs are unreasonable.
The processing options, pre-heating of scrap and degreasing, appear to
be reasonable for the 10 TPH furnace with the cost being $2.56 and $1.34
per ton product, respectively, for the two processes. For the 4 TPH furnace,
the two options are $5.91 and $7.34 per ton, respectively. The third tech-
nical option, briquetting, appears to have a somewhat significant impact
upon these small furnaces - with the cost at approximately $11 to $13 per
ton over that for state standards. Of the three options, however, only the
briquetting option makes available the use of scrap that otherwise could not
be used efficiently in the electric furnace, namely loose borings and
turnings. In so doing, the processing of cheap, otherwise useless, material
into a good charge material can offer a viable economic solution to the
small foundryman. As previously discussed in Section 8.2.1.3, a savings of
$20 per ton for scrap will make this option viable for the 4 TPH producer
and $15 per ton will do the same for the 10 PTH producer.
In contrast to the viability of the briquetting option, the additional
cost of processing for the pre-heater and the degreaser cannot be offset by
8-30
-------
any immediate savings in raw materials because the affected foundryman is
already utilizing dirty scrap. However, in some cases, these options may allow
the foundryman to purchase a somewhat poorer quality scrap, at a lower price,
because of this additional processing capability.
A last option of note is the possibility of purchasing clean scrap in
lieu of processing. For this option, the foundryman's incremental control
cost over state requirements is the cost difference between that for clean
scrap over dirty scrap. This option seems particularly attractive for the
very small foundryman because the control cost becomes strictly an operating
cost. It does not burden the foundryman with capital charges. If he cannot
pass on the increased raw material costs, he doesn't sell.
8.4.1.3 Impact on Plant Profitability
In the previous section, the alternative control systems were compared
with one another by analyzing their annualized control costs as percentages
of current industry-wide castings prices. A mechanism was proposed for analyzing
the impact of incremental costs over the SlP's—comparison of the new source meeting
the Federal standard of performance (SOP) versus the new source meeting the
SIP (as if there were no SOP). In this section, the profitability of selected
plant confic rations highlighting the contrasts in costs of control systems will
be examined. Those control systems that would reduce profitability by as much as
fifty per cent or more for new plants trying to compete most likely would not be
built.
The initial assumption is that 4 TPH, 10 TPH, and 25 TPH arc furnaces are
being built and meeting state regulations. The determination of profitability
parameters requires information on the cost structure of model firms depicting
8-31
-------
the industry Infrastructure. Table 8-9 has been prepared to relate historical
sales and cost data in terms of today's castings prices, which is $340 per ton.
These data are used to derive total variable costs (raw materials, labor, utili-
ties, packaging, and distribution) which are assumed to remain the same for new
4 TPH, 10 TPH, and 25 TPH plants meeting SIP regulations. However, increased
depreciation charges and interests costs are introduced into the cost structures
to reflect the investment of electric arc furnaces and controls to meet SIP's;
administrative costs remain the same. (Former depreciation charges assumed to
be one-half of current charges have been deducted from "cost of sales" in Table 8-9.)
Non-fixed assets (current and non-current) which are shown in Table 8-9 are com-
bined with new plant capital requirements to derive the new capitalization, the
basis for the profitability analysis. The same ratios (profit-after-tax divided
by total plant capital) in Table 8-9 will be assumed for the new SIP plants.
Combining these assumptions to calculate revised production costs determines the
necessary sales prices for each model plant to sustain historic profitability,
measured by ROA, for the industry.
The respective higher sales prices in Table 8-10 relative to the uniform
sales price of $340 in Table 8-9 implies small plants are unable to enter into
a competitive industry where captive plants and large jobbers prevail. However,
a small plant specializing in non-competitive castings or those orders rejected
by larger producers, may possibly simulate the type of performance shown in
Table 8-10. In the absence of real information on prices and profitability,
constructing a model plant(s) in this fashion to determine sale prices is the
only available methodology.
The next step is to use the respective sales prices as shown in Table 8-10
to calculate cost structures for new plant configurations incorporating more
8-32
-------
TABLE 8-9. HISTORICAL FINANCIAL PERFORMANCE FOR IRON FOUNDRIES
oo
to
CJ
Melt Rate, TPH
Annual Hours of Melting m
Shipments of Castings, TPYu;
Jncome Statement
Sales (= $340 per Ton)
Cost of Sales
Gross Profit
Administrative, Interest
Costs
Profit Before Tax,,x
Profit After Taxu;
Balance Sheet
Non-Fixed Assets
Fixed Assets
Total Assets
Current Liabilities
Long Term Debt
Net Worth
Total Liabilities
Selected Financial Ratios
a) Cost/Sales * Sales
b) Profit after Tax * Total Assets
Model Plant A
4
1,600
3,840
$1,300,000
1,070,000
237,000
195,000
42,000
27,600
337,000
240,000
577,000
218,000
122,000
237,000
577,000
0.82
0.048
Model Plant B
10
1,920
11,520
$3,928,000
3,134,000
790,000
522,000
267,000
144,600
1,241,000
763,000
2,004,000
629,000
273,000
1,102,000
2,004,000
0.80
0.072
Model Plant C
25
2,880
43,200
$14,730,000
11,830,000
2,900,000
1,708,000
1,193,000
626,000
5,140,000
2,954,000
8,094,000
2,032,000
1,408,000
4,654,000
8,094,000
0.80
0.077
(1) Assumes a yield for marketable casting of 60% of annual melt rate.
(2) Derived on basis of Federal tax schedules: 25% of 1st $25,000; 48% on profits more than $25,000.
SOURCE: Battelle Memorial Institute and Robert Morris Associates Annual Statement Studies. 1974 edition.
-------
TABLE 8-10. DERIVED COST STRUCTURES FOR NEW PLANTS
MEETING STATE REGULATIONS
Model Plant A
Model Plant B
Model Plant C
00
co
-(2)
Melt Rate, TPH
Annual Hours of Melting
Shipments, TPY
Required Sales Price
Income Statement
Sales m
Cost of Sales11'
Depreciation/New Plantv
Administrative, interest costs
Interest/New Plant^ ;
Profit Before Tax.v
Profit After Tax^ '
Balance Sheet
Non-Fixed Assets
Fixed Assets
Total Assets
Profit After Tax *• Total Assets
$1
1
1
$1
4
1600
3840
$404
,551 ,000
,017,000
107,000
195,000
64,000
168,000
93,000
337,000
,600,000
,937,000
0.048
10
1920
11,520
$374
$4,305,000
3,051,000
165,000
522,000
65,000
502,000
267,000
1 ,241 ,000
2,470,000
$3,711,000
0.072
25
2880
43,200
$357
$15,423,000
11,647,000
365,000
1,708,000
145,000
1,558,000
816,000
5,140,000
5,460,000
$10,600,000
0.077
(1)
(2)
(3)
(4)
Cost of Sales excluding depreciatbn. Represents variable costs for existing industry (Table 8-9);
assume the excluded depreciation charges for old plant are 50 per cent of depreciation charges of
a new plant (Footnote 2)
Depreciation for new plant calculated on straight-line basis, 15 years.
Interest costs based on interest rate of 12 percent. Debt is assumed to be 50 percent of new plant
capital for 4 TPH plant; 33-1/3 percent for 10 TPH and 25 TPH facilities.
Federal tax schedule: 25 percent tax on 1st $25,000 profits; 48 percent on profits more than $25,000.
-------
stringent controls. This is consistent with the rationale of a SOP source
competing with a new SIP source. Also the total plant capital for each
configuration must be derived. Plant configurations superimposing the
canopy hood for one example and the scrap pre-heater for another were
selected for analysis. Revised profit and the return-on-total capital
calculated are presented in Table 8-11.
Referring to Table 8-11, one observes the canopy hood system on the
4 TPH plant almost obliterates all profits for the plant owner competing
with a plant in compliance with the SIP. On the 10 TPH facility, the
canopy hood system reduces profitability (ROA) by 44 per cent for the
similar situation. Impacts of these magnitudes appear to be significant
and are in EPA judgment considered to be prohibitive for a new source
requiring this control system. In order to maintain the profitability
level of the SIP plant, the new 4 TPH plant employing the canopy hood
would need a price of $461, an increase of $57 or 14. per cent. The
10 TPH plant would need a price of $398, an increase of $28 per ton,
or 6.4 per cent.
The plant configuration including the scrap pre-heater would incur
a loss in p ^fitability, as measured by ROA, of about 8 to 9 per cent
for either size plant. This does not appear significant. Also, the
annualized costs for the pre-heater do not include any credits for
saving in raw material costs. As mentioned earlier, raw material
savings would make this plant competitive with the plant configuration
utilizing the "side-draft hood" only control system (SIP plant).
The subject of capital availability is also important in economic
impact analysis because it is another decision tool, which may refute
8-35
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TABLE 8-11. PROFITABILITY IMPACT ANALYSIS FOR SELECTED CONTROL SYSTEMS
FOR 4 AND 10 TPH PLANTS
(All values in $ per ton, unless stated otherwise)
00
i
GO
en
Sales,
Baseline Production Costs, »,%
Incremental Control Costs * '
Profit Before Tax,
Profit After Tax (PAT)
Total Assets
Profit * Total Assets (ROA), %
Decline in ROA, %
Price to Maintain ROA
Price Increase to Maintain ROA
Plant
With
SIP Controls
404
360
—
44
24
504
4.8
—
404
, % -
Plant:
Side -Draft
Scrap Pre-heater
404
360
6
38
21.3
527
4.0
8.4
412
1.9
Plant:
Canopy
Hood
404
360
40
3
2.3
693
0.3
94.
461
14.1
Plant
With
SIP Controls
374
330
—
44
23.
322
7.2
~
374
~
Plant:
Side-Draft
Scrap Pre-heater
374
330
3
41
21.8
331
6.6
9.1
378
1.0
Plant:
Canopy
Hood
374
330
15
29
15.6
389
4.0
44.
398
6.4
(1)
Annualized Control Costs for Plant (with specific control system) over plant meeting SIP.
-------
a seemingly profitable project. This is so because heavy capital intensive
projects may be turned down due to limitations on a firm's capital budget.
In this analysis then, the capital requirements for the five possible
plant configurations, or control options, discussed in Section 8.2 are
summarized in Table 8-12. Assuming the baseline control option as the
"side-draft hood only" system, total plant capital for each of the
remaining configurations are compared with the baseline system. Table 8-12
shows the 4 TPH plant with the canopy hood requires 45 per cent more plant
capital than the same size of plant for the baseline. Similarly, the
10 TPH plant with the canopy hood requires 31 per cent more capital than
its respective baseline plant. The capital requirements of these
magnitudes are considered in EPA judgment to be so prohibitive to preclude
construction of these plants.
The capital requirements for the scrap processing techniques increase
baseline capital by approximately 6-10 per cent. No conclusion of signi-
ficant impact can be drawn on these plant configurations that utilize
scrap processing. Reinforcing an earlier comment on clean scrap, the
plant purchasing clean scrap would have no increased capital requirements
above the baseline for this option.
8.4.1.4 Impact on Imports
— 12
In their report to EPA, Battelle had the following to say about imports.
"The value of the exports of gray, ductile, and malleable iron castings and
steel castings was about 2 percent of the value of all domestic shipments of
these castings from 1967 through the present, and about the same level is
projected through 1975. The value of the imports of ferrous castings has
8-37
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TABLE 8-12. CAPITAL REQUIREMENTS FOR FIVE CONTROL OPTIONS ON SMALL FOUNDRIES, LESS THAN 25 TPH MELT CAPACITY
Control Option
CanoD.v
Hood
MODEL PLANT A
(Melt Rate, 4 TPH)
Side Draft Side Draft
Side Draft With With
With Scrap Scrap
Pre-heater Degreasinq Briquetting
Side Draft
Only
MODEL PLANT B
(Melt Rate, 10 TPH)
Side Draft Side Draft
Side Draft With With
Canopy With Scrap Scrap
Hood Pre-heater Degreasing Briquetting
Side Draft
Only
Basic Melting + Auxiliary 1320
Equipment Capital, $1000
CD
Total Plant Capital with
Air Pollution Control,
$1000
oc Relative Magnitud
Baseline, % u'
2320
145
1410
1690
106
1430
1710
107
1470
1750
109
1320
1600
100
2100
3240
131
2200
2570
104
2210
2580
104
2250
2620
106
2100
2470
100
0)
Baseline control option can be assumed to be that required for complaince with typical State Regulation.
-------
been slightly less than 1 percent of the value of all domestic shipments
during the same period of time. The value of the imports of ferrous castings
is expected to increase to about 110 million dollars by 1980, and the value
of the exports is expected to increase to about 235 million dollars by 1980.
