United States Office of Air Noise and
Environmental Protection Radiation Enforcement
Agency Washington DC 20460
Stationary Source Enforcement Series
FERROUS FOUNDRY
INSPECTION GUIDE
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EPA-340/1-81-005
Ferrous Foundry
Inspection Guide
Final Report
by
MIDWEST Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
EPA Contract No. 68-01-6314
Task No. 2
MRI Project No. 7101 - L (2)
John R. Busik, Project Officer
Robert L. King, Task Manager, DSSE
Division of Stationary Source Enforcement
Office of Air, Noise and Radiation Enforpement
U.S. Environment*! Protection
««gk>n 5, Library (PI-12J)
•J' west Jackson Boufevard, 12th Fbw
<*'«go. It 60604-3590
U.S. ENVIRONMENTAL PROTECTION AGENCY
401 M. Street, S.W.
Washington, D.C. 20460
December 30, 1981
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US. CnyiVo'"'"" ••••* r-v .. . ' -. -"-,. •
Agency
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PREFACE
Midwest Research Institute (MRI) has prepared this Ferrous Foundry In-
spection Guide for the U.S. Environmental Protection Agency, Division of
Stationary Source Enforcement (EPA-DSSE) under EPA Contract No. 68-01-6314.
Mr. Robert L. King of EPA-DSSE was task manager for this project.
This project was conducted by Mr. Raj Shah, Task Leader, under the
supervision of Mr. Andrew Trenholm, Head, Environmental Control Systems
Section.
MRI would like to express its appreciation to the many individuals in
federal, state, and local air pollution agencies and the foundry industry
who contributed to the study.
Approved for:
MIDWEST RESEARCH INSTITUTE
M. P. Schrag, Director
Environmental Systems Dep4rtment
December 30, 1981
111
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CONTENTS
Preface iii
Figures vii
Tables ix
1.0 Introduction 1
2.0 Ferrous Foundry Processes and Emissions Control Systems. . 3
2.1 Raw material storage and handling 6
2.2 Mold and core preparation 6
2.2.1 Molding processes 6
2.2.2 Coremaking processes 12
2.3 Melting and casting 15
2.3.1 Ferrous foundry furnaces 15
2.3.1.1 Cupola furnace 15
2.3.1.2 Electric arc furnace 18
2.3.1.3 Electric induction furnace. . . 27
2.3.2 Inoculation 27
2.3.3 Pouring and cooling 27
2.4 Cleaning and finishing 31
2.5 Sand handling system 34
3.0 Foundry Emission Problems and Causes 51
3.1 Introduction 51
3.2 Raw material storage and charge preparation area. . 51
3.3 Mold and core operation 55
3.4 Metal melting 55
3.4.1 Cupola 55
3.4.2 Electric arc furnace 56
3.4.3 Electric induction furnace 57
3.5 Iron inoculation 57
3.6 Pouring and cooling 57
3.7 Shakeout, cleaning, and finishing 57
3.8 Sand handling system 58
3.9 Other areas for potential emission problems .... 58
3.9.1 Waste handling 58
3.9.2 Housekeeping 58
3.9.3 Routine maintenance 58
4.0 Inspection Procedures 59
4.1 Preinspection procedures 59
4.1.1 File review 59
4.1.2 Announcement of inspection 60
4.1.3 Safety and pre-plant entry 60
4.1.4 Plant entry 60
4.1.5 Preinspection meeting 60
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CONTENTS (continued)
Appendices
Page
4.2 Process and control equipment inspection proce-
dures 61
4.2.1 Melting operations 62
4.2.1.1 Inspection of charge prepara-
tion area 62
4.2.1.2 Inspection of cupola with
high energy scrubber 62
4.2.1.3 Inspection of cupola with gas
cooling system, fabric
filter 65
4.2.1.4 Inspection of electric arc
furnace or electric induc-
tion furnace, fabric filter . 67
4.2.2 Nonmelting operations 68
4.2.2.1 Local exhaust system with low
energy scrubber 69
4.2.2.2 Local exhaust system with
mechanical collectors .... 70
5.0 Health and safety guidelines for foundry inspectors. ... 73
5.1 Introduction 73
5.2 Foundry processes and associated safety and health
hazards 73
5.2.1 Sand preparation 73
5.2.2 Coremaking, molding, melting, and pouring
operations 74
5.2.3 Shakeout, cleaning, and grinding opera-
tions 74
5.2.4 Other miscellaneous operations 74
6.0 References 75
A. Glossary of terms used in foundry industry A-l
B. Checklist forms for various process control equipment
systems in foundry B-l
VI
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FIGURES
Number Page
2-1 Flow diagram of ferrous foundry 5
2-2 Typical muller for mixing molding sand 8
2-3 Modern continuous sand cooler rides piggyback on continu-
ous figure-8 muller 9
2-4 (a) A ram-jolt-squeeze-stripper mold-making machine; (b)
a ram-jolt-squeeze-turnover-stripper mold-making
machine 11
2-5 (a) Shell molding and storage area with area ventilation;
(b) typical exhaust system for shell molding 14
2-6 Flow diagram of ferrous foundry melt shop 16
2-7 Three types of cupola furnaces 17
2-8 Typical cupola scrubber system 19
2-9 An electric arc furnace 20
2-10 An electric arc furnace controlled by a canopy hood during
tapping 21
2-11 Roof hood, side draft hood, and direct shell evacuation
for capturing electric arc furnace emissions 23
2-12 Canopy hood for capturing electric arc furnace emissions . 24
2-13 Hawley close capture hoods for capturing electric arc
furnace emissions 25
2-14 Close capture hooding system for electric arc furnace. . . 26
2-15 A coreless electric induction furnace 28
2-16 Close capture hooding system for electric induction
furnace 29
2-17 Methods of iron inoculation methods used to inoculate
ductile iron 30
vii
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FIGURES (continued)
lumber
2-18
2-19
2-20
2-21
2-22
2-23
2-24
2-25
2-26
2-27
2-28
3-1
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
A 33,000-cfm compensating hood on the pouring line ....
Flow diagram of cleaning and finishing process
Three enclosed shakeouts, automatic discharge mold con-
veyor lines and sand distribution
Side draft shakeout hood
Abrasive cutoff of sprues and risers in cleaning and
finishing process
Torch cutoff of risers in cleaning and finishing process .
Swing grinder booth
Swing grinding operation
Downdraft chipping and grinding bench
Abrasive blast cleaning unit
A high volume sand handling system
Flow diagram of representative ferrous foundry
Reduction in spraying action of worn nozzle
Typical fan problems
Disturbance in air flow due to holes in cyclone
Various types of valve related problems found in mechani-
cal collectors
Page
32
33
35
37
39
41
42
43
45
47
49
54
64
64
71
71
Vlll
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TABLES
Number Page
2-1 Chemical Composition of Ferrous Castings 4
2-2 Principal Organic Core Binders in Use in the Coremaking
Processes 13
3-1 Emissions from Metallurgical Processes, Industry: Gray
Iron Foundry 52
IX
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SECTION 1.0
INTRODUCTION
The success of a field enforcement program ultimately depends on the
field inspectors and the results of their inspections. The importance of
following inspection procedures closely cannot be overly emphasized. Air
pollution control agencies with adequate enforcement powers, but inadequate
inspection and enforcement procedures, may lose some of these powers as a
result of adverse court decisions. The ability to identify, describe, and
evaluate air pollution emissions and the factors contributing to their for-
mation is fundamental to inspection procedures.