The increase in value of the exports and imports is expected to be about
proportional to the increase in value of all domestic shipments. No increase
in the percentage of imports is expected.
The cost of importing rough castings is estimated to be about 3.5
to 4.5 cents per pound (dock to dock), with an additional cost of 1.5 to 2
cents per pound to ship overland by truck from a New York port of entry to
an inland market such as Columbus, Ohio. Thus, the total cost of importing
rough castings to inland markets is about 5.0 to 6.5 cents per pound. These
data were derived from the following shipping information:
Shipping Cost of Imported Castings,
dollars per ton
Origin and Destination
.(a)
Dock to DOCK
FinishedRough
Castings Castings
Overland by
Truck
(Rough Castings)
Europe to East Coasr
(a)
Europe to West Coast
.(b)
Japan to We*-*, Coastv
Japan to East Coast
Inland, New York to
Columbus, Ohio
(b)
105
135
110
125
70
90
75
85
38.60
(c)
(^United States Lines.
' 'American President Lines.
'c'National Motor Freight classification.
8-39
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The shipping costs for importing rough castings will add about 3.5 to
6.5 cents per pound to the FOB price of imported castings, depending on
the source and destination."
The highest incremental price increase for any control system discussed
in Section 8.2 and 8.4--canopy hood for the 4 TPH plant—amounted to approx-
imately $60 per ton, or 3.0 cents per pound. The range of shipping costs
cited above well exceed the maximum incremental control costs. Therefore,
one can conclude that the cost of the best available control systems will
not singularly effect an increase in imports of castings.
8.5 SOCIO-ECONOMIC IMPACT
8.5.1 Introduction
The purpose of this section is to address those socio-economic impacts
that might result from the promulgation of standards based on the recommendation
of one of the several control systems discussed in previous sections. With
regard to electric arc furnaces, there are three areas of concern where these
impacts are addressed:
(1) market dislocations in those product areas where key castings may
be vital in achieving national goals (i.e., Project Independence)
(2) denial of small businesses to enter or expand markets
(3) EPA guidelines for screening inflationary impacts.
Other issues, such as foreign trade and employment will not be
affected in the aggregate. Transportation costs are a barrier to imports.
Total employment in the industry has been increasing and will not be affected
by the standards because the impact appears to be negligible for large
sources. Substitutes in technology and materials are available. Tech-
nological substitutes are cupolas and electric induction furnaces. Plastics
8-40
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and steel castings and forgings compete with finished iron casting products
in many areas. Consequently, the only issues to be discussed are those three
points enumerated above. Now each will be discussed individually.
8.5.2 Market Dislocations
During recent years, 1971 in particular, the iron foundry industry has
gone through a difficult period of a business recession, raw material
shortages, and compliance with environmental and OSHA regulations. Table 8-13
shows the number of closings, expansions, and new facilities over the past seven
years. The number of closings has exceeded new plants by some 360 to 56.
According to industry spokesmen, this attrition has been mostly in small
firms where shortage of capital, loss of interest in maintaining the
business, loss of markets, and profits squeeze have accounted for these
closures.
The one area of the foundry business that has been affected during this
difficult period has been the limited production or specialty castings product
Table 8-13. CHANGES AND EXPANSIONS IN FOUNDRY
PLANTS OF ALL TYPES
Year
1968
1969
1970
1971
1972
1973
1974(a)
Closings
7
27
39
159
89
23
16
Expansions
N.A.
11
4
3
6
18
23_
New
N.A.
8
9
7
5
8
li
8-41
-------
Totals 1968-
1974 360 65 56
(a) Data through September, 1974.
(b) N.A. = not available.
SOURCE: Battelle Columbus.
area. The jobbing foundries who produce the small number of specialty
castings are generally those that melt raw scrap in small furnaces ranging
in size from 1/2 TPH to 6 TPH only for a few hours a week. The nature of the
jobbing foundry affords the flexibility to cast a variety of patterns. Captive
plants are set up with automatic molding and coring equipment to produce a large
volume of limited patterns and are inflexible to frequent pattern changes.
As shown in Sections 8.2 and 8.4, the cost per ton for any control
system is disproportionately higher for the small furnaces. Hence, setting
a standard based on the canopy hood design will prevent construction of new
electric arc furnaces less than 25 tons per hour melt. As for as the scrap
processing techniques are concerned, no evidence is available to indicate
that these requirements will present any problems. Although these tech-
niques increase plant capital investment, plants utilizing these techniques
can be competitive. If the foundry doesn't process the scrap, the scrap
dealer may find processing of scrap profitable. Hence, promulgation of
standards which necessitate scrap processing should not create any adverse
socio-economic and inflationary impacts.
With regard to critical castings that may be important in the economy
13
for the immediate future, Battelle says that the existing foundry industry
8-42
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has sufficient melt capacity in the jobbing foundry sector to gear up to
increased demands. The reason for this is that the large corporations in
auto manufacture, in heavy industrial and agricultural tools production
have been building their own captive foundries in most recent years. These
corporations formerly relied quite extensively on jobbing foundries. As
a result, the latter, many of which are large, will be looking for new
business once new markets are available.
According to a Department of Commerce paper 14, production of existing
and medium sized jobbing foundries could be increased substantially by
adding additional shifts. Lack of trained manpower is a problem and may be
a constraint to expansion. In spite of these reasons, which suggest low growth
in the way of additional melt capacity (overall in the foundry industry), a
standard which would require extreme investment costs for controls, such as the
canopy hood, does limit the flexibility for an industry to replace old equipment.
8.5.3 Small Businesses
The SBA (Small Business Administration) defines any foundry with
less than 500 employees as a small business. In the analysis of the foundry
industry, only 166 foundries out of a total 1496 iron foundries employed over
250 persons ' i 1973. The number of iron foundries with more than 500 employees
is not known, but it is probably about 100. If 100 foundries employ over 500
people, then about 93 percent of the iron foundries would be classed as small
businesses. Each of the 100 foundries that employ more than 500 people would
be expected to have a melting rate of more than 50 tons per hour. Consequently,
the model plants discussed in Sections 8.2 and 8.4 would be classified as small
businesses if such a brand new source (an entire new plant) were built.
Even where such furnaces might constitute expansion, that company may
possibly be a small business. Jobbing foundries are much more likely to be
8-43
-------
small businesses than captive foundries. However, not all jobbing foundries
are small businesses; a handful are public corporations listed on the major
stock exchanges.
Similarly as discussed in Section 8.5.2, the impact of a standard requiring
the canopy hood will discriminate against small businesses. The canopy hood
is a highly capital-intensive control option; and small businesses usually have
the most difficulty in acquiring capital. In accordance with the discussion
in Section 8.4, particularly on capital availability, the requirement of scrap
processing is unlikely to preclude the small business from building the 4 TPH
plant. Savings in raw material costs or increased plant output can offset
fixed costs for such techniques. An alternative to scrap processing by the
small business foundry is the purchase of clean scrap from the scrap dealer.
8.5.3 EPA Guidelines-Screening Inflationary Impacts
The Agency's interim guidelines for preparation of an inflationary
impact statement (IIS) are that an IIS must be prepared if one or more
of the following conditions are met:
(1) The action results in a total 5-year investment cost of $100
million or more,
(2) The action results in a fifth year annualized cost of $50
million or more,
(3) The action results in a price increase of 5 per cent or more.
Of the three guidelines, only the last one would be exceeded for the
following situations: a) Canopy hood system/4 TPH, price increase of 14 per
cent, b) Canopy hood system/ 10 TPH, price increase of 6.4 per cent (see
Table 8-11). Guideline No. 1 is quickly dismissed because an estimate of
capital derived by multiplying the number of projected 20 new furnaces over
8-44
-------
a five-year period by some $800,000 incremental capital for a canopy hood
system amounts to only $16 million. Guideline No. 2 is also easily dismissed
because the total incremental annualized costs would not exceed $3.5 million
in the fifth year (20 furnaces x $175,000).
8-45
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REFERENCES FOR CHAPTER 8
1. Private communication, telephone call from F. L. Bunyard, OAQPS, EPA,
to Jim Brown, Union Carbide, October 31, 1975.
2. "Foundry Statistics", Foundry Management and Technology, 103 (2), 44,
February, 1975.
3. Private communication from Battelle to Malleable Founders Society,
Rocky River, Ohio, February 1975.
4. Current Industrial Reports, U. S. Department of Commerce, Bureau of the
Census.
5. U. S. Industrial 1975 Outlook, U. S. Department of Commerce, Domestic
and International Business Administration, 1974.
6. Op cit, Reference 5.
7. "Air Pollution Control Technology and Costs for Electric Arc Furnaces
in Gray Iron Foundries", by Industrial Gas Cleaning Institute, EPA
Contract No. 68-02-1473, Task No. 1, December 16, 1974.
8. "Economic Impact of the Proposed New Source Performance Standards upon
Construction of Arc Furnaces in the Gray Iron Foundry Industry", by
Battene-Columbus Laboratories, EPA Contract No. 68-02-1323, Task No. 28,
August 29, 1975.
9. Private communication, letter from T. J. Kearney, Detrex Chemical Industries,
Inc., to N. T. Georqieff, OAOPS, EPA, July 24, 1975.
10. Private communication, telephone call from N. T. Georqieff, OAOPS, EPA,
to A. C. Schulz, W. F. Tyler, Inc., September 18, 1975.
11. Op cit, Reference 7.
12. Op cit, Reference 7.
13. Op cit, Reference 7.
14. "Shortage of Casting - Potential Impact on Project Independence", Bureau
of Domestic Commerce, U. S. Department of Commerce, January 20, 1975.
8-46
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9. TECHNICAL STUDIES TO DEFINE PERFORMANCE
OF BEST SYSTEMS OF EMISSION REDUCTION
9.1 SELECTION OF SOURCE FOR CONTROL
The Committee on Public Works of the U.S. Senate included gray iron
foundries in a list of industries which are significant sources of air
pollution in two or more States in a Senate Report (No. 91-63) titled
"National Emission Standard Study" dated March, 1970. Furthermore, in
September of the same year foundries were listed as a source for which
standards of performance would be developed in the National Air Quality
Standards Act of 1970 (Senate Committee Report No. 91-1196).
Within the foundry there are a number of sources of air pollution. The
dominant source, however, is the furnace, and particularly electric-arc
furnaces. The major pollutant from electric-arc furnaces is particulates,
a pollutant for which ambient air quality standards were promulgated in
40 CFR 5°. In addition to the deleterous health effect, particulates emis-
sions also have welfare effects such as soiling, reduction of visibility,
and general nuisance. Electric-arc furnaces were selected as the first
candidate for standards in the industry based on estimates that these furnace
emit more dust per ton of product than do cupola or induction furnaces.
Furthermore, arc furnaces appear to haye the greatest growth rate of the three
furnace processes. The projected growth rate as of 1974 is as follows:
a) Arc furnaces - 400 tons per hour, based on 6000 to 7000 hours
per year operating time
9-1
-------
b) Induction furnaces - 370 tons per hour based on 5000 hours per
year operating time
c) Cupolas - 160 tons per hour based on 5000 hours per year operating
time
Obviously, based on the tonnage of gray iron produced, the arc furnace was
the most favored equipment for melting, although the number of such furnaces
to be installed is certainly several times less than the one for induction
furnaces. Another factor which influenced the decision to investigate arc
furnaces is that they are equipped with good control devices whereas few induction
furnaces are equipped with control equipment. The reason so few induction fur-
naces have controls is that their inherent relatively low emissions have been
considered primarily a problem of the employees work area rather than an air
pollution problem. There are several other sources of air pollutants in a
gray iron foundry. Chapter 3.2 presents information on the other sources.
The contribution to the nationwide pollutant emissions of electric-arc
furnaces is small, however, since most of these facilities are located in
urban areas, emissions from foundries are of greater concern than would be
reflected by a casual comparison with other sources on a nationwide basis.
9-2
-------
9.2 SELECTION OF POLLUTANTS AND AFFECTED FACILITIES
9.2.1 Pollutants.
In addition to participates, emissions from gray iron foundries include
carbon monoxide, hydrocarbons, nitrogen oxides, and sulfur oxides. Particu-
lates emissions from an uncontrolled furnace are estimated at 10 to 30 pounds
per ton. In addition to hydrocarbons and metal particles, the particulate
includes silica (sand from foundry castings) the causitive agent of silicosis.
Significant quantities of carbon monoxide (CO) may also be emitted. If con-
trolled, emissions of carbon monoxide are 1.1 pounds per ton of gray iron
produced (based on EPA's test at Plant A). Assuming this emission rate for
production of all gray iron from electric arc furnaces, the CO emissions would
be 0.209 percent of the emissions of this pollutant from the metals production
industry in the U. S. (based on 7.1 million tons per year total CO emissions
in 1973 1 and 23.2 million tons per year of electric-arc-furnace, gray-iron
production in 1973. Near very large shops, the maximum ground level concen-
tration (worst meteorological conditions) of CO may exceed the air quality
standard of 40 mg/nr* (one hour average). The only known technique to control
CO emissions is to supply enough air to the exit gases leaving the furnace
convert che CO to C02 to the control device. The dilution effect of the
additional air, however, increases the particulate emissions since most con-
trol devices tend to maintain a constant outlet concentration. Data provided
by industry tests carried out by EPA on emissions of nitrogen oxides indicates
they are less than 0.1 pounds per ton of gray iron produced (Ib/ton). Emis-
sions of sulfur oxides range from 0.01 to 0.5 Ib/ton. The industry now makes
attempts to minimize the emissions of these pollutants. Because of the low
emission levels and the absence of demonstrated emission control techniques,
standards for these two pollutants have not been considered.
9-3
-------
9.2.2 Affected Facilities.
The electric-arc furnace is overwhelmingly the major emitter of air
pollution in an electric-arc furnace shop. There are, however, other
polluting facilities or activities which include:
1. Charging of scrap into the bucket
2. Handling of scrap
3. Pouring of molten iron from transfer ladle into holding furnaces
or teeming ladles.
Since most of the pollutants emitted from a melting shop are from the
electric-arc production furnaces, they were selected as the initial affected
facility. Although the others may 6e candidates for standards of perfor-
mance in the future, they are not now considered because of their relative
smaller contribution to the total emissions from a melting shop. An
auxiliary facility for which limitations are recommended is the equipment
for on-site handling of dust collected by the air pollution control device.
Although this is usually a small source, this will assure proper diligence
in disposal of the solid waste since there is a potential for large quantities
of dust to become airborne if it is handled improperly. Although the furnace
is the only affected facility within a shop (the building that houses the
furnaces), the recommended standards apply to one emission point other than
those directly connected to the furnace, A portion of the emissions from a
furnace can evolve into the shop atmosphere and escape through the monitor
on the roof of the shop, A standard applicable only to the discharge of the
control device would not limit these emissions. Consequently, a limitation
on the visibility of emi.ssj'ons from the shop is a necessary part of a restric-
tion on emissions from a foundry.
9-4
-------
9.3 SELECTION OF THE BEST SYSTEM OF EMISSION REDUCTION CONSIDERING COST
9.3.1 General
Without ai.r pollution control equipment, emissions from a furnace
amount to about 10 to 30 pounds of partial!ate per ton of gray iron produced.
These emissions are created during three phases of the furnace's operation;
charging, melting and tapping. Emissions during charging have the largest
instantaneous levels but fortunately only last for a few minutes. These
high levels are a direct consequence of the contamination of the scrap with
oil (which is normally adhered to machine shop waste but may be contained
in scrap such as engine crankcases and automobile shock absorbers). It has
been estimated that up to 20 percent of the oil contained in the charge may
burn during the relatively brief time the furnace is open to accept the
scrap.
Although the potential for emissions exists during the melt-down and
refining portion of the heat cycle, almost all foundry electric arc furnaces
are equipped with some type of fume capture system mounted on the roof of
the furnace. Emissions from several furnaces so equipped were measured as
a part of this study. Results of the tests are reported elsewhere in this
document.
Unlike similar electric arc furnaces used for manufacturing steel, the
emissions during the tapping operation from a foundry furnace are relatively
small. The major difference in the two processes is the temperature of the
melt during the tap. The lower temperature of the iron (1544° vs 1700°C) has a
dampening effect on the melt's tendency to form airborne parti oilates.
In addition to particulate, foundries also emit limited amounts of
carbon monoxide, nitrogen oxides and sulfur oxides. Carbon monoxide is formed
9-5
-------
by oxidation of the carbon within the melt (or during its addition}. The
nitrogen oxides are formed by the heat of the arc and the sulfur oxides are
a consequence of the sulfur content of the oil included in the oily scrap
and electrodes.
Capture of emissions during the melt and refining portion of a heat
cycle has been general practice in the industry for a number of years. For
convenience and minimum operating cost, the capture devices have been closely
mounted on the lid of the furnace to minimize the volume of gas which must
subsequently be treated. Historically, capture of these emissions has been
effected by a side-draft hood, a furnace hood or a direct furnace evacuation
system. All, when properly operated, will continue as acceptable methods
of precluding emissions during meltdown and refining.
The more difficult problem of containing emissions from furnaces is
during the period when the furnace lid is rotated away from the furnace to
permit raw materials to be charged. Rotation of the lid carries the traditional
capture device along with it, thereby rendering it ineffective.
Unfortunately, this period when the capture device is inoperative is
the very time when the highest instantaneous emissions may be released from
the furnace area. The quantity of these emissions tend to be directly pro-
portional to the amount of contamination, especially combustable material,
in the scrap.
The load of raw materials is contained in a charging bucket which is
suspended from a crane and centered above the open furnace. Often if there
is oil present in the scrap, heat from the furnace will Ignite it even before
it is dropped into the furnace. It has been reported that up to 20 percent of
the oil may burn before the furnace lid is moved back into position. It is
9-6
-------
elimination of these emissions, perhaps the largest instantaneous pollution
release during the entire cycle, which presents the most significant problem.
There are several approaches that an operator may take to preclude the
charging emissions.
9.3.2 Canopy Hood
The canopy hood is one possible means of controlling emissions during
charging. Additional advantages of the canopy hood are its ability to capture
emissions during tapping, furnace upset conditions and, through dilution with
entrained air, to reduce the heat load which might otherwise endanger the
bags in the filter. Its disadvantage is the rather large volume of air that
has to be in to assure good capture of the furnace fumes. These
requisite large volumes of air increase the size of the control device (and
power requirements) which result in higher costs (both first and operating).
Also, canopy hoods have the disadvantage that their efficiency is seriously
affected by wind currents within the melting shop. Although the canopy hood
is essential for only a couple of minutes each heat, very often, especially
in summer, its effectiveness is reduced by opening of shop doors (usual
practice, even in new foundries) resulting in crosscurrents of air within
the shop which divert the vertical rise of the fumes and cause them to
circumvent the canopy hood.
9.3.3 Enclosures
Enclosures are being installed on new arc furnace installations in the
steel industry. Enclosures protect the rising emission plumes during
charging from the influence of air crosscurrents in the building. The
enclosure walls are built of light metal to permit easy replacement if
damaged fay the charging bucket or the hot metal ladle. Two types are being
9-7
-------
built. The first requires a conventional overhead canopy hood, but, because
it acts as a chimney to direct the fume to the canopy, significantly reduces
the gas volume which, must be withdrawn through the canopy to effect capture.
This type incorporates a special hood above the tapping ladle to assist in
controlling tapping fumes. This enclosure also requires a furnace evacuation
system, which permits better control of the atmosphere around the furnace,
i.e. during meltdown and refining. Operators can easily perform minor
activities around the furnace, such as slagging, adjustment of the chemistry
of the melt or take samples.
The second type of enclosure has the advantage that it dispenses with
both the canopy hood and furnace evacuation and requires only 40 to 50% of
the gas volume of a conventional canopy hood. It is large enough to permit
tapping to take place within the enclosure hence it captures all tapping
fumes. One disadvantage of this system is that some emissions will escape
when the side doors are opened to remove the charging bucket.
9.3.4 Hooded Charging Buckets
The hooded scrap bucket offers the advantage of withdrawing emissions
during charging into the same (conventional) dust control device that cleanses
the emissions during meltdown and refining. If emissions are excessive during
charging, the fan may not be adequate to contain all emissions. Another
disadvantage of this technique is that the charging bucket must be taller
to allow space for the bottom of the bucket to open. This might require a
higher melt shop, therefore increased building costs. Also during the period
of time between removal of the bucket and swinging of the roof back onto the
furnace, some emissions will likely escape. Any hood suspended from the
crane would have the same disadvantage as the scrap bucket-ho.od. In addition,
9-8
-------
both of these techniques would be of no value in reducing emissions during
upset conditions or tapping. Finally, the operator will not permit a
prolonged stay of the hooded charge bucket above the furnace because he
cannot insert the electrodes so the heat eycle is prolonged and production
decreases.
9.3.5 Pretreatment
Since the bulk of the emissions during the charging operation are a
consequence of the organic content of the charge, removal of that material
prior to charging will eliminate the need for air pollution control during
charging. Several systems to remove this material are available.
9.3.5.1 Preheaters -
Preheaters eliminate the oil, grease, water, some dirt, and other
combustibles which adhere to the scrap. This eliminates the need for a
canopy hood. Furthermore, since they are generally fossil fuel fired,
energy savings can result if the scrap is heated to 650°C and immediately
introduced to the furnace. The dust control devices for a preheater are
very small (gas volumes of 350 dry standard cubic feet per minute per ton
of product) compared to those required by a canopy hood (10,000 to 40,000
actual eikic feet per minute per ton). Some designs utilize the same
control device for the preheater and the side draft hood. Fumes from a
preheater are coarser and should be easier to filter from the gas stream
than those during melting and refining. Preheaters discussed in this
document have the disadvantage that they cannot handle turnings> .swarf, and
borings. Some preheaters need control devices and after burners.
9.3.5.2 Deqreasing -
Degreasing is another way to remove organic matter that would otherwise
contribute to charging emissions and eliminate the need for a canopy hood.
9-9
-------
The pri,me disadvantage of the degreaser is that it requires a uniform scrapf
such as engine blocks, smaller motors, or turnings and borings. For example,
some degreasers are made to process only turnings and borings. This might
mean that to process coarser scrap a second degreaser must be installed.
The solvents necessary for removal of the grease and oil are increasingly
difficult to obtain. The space requirements for a degreaser are moderate;
degreasing can be carried out either by the large scrap processors, or large
foundries may perform their own degreasing.
9.3.5.3 Briguetting -
Briquetting can result in complete removal of oil and grease, if the
scrap material is coincidentally heated in a reducing atmosphere. This
document deals only with briquettes produced by single compacting, considered
equivalent in reducing emissions to the installation of a canopy hood or
enclosures. The oil and grease contents of such briquettes will range from
1 to 2% depending on the level in the original scrap.. Another advantage of
briquetting is that alloying agents such as ferrosilicon and carbon may be
added at the briquetting machine. Also the size of the furnace can be reduced
in proportion to the reduced bulk of the briquettes. Power consumption is
also reduced, and melt rate increased.
9.3.5.4 Automated Charging Systems -
Automated charging via the fourth hole elbow has the disadvantage of
charging the scrap material somewhat slower thus extending the processing
time of the furnace. Chutes connected to a special opening in the furnace
are better inasmuch as they allow for charging the furnace continuously (or
in batches) but do not obstruct the withdrawing of the gases from the furnace
as might be the case through the elbow. Another disadvantage of such charging
9-10
-------
techniques is the need for properly fragmentized scrap, Although it is
possible to obtain such scrap, it is more expensive and the operation of
a shredder is economical only in scrap processing yards or very large
foundries. The small foundry has to depend on its supplier.
As mentioned earlier pellets produced from iron ores by reduction
have been tried in cupolas. In electric furnaces producing steel they often
represent the largest part of the charge. Interest in pellets as raw
material is mounting. Mixed with good clean scrap this material can reduce
charging emissions, regardless of how it is introduced into the furnace.
Pig iron, if available, is one material which when charged into a furnace
will cause practically no emissions.
One automated charging technique, shown in Figure 6.6, may eliminate
upset conditions during which fumes leave the furnace through openings such
as electrode holes and the pouring spout. By removing the flammables from
the dirty scrap, interruptions in the power supply to the electrodes don't
produce excessive emissions. The most important advantage of this technique
is the saving in power for the production of the molten metal. The disadvantage
is the requirement for fossil fuel to fire the rotary drum (kiln). This
disadvantage, however, is offset by savings in energy for melting of the
metal charge.
The first such installation has operated continuously for three years
in perennially energy-starved Italy. Another advantage of the installation
is that one drum (kiln) can service two furnaces by swinging the drum to the
next furnace when the first furnace is ready for refining. One disadvantage
2
is the higher carbon monoxide emissions reported , about 4%, These
experimental data are from a period when the plant's primary purpose was
9-11
-------
increasing the production of the arc furnace, Besides the furnace produces
steel, in which case the purpose is to remove as much of the carbon as
possible. More recent experimental data wi.ll be available to EPA prior to
which attempts were made to reduce such emissions. The Kemmetmueller concept
seems to take care of this deficiency by introducing air into the furnace
by means of two-satellite fans located in the middle of the drum. This way
if the oxygen level is zero as reported , , the fans will supply the necessary
oxygen for the combustion of the carbon monoxide. No economic data, i.e.
first procurement costs, are available, therefore, they are not included in
this document. It suffices to repeat, however, that the operating conditions
result in high savings, about 50% reduction in the electric energy require-
ments and in speeding up the melting process, i.e. increasing production per
furnace.