The field inspectors are involved in field surveillance and monitoring
of a variety of sources for continuing compliance. A "continuing compli-
ance inspection" is an inspection of sources which have previously proved
initial compliance with the regulations in that they have installed the
necessary air pollution control equipment and/or modified their process(s)
to be able to meet required emission limits on a continuing, long term
basis. Most agencies perform a continuing compliance inspection once or
twice a year depending upon their resources or any complaints received.
This inspection guide designed by the Environmental Protection Agency
(EPA) has been written and organized for use by state and local enforcement
field inspectors and entry-level engineers whose familiarity with foundry
operations may be limited. The guide can be useful both as a training man-
ual in foundry operations and as a guidebook during field inspections.
A main objective of this guide is to present relevant information about
foundries in layman's language. Thus, we have purposely not included tech-
nical discussions on subjects such as stack testing, emission factors, ef-
fects of control and process equipment variables on emissions, engineering
calculations, etc. For this reason, the guide will be considered "basic" by
those senior engineering staff with experience in foundry operations. Such
staff should consult the extensive references listed in the bibliography for
information on unique or complex foundry problems. More experienced staff
may prefer to start this guide with Chapter 4. Also, it is expected that
the users of this guide, field inspectors, will seek out senior engineering
staff for guidance when a serious or potentially serious emission problem is
discovered. By using this guide, field inspectors will become competent
problem locators.
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This guide presents an overview of foundry operations and describes
typical emission problems in a foundry. It explains causes of the problems
and possible corrective measures. It also describes types of control equip-
ment used in foundry operations and typical problems with control equipment.
Throughout this guide are terms used in the ferrous foundry industry.
A glossary of these terms is contained in Appendix A.
Appendix B contains process and control equipment checklists that have
been prepared for use during inspections to assure continued compliance of
foundry operations. In using these checklists, it is assumed that basic
data on the processes already exist in the agency files and that the foundry
being inspected has an operating permit showing initial compliance with the
regulations.
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SECTION 2.0
FERROUS FOUNDRY PROCESSES AND EMISSIONS CONTROL SYSTEMS
A ferrous foundry converts scrap iron and steel to usable cast iron and
cast steel products. The field inspector with a basic understanding of
foundries is able to identify compliance problems. In addition, information
from past surveys suggests that the inspector who demonstrates such an un-
derstanding can expect more cooperation from foundry personnel.
There is no "typical" ferrous foundry. Ferrous foundries vary with re-
spect to type and size of casting produced, quantity of metal melted daily,
choice of equipment and materials for a particular function, and the degree
of mechanization of different processes. Therefore, this chapter cannot
provide a walkthrough inspection guide for a given foundry, but it does pro-
vide enough information about the different operations of a foundry that the
inspector can direct an inspection tour.
Ferrous foundries process various grades of iron and steel scrap, and
sometimes pig iron, to produce cast products from one or more of the follow-
ing ferrous metals: gray iron, ductile (or nodular) iron, malleable (some-
times called white) iron, and steel. These various types of ferrous metals
are differentiated by their chemical compositions as shown in Table 2-1.
Pig iron is different in comparison to other ferrous metals, as it is manu-
factured by the reduction of iron ore smelted in a blast furnace with coke
and limestone. Generally, pig iron is produced in large steel mills and is
used directly in the manufacture of steel and steel products. In some
cases, it is used to produce ferrous castings with or without refining or
alloying treatments. Other ferrous metals are generally made from the mix-
tures of steel and ferrous scrap with or without various alloying agents.
The type of metal used will depend upon what type of final casting is re-
quired.
Most foundries have five basic process areas: (a) the pattern shop;
(b) the core and mold making area; (c) the melt shop, which includes both
melting and casting; (d) the cleaning and finishing area; and (e) the sand
handling system. In addition, each foundry has raw material and waste han-
dling and storage operations. The general flow system of a ferrous foundry
is shown in Figure 2-1. The reader is reminded that these operations vary
considerably from foundry to foundry.
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TABLE 2-1. CHEMICAL COMPOSITION OF FERROUS CASTINGS27'9
Gray iron
Element
Carbon
Silicon
Manganese
Sulfur
Phosphorus
2
I
0
0
0
(%)
.5-4.0
.0-3.0
.40-1.0
.05-0.25
.05-1.0
Malleable
(as white
1.
0.
0.
0.
0.
(%)
8-3.6
5-1.9
25-0.
06-0.
06-0.
iron
iron)
80
20
18
o
Ductile iron
3.
1.
0.
<
<
(%)
0-4.0
4-2.0
5-0.8
0.12
0.15
Steel
(
< 2
0.50%.
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Melting and Casting
Waste Sand
T ~
Sand Handling System
Sand
Discards
Good
Scrap
Metal
Cleaning and Finishing
Core and
Mold Preparation
Figure 2-1. Flow diagram of ferrous foundry.
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This chapter describes the unit operations, except pattern making, that
are most often found within each of the operating areas. The pattern shop
was excluded because industry and control agency personnel have not identi-
fied it as contributing to the air pollution problem. The type of control
associated with the process equipment is also described. The control de-
vices themselves are not described in detail since it is assumed that the
inspector is familiar with the air pollution control equipment.
2.1 RAW MATERIAL STORAGE AND HANDLING
Raw materials are used in the foundry melt shop and core and mold mak-
ing area. Raw materials used for melting include scrap iron and steel, bor-
ings and turnings, limited quantities of pig iron, and foundry returns for
metallic content; coke for energy in the cupolas and in limited quantities
for metallurgical control in electric furnaces; and fluxing material such as
limestone, dolomite, fluorspar, and calcium carbonate. The primary raw ma-
terials used in core and mold making are sand, fillers such as cereal and
sea coal, organic binders, and precoated sands for chemically bound cores
and molds.
Handling and storage practices vary depending upon the size and degree
of mechanization of the foundry. Most of the furnace charge materials are
received by truck or rail and are transferred mechanically to storage bins
or piles. In most cases the coke and fluxing agents are stored in covered
areas to prevent degradation. Both covered and open storage are used for
the metallics. Covered storage is preferable environmentally because it
reduces windblown fugitive emissions, and cleaner materials ultimately re-
duce furnace emissions. Other than covering, no control measures are typi-
cally used with these operations.
Sand for core and mold making may be handled either mechanically or
pneumatically. However, environmental and material considerations have
resulted in increased pneumatic transport in the modern foundry. Sand is
almost always stored in enclosed silos. Nearly all pneumatic systems are
equipped with fabric filters for material recovery and emission control.
2.2 MOLD AND CORE PREPARATION
One of the preliminary steps in the production of ferrous casting is
the production of molds and cores. The mold gives the casting its basic
exterior shape while the core is used to form indentations or the internal
shape of the casting, such as cylinders in an engine block. The following
sections describe various processes which can be used to produce molds and
cores.
2.2.1 Molding Processes
The foundry operator has many molding techniques from which to choose.
These include green sand molding, dry sand molding, pit molding, various
types of chemically bonded sand molding, permanent mold casting, die cast-
ing, investment casting, centrifugal casting, plaster molding, and ceramic
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molding.1'2 This section discusses green sand molds, dry sand molds, and
pit molds since these methods account for the vast majority of castings and
have the greatest emission potential. Since chemically bonded sand molding
processes and emissions are similar to coremaking processes, they are de-
scribed in Section 2.2.2, Coremaking Process.
By far the greatest tonnage of castings is poured in green sand molds.