9.3.6 Alternative Control Systems
The affected facility selected for control within the iron foundry
is the arc furnace. The options for capture of the two phases of emissions
from this source are listed below in Table 9-1. Although it appears that
any of the three conventional control devices, venturi scrubbers, electro-
static precipitators, and fabric filters can be used, the overwhelming
preponderance of fabric filters now in use argues that they will continue
to be the probable favorite.
Table 9-1
Phases Option
Charging Canopy Hood
Hooded Charge Bucket
Enclosure
Preheating
Briquetting
Degreasing
Automatic Charging
Hood Charging
9-12
-------
Melting and Refining Enclosure
Side Draft
Roof Hood
Direct Furnace Evacuation
Both Phases Canopy Hood + Side Draft
Side Draft + Preheating
Side Draft + Degreasing
Side Draft + Briquetting
Side Draft + Automatic Charging
Since side draft hoods, roof hoods, and direct furnace evacuation systems
(as well as occassional combinations of these) now coexist in the industry,
we've assumed all are economically competitive and have not performed separate
economic analyses for each. Similarly, the cost of enclosure systems has
not been investigated in detail because of their relatively late arrival in
the industry and the absence of data on its effectiveness.
Finally, automatic charging, although a viable alternative, presently
used in the steel industry, will probably not be used in the future because
of a relatively new process which simultaneously automatically charges and
preheats. (See Figure 6.6.) Consequently, no attempt has been made to
evaluate automatic charging alone as a separate alternative.
9.3.7 Background
Several other remarks are essential to placing the selection of the
best system of reduction into perspective.
1. Induction furnaces using clean scrap or scrap pretreatment are now
competitive with electric arc furnaces with currently used air pollution
control systems.
2. The necessity for a furnace to incorporate any system to limit
emissions during charging depends wholly on the quality of the scrap. A
9-13
-------
furnace that processes a scrap with low organic contamination will not
require any equipment other than the side draft system Cor equivalent)
whereas a dirty raw material will require a system for capturing charging
emissions.
3. It is difficult to estimate the incremental cost to the owner of
limitation based on best technology (.the impact of which will be to primarily
force elimination of charging emissions) beyond that required by a State
standard.
The latter two items are dramatically illustrated in Figure 9.1. Line
A represents a level of charging emissions (or quality of scrap) below
which no control equipment would be required by either a State or a Federal
regulation, hence the economic impact of the Federal regulation is zero.
Line B represents that level of emissions above which both State and Federal
regulations would require control of the charging emissions and again the
economic impact of the Federal regulation is zero.
Unfortunately, not only can neither A nor B be defined in absolute
terms, they will vary from State to State. Furthermore, line B may not
exist at some plants for the following reasons.
1. Although most State regulations for particulates are of the process
weight type, it is possible that the contribution of the charging emissions
(which escape the furnace into a building as a fugitive emission) may not
be included in the enforcement investigation. (Since they cannot be measured,
only estimates of the emission factor can be used.)
2. Even though the State's visible emission limitation might normally
force control of the charging emissions, the configuration of the building
and ventilation system might sufficiently dilute the plume to allow it to
meet the limitation.
9-14
-------
to
o
>—>
GO
CD
I
INCREMENTAL COST = 0
INCREMENTAL COST = 0
OIL CONTENT OF SCRAP
Figure 9.1 Incremental cost of a Federal Standard (which
requires control of charging emissions) beyond
a "typical" State Regulation.
9-15
-------
As a consequence of the above, the impact of a federal standard will
not be uniform across the industry, For comparison purposes> the cost
analysis presumes that State regulations will require only the equivalent
of a side draft hood regardless of the quality of the scrap.
9.3.8 Data
Table 9.2 presents a summary of the cost resulting from application
of alternative systems for the control of emissions from furnaces of
different size.
The only control system that clearly seems unreasonable is a canopy
hood-side draft combination on small (.4 and 10 tons per hour melt rate)
furnaces where the additional capital costs exceed half the cost of the
basic melting and auxiliary equipment. To maintain profitability, these
smaller plants would have to increase the price of their products by $30
to $60 per ton.
On the other hand, none of the pretreating processes seem unreasonable.
This conclusion is readily confirmed by experience of melters which use
induction furnaces. They have, out of necessity, historically absorbed the
cost of pretreating, yet remained competitive with the arc furnace. With
the exception of the briquettes used with a very small furnace, none of
these processes increase the base case (side draft hood) by more than 10
percent. Incremental capital requirements of this magnitude are not
considered to be significant enough to prohibit plant construction. Given
a wide choise of available processing options, the foundryman can select
any one technique that will be compatible with his raw material supply and
allow hi,m to be competitive with the plants which are in compliance with
the State Implementation Plans. In fact, savings in the cost of raw material
($ 9 to 20/ton) may more than offset processing costs necessary to produce
clean scrap.
9-16
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Table 9.2
SUMMARY OF COST OF CONTROL
($1,000)
Side Draft Side Draft Side Draft Side Draft
Plant Size Briquetter
4 Tons/Hr Melt Rate
Plant Investment Cost $1,320
Cost of Control Equipment 150
Percent of Plant Investment 11
Increased Product Cost $/Ton
Control Cost as % of Price*
10 Tons/Hr Melt Rate
Plant Investment Cost $2,100
Cost of Control Equipment 150
Percent of Plant Investment 7
Increased Product Cost $/Ton
Control Cost as % of Price*
25 Tons/Hr Melt Rate
Plant Investment Cost $4,030
Cost of Control Equipment
Percent of Plant Investment
Increased Product Cost $/Ton
Control Cost as % of Price*
*Price presumed to be $340/Ton.
Side Draft
280
21
14.90
4.4
370
18
6.13
1.8
825
20
4.46
1.3
+ Canopy
1,000
75
54.71
16.1
1,140
54
21.30
6.3
1,430
35
7.65
2.3
+ Preheater
370
28
20.81
6.1
470
23
8.69
2.6
1,050
26
6.31
1.8
+ Degreaser
380
29
22.24
6.5
480
23
7.47
2.2
1,050
26
6.18
1.8
+ Briquetti
430
32
27.47
8.1
520
25
16.55
4.9
1,125
28
11.10
3.3
-------
REFERENCES FOR CHAPTER 9
1. Air Pollution Emissions Estimates, 1970-1974, EPA preliminary survey,
Monitoring and Data Analysis Division, Durham, North Carolina.
2. Neuman, F. et al, Das BBC/Brusa-Verfahren zum Schmelzen von Stahl.
Stahl und Eisen (1975) No. 1, Jan. 8, pp. 16-23.
3. United States Petent Kemmutmueller, No. 3, 645, 515, Feb. 29, 1972.
9.18
-------
APPENDIX A. EVOLUTION OF THE SELECTION OF THE
BEST SYSTEM OF EMISSION REDUCTION
A.I LITERATURE REVIEW
Available literature was reviewed to gather background information on
the industry and its progress in control of its air pollution emissions.
A prime literature source was the Air Pollution Technical Information Center,
EPA, which routinely abstracts and catalogues literature related to air
pollution. Other sources were periodicals on air pollution and the industry,
meetings of technical societies and pertinent textbooks.
A.2 SELECTION OF PLANTS FROM WHICH TO SAMPLE EMISSIONS
As a consequence of reviewing the literature and contacting several
representatives of the gray iron industry several plants were identified
which were reported to effectively control emissions from electric arc
furnaces. Seven were subsequently visited. During the visit, the visibility
of emissions was evaluated and information was obtained on the process and
the equipment used to control emissions, i-our of these plants were then
selected for closer scrutiny to include actually extracting quantitative
samples of their emissions downstream of the control device. Three were
rejected from further investigation due to the fact that they used control
devices to service more than two furnaces.
The capacities of the furnaces at these four plants ranged from 6 to 15
tons per heat.
A-l
-------
Furnaces of this size are typical of small to mid-range furnaces in
the industry. All were sampled while producing grey iron except for one
which was melting a melt of gray iron destined for production of ductile
iron. Three were controlled by a combination of side draft-fabric filter
system which discharged through a single stack thereby minimizing the
complexity of the sampling program. The fourth was controlled by a roof hood
and fabric filter system.
In addition to the analyses of the samples obtained from these four
plants, this report also includes emission data from two other plants. One
was ampled in accordance with EPA techniques, the second although performed
slightly different from the EPA technique, has been judged to provide similar
results.
A.3 METHODOLOGY
During the investigation, successive meetings were held with two of the
leading domestic manufacturers of electric arc furnaces; the first for a
general review of the industry's problems, the second as a consequence of
specific questions that arose during the study. Many contacts were made,
both by telephone and letter, with manufacturers of electric arc furnaces,
foundry equipment, and equipment for control of air pollution. Visits were
made to the two leading foundry associations, the American Foundrymen's Society
and the Grey Ductile Iron Founder's Society Incorporated. The Malleable
Founders Society was also contacted and asked to comment on different problems
pertaining to the study.
Early in the consideration of air pollution control in the industry, it
became apparent that there are two major aspects of a good system; capture of
A-2
-------
the pollutants released from the furnace and removal of those pollutants from
the exhaust gas stream. Further, there are two totally different circumstances
under which the fumes must be captured; when the lid is on the furnace and
when its not.
When the furnace lid is in place above the furnace, the conventional
furnace evacuation techniques, roof hoods, and side draft hoods and fourth
hole are all effective. Furthermore, since all are fixed to the lid, when
it is rotated away from the furnace, these close mounted capture devices
are ineffective, unfortunately during those very moments when instantaneous
emissions can be the greatest.
Since these capture devices, which are effective only during the melt-
down and refining portion of a cycle, are commonly used in the industry, to
define the best system for control of emissions, we merely had to quantify
requisite gas volumes and define the emission levels from the downstream
control devices which service these capture devices.
To define the best technology for control of emissions during that period
when the furnace lid is rotated out of position to permit scrap to be charged,
however, was a more difficult matter. One obvious method of capturing emissions
during that period is via a canopy-type hood mounted high in the roof of the
building that will receive the voluminous clouds of smoke that rise to the
top of the shop by thermal impetus during the charging period. And, in fact
one such system was seen. At that plant, however, the canopy hood was used
merely to expedite the removal of the fume from the shop, so it vented directly
to the atmosphere rather than directing the pollutants to a control device.
Furthermore, since such canopy hood devices must be mounted high above the
furnace to avoid interfering with normal furnace operations, to be effective
A-3
-------
they must be designed for a relatively large indraft volume which, requires
large fans and consumes large amounts of energy.
One alternative to the relatively large energy requirements of the
conventional canopy hood system is being explored by two corporations. Both
are installing what we've referred to as "enclosure type" housings around
furnaces. Both systems are basically specially designed light sheet metal
buildings which encase the perimeter of the entire furnace and are large
enough to accomodate the tapping ladle and the furnace roof in its off
position. On one, the sides and roof are fitted to accept movement of
the charging ladle suspended from the crane overhead. By encasing the entire
furnace in this manner, the indraft volumes necessary to contain the fume
from the furnace can be substantially reduced. The second enclosure system
has no roof. It merely protects the furnace emissions from wind currents
within the shop and directs them toward a conventional canopy hood mounted
above the charging crane tracks.
Still another approach to precluding emissions during charging is the
elimination of their source. It has long been recognized that the voluminous
black clouds that eminate during charging are a consequence of combustafale
material in the scrap when it is charged to the furnace. This material con-
sists primarily of oil and grease. In truth, the "quality" of the scrap,
determined largely by the combustable composition, has been the determinant
for the value of scrap for a long time. Many foundries operating induction
furnaces have traditionally purchased "clean-scrap" at a higher cost, either
to avoid the emissions from dirty scrap or because their furnaces could not
accommodate a wet or oily charge (either charged into an induction furnace can
A-4
-------
result in dangerous operating conditions). Other operators have, chosen to
install pretreating facilities that permit them to buy poor grades of scrap
but remove the oil either by burning or degreasing.
When the burning technique is used, the conditions are controlled in
a manner such that a minimal volume of combustion products must be treated.
This minimizes the cost of control systems.
In summary then, the program was directed toward controlling emissions
from the iron foundry industry in the following manner.