Green sand molds are made with a moist sand, and the moisture is retained
in the sand through the time when the metal is poured. The four steps in
green sand molding -re: (a) preparation of the pattern; (b) preparation of
the sand (mulling); (v^) making of the mold; and (d) core setting. The only
step in the process which produces significant particulate emissions is
mulling. Water, sand, and binding materials such as bentonite clay, sea
coal, and cereal additives are mixed in a muller, examples of which are
shown in Figures 2-2 and 2-3. Since the materials are wetted quickly during
mulling, some potential for emissions occurs during the charging of materi-
als, particularly binders, to the muller, but these emissions are well con-
trolled in most mechanized operations. Mechanized molding machines are then
used to form the mold in two halves, the cope or upper half and the drag or
lower half. After both halves are formed, cores are placed in the mold and
the cope and drag are fastened together. Examples of molding machines are
shown in Figure 2-4.
Because of the moisture content of the sand, the emissions from molding
are generally quite low, precluding the necessity for air pollution control
equipment. The mullers are generally controlled by an exhaust ventilation
system such as the one shown in Figure 2-3. The exhaust from the muller is
vented to a fabric filter or low energy wet scrubber before discharge to
the atmosphere.
Dry sand molds are used to produce steel castings or thick section
castings of a large size and weight. Dry sand molds are prepared with sands
and binders which do not require moisture. Additives include pitch, sodium
silicate, gilsonite, cereal, molasses, dextrine, gluten, and resins. These
additives are mixed with the sand in a muller and the mixture is formed into
molds. The molds are then healed in an oven to produce strong, rigid mold
•walls. Controls are similar to those used in green sand mold product '•• r i.
Pit molds, which are used to produce castings too large for a flask,
may be made in a pit by a bedding-in method. The pattern is set in a pit
in the position in which the casting is to be poured, and sand is rammed or
tucked under and around the sides of the pattern. The cope for the complete
mold may rest on the drag at or above floor level and may be bolted down
to prevent runout at the parting plane. Many foundries have a concrete-
lined pit equivalent to the size of the mold they customarily produce. The
mold may be rammed up, striking off the surface to produce the desired
shape. At times, when the design of the casting is such that a pattern can-
not be drawn 01t of the mold the entire mold cavity may be constructed with
cores.
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Figure 2-2. Typical muller for mixing molding sand (courtesy National
Engineering Company).2
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Figure 2-3. Modern continuous sand cooler rides piggyback on continuous figure-8
muller--can put out 70 tons/hr of prepared sand without a whisp of
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This page intentionally left blank.
10
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Rotates to
allow sand
fill from
hopper
over the
mold
Cope or drag
pattern
fastened here
Rotates to
allow sand fill
from hopper
Figure 2-4. (a) A ram-jolt-squeeze-stripper mold-making machine; (b) a ram-jolt-
squeeze-turnover-stripper mold-making machine. A complete mold is
produced at each cycle of 3 to 5 min (The Osborn Manufacturing Com-
pany).4
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2.2.2 Coremaking Processes
Cores are prepared by mixing clean sand with one of several types of
organic binders followed by a chemical or thermal setting process to form a
hard, rigid core. There are five types of coremaking processes: oven bake,
shell, hot box, cold box or gassed core, and no-bake. The level of usage of
each process is shown in Table 2-2. Emissions from coremaking processes are
primarily organic vapors from the binders. The following paragraphs briefly
describe each of the processes and identify the organic emissions that can
be expected from each process.
Oven-baked cores are formed in much the same manner as green sand and
dry sand molds. After the oven-baked core is molded, it is placed on a flat
core plate or formed core dryer and transferred to a gas- or oil-fired oven.
In the oven the light oil fractions and moisture are driven off with acids,
aldehydes, and photochemically active hydrocarbons.5 All ovens are vented
to the atmosphere, and some ovens have afterburners or chemical scrubbers
to minimize organic emissions.
Shell coremaking or shell molding produces cores or molds having a
thickness of 1/8 to 3/8 in. These are used in applications requiring great
precision. Sand and approximately 5% thermosetting resin (usually having a
phenol-formaldehyde base) may be dry-mixed in a muller.6'7 The sands may
also be prepared by cold, warm, or hot coating. This mix is then blown into
a metal box housing the pattern plate which has been heated to a temperature
of 350 to 700°F.5 The binder within 1/8 to 3/8 in. of the pattern is melted
and the material is turned into a dough-like substance. Excess sand is
dumped off, and the shell is allowed to harden. The primary emissions from
the process are carbon monoxide, formaldehydes, amines, ammonia, and phenols.
A shell core machine with its exhaust system is shown in Figure 2-5.
Hot box binders are those resins that rapidly polymerize in the pres-
ence of acidic chemicals and heat to form a mold or core. The original hot
box resins are developed by modifying urea-formaldehyde resins with the
addition of 20 to 45% of furfuryl alcohol. This type of hot box resin is
commonly referred to as furan resin. The furan resins are then modified
with the addition of phenol to produce urea-phenol-formaldehyde hot box
resins, referred to as phenolic resins or UPF resins. The UPF resins have
a pungent odor, and adequate ventilation at the coremaking machines is re-
quired. More recently, urea-free phenol-formaldehyde-furfuryl alcohol bind-
ers have been developed. Eliminating urea from the formulation has rendered
these resins less volatile and odorous than other hot box resins.6
A two-part polyurethane cold box binder system was developed about
1967 that required gassing rather than baking or heating to achieve a cure.
Part I of the system is a phenolic resin, and Part II is a polyisocyanate.
Both are dissolved in solvents. In the presence of a catalyst, triethyl-
amine or dimethyl ethylamine, the hydroxy groups of the liquid phenolic
resin combine with the isocyanate groups of the liquid polyisocyanate to
form a solid urethane resin which serves as the sand binder. Following in-
troduction of the catalyst into the cold box, air is used to sweep any re-
maining vapors through the core, after which the core is removed from the
core box.
12
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TABLE 2-2. PRINCIPAL ORGANIC CORE BINDERS IN USE IN
THE COREMAKING PROCESSES
Coremaking process
Organic binder
Oven bake
Heated core box
Shell
Hot box
Gassed core (cold box)
No-bake
1. Oleoresinous
2. Urea-formaldehyde resins
3. Phenol-formaldehyde resins
4. Cereal binders
1. Phenol-formaldehyde novolaks
2. Furan resins (UFFA)
3. Phenol resins (UPF)
4. Phenol-modified resins
1. Isocyanate
1. Air set (oil-oxygen)
2. Furan no-bake
3. Oil no-bake
4. Urethane (phenolic-isocyanate)
Source: Bates, C. E., and L. D. Scheel, "Processing Emissions
and Occupational Health in the Ferrous Foundry Indus-
try," American Industrial Hygiene Journal, August 1974.
13
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Figure 2-5(a). Shell molding and storage area with area ventilation.
Figure 2-5(b). Typical exhaust system for shell molding.
14
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The amine catalysts are volatile, flammable organic liquids, and their
vapors present safety hazards.6
The no-bake binders represent modifications of the oleoresinous, urea-
formaldehyde, phenol-formaldehyde, and polyurethane binder systems previ-
ously described, in which various chemicals are incorporated to produce
polymerization in an unheated core box.7
For each of the coremaking methods, ventilation is needed, and after-
burners or chemical scrubbers may be used to control organic emissions.
2.3 MELTING AND CASTING
The area of the foundry which has traditionally been of greatest con-
cern to control agency personnel is the melt shop. Operations which may be
found in the melting and casting department of a ferrous foundry include
melting, superheating, or duplexing; inoculation, and pouring and cooling
of the ferrous castings. The types of operation and specific equipment
used in these operations vary from foundry to foundry depending on foundry
size, type of metal cast, type and size of casting, number of castings pro-
duced, energy availability, and local environmental regulations. Figure 2-6
shows the materials flow commonly found in ferrous foundry melt shops.