1. Emissions during melting and refining:
a. Installation of conventional capture systems
b. Installation of a control system which can limit emissions
to a value selected by EPA based on actual samples from
operating plants
2. Emissions during charging: either
a. Capture and control via:
1. installation of an efficient canopy hood which feeds
a control device which can meet standards specified
by EPA, or
2. installation of an enclosure type capture device which
feeds a control device which can meet standards
specified by EPA, or
b. Obviate the need for controlling charging emissions via
installation of a pretreating system.
After fragmenting the problem in this way, EPA attempted to define the best
demonstrated technology for control emissions during melting and refining
A-5
-------
by measuring the levels of control which can be achieved by the best capture
devices presently being used by the industry.
The second part of the problem is not so easily approached. Although
there seems little doubt that a control device could reduce the concentration
of emissions from a canopy hood system to levels at least as low as those
from the conventional capture hoods, no such systems now-sexist, and we must
turn to the steel industry for precident information. Furthermore, because
of the decreasing availability of energy, the energy intensive canopy hood
would probably be installed only as a last resort. The operator would first
attempt to avoid the problem either by more judicious selection of only the
cleaner types of scrap or through some type of pretreatment process that
removes the organics. The latter is the more likely since any decrease in
demand for turnings and borings would decrease their value and increase
the already healthy cost differential to the operator. This would make
pretreating even more economically attractive.
A-6
-------
APPENDIX C. SUMMARY OF PARTICULATE AND QASEOUS
EMISSION TEST RESULTS
A program was undertaken by EPA to evaluate the participate control
techniques available for installation on new or substantially modified elec-
tric arc furnaces which produce gray iron. Information was obtained from
the literature, contacts with companies which manufacture gray iron castings
and control agencies. Seven plants which, produce gray iron were visited.
All plants used roof fans and monitors evacuation and a baghouse for air
pollution control. Two of the seven facilities use multiple dust collectors,
with duplexing furnaces ventilated into the same collector. A third plant
had a dust collector servicing three furnaces. Since installations of such
size and arrangements are seldom built, it was decided not to sample those
three plants. Sample of particulate matter were taken from the control devices
at four shops. Measurements of carbon monoxide, nitrogen dioxide, hydrocarbons,
sulfur dioxide and visible emissions were also made. In addition, some data
on particulate emissions has also been obtained from industry for other well-
controlled electric arc furnace shops. AH test results are presented
graphically in Figures C.I, C.2 and C.3, and summarized in Tables 1 through
38,
C.I FACILITIES
A. This facility has three furnaces wh.ich produce 15 to 16 tons of gray
iron per heat. Located in the same furnace bay area are two induction holding
C-l
-------
CO
o
I—I
oo
uu -^
LU O
•a:
Q-
. 130 _ 0.128
0.120 _
0.110
0-100
0.174 in
0.126 I
0.1057 p
0.098
I-
0.090 (- §;§892 V
0,087 to
0.080
0.070
0.060
0.050
0.040
0.030
0.020
PLANTS
n no
°-98
0.9
I
0.067 jj
Cf
b
KEY
average
0 EPA test methods
^ other test methods
0.2
0.108
0.042 f>'
0.46
0.292
B
D
Figure C.I Participate Emissions from electric
arc furnaces in gray iron foundries.
C-2
-------
0.030
0.025
0.020
0.015
«=;
0.010
g 0.009
o
0.008
«C •'-
cz
other test methods
M)
^
«
PLANTS
B C D E F
Figure C.2 Participate Emissions from electric
arc furnaces in gray iron foundries.
C-3
-------
2.0r-
I/)
g^
Q C
1-1 O
X •!->
o~-»
z s-
O JC
O
03
1.5
1.0
Q
b
8
0.5
PLANT
a
Figure C.3 Carbon Monoxide Emissions from electric
arc furnaces in gray iron foundries.
C-4
-------
furnaces which are not controlled. Behind the transformers substations, is
the scrap area with two charge make-up stations. One charge make-up station
is used most of the time. The furnaces are equipped with side draft hoods as
well as hoods above the pouring spout and the slag door. All three hoods are
connected to the take-off box which is under suction via the baghouse by a
centrigual fan. The bags are made of Dacron and withstand a maximum temper-
ature of 275°F. The air to cloth ratio is 2.54. Roof fans and monitors (evacu-
ate) ventilate not only the furnace and scrap bay areas but also withdraw a
small amount of air from adjacent areas. An open end duct above each furnace is
manifolded to the main duct which leads from the furnace area to the collector.
Two furnaces are connected to the one dust collector which was sampled. The
inlet and outlet of the collector were tested for particulates, (by Method 5),
carbon monoxide (using a non-dispersive infrared (NDIR) analyzer), hydrocarbons
(using a Beckman Hydrocarbon Analyzer), sulfur dioxide (EPA Method 6), and
nitrogen oxides (EPA Method 7). Both furnaces in the plant were operating, two
of them at design capacity during the tests and the control system appeared to
be operating well.
The furnaces are on a staggered schedule. The test cycle was coordinated
by starting the test at the beginning of the heat on one of the furnaces.
B. This facility has four furnaces producing 12 to 13 tons of gray iron
per heat. In the arc furnace bay area are located 3 induction holding furnaces
and two charge make-up stations which are not controlled. Behind the trans-
former substations are located the s.crap bins. In the same building, but not
exactly the same bag area, are located three inoculation stations, pigging
stations, and pouring lines. The furnaces are equipped with side draft hoods
as well as hoods above the pouring spout and the slag door. All three hoods
are connected to the take-off box which is under suction via the baghouse by a
C-5
-------
centrifugal fan. Two haghouse dus.t collectors control emissions from the
furnaces,. Each, collector services two furnaces. The hags are made of Dacron
and withstand a maximum temperature of 275°F. The air to cloth ratio is
2.26. Roof fans and monitors ventilate the furnace and scrap bay areas
withdrawing small amounts of air along from adjacent areas. The same analyses
were carried out 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 operating
at design capacity and the dust control system was operating normally. The
furnaces are on a staggered schedule. The test cycle was coordinated by start-
ing the test at the beginning of the heat on one of the furnaces.
C. This facility has two furnaces producing up to 8 tons of gray iron
each per heat. The furnaces are located in a bay together with an induction
holding furnace which is not controlled for emissions. In front of the furnaces
are areas where molding and core making operations are performed. Each arc
furnace is controlled by a separate baghouse dust collector. The furnaces are
equipped with roof type hoods as well as hoods above the pouring spout and slag
door. All these hoods are connected to the take-off box which is under suction
via the baghouse by a centrifugal fan. The bags are made of Orion and withstand
a maximum temperature of 225°F. The air to cloth ratio is 2.83. Roof fans and
monitors ventilate the furnace bay area and adjacent aisles. The same kind of
samples were obtained from the outlet at this plant as at the other plants.
Both furnaces were operating during the tests. The dust control system was
operating normally. Each test began when operations were started on the furnace.
\
The tests lasted for slightly over one hour, excluding the time to change sampling
ports. The furnace capacity during each test was different, namely 8, 7 and 5
tons, respectively, per heat.
C-6
-------
Emissions at facility C are higher tlian at the other facilities probably
due to tv\to reasons:
1. The collector is manually snaked, i.e., the shaking mechanism is.
activated by hand. This kind of shaking joeans that the collector
cleaned at irregular intervals and subject to overcleaning, which
results in a poor filter cake buildup and higher emissions.
2. Injection of carbon raiser is carried out via a lance fay means of
compressed air. During injection of carbon into a molten bath,
only about 85 percent of the carbon is dissolved in the metal, and
although much of the balance should end up in the slag, some portion
escapes the furnace to the baghouse. Due to its small particle size,
some of the carbon particles are not collected even in the baghouse.
D. This facility has one furnace producing 6 tons of gray iron per heat.
Opposite to the arc furnace in the same building is located one induction hold-
ing furnace which is uncontrolled. The arc furnace is surrounded on three sides,
with two walls and the transformer is on the third side. Fumes emitted during
charging and upset conditions (gas puffs escaping through the electrode holes
or other furnace openings) are channelled upward by the three walls and with-
drawn by the ventilation fan located abrve the furnace. The furnace is
equipped with a side draft hood as well as hoods above the pouring spout and
slag door. The bags are made of Dacron and withstand a maximum temperature
of 275°F, The air to cloth ratio is 2.61. The same tests were carried out
as in plant A. The first test was run only for one hour, i.e., only during
one heat. However, the next two tests were extended over two heats to assure
a greater quantity of dust was captured on the filters. Each, of these tests
was started at the beginning of two consecutive heats and continued for one
C-7
-------
hour during each. heat, farti.culate readings were taken at inlet and outlet of
the collector. The furnace was operating at design capacity. The dust con-
trol system was operating normally.
On all tests, opacity readings by EPA Method 9 were taken at the stack
of the control device and at the one ventilation fan discharge judged to be
handling the largest amount of emissions generated during charging and tapping.
The summary of visible emissions is presented in Table C.5 through C.12.
E. This facility has one electric arc furnace, installed in 1974, which
produces 7 tons/hour of gray iron. The furnace is equipped with side draft
hood as well as hoods above the pouring spout and slag door. The furnace
gases are cleaned by a baghouse dust collector. The bags are made of Dacron
and withstand a maximum temperature of 275°F. The air to cloth ratio is 3.1.
Roof fans and monitors ventilate the furnace bay area. The emissions were
sampled at the outlet of the collector by EPA Method 5, and analyzed for
particulates only. The reported emissions represent the front half (probe
and filter catch) of the EPA sampling train. The tests were carried out at
different phases of the furnace heat. The first test was started at the
beginning of a heat, the second one-third of the way into the heat, and the
last test at the middle of the heat. The furnace was operating at design
capacity during the tests and the control system was operating normally.
Opacity readings, although not recorded in accordance with EPA's method,
were made by a certified smoke reader. The opacity at the stack was below
10 percent.
F. This, facility has a dust collector to which are connected two gray
iron producing arc furnaces, two induction holding furnaces and one duplex-
ing arc furnace. The volume withdrawn at each arc furnace is 157,000 CFM
at 275°F. The tests were carried out at the outlet of the collector. The
C-8
-------
test method is siroilar to EPA test method. The furnace is equipped with, a
side draft hood and direct evacuation elfapw as well as hoods above the pouring
and slag door. All these hoods are connected to the take-off box which is
under suction via the Baghouse by a centrifugal fan. The bags are made of
Nomex and withstand a maximum temperature of 400°F. The air to cloth ratio
is 3. Roof fans installed on canopy hoods and monitors ventilate the furnace
bay area and adjacent aisles directly to the atmosphere.
Gaseous emissions measured during the EPA testing at plants A, B, C
and D are represented in tables
C-9
-------
TABLE 1
FACILITY A (Ba&house Inlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity - tons
Flow Rate - ACFM
Flow Irate - DSCFM
Flow rate - DSCFM/ton of
furnace capacity
Temperature - °F
Water Vapor - Vol. %
C02 - Vol. % dry
02 - Vol. % dry
CO - Vol % dry
Partlcu1 ate Emi ssi 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
2.5
0.3
19.7
0.2766
0.2132
172.5
6.28
0.2960
0.2281
185
5.96
C-10
2
6/19/74
210
15.5
85721
65721
2120
185
3.1
0.3
1925
REPORTED
0.3415
0.2626
190.7
7.23
0.3690
0.2837
206
6.^4
3
6/20/74
210
15.5
90990
76069
2453
189
1.5
0.3
19.5
ELSEWHERE
0.3201
0.2491
192,2
7.0
0.3250
0.2529
195
6.3
Averag
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
-------
TABLE 2
FACILITY A (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
Parti cul ate 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
2
6/19/74
210
115.5
99797
79331
2550
174
1.5
3
6/19/74
210
15.5
98140
76140
2460
185
2,4
4
6/20/74
240
15.5
100111
76985
2475
188
2.9
Average
217
15.5
99349
77465
2490
182
2.3
SAME AS INLET
0.0038
0.0029
2.44
0.089
0.0072
0.0056
4.62
0.167
0.0035
0,0028
2.38
0.087
0.0057
0.0045
3,89
0.142
0.0028
0.0022
1.83
0.067
0.0044
0.0034
2.87
0.105
0.0054
0.0042
3.56
0.128
0.0073
0.0056
4.83
0.177
0.0039
0.0031
2.59
0.094
0,0058
0.0045'-
4.05
0.146
C-ll
-------
TABLE 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
nater vapor - Vol. %
C02 - 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
6/8/74
215
12,5
85212
65973
2615
197
3.0
0.3
19.3
0.0066
0.0051
3.72
*U74
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
C-12
-------
TABLE 4
FACILITY C (baghouse Outlet)
Summary of Results
Run Number
Date
Test Tine - 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
Psrticulate 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
C-13
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
-------
TABLE 5
FACILITY D (Baghouse Inlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity - tons
Shop Effluent
Flow rate - ACFM
Flow rate - DSCFM
F!c« rate - DSCFM/ton of
furnace capacity
Tercerature - °F
Water vapor -Vol. %
C0? - Vol. % dry
C2 - Vol. % dry
CO - Yol . % dry
Participate Emissions
Probe and filter catch
gr/DSCF
gr/ACF
Ib/hr
Ib/hr per ton/hr
Total catch
gr/DSCF 0
gr/ACF 0
Ib/hr
Ib/hr per ton/hr
1
10/1/74
60
6
21783
19166
3194
124.7
0.8
0.8
19.7
0.0
0.41254
0.36297
6.7,. 76
11.29
.42624
.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
11.65
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
C-14
-------
TABLE 6
FACILITY D (Baghouse Outlet)
Summary of Results
Run Number
Date
Test Time - Minutes
Total Furnace Capacity -
Shop Effluent
Flow rate - ACFM
Flow rate - DSCFM
Flow rate - DSC FM/ ton
furnace capacity
Temperature - °F
Water vapor - Vol . %
C02 - Vol. % dry
02 - Vol. % do
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
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
0,042
0.00319
0.00294
0.55
0.053
C-15
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
0.00855
1.463
0.213
-------
TABLE 7
FACILITY E (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
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
Averag<
60
15
49700
42205
2990
120
0.341
20.55
0.1
0.00723
0.00243
2.41
0.3462
C-16
-------
TABLE 8
Gaseous Emission Data
Facility A
Summary of Results
Run Number
Date
Carbon Monoxide Emissions
Average ppm (by volume)
Ib/hr
i
Ib/hr per ton per hour
Nitrogen Oxides (as N02) Emissions
Average ppm (by volume)
Ib/hr :
Ib/hr per ton per hour
Hydrocarbon (as CHy,) 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
1.5.9
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
4.4Q
3.32
0.121
Average
-
95
34.61
1.26
2.48
1.36
0.0395
7.6
1.566
0.057
4.84
3.68
0.134
C-17
-------
TABLE 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 N00) Emissions
Average ppm by volume
Ib/hr
Ib/hr per ton per hour
Hydrocarbon (as OU) 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
C-18
-------
TABLE 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 Diode1- 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
C-19
-------
TABLE 11
Facility D
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 CHj 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
10/1/74
107
4.805
0.933
S^
2.88
0.604
0.117
1.7
0.245
0.047
2
10/2/74
143
5.166
1.00
Vfftf
7.3
1.487
0.289
2.5
0.492
0.095
3
10/3/74
60
2.03
0.394
r
\* ^
fr
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
C-20
-------
TABLE 12
FACILITY A-
Summary of Visible Emissions
Lfate: June 18, 1974
Type of Plant: 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
Wind Direction: North
Color of Plume: Brown
Duration of Observation: 4 Hours, 15 Minutes
SUMMARY OF AVERAGE OPACITY
Distance from Observer to Discharge Point: TOO
Feet
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
Time
Opacity
Time
TTpaci ty
Set Number Start End
Sum
Average Set Number Start End Sum Average
1
2
3
4
5
6
7
8
•9
10
n
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
12:08
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
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
2:56
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
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
10.00
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
c.
91
U
!_
0)
a.
u
ra
a.
o
10
n
r
I
Time, hours
C-21
-------
TABLE 13
FACILITY A
Summary of Visible Emissions
u;te: June 18, 1974
Typo of Plant: Gray Iron Foundry
Type of Discharge: Participates
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
Time Opacity
Set liumber Start End Sum Average Set Number
1 10:50 10:56 75 3.13 ' 21
2 11:56 11:02 35 1.46 22
3 11:02 11:08 5 0.21 23
4 11:08 1:14 0 0 24
5 11:14 11:20 00 25
"6 11:20 11:26 00 26
7 11:26 11:32 0 0 27
8 11:32 11:38 00 28
•° 11:38 11:44 00 29
10 11:44 11:50 00 30
11 11:50 11:56 90 3.75 31
12 11:56 12:02 55 2.39 32
13 12:02 12:08 110 4.58 33
14 12:08 12:14 55 2.39 34
15 12:14 12:20 0 0 35
16 12:20 12:26 150 6.24 36
17 12:26 12:32 10 0.418 37
18 12:32 12:38 30 1.25 38
19 12:33 12:44 00 39
20 12:44 12:50 95 3.95 40
Sketch Showing How Opacity Varied With Time:
2 3
-
1 0 ~"
4J
C
-------
TABLE 14"
FACILITY A
Summary of Visible Emissions
uate: June 19, 1974
Type 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: TOO
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: 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
Opacity
Time
Opacity
Time
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
10
c
s
a.
o
10
Time, hours
C-23
-------
TA3LE 15
FACILITY A
Summary of Visible Emissions
uate: June 19, 1974
Typ-:' of Plant: Gray Iron Foundry
Type of Discharge: Roof Vent
Distance from Observer to Discharge Point: 24
Feet
Location of Discharge: Over Furnace No. 2 Height of Observation Point: 60 Feet
Height of Point of Discharge: 3 Feet
Description of Background: Sky
Description of Sky: Cloudy, Bright Sun
Wind Direction: Not Recorded
Color of Plums: Brown
Duration of Observation: 3 Hours, 18 Minutes
SUMMARY OF AVERAGE OPACITY
Direction of Observer from Discharge Point:
Sun in the Back of Observer
Wind Velocity: Not Recorded
Detached Plume: No
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
n
12
13
14
15
16
17
18
19
20
Start
10:00
10:06
10:12
10:18
10:24
It): 30
10:36
10:42
10:48
10:54
11:00
11:06
11:12
11:18
11 : 24
11 : 30
11:36
1 1 : 42
11:48
11: 5-5
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
1 1 : 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
1.45
Set iiu."ber
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
3S
39
40
Time
Start
12:00
12:05
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 3
i i
10~.
01
o.
o
to
OL
o
5
0
10
5
0
J~L_,~, ri
_L
0
Time, hours
C-24
-------
TABLE 16
FACILITY A
Summary of Visible Emissions
Date: June 19, 1975
Typ? 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
rime
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
n
12
13
14
15
16
17
18
19
20
4:04
4:10
4:16
4:22
4:28
4:34
4:40
46
52
58
04
10
16
22
28
34
40
5:45
5:52
5:58
10
16
22
28
34
40
46
52
58
04
10
16
22
28
34
40
46
52
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
Sketch Showing How Opacity Varied With Time:
2 3
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
04
10
16
22
6:28
6:34
6:40
6:46
6:52
58
04
10
16
22
28
34
40
46
52
7:
7:
7:
7:
7:
7:
7:
7:
7:
7:58
10
I
0)
G.
u
(3
0.
O
10
1 Time, hours
C-25
6:10
6:16
6:22
:28
:34
:40
:46
:52
6:58
7:04
7:10
7:16
22
28
:34
:40
:46
:52
: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.
3.
.875
.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
-------
TAULE 17
FACILITY A
Summary of Visible Emissions
uaic: June 19, 1974
Typo of Plant: Gray Iron Foundry
Typo of Discharge: Roof Vent
Distance from Observer to Discharge Point: 24
Feet
Location of Discharge: Over Furnace No. 2 Height, of Observation Point: 60 Feet
Direction of Observer from Discharge Point:
East of Roof Fan
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
rime
"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
4:04
4:10
4:16
4:22
4:28
4:34
4:40
4:46
4:52
58
09
10
16
5:22
28
34
40
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
10
16
22
28
34
40
46
5:50
5:58
6:04
0
0
0
20
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.8
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Sketch Showing How Opacity Varied With Time:
2 3
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
04
10
at
u
t.
-------
IA13LL 18
FACILITY A
Summary of Visible Emissions
Date: June 20, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Particulates
Location of Discharge: Stack
Height of Point of Discharge: 80 ft.
Description of Background: Dark Gray Side of Quildinq
Description of Sky: Clear
Vi'ind Direction: Not Recorded Winc| 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. above observer
Height of Observation Point: Ground level
Direction of Observer from Discharge Point:North
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IS
19
Start
9
9
9
9
9
9
9
10
10
10
10
10
10
10
10
10
10
10
11
n
:20
:25
:32
:38
:44
:50
:55
:02
:08
:14
:20
:26
:3?
:38
:44
:50
:56
:02
:03
:14
End
9:26
9:32
9:38
9:44
9:50
9:55
10:02
10:03
10:T4
10:20
10:25
10:32
10:38
10:44
10:50
10:56
11:02
11:03
11:14
11:20
Opacity
Sum
0
0
0
0
0
15
0
0
0
0
0
0
0
0
0
0
0
^
10
40
Average
0
0
0
0
0
2.99
0
0
4.37
0
0
0
1.25
0
0
1.45
0.417
1.25
0
0.84
Time
Set Number Start
' 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
11
11
n
n
n
n
n
12
12
12
12
12
12
:20
:26
:32
:38
:44
:50
:5S
:0?
:08
:14
:20
:26
:32
End
11:26
11:3?
11:38
11:44
11:50
11:56
12:0?
12:08
12:14
12:20
12:26
12:3?
12:38
Opaci ty
Sum
120
125
50
:60
150
55
15
5
0
• 0
0
0
0
Average
5
5.13
2.08
5
6.25
2.3Q
6.27
O.?l
0
0
0
0
0
Sketch Showing How Opacity Varied With Time:
3
10
c
o
s_
Q.
n
>,
(O
d
o
T
n
JL
Time, hours
C-27
I
-------
IT:-;L:: 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
Mme
Opacity
Opacity
Set Number Start End
Sum
Average Set Number Start
End
Sum
Averace
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
9:56
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
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
0
0
0
0
0
70
0
0
105
0
0
0
30
0
0
35
10
30
0
20
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
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
11:20
11:26
11:32
11:38
11:44
11:50
11:55
12:02
12:08
12:14
12:20
12:26
12:32
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
80
0
0
0
5
50
0
20
0
0
55
5
100
3.34
0
0
0
0.21
2.08
0
0.84
0
0
2.3
0.21
4.17
Sketch Snowing How Opacity Varied With Time:
c
S
01
a.
o
10
D.
O
10
5
0
10
5
0
i_ n
Time, hours
C-28
-------
IA1JU. 2(J"
FACILITY B
Summary of Visible Emissions
uate: 'July 8, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Particulates
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
Vlind Direction: Calm Wind Velocity: Hot Recorded
Color of Plume: Brown ' Detached Plume: No
Duration of Observation: 3 Hours, 40 Minutes.
SUMMARY OF AVERAGE OPACITY . SUMMARY OF AVEPvAGE OPACITY
Set Number
1
2
3
4
5
6
7
8
•9
10
n
12
13
14
15
16
17
18
19
20
Time
Start End
1:20 1:26
1:27 1:32
1:33 1:39
1:45" 1:51
1:52 1:56
1:57 2:02
2:03 2:08
2:08 2:14
2:14 2:20
2:20 2:26
2:26 2:32
2:32 2:38
2:38 2:44
2:44 2:50
2:50 2:56
2:56 3:02
3:02 3:08
3:08 3:14
3:14 3:20
3:21 3:26
Sketch Showing How Opacity
25
c
8 20
s~
to
o.
£ 15
"o 10
re)
a.