The melt shop operations are briefly described in the following sec-
tions. The first section describes the three major types of furnaces used
in ferrous foundries: the cupola, which is used for melting, and electric
arc and electric induction furnaces, which are used for melting, duplexing,
and holding molten metal. The second section describes the different meth-
ods used to inoculate ductile iron. The final section describes pouring and
cooling operations.
2.3.1 Ferrous Foundry Furnaces
Almost all the metal used in ferrous foundries is melted in one of
three furnaces. Cupolas account for about 75% of the ferrous foundry pro-
duction, electric arc furnaces about 17%, and electric induction furnaces
about 7%. The operations and controls for these furnaces are described
below.
2.3.1.1 Cupola Furnace—
The cupola furnace is the principal melting unit in gray iron and
ductile iron foundries. The cupola is an upright, cylinder-shaped vessel
which uses the heat from the charged coke to melt iron. Three types of
cupolas are illustrated in Figure 2-7. The cupola operation may be con-
tinuous. Metallics, coke, and fluxing agents are charged in layers near
the top of the furnace, and the molten iron is tapped from the bottom.
The cupola bottom consists of two hinged doors which are blocked closed
during the operation but are opened after melting is completed to dump the
remaining charge. Before melting is started, the doors are closed and the
floor packed with 8 to 10 in. of sand to seal the cupola.
15
-------
Coke
Fluxing
Agents
Me tallies
i
Cupola
Electric Arc
Furnace
Electric
Induction
Furnace
t
Preheater
Malleable
Iron
Duplexing
Furnace
Gray Iron
'
Ductile '
Iron
Steel
Inoculation
or Ladle
Additions
Pouring
of tasting
t
To Shakeout
Figure 2-6. Common flow diagram for ferrous foundry melt shops.
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Skip-Hoist Rail
(1 of 2)
Brick Lining
Cast Iron Lining
Charging Door
Wind Box
Skip-Hoist Rail
Stack 0°r2)
Brick Lining
Cast Iron Lining
Charging Door
- Refractory Lining Wah}(. Quf|ef
Charging
Deck
Blast Duct
Steel Outer Shell
Steel lnner Sne"
Water Inlet
Tuyere^" lron Trou9h
Taphole for Iron
(Slag Hole is 180•
Opposite)
Sand Bed
Door (1 of 2)
Stack
Charging
Deck
Skip-Hoist Rail
()of 2)
Brick Lining
Cast Iron Lining
Charging Door
Water Flow Between
Inner and Outer Shell
Blast Duct
Wind Box
Water-Cooled
Tuyere
Taphole
Slag
Dam
Carbon
Block
Slag and
S. Iron Trough
N. Sand Bed
Door (1 of 2 )
Solid Steel
Shell
Water
Curtain
Water
Trough
Stack
Charging
Deck
Prop
Blast Duct
Wind Box
Taphole
Water-Cooled
Tuyere
Carbon
Block
Sand Bed
Door (1 of 2 )
Slag
Dam
Conventional Cupola
Water-Cooled Cupola (Water-Wall)
Water-Cooled Cupola (Flood Cooled)
Figure 2-7. Three types of cupola furnaces.'
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Combustion air for the melt is injected through tuyeres just above the
level of the sand. The taphole is also located at this level. For con-
tinuously operating cupolas, the slag and iron are tapped together arid the
slag skimmed off in the runner or in a forehearth. For intermittent oper-
ations, the slag hole is located at the top of the level of the iron.
The charging door is located 15 to 25 ft above the bottom of the cu-
pola, usually on a separate floor. The stack extends above the charging
door to sufficient height to clear the roof of the foundry. In most cupolas
this stack is capped and the exhaust gases are emitted through a control
device.
In most modern cupolas, the control systems have three components.
First, the gases are passed through an afterburner which raises the tempera-
ture to about 1300°C. This afterburner oxidizes the carbon monoxide to car-
bon dioxide and burns any tars and oils that were liberated from dirty
scrap. The gas stream then passes through a cooling mechanism which may
rely on radiant, evaporative, or dilution cooling. For hot blast cupolas
(cupolas which inject heated blast air through the tuyeres) a radiant air-
to-air heat exchanger is most common. For cold blast cupolas, an evapora-
tive spray chamber is the most common device. Finally, the gases pass
through a fabric filter or high energy wet scrubber before being exhausted
to the atmosphere. Figure 2-8 shows a schematic of a typical evaporative
cooler and wet scrubber system.
2.3.1.2 Electric Arc Furnace--
The electric arc furnace is found in both iron and steel foundries and
is the principal melting unit in steel foundries. The electric arc furnace
is a refractory-lined, cup-shaped vessel with a refractory-lined roof. As
with the cupola, the lining may be either acidic or basic. Three graphite
electrodes are placed through holes in the roof to provide the electrical
energy for melting iron. Figure 2-9 is a schematic of an electric arc fur-
nace, and Figure 2-10 shows an electric arc furnace in operation.
Unlike the cupola, the electric arc furnace is a batch type operation;
its production cycle consists of charging, melting or refining, and tapping.
Two additional steps that are often found are backcharging and, in steel
foundries, oxygen lancing. These five operational steps and the associated
emissions are described in the following paragraphs.
An electric arc furnace can be charged through a side door, or the roof
can be removed so the furnace can be charged through the top. The top
charging method predominates in ferrous foundries. The charge is introduced
to the furnace through the use of a charge bucket or, in smaller, less mech-
anized foundries, by hand. Top charging produces emissions which are not
controlled in most of the existing plants. Emissions result from: (a) va-
porization and partial combustion of the oil introduced with any scrap, bor-
ings, turnings, and chips contained in the charge; (b) oxidation of organic
matter which may adhere to the scrap; and (c) liberation of sand particles
introduced into the furnace on the surface of casting returns. High oil
content is characteristic of the least expensive scrap (swarf, or turnings,
chips, and borings, from machine operations). Charging emissions are made
up of particulate matter, carbon monoxide, hydrocarbon vapors, and soot.
18
-------
Failsafe
Cupola Cap
Combustion
Zone
Air Indraft
Through
Charge Door
From Water Cooling
Tower
To Water Cooling
Tower
Sound
Attenuation
Thicking
Tank Concentrated
Fines to Recycle
Disposal Pump
Figure 2-8. Typical cupola scrubber system.
10
19
-------
Carbon Electrodes
Spout
Door
Slag
Metal
Furnace Ti Ited to Pour Rammed
Hearth
Ladle
Figure 2-9. An electric arc furnace/
20
-------
Figure 2-10. An electric arc furnace controlled by a canopy hood during tapping.