O
5
—
—
L-r-up-
. i . ii i i anj i— j
0
Opacity
Su.m,
0
0
0
0
55
10
0
85
30
65
25
0
0
0
0
0
0
0
45
50
Varied
"H
i
Average
0
0
0
0
2.2
0.41
0
3.54
1.25
2.7
1.04
0
0
0
0
0
0
0
1.88
0.21
With Time:
2
Set Number
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
^J\I
1
3
Time, hours
C-29
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
n
A
Time Opacity
End Sum
3:32 25
3:36 35
3:42 0
3:46 30
3:52 10
3:58 0
4:04 0
4:10 0
4:16 115
4:22 130
4:28 50
4:34 55
4:40 65
4:46 195
4:52 45
4:58 0
5:04 0
,
4
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
-------
TABLC 21
FACILITY B
Summary of Visible Emissions
uate: July 8, 1974
Typ-: of P'tant: Gray Iron Foundry
lype of Discharge: Participates
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: 30
Feet
Height of Observation Point: At Vent Level
Direction of Observer from Discharge Point:
30 Feet South of Discharge Point
Wind Velocity:
Detached Plume:
Hot Recorded
No
Duration of Observation: 3 Hours, 40 Minutes
SUMMARY OF AVERAGE OPACITY
SUMMARY OF AVERAGE OPACITY
Ti me Opacity"
Time
"Opacity
Set Number Start End
Sum
Average Set Number Start
End
Sum
Sketch Snowing How Opacity Varied With Time:
Averace
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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
2:56
3:02
3:08
3:14
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
2:56
3:02
3:08
3:14
3:20
0
0
0
0
20
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.835
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
r-
' 21
22
23
24
25
26
27
28
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
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
4:50
4:56
5:02
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
0
0
0
20
20
0
0
0
5
5
5
5
5
0
15
0
0
0
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
O)
o
S-
a>
a.
u
-------
TABLE 22
FACILITY B
Summary of Visible Emissions
Udte: July 9, 1974
Typo of Plant: Gray Iron Foundry
Type of Discharge: Particulates
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
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
n
12
13
14
15
16
17
18
19
20
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
9:25
9:32
9:38
9:44
9:50
8:01
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
25
15
30
30
55
0
10
15
135
130
no
70
0
0
45
0
0
5
5
25
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
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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
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
10
0
0
0
0
25
10
10
0
0
0
0
0
0
10
5
0
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:
I
-------
TABLE 23
FACILITY B
Summary of Visible Emissions
iwte: July 9, 1974
Type of Plant: 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
Wine! 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
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
8:00
8:06
8:12
8:18
8:24
8:3Q
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
6
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
10:28
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
c
0
0
0
0
0
0
0
0
0
Sketch Showing Hew Opacity Varied With Time:
25
20
. 15
1 10
a.
o
5
0
2 3
Time, hours
C-32
-------
TA2LE 24
FACILITY B
Summary of Visible Emissions
uate: July 9, 1974
Type of Plant: 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
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
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
2:56
3:C2
3:08
3:14
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
2:56
3:02
3:08
3:14
3:20
5
0
0
0
60
0
0
0
0
0
0
27
0
85
95
5
0
0
0
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
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
4:02
4:08
4:14
4:20
4:26
4:32
4:38
4:44
4:50
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 Snowing How Opacity Varied With Time:
25
o on
o £u
I
. 15
I?
s 10
n.
O
5
Time, hours
C-33
-------
TABLE 25
FACILITY B
Summary of Visible Emissions
uate: July 9, 1974
Typ:- of Plant: 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: Clear
Wind Direction: Calm
Color of Plume: Brown
Duration of Observation: 3 Hours, 30 Minutes
SUMMARY OF AVERAGE OPACITY
Direction of Observer from Discharge Point:
30 Feet South of Discharge Point
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
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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
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
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
0
0
0
0
0
0
0
0
• 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
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
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
0
0
55
0
0
0
0
0
0
0
0
30
0
0
0
0
0
0.23
0
0
0
0
0
0
0
0
0.124
0
0
0
Sketch Showing How Opacity Varied With Time:
s.
25
20
15
S. 10
a.
o
J_
2 3
Time, hours
C-34
-------
TABLE '26
FACILITY C
Summary of Visible Emissions
uate: Sept. 18, 1974
Typo 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 stacktop
Height of Point of Discharge: 15 feet above Direction of Observer from Discharge Point:
flat roof Roof, N-W. of stack
Description of Background: Sky
Description of Sky: 100% overcast
Wind Direction: N.W. Wind Velocity: Q-5
Color of Plume: brown Detached Plume: no
Duration of Observation: 2 Hours, 7 Minutes
SUMMARY OF AVERAGE OPACITY
Time
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
I ~
15
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
1:13
1:24
End
11:36
11:42
11:48
11:54
12:00
12:05
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
Opacity
Sum^
330
95
5
30
10
15
0
45
120
185
235
145
165
140
40
90
35
20
0
40
Average
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
SUMMARY OF AVERAGE OPACITY
Time Opacity
Set Number Start End Sum Average
' 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:
25
§ 20
s_
QJ
Q.
. 15
Q.
o
10
5
Time, hours
C-35
-------
TASLE 27
FACILITY C
Summary of Visible Emissions
uate: Sept. 18- 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Particulates
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
SUMMARY OF AVERAGE OPACITY
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 OPACITY
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
n
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
200
130
0
20
0
0
0
40
120
235
200
150
150
120
25
90
15
15
5
50
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
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
8 20
O)
t 15
£ 10
ia
a.
o
Time, hours
C-36
-------
TABLE 28
FACILITY C
Summary of Visible Emissions
uate: Sept. 18, 1974
Tyf;- of Plant:'Gray Iron Foundry
Type of Discharge: Particulates Distance from Observer to Discharge Point: 20 feet
Location of Discharge: st*ck Height of Observation Point: Even with stack top
Height of Point of Discharge: 15 feet above Direction of Observer from Discharge Point:
flat roof Roof N 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
n
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 Time:
25
c
0} on
o 20
0.
. 15
£•
3 10
o.
o
5
0
__
—
—
_
—
f— - \
i
— «~"1__J L-J
1 1 ! I
n 1 2
u Time, hours
C-37
-------
IABLL *y
FACILITY C
Summary of Visible Emissions
Uate: Sept. 18, 1974
Typo of Plcint: Gray Iron Foundry
Typo of Discharge: Particulates
Location of Discharge: Stack
Height of Point of Discharge: 15 feet
Description of Background: Sky
Description of Sky: 95X 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
Wind Velocity: 0-5 mph
Detached Plume: no
Duration of Observation: One Hour, 23 Minutes
SUMMARY OF AVEPvAGE OPACITY
nme
Set Number
1
2
3
4
5
6
7
8
9
10
n
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
Sumj
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:
I
0)
(J
-------
FACILITY C
Summary of Visible Emissions
Date: Sept. 19, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Particulates
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 . SUMMARY OF AVERAGE OPACITY
ime
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
n
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
9:36
9:42
9:48
9:54
10:00
10:06
10:12
10:18
10:24
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
10:06
10:12
10:18
10:24
10:30
290
5
0
0
0
0
40
40
80
5
60
50
75
20
80
315
310
730
135
10
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
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
10:30 10:36 25 1.05
10:36 10:42 15 0.627
10:42 10:48 0 0
Sketch Showing How Opacity Varied With Time:
25
4J
§20
o.
o
£ 10
5
0
35
30
Time, hours
C-39
-------
L'.SLC 31
FACILITY C
Summary of Visible Emissions
uate: Sept. 19, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Particulates
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
3 stack
Direction of Observer from Discharge Point:
30 feet east of stack
Wind Velocity: 0-5 mph
Detached Plume: no
SUMMARY OF AVERAGE OPACITY
Opaci ty
lime
Time
Set Number Start End Sum Average Set Number Start End Sum Average
1
2
3
4
5
6
7
8
•9
10
n
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
9:1'2'
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
•"- o
• o
0
• 0
35
15
60
0
40
70
55
20
75
335
500
530
140
5
5
10.2
0
0
0
0
1.4,5
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
4->
8 20
O)
Q.
- 15
o
-------
FACILITY D
Summary of Visible Emissions
Date: October 1, 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: Overcast
Wind Direction: East
Color of Plume: White
Duration of Observation: 87 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: 3 to 5
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
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
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
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
4-9
I 20
a.
. 15
Sf
I 10
CL
O
5
Time, hours
C-41
-------
TABLE 33
FACILITY D
Summary of Visible Emissions
Date: October 1, 1974
Type of Plant: Gray Iron Foundry
Type of Discharge: Furnace Roof Exhaust Distance from Observer to Discharge ^
Location of Discharge: Furnace Roof Exhaust Height of Observation Point: Ground
. L.GVS 1
Direction of Observer from Discharge Point:
South
Height of Point of Discharge: 80 Feet
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
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
3:20 3:26
3:26 3:32
3:32 3:38
3:38 3:44
3:44 3:50
3:50 3:56
3:56 4:02
4:02 4:08
4:08 4:14
4:14 4:20
4:20 4:26
4:26 4:32
4:32 4:38
4:38 4:44
4:44 4:50
4:50 4:56
4:56 5:02
5:02 5:08
5:08 5:14
5:14 5:20
Sketch Showing How Opacity
~~ 25
c
8 20
OJ
O.
. 15
1 10
0.
o
5
0
Opacity
Sum<
120
120
120
120
120
120
120
120
175
120
120
120
120
120
120
120
120
120
120
120
Varied
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
With Time
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
:
n
1
0
1
1
1 1
2
Time, hours
C-42
-------
lABLt 34
FACILITY D
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
Set Number
1 A.M.
2
3
4
5
6
7
8
9
10
11
12 P.M.
13
14
15
16
17
18
19
2r • "
Start
9:25
9:31
9:37
9:55
10:01
10:07
10:13
10:15
10:21
10:27
10:39
3:10
3:16
3:22
3:28
3:34
3:40
3:46
3:52
3:58
Sketch Showing How
4,10
C
01
o c
j_ O
o.
^ o
lio
o.
o
5
0
-
~
—
•• ii^mii i
0
lime
End
9:31
9:37
9:55
10:01
10:07
10:13
10:15
10:21
10:27
10:39
10:41
3:16
3:22
3:28
3:34
3:40
3:46
3:52
3:58
4:04
Opacity
^-.-,-FJJa-JlJ^.J.iw ••
— r
Opacity
Sum
0
0
No
0
0
0
0
No
10
No
5
0
0
0
0
0
0
0
0
0
Average
0
0
Readings
0
0
0
0
Readings
0.4
Readings
0.6
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
41
Start
4:04
4:10
4:16
4:22
4:28
4:34
4:38
4:48
4:54
5:00
5:06
5:12
5:18
5:24
5:30
5:36
5:42
5:48
5:54
6:00
6:06
Time Opacity
End Sum
4:10 0
4:16 0
4:22 0
4:28 0
4:34 0
4:38 0
4:48 No
4:54 0
5:00 0
5:06 0
5:12 0
5:18 0
5:24 0
5:30 0
5:36 0
5:42 0
5:48 0
5:54 0
6:00 0
6:06 0
6:10 0
Average
0
0
0
0
0
0
Readings
b
0
0
0
0
0
0
0
0
0
0
0
0
0
Varied With Time:
1
1_
1
_L
Time, hours
C-43
.... .-l
.. I.
2
-------
IAOLE 3b
FACILITY D
Summary of Visible Emissions
uatc: 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
Set Number
1
2
3
4
5
6
7
8
•9
10
11
12
13
14
15
16
17
18
19
20
Time
Opacity
Start End Sum
9:25 9:31 5
9:31 9:37 10
9:37 9:43 110
9:43 9:49 0
9:49 9:55 0
9:55 10:01 65
10:01 10:07 120
10:07 10:13 120
10:13 10:19 120
10:19 10:25 120
10:25 10:31 120
10:31 10:37 120
10:37 10:43 120
10:43 10:49 120
10:49 10:55 120
10:55 11:01 120
11:01 11:07 120
11:07 11:13 120
11:13 11:19 120
11:19 11:25 120
Sketch Showing How Opacity Varied
25
| 20
o.
. 15
1 10
CL
O
5
0
0
-
-
— ->» J 1
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 ...
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
:
~ — 4
L j
Time, hours 2
C-44
-------
FACILITY D
Summary of Visible Emissions
Date: 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
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
Set Number
1
2
3
4
5
6
7
8
9
10
11
12
13
Time
Start End
3:10 3:16
3:16 3:22
3:22 3:28
3:28 3:34
3:34 3:40
3:40 3:46
3:46 3:52
3:52 3:58
3:58 4:04
4:04 4:10
4:10 4:16
4:16 4:22
4:22 4:28
14 4:28 4:34
15 4:34 4:40
16 4:40 4:46
17 4:46 4:52
18 4:52 4:58
19 4:58 5:04
20-.' 5:04 5:10
Sketch Showing How Opacity
10
c
0) _
if 5
-------
FACILITY D
Summary of Visible Emissions
uate: October 3, 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: 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 .
10:05
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 Average
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Sketch Showing Kow Opacity Varied With Time:
25 -
o>
20 ~
o
0 10
5
0
Time, hours
C-46
-------
FACILITY D
Summary of Visible Emissions
Date: October 3, 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: Partly Cloudy
Wind Direction: Southwest
Color of Plume: White
Duration of Observation: 63 Minutes
Direction of Observer from Discharge Point:
South
Wind Velocity: 20 to 35
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
9:03
9:
9:
9:
10:
10:
10:
11:
11:
11:
11:
11:
11:
11:
09
15
18
47
53
57
08
14
20
26
32
38
44
End
9:
9:
9:
10:
10:
10:
11:
11:
11:
11:
11:
11:
11:
11:
09
15
18
47
53
57
08
14
20
26
32
38
44
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
Readings
5.0
5.0
5.0
5.0
5.0
5.0
5.0
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:
*>
c
01
o
Q.