11
21
-------
When the furnace is ready for the melting cycle, the electrodes are
lowered through the roof to a position about 1 in. above the metallic charge
and then energized. Melting is accomplished from the heat supplied by radi-
ation from the arc formed between the electrodes and the metallic charge,
radiation from the furnace lining, and resistance of the metal between the
arc paths. During melting operations (meltdown, slagging, and refining),
emissions consist of: (a) particulates as metallic and mineral oxides gen-
erated from vaporization of iron and transformation of mineral additives;
(b) carbon monoxide from combustion losses of the graphite electrodes, car-
bon raisers, and carbon in the metal; and (c) hydrocarbons from vaporization
and partial combustion of oil remaining in the charge. During melting,
emissions escape from the furnace through electrode annuli (holes), the slag
doors, the roof ring (the joint between the furnace shell and roof), and
sometimes the tap spout.12
Steel furnaces are sometimes backcharged; that is, a second charge is
added to the furnace as soon as sufficient volume is available in the fur-
nace. (Iron furnaces are generally charged only one time.) Backcharging
produces a violent eruption of emissions with a strong thermal driving
force. The amount of pollutants generated during this phase of the opera-
tion is probably greater than during either the first charge or during
treatment of the molten bath in the transfer ladle.13
Oxygen lancing in steel furnaces is used mainly for adjusting of the
chemistry of the steel, for speeding up of the melting process, and for su-
perheating the bath. Oxygen lancing results in increased temperature, gas
evolution, and generation of particulates (particularly iron oxide) and
carbon monoxide. Oxygen lancing can be carried out with moderate rates of
oxygen addition, thereby avoiding generating excessively high temperatures,
gas evolution, and particulate emissions. However, extended periods of oxy-
gen lancing can increase energy consumption, refractory wear, and oxidation
of the bath and can change the production rate.
When the melting and refining cycle is completed, the electrodes are
raised. The furnace is then tilted by as much as 45 degrees, and the re-
fined metal is tapped into a ladle.
Most electric arc furnace emissions are controlled by fabric filters.
However, the mechanisms used to capture these emissions vary considerably.
Figures 2-11 through 2-14 depict five common methods of emission capture:
side draft hoods, roof hoods, direct shell evacuation, canopy hoods, and
multiple close capture hooding. The roof hood, side draft hood, and direct
shell evacuation systems shown in Figure 2-11 are effective in capturing
emissions only during melting and refining. The canopy hood system (if
cross drafts are eliminated) (Figure 2-12) and close capture system (Fig-
ures 2-13 and 2-14) capture charging and tapping emissions as well as melt-
ing emissions.
22
-------
s
1
/
t v
d
, d
<
^
Roof Hood
Side Draft Hoo
-------
Figure 2-12. Canopy hood for capturing electric arc furnace emissions.
24
-------
HOOD EXHAUSTING
SLAG DOOR
ELECTRODE AREA
ENCLOSED WITH
RECTANGULAR HOOD
SWIVEL JOINT
HOOD ENCLOSING
TAP SPOUT
(STATIONARY)
.TO
BAGHOUSE
ANNULAR RING HOOD
SWINGS OVER
FURNACE TOP
DURING CHARGING
ANNULAR RING HOOD
IN PLACE TO COLLECT
CHARGING EMISSIONS
JO
HOOD ENCLOSING
TAP SPOUT
TO
BAGHOUSE
Figure 2-13.
Hawley close capture hoods for capturing
electric arc furnace emissions.
25
-------
Figure 2-14.
Close capture hooding system for
electric arc furnace.
26
-------
2.3.1.3 Electric Induction Furnace--
Although some foundries use the channel induction furnace, the coreless
induction furnace is more frequently used for iron melting, as shown in
Figure 2-15. The coreless induction furnace is a cup-shaped vessel which
uses electrical energy to induce eddy currents in the metallic charge to
produce molten iron. Since wet or oily scrap can lead to explosions in a
furnace, the scrap is generally cleaned and often preheated before charging.
Clean scrap generally results in little particulate emission and no carbon
monoxide and hydrocarbon emission. As a result of the low pollutant levels,
induction furnaces are finding increased use in ferrous foundries. Those
furnaces which are controlled generally have a close capture hooding system
vented to a fabric filter, such as the one shown in Figure 2-16 .
2.3.2 Inoculation
Iron inoculation is an operation used primarily in the production of
ductile iron. During inoculation a nodulizing agent, most frequently mag-
nesium, is added to the molten gray iron. This agent causes the flaked
carbon found in gray iron to become graphite spheroids. This chemical
transformation produces a material which is less brittle than gray iron.
The magnesium (or other nodulizing agent) is added to the molten metal
after it has been tapped into the ladle. Several methods used to inoculate
ductile iron are shown in Figure 2-17. Modi describes these processes in
more detail and discusses their advantages.16
Matter indicates that 75 to 80% of the ductile iron produced in the
United States is inoculated using the pour-over and sandwich methods.17 In
the pour-over method the nodulizing alloy is placed in the bottom of the
ladle and the hot metal is poured on top. This method results in 20 to 30%
inoculant recovery, with the remainder of the inoculant emitted as a fine
oxide. With the sandwich method, the alloy is covered with 1 to 2% steel
punching or plate or ferrosilicon. This allows more hot metal to be poured
before the reaction starts and results in magnesium recovery of 40 to 50%.17
Industry personnel indicate that newer methods of inoculation are re-
sulting in a magnesium recovery of 50 to 90%. 15 One method which shows
particular promise inoculates the metal in the mold rather than in the
ladle. Matter indicates that magnesium recoveries of 80 to 90% have been
obtained with in-mold inoculation.17
2.3.3 Pouring and Cooling
The final operation in metal casting is the pouring of the molten iron
into the mold and the subsequent cooling of the casting. The types of pour-
ing operations found in ferrous foundries vary widely depending upon the
type of mold used and the degree of mechanization in a given foundry. Pour-
ing and cooling operations involving sand molds, the mold making most fre-
quently found in foundries, is discussed in the following paragraphs. Pour-
ing of metal into sand molds also has a greater potential for emissions than
pouring into permanent molds. Two major classes of pouring operations,
mechanized pouring lines and floor pouring, are described.
27
-------
A. Hydraulic tilt cylinders
B. Shunts
C. Stanchion
D. Cover
E. Coil
F. Leads
G. Working refractory
H. Operator's platform
I. Steel shell
J. Tie rods
K. Clamping bolts
L. Coil support
M. Spout
N. Refractory brick
0. Access port
P. Lid hoist mechanism
Figure 2-15. A coreless electric induction furnace.
18
28
-------
Figure 2-16. Close capture hooding system for electric
induction furnace.
29
-------
"SANDWICH
"TRIGGER"
POUR-OVER
THROW-IN
PLUNGING
Figure 2-17. Methods of iron inoculation methods used to inoculate ductile iron.
16
30
-------
Mechanized pouring lines are generally found in medium to large found-
ries which produce small- to medium-sized castings. The pouring line has
one or more pouring ladles located along a conveyor. These ladles may be
stationary or may be capable of moving parallel to the conveyor. The molds
are placed on a conveyor and moved to the pouring station. After the pour-
ing operation is completed, the mold and casting are carried by the conveyor
through a cooling area, often an enclosed "tunnel" made of sheet metal.
Floor pouring is found in small- to medium-sized foundries which gen-
erally do not have sufficient capital to finance mechanization, and in
larger foundries which produce castings that are too large to be transported
by conveyor. In these foundries the mold is placed on an open floor or in a
pit, and the ladle is transported to the mold generally by an overhead trol-
ley. When the ladle reaches the mold, the molten iron is poured into the
mold and the casting is then cooled in place.
No controlled pouring and cooling operations were identified by EPA
studies. For floor pouring and pit molds no capture methods were identi-
fied. For mechanized pouring lines, ventilation systems, such as that
shown in Figure 2-18 are often installed although no installations were
identified in which the exhausts from such systems were vented to an air
pollution control device.
2.4 CLEANING AND FINISHING
After the casting has cooled, it is removed from the mold, cleaned, and
finished into a final product. A flow diagram of the cleaning and finishing
process is presented in Figure 2-19.
A number of techniques are available to perform each of the operations
shown in Figure 2-19. The choice of technique depends on the type of metal
cast, the type of mold, the size of the casting, and the degree of mechani-
zation in the foundry.
Because of the wide variety of cleaning practices, it is not possible
to describe what process an inspector might find in a particular foundry.
The following paragraphs trace the flow of the casting through the cleaning
room. Whenever possible, pictures or diagrams of the major pieces of equip-
ment used to perform the various operations are included. Also described
are some of the ventilation systems used to capture emissions. Captured
emissions are generally exhausted through a fabric filter and either vented
to the atmosphere or recycled to the foundry.
After the casting has cooled, it must be removed from the mold. If a
sand mold is used, this process is generally called shakeout. Shakeout me-
thods probably vary more from plant to plant than any other operation with
the possible exception of mold and coremaking. In foundries where large
pit molds are used, the sand is often removed from the mold with front end
loaders and shovels. In small, unmechanized foundries methods consist of
dumping the molds onto the floor, using pneumatic tools to break the sand
loose, and manually removing the sand with shovels.
31
-------
Figure 2-18. A 33,000-cfm compensating hood on the pouring
line.19
32
-------
from Pouring
I
Shakeout
Remove Gates
& Risers
Figure 2-19. Flow diagram of cleaning and finishing process.
33
18
-------
The most typical method of removal is to place the flask on a vibrating
screen. The sand is knocked loose from the casting and falls through the
screen, and the castings are carried on the vibrating screen to a conveyor
and then moved on to other the next cleaning step. One newer method of
shakeout substitutes a rotating screen for the traditional vibrating screen.
Emissions from shakeout are generally captured by either a hood enclosure or
a side draft hood such as the ones shown in Figures 2-20 and 2-21.
The next step in the cleaning and finishing process is removal of the
sprues, gates, and risers, if these have not been knocked off during shake-
out. These appendages can be knocked off manually with hammers; cut off
with abrasive, band, or friction cutting; or removed with an oxygen torch.
Examples of abrasive cutoff and oxygen cutting are shown in Figures 2-22
and 2-23. The ventilation system associated with appendage removal will de-
pend upon the size and shape of the casting and the method of removal. With
larger castings where oxygen cutting is used, a booth with air exhaust such
as the one shown in Figure 2-23 may be used. In other cases downdraft
benches or close capture type hooding systems may be used. Often these op-
erations are not controlled.
After the appendages are removed, chipping hammers and various types
of grinders are used to remove other irregularities from the casting. Again,
the method of emission control is dependent upon the size and shape of the
casting and the type of tool being used. Figures 2-24, 2-25, and 2-26 show
examples of controlled chipping and grinding emissions.
Finally, the castings are subjected to blast cleaning or tumbling to
remove the remaining scale or burned on sand. Both shot and sand blasting
are used in ferrous foundries. A typical abrasive blast system is shown in
Figure 2-27. Generally, the blast unit is enclosed and air is exhausted to
a fabric filter.
2.5 SAND HANDLING SYSTEM
In foundries which practice sand molding, the sand is reused many
times. In a typical system the sand is removed from the shakeout hopper,
reconditioned to remove lumps and any metallics that have fallen through the
shakeout grate, and returned to the sand storage bins before being used in
the muller.
The specific sand handling steps vary depending upon the degree of
mechanization in the foundry. At unmechanized foundries the sand may be
dumped onto the floor during the shakeout, transferred manually by front
end loader to a screening operation, and transferred manually again to a
storage pile near the muller from where it is manually charged to the
muller.
34
-------
OJ
t-n
Figure 2-20.
Three enclosed shakeouts, automatic discharge mold conveyor lines and sand distribution.
Casting conveyor brings castings from tunnel to working level on floor where castings
are desprued and sorted. Part of a complete handling and preparation system.
-------
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36
-------
CONTROL OPENING = FRONT
OPENING +2 END OPENINGS
Figure 2-21. Side draft shakeout hood."
37
-------
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38
-------
Figure 2-22.
Abrasive cutoff of
sprues and risers
in cleaning and
finishing process.
20
39
-------
This page intentionally left blank.
40
-------
(a)
(b)
Figure 2-23. Torch cut-off of risers in cleaning and finishing process.
8,20
41
-------
—Branch take -off at top or back. Central kxation
or multiple branches if several booths art used.
Additional adjoining
booths if needed.
45° slope
Booth encloses grinder
frame and suspension.
Grinder to operate in or
close to face opening.-
4'-6'- large opening - face
velocity - IOO to ISO fpm -
never below IOO fpm
2 '-0"- 2'-6 ' - small opening -
grinder in front - face velocity=
2OO fpm
Minimum duct velocity =3OOOfpm
Entry loss =O.5VP
NOTE: Small local exhaust hoods mounted behind
grinder wheel may trap the stream of sparks,
but are usually not effective in control of
> air - borne dust.
Figure 2-24. Swing grinder booth.
21
42
-------
Figure 2-25. Swing grinding operation. The hood cjfcite is adjusted to capture
the entire grinding swarf.
8
43
-------
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44
-------
Figure 2-26. Downdraft chipping and grinding bench.
45
-------
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46
-------
separators
elevator
blast wheel
abrasive
blast
- castings
mill
Figure 2-27. Abrasive blast cleaning unit.
20
47
-------
More commonly, sand falls through the shakeout floor. At this level
the metal is separated from the sand on a drum separator. The sand is then
aerated and cooled and transferred by conveyors and bucket elevators to sand
hoppers located above the mullers. Figure 2-28 shows a modern high volume
sand system. This particular system was modified to use the Schumacher sys-
tem to decrease emissions. In this system damp sand is introduced into the
stream immediately after shakeout to inhibit dust release. Most sand han-
dling systems use common materials handling hooding and ventilation systems,
and the exhaust is directed to a fabric filter or low energy wet scrubber.
48
-------
New
150 Ton
Muller
Planned
i I—I
Shakeout Sand Belt
Sand Storage Bin Temperature
Varies with Ambient:
85-90°F AMB. = 115°F Bin (9-11-69)
73° F AMB. = 105° F Bin (12-9-69)
Figure 2-28. A high volume sand handling system.22
-------
SECTION 3.0
FOUNDRY EMISSION PROBLEMS AND CAUSES
3.1 INTRODUCTION
Ferrous foundries utilize a variety of processes. The specific pro-
cesses used vary with the size and type of foundry. A fully mechanized mod-
ern foundry has most of the processes discussed in the foregoing section
while a small jobber foundry may have very few processes (melting and cast-
ing only). &
Emission problems in foundries also vary from foundry to foundry In a
well controlled, large, modern foundry one can expect to find fewer emission
problems than in small jobber foundries. In foundries that have properly
designed control systems, emission problems can be related to one of the
following causes:
Poor operating practices.
Poor maintenance of process and emission control equipment.
Poor housekeeping.
This section discusses emission problems by process. The processes in-
cluded are raw material storage and charge preparation, mold and coremaking-
metal melting (emissions from cupolas, electric arc furnaces, and electric '
induction furnaces), iron inoculation; pouring and cooling; shakeout, clean-
ing and finishing; sand handling; and other miscellaneous areas. Table 3-1
shows in detail various types of emissions from different metallurgical pro-
cesses. The source numbers on Table 3-1 are keyed to numbers on Figure 3-1
a flow diagram of a representative ferrous foundry. '
3.2 RAW MATERIAL STORAGE AND CHARGE PREPARATION AREA
The storage, handling, and charge preparation of a ferrous foundry's
raw materials (scrap metal, coke, fluxing agents) produces emissions in a
variety of ways. The open storage of raw materials over time may result in
the disintegration of these materials from the action of the sun, rain and
repeated freezing and thawing. Ferrous scrap rusts rapidly. Subsequent
handling of these materials causes fugitive emissions around the storage and
preparation area. When some of these emissions are carried away from
foundry properties by wind or vehicular traffic, they become a nuisance
problem. Visual observation of cupola plumes indicates that the degradation
of coke and limestone also affects those emissions, although specific test
data are not available to relate emissions from cupola to coke, limestone
and scrap quality.