25
20
15
5
0
I
Time, hours
C-47
-------
APPENDIX D. EMISSION MEASUREMENT AND CONTINUOUS MONITORING
D.I Emission Measurement Methods
For the gray iron foundry industry employing electric arc furnaces,
EPA used Method 5 for particulate emission measurement, Method 9 for visible
emission determination, and Method 10 for carbon monoxide measurement. These
emission data were collected with these methods as described in Appendix A
of 40 CFR Part 60 and published in the Federal Register (December 23, 1971
and June 11, 1973).
The particulate mass catches for these emissions were low. They ranged
from 12.4 to 40.3 mg for the EPA Method 5 dry sampling train. In an effort
to ensure accurately measurable catches, some test runs were extended to 3
hours. The preferable lower limit for total mass catch is 25 mg. In-house
test runs have shown that acceptable accuracy (+_ 10%) can be obtained at this
level with most of the inaccuracy found on the high side of the measurement.
That is, at these low mass levels somewhat more mass is measured than is
actually collected.
D.2 Continuous Monitoring
The effluent gas stream from the foundry industry baghouses are not
excessively hot (less than 95°C or 200°F). Therefore, the visible emission
monitoring instruments found adequate for power plants would also be appli-
cable for this industry. These systems are covered by EPA performance stan-
dards contained in Appendix B of 40 CFR Part 60(Federal Register, September 11,
1974).
D-l
-------
Equipment and installation costs are estimated to be $18,000 to
$20,000 and annual operating costs, including data recording and reduction,
are estimated at $8,000 and $9,000.
Carbon monoxide monitoring equipment is available for sources such
as gray iron foundries. However, EPA has not completed a comprehensive
evaluation needed to identify critical operating parameters and minimum
performance specifications for such equipment.
Carbon monoxide monitoring equipment and installation costs are
estimated to be $7,000 to $10,000 and annual operating costs are estimated
at $2,000 to $3,000.
D.3 Performance Test Methods
The performance test method recommended for particulate matter is
Method 5. Because of the construction of some control equipment, special
stack extensions may be required to obtain acceptable sampling conditions.
Low particulate concentrations in the stack gases from fabric collectors
necessitate longer sampling times and larger sample volumes. The recom-
o
mended minimum sampling volume is 4.5 dsm (160 dscf). Commercially
available high volume sampling trains conforming to Method 5 specifications
would allow tests of shorter duration while obtaining the minimum sample
volume, thus reducing time and expense of test.
Sampling costs for a test consisting of 3 particulate runs is estimated
to be about $5,000 to $9,000. This estimation is based on the sampling site
modifications such as ports, scaffolding, ladders, and extensions costing from
D-2
-------
$2,000 to $4,000 and testing being conducted by contractors. If in-plant
personnel are used to conduct the tests, the costs will be somewhat less.
Method 9 is recommended for visible emission measurement and Method 10
for the measurement of carbon monoxide emissions.
Cost of performing a Method 10 test including equipment set-up, cali-
bration, and data reduction is estimated to be about $1,000 to $2,000.
Assuming these tests are conducted at the same time as the particulate and
visible emission tests, no further costs for ports, scaffolding, or other
modifications should be incurred.
D-3
-------
APPENDIX E. ENFORCEMENT ASPECTS OF THE
RECOMMENDED STANDARD
E.I GENERAL
One difficult situation that may be encountered during enforcement
of the proposed standards is an affected facility located in the same
building with other sources of particulate emissions. Emissions from
these other sources may mix with those from the affected facility and
leave the buildings through monitors, roof fans or the canopy hood. The
effects of such additions to canopy hoods ventilated to a dust collector
are negligible. The proposed regulation specifies that when the other
emissions are from existing furnaces, compliance may (subject to approval
by the Administrator) be demonstrated for the new furnace without a test.
The operator must show that the control system is equivalent or superior
to that which would be required if the furnace were installed in a new
shop. Another option for the operator is to base compliance on control of
all the sources.
When the extraneous emissions are from sources other than furnaces,
the plant operator may choose from the following options.
i
1. Base compliance on control of all emission sources.
2. Shut down the other emission sources during the compliance
test.
3. Use a method acceptable to the enforcement agency to compensate
for the effect of the other emission sources on results of the
E-l
-------
compliance test, or
4. Any combination of the above.
E.2 DETERMINATION OF COMPLIANCE WITH THE CONCENTRATION REGULATION
The control system installed to comply with the proposed standards
may have any of several configurations. One control device may serve
several affected facilities, or several control devices may serve one
affected facility. Where several control devices are involved, the pro-
posed regulations provide for use of a flow-weighted average concentration
to determine compliance. For the other case, the regulation provides that
a common compliance test of the single control device is sufficient to
show compliance for all the affected facilities. These provisions allow
the proposed standards to be reasonably enforced without restricting
options for the design of control systems.
From the standpoint of measuring the concentration of emissions,
effluents containing particulate matter can be placed into three broad
categories; (1) those confined within a single stack, (2\ those exhausted
through multiple stacks, and (3) those not constrained within a stack or
duct after exiting the control device. The enforcement aspects of
complinace testing vary according to the category and are discussed below.
(1) Effluent confined within a single stack. The methods specified
in 40 CFR 60 (Methods 1, 2, 3, 4 and 5) provide specific guidelines
applicable for measurement of emissions from a stack. Unlike existing
sources which sometimes require deviation from optimum sampling procedures
due to the physical limitations of the facility, new sources can and
should be designed for optimum accuracy of sampling. As an example, an
E-2
-------
optimum sampling location is 8 or more diameters downstream and 2 or more
diameters upstream from anything that might disturb, the flow of exhaust gas
such as an orifice or elbow in the line, Although the reference methods allow
deviation froio this optimum criteria, new facilities should be designed for
accurate and precise results from sampling. Furthermore, utility services and
sample access points can also be incorporated in the design of new sources to
facilitate sampling.
(2) Effluent exhausted through multiple stacks. Actual test
procedures are similar to category 1 except the number of samples required
and the attendant costs may become excessive. In such a case, a limited
sampling plan may be suggested by the enforcement agency. Possible
variations are: a) particulate tests of select representative stacks
with concurrent velocity measurements at similar stacks; b] particulate
tests on a limited number of stacks combined with an evaluation of design
and operating parameters to determine comparability between those stacks
sampled and those not sampled.
(3) Effluent not constrained within a stack. This category will
include emissions from open or pressure baghouses. Compliance test
methods applicable to these configurations have not been specified due
to the l-'Tiited experience and the lack of proven techniques available
for testing.
Several problems are involved in such testing. First, due to
large (and sometimes multiple) cross sectional areas through which emissions
are exhausted, it is not practical to sample at enough points to totally
define the flow profile. To overcome this limitation, assumptions are
made to determine the minimum number of samples necessary to estimate the
actual flow characteristics. When their locations are determined, the
-------
sub-areas they represent may then be sampled with Method 5 Cor other
sampling techniques, Including high volume sampling). These Individual
points may be sampled by traversing, or by simultaneous sampling at
multiple points. One scheme is to draw a high volume sampler across the
horizontal cross-section of a roof monitor. Another, used in the aluminum
industry, involves extraction of effluent from representative sampling
points by use of a permanent multipoint sampling manifold. The manifold
discharges into a single stack which can then be sampled with conventional
techniques.
A second problem results from low flow rates common in large
area discharges. They often cannot be measured with conventional equip-
ment. This precludes accurate isokinetic sampling and determination of
actual volumetric flow rates. This problem is usually resolved by
determining average velocities with sensitive measuring devices and then
by sampling at this average rate. Volumetric flow rate may be determined
in a similar manner. (If dilution air is not present, volumetric flow
rate may be more accurately determined on the inlet side of the control
device.)
Use of dilution air presents a third and equally serious impediment
to accurate emission measurements. Since a concentration limit (mass
per volume) requires a correction for dilution air and a mass emission
limit requires measurement of actual volumetric flow rates, in either
case it is necessary to measure flow rates. This may prevent, or at
least will seriously hamper accurate emission measurements.
Due to these problems, the accuracy and precision attainable in
making mass determinations appears limited and, in fact, certain source
E-4
-------
configurations totally defy representative sampling. For most sources,
however, plans can be developed which should yield sufficiently accurate
data to determine compliance. Due to the potential cost, the owner and
the enforcement agency should consider and agree, prior to construction
of a new facility, on a specific means for determining compliance.
EPA is now examining typical configurations being marketed to deter-
mine optimum test criteria. Until such criteria are available, owners
should select exhaust systems which will allow sampling in accordance
with the standardized methods presented in 40 CFR 60.
E.3 DETERMINATION OF COMPLIANCE WITH VISIBLE EMISSION REGULATIONS
Generally, visible emission limitations are easily enforceable
regulations that require very little prior preparation and often
don't even require that the plant be notified before a determination
of compliance. Their prime function is to insure that air pollution
control equipment is properly maintained. In the case of EAF's this
is true for visible emissions from the control device, however,
enforcement of the other visible standards is not so straightforward.
Enforcement of the standards for handling of dust collected by
the control device and on emissions from the electric arc furnace
shop (except during charging and tapping) require some knowledge of
what operations are actually occurring during the test. Since dust
is only occasionally removed from the control device, the observer may
have to determine when this operation is scheduled before visiting a
plant for opacity readings. Another example is, if excessive emissions
are noted from a shop, the observer must determine if they resulted from
charging or tapping before he can be sure that the standard was
E-.5
-------
indeed violated.
The visible emission standards limit the opacity during speciftcally
defined charging and tapping periods. To properly enforce them, the
periods of observation must be correlated with process operations which
are actually taking place. One man must monitor the process while another
evaluates the opacity of emissions during each compliance test.
E.4 INSTALLATION AND OPERATION OF AN OPACITY MONITORING DEVICE
EPA promulgated performance specifications for opacity instru-
ments on October 6, 1975 (40 FR 46250). These are based on
commercial instruments now available which are capable of measuring
opacity within a narrow path up to 30 or more feet in length.
Other instruments are available for longer paths. EPA is currently
evaluating these instruments for applications to open top baghouses
and other long path applications such as roof monitors. Instruments
which meet the specifications will present no enforcement problems
as far as instrument operation is concerned.
Application of continuous opacity monitoring instruments can present
difficulties. Their applicability is influenced by the configuration of
the equipment through which the exhaust gases discharge. Although
effluent discharged through a stack or duct can be readily monitored,
other discharge systems can present problems, as in the case of a pressure
baghouse. At constant particulate concentration, opacity increases
proportionately with the length of the optical path under surveillance.
Thus, the absolute value of a measurement of opacity down the length of a
100' X 50' baghouse exit will be twice that of the width. Another
potential complicating factor is downdraft through a stack or
E-6
-------
extraneous dilution atr which may pass 1n view of the instrument.
To compensate for the effect of dilution air or path length,
it will be necessary to establish a "reference" or base line opacity
value for each instrument on each such source. The reference opacity
would be established during a period in which the source is in compliance
with the opacity standard as determined with Method 9. Subsequent data
obtained by the instrument (;s) will then be compared to the reference
value to assure the operation and maintenance of the control device are
adequate. Although this reference value can be established directly as
opacity, a more useful form may be opacity per unit of path length.
The opacity monitoring system and reporting plan should be
agreed upon by the owner and the enforcement agency prior to its
installation.
E.5 STARTUP, SHUTDOWN AND MALFUNCTIONS
Excessive emissions during startup of electric arc furnaces are
not anticipated if the charge make-up is properly adjusted. However,
excessive fumes can be generated during charging and mostly during the
beginning of the meltdown, if the charge contains higher levels of oil
in the charge portion consisting of turnings, borings and chips. Charges
containing 15 percent of turnings, borings and chips with 2 percent oil
content are satisfactory. However, increasing the 15 percent or 2 percent
levels will result in excessive emissions which can be evacuated from the
furnace with difficulty.
Malfunctions happen seldom on electric arc furnaces, if the charge
make-up is properly adjusted. One typical, seldom occuring malfunction
is the presence of some non-conductive piece of material between the
E-7
-------
electrode and the charge. In this case, the furnace door must be opened and
the piece removed. Emissions during this operation cannot be prevented unless
there is a canopy hood.
Delays in chargings often resulting in excessive emissions can be due
to use of too much light large sheet metal pieces, which sometimes have to be
smashed into the furnace by means of the charging bucket. In order to prevent
this from happening, the scrap make-up should be correspondingly adjusted.
The size of pieces charged to the furnace depends on the furnace volume.
Excessive emissions develop if the furnace roof cannot be properly closed
following charging of the furnace. In such cases the roof has to be swung
open and the piece obstructing the closing of the roof readjusted. This
occurence is observed rather often, if the furnace is to be brim-filled.
Normal shutdown procedures on arc furnaces do not result in excessive
air pollution emissions.
Therefore no special exemptions are granted for higher emissions than
the ones anticipated under normal operating conditions.
E-8
------- |