51
-------
TABLE 3-1. EMISSIONS FROM METALLURGICAL PROCESSES, INDUSTRY:
GRAY IRON FOUNDRY 15
Source Source Sulfur Carbon Nitrogen Hydrogen Metal
No. identification Particulates oxides monoxide oxides sulfide fumes
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Limestone Handling
Limestone unloading
Limestone to storage
Limestone storage
Limestone to cupola
furnace
Coke Handling
Coke unloading
Coke to storage
Coke storage pile
Coke to cupola furnace
Pig and Scrap Iron Handling
Pig and scrap iron
unloading
Pig and scrap iron pile
Pig and scrap iron
furnace
Cupola Furnace
Electric Arc Furnace
Induction Furnace
Ductile Iron Innoculation
X
X
X
X
X
X
X
X
X
X
X
1 X X X
X X
X X
X
X
X
X
(continued)
-------
TABLE 3-1. (continued)
Source Source Sulfur Carbon Nitrogen Hydrogen Metal
No. identification Particulates oxides monoxide oxides sulfide fumes
Casting
17 Casting shakeout
18 Return sand to mold
making
19 Cooling and cleaning
20 Finishing
X
X
X
21 Castings loading (shipping)
Mold Making
22 Mold binder unloading
23 Mold binder storage
24 Sand unloading
25 Sand storage
26 Sand to mix
27 Mold mix
28 Mold molding
29 Spill sand return to mold
mix
Core Making
30 Core sand unloading
31 Core sand unloading
32 Core sand to core mix
33 Core binder unloading
34 Core binder storage
35 Core binder to core mix
36 Core mix
37 Core molding
38 Core baking
Pollution Control
/
X
X
X
X
X
X
X
X
X
X
X
X
X
X
XXX
39 Baghouse dust
-------
LIMESTONE
-P-
DUCTILE IRON
INNOCULATION
EMISSIONS
CASTINGS
SHIPPING
' '(21)
Figure 3-1. Flow diagram of representative ferrous foundry.
-------
The preparation of metallic charge materials includes breaking and cut-
ting large scrap materials and removing cutting oil residue from machine
shop turnings and borings in preparation for briquetting. The cutting of
oily, painted, or other contaminated scrap causes excessive smoke and par-
ticulate emissions. Similar emission problems may exist in foundries where
scrap is preheated before it is charged to an electric induction furnace.
These emission problems are seen more often in smaller, older foundries
than in modern, larger foundries. The emissions from the former are consid-
ered a minor problem and more of a nuisance problem than a compliance prob-
lem.
3.3 MOLD AND CORE OPERATION
The only source of particulate emissions from mold and core operations
is fugitive emissions during the transfer of dry materials such as clean
sand, spent sand from the shakeout area, and the dry mixing of sand and
binder. One especially vulnerable point in the operation is sand charging
at the muller. Other emissions resulting from these operations are carbon
monoxide and organic vapors (formaldehydes, amines, ammonia, and phenols)
from the binders used in molding operation; such mixtures of organic vapors
have a "typical foundry odor." Most foundries have good ventilation and a
fresh air system to protect workers in these areas. Emission problems be-
come noticeable when the hooding or exhaust system does not effectively cap-
ture the emissions or when the control device does not effectively remove
pollutants from the emission-laden stream.
3.4 METAL MELTING
The greatest amount and heaviest concentration of emissions are gener-
ated in this area of a foundry, thus requiring control equipment on cupolas
and some electric arc furnaces and electric induction furnaces.
3.4.1
The cupola is the single largest source of emissions, emitting fumes,
smoke, metallic dust, and gases. Several studies show that cupola emission
rates are not significantly affected by the design of a furnace within the
parameters established by current U.S. design practices. These parameters
include the method of blast heating, top or side charging, charging door size
and whether the opening is closed or open, the location of the gas takeoff
above or below the door, or an open stack permitting the gases to escape out
the top. In addition, no significant effect on emission rates was found for
specific melting rates.18
Some factors do affect emissions. In general, if all other factors are
equal, unlined cupolas have emission rates greater than lined cupolas. The
use of briquettes also increases emissions.18
Acid-lined cupolas show a significant correlation between emissions and
blast rate, expressed by the equation.18
55
-------
E = 0.05 + 0.07B
where: E = Particulate emissions (Ib/ton melt)
B = Specific blast rate (SCFM 1 ft2 furnace area)
A U.S. Department of Energy study of the effect of blast rate on cupola
emissions shows that in seven of eight cases the blast rate had a signifi-
cant relationship to emissions. Also, melting metal at a higher rate pro-
duces a higher loading of fine particles.23
Data from a Canadian Department of Energy, Mines and Resources study
indicated that at least 40% and perhaps as much as 6Q7<> reduction in emis-
sions was obtained from the use of screens and other precautions to limit
the amount of loose sands, rust, and coke fines charged to the furnace.
Since the cupola is kept under negative pressure for emission control pur-
poses, charging is generally not a fugitive emission problem.23'24
Tapping a cupola is done in one of two ways. In the first case, the
metal is tapped to a forehearth where slag is skimmed and then the iron is
transferred into a ladle for pouring. In this case, the slag skimming and
transfer into the ladle are minor sources of fine particulate emissions. In
the second case, the metal is tapped directly to a ladle and the slag is
skimmed from the ladle. This is also a minor source of fine particulate
emissions.
Cupolas equipped with a takeoff for collecting emissions that are below
the charge door will have a potential emissions problem during the burndown
operation. Significant emissions may be released to the atmosphere through
the charge door, unless some means were provided to physically seal off the
stack between the charge door and the point of emissions takeoff.
If a cupola has correctly designed air pollution devices installed on
it, typical emission problems usually result from incorrect operating prac-
tices or malfunctions of the control equipment.
3.4.2 Electric Arc Furnace
Emissions from the electric arc furnace (EAF) occur at five stages of
the operation: charging, melting, backcharging, oxygen lancing (generally
used only in steel foundries), and tapping.
In general, an EAF which is well-controlled (emissions controlled by
direct shell evacuation, canopy hood, and fabric filter) will have very few
emission problems. Excessive emissions will occur only if:
Above-average dirty scrap with high oil content (turnings,
chips, and borings from machine shops) is charged.
56
-------
The foundry increases production with short melting cycles;
there is a direct relationship between the rate of emissions
produced and the rapidity with which melting occurs.
Inefficient capture takes place during charging, oxygen lanc-
ing, or tapping operations due to cross drafts through open
doorways.
Oxygen lancing is used to speed up the melting process and
superheat the bath.
3.4.3 Electric Induction Furnace
No serious emission problem exists for induction melting of iron since
in an electric induction furnace (EIF) the metal scrap used must be dry and
free of oil. Many of these furnaces are uncontrolled. A fugitive emission
problem may occur when oil residue on the scrap is burned off. This may re-
quire emission control equipment.
3.5 IRON INOCULATION
The emissions produced in the inoculation process are directly related
to the level of inoculant (magnesium or similar alloying compound) recovery
for the particular method used by the foundry. For example, in the pour-
over method of inoculation only 20 to 30% inoculant recovery is obtained
while the remainder of the inoculant is emitted as a fine oxide. This com-
pares to the mold inoculation method where 80 to 90% inoculant recovery has
been obtained; very few oxides are emitted.
3.6 POURING AND COOLING
The total emissions generated from pouring and cooling castings are not
significant compared to total emissions from the foundry operations, al-
though limited data indicate that they may be the most significant fugitive
emissions. As the hot metal is poured into the mold, metallic fumes and
products of combustion and decomposition of the binder systems are released
to the foundry environment. The quantity of these emissions is related to
mold size, mold composition, sand-to-metal ratio, pouring temperature, and
pouring rate. These processes vary significantly among foundries. In
mechanized foundries the molds are placed on a conveyor and moved to the
pouring station and then moved to the cooling area where they are captured
by a local exhaust system. In unmechanized foundries, this process takes
place in large open areas in the foundry. The emissions are contained in
a relatively high temperature, buoyant, moist stream and released to the
foundry environment. The control of these emissions is difficult, and in
most small foundries the emissions are uncontrolled.
3.7 SHAKEOUT, CLEANING, AND FINISHING
In general, emissions from these areas consist of dust from dried sand,
organic residue from binders, steam, fine metallic particulates, iron oxide\
57
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and fumes. In most cases these emissions are controlled by local exhaust
systems at the source. Exceptions are found in small foundries.
The major emission problem is caused by insufficient capture velocities
in local exhaust systems. Airborne dust from handling and processing of ma-
terials also can add to inplant fugitive emissions. Most of these emissions
are localized and are not released directly to the ambient air. For sources
where local exhaust systems are used, most of the problems may be related to
malfunctioning of a local exhaust system and air pollution control device.
3.8 SAND HANDLING SYSTEM
Dry sand from the shakeout goes through magnetic separation, cooling,
and screening and is returned to storage or the muller. Each of these pro'-
cessing steps and conveyor transfer points is a potential source of fugitive
particulate emissions. In most foundries, sand is moved by conveyor, usu-
ally an enclosed system, and some type of exhaust system is used at all
transfer points. The major potential fugitive emissions problem from sand
handling is malfunctioning control equipment or poor housekeeping. Many
times, due to poor housekeeping, spillover sand and other materials become
major sources of fugitive emissions within a plant area.
3.9 OTHER AREAS FOR POTENTIAL EMISSION PROBLEMS
3.9.1 Waste Handling
The primary waste materials produced at a foundry are slag from the
melting operations and spent sand from molds and cores.
The slag, once skimmed off the molten metal, is solidified by air cool-
ing or water quenching. Either cooling method can produce small amounts of
sulfur dioxide, while hydrogen sulfide (H2S) can be produced with water
quenching.
Foundries that use green sand molds replace about 2 to 3% of total
foundry sand daily to ensure proper sand quality. This spent sand is gener-
ally stored temporarily in either outdoor piles or hoppers. It is then
transferred, along with slag, to a landfill for disposal. Potential for
fugitive emissions exists during handling and transfer of the materials to
the storage area, from wind erosion of outdoor storage piles, and, if cov-
ered transport vehicles are not used, during transfer to a landfill for
final disposal.
3.9.2 Housekeeping
Many particulate fugitive emission problems in foundries are caused by
poor housekeeping through reentrainment of dust by workers, mobile vehicles,
machinery vibrations, and compressed air tools.
3-9.3 Routine Maintenance
Lack of routine maintenance of ventilation systems, local exhaust sys-
tems, ductwork, and air cleaning equipment also can contribute significantly
to emission problems.
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SECTION 4.0
INSPECTION PROCEDURES
It is relatively easy to demonstrate that a source is in violation of
visible emissions (VE) or permit requirements, but not all inspections are
this straightforward. Violations of standards regulating grain loading, pro-
cess weight, fuel composition, or gaseous contaminants are more difficult to
demonstrate and require greater effort. Compliance determinations in these
cases are made only after sufficient information has been gathered on the
operation and maintenance of the process and control equipment. The role of
field inspectors is to obtain this information or to identify possible indi-
cators that the source is out of compliance or will be out of compliance in
the near future.
After receiving the inspection report from the field inspector, a staff
engineer may require further fuel and material sampling, operational data,
or special stack tests to show whether or not the source is in continuing
compliance through all ranges of its operation. In some cases the field in-
spector may be the person who requires further information.
In the following subsections of this guide, the inspection procedures
and checklists for typical processes and control equipment found in ferrous
foundries are discussed. Inspections are described step by step, including
what information the inspector should note and the reasons behind the re-
quired information. The checklists for various types of equipment are found
in Appendix B.
4.1 PREINSPECTION PROCEDURES
The following paragraphs suggest preinspection procedures. They are
intended as general guidelines and are not meant to supersede procedures
that may have already been established by an agency.
4.1.1 File Review
The first step in preparing for an inspection is to review information
in your agency's file. You should review the types of processes and control
equipment you will be inspecting, previous reports from other inspections,
past conditions of noncompliance, history of malfunctions, citizen's com-
plaints, and other relevant information which will give you some background
on the source's continuing compliance efforts. During this file review,
you can complete the "Cover Sheet for Process and Control Equipment Check-
list" (see Appendix B).
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In the agency file, you may also find data on the normal range of op-
erating conditions for processes and control equipment. This baseline data
should be compared to data collected during the actual inspection. For ex-
ample, if the melt rate of the cupola is higher than the melt rate in the
original file, the cupola may be in violation of mass emission regulations.
4.1.2 Announcement of Inspection
If the inspection is to be announced, the inspector should inform the
source a few days to a week in advance so the proper plant personnel will
be available as escort during the inspection. The plant should be inspected
when all or most of the operations are running to avoid the necessity for
additional visits to the plant.
4.1.3 Safety and Pre-Plant Entry
A hardhat, safety glasses, safety shoes, and earplugs are the most
likely safety equipment items you will need for the inspection. Suitable
clothing should be worn and an OSHA-approved dust mask should be available.
See Section 5 for detailed discussion of equipment needs.
If it is possible before entry, drive around the perimeter of the plant
property to observe any visible emissions, fugitive emissions, or odor prob-
lems. If you notice any violations, take VE readings from an appropriate
position. If your agency provides a camera, then you should take pictures.
In some cases you might have to enter the plant property to take VE read-
ings. If so, you may have to get permission from the source to be on plant
property.
4.1.4 Plant Entry
When you arrive at the gate or front office of the plant, introduce
yourself, show proper identification, and request to see the responsible
plant official. Follow your agency's instructions regarding the signing of
any forms that limit the plant's liability for your safety or that restrict
the scope of your inspection.
If this is an unannounced inspection and for some reason the plant
denies your entry to all or part of the facility, note the reasons for re-
fusal, the name and title of the plant official responsible for the refusal,
and the precise time of the refusal. Notify your supervisor by telephone
immediately, and let your agency's legal staff handle the matter.
4.1.5 Preinspection Meeting
Before starting an inspection you should meet briefly with plant offi-
cials to discuss the following points:
Purpose of the inspection.
Any hazardous areas.
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Process(es) and control equipment to be inspected.
Any changes in responsible officials since the last inspection.
Any changes or modifications in plant operations since the last
inspection.
Current data on production including raw material and process
weight rate and that day's melting rate.
Treatment of confidential data.
Avoid requesting redundant data from the plant officials. However, be sure
to request all information that is essential to your inspection. Know ex-
actly what you want to inspect to avoid wasting your time and that of the
plant personnel.
4.2 PROCESS AND CONTROL EQUIPMENT INSPECTION PROCEDURES
The typical ferrous foundry has a variety of operations which may be
sources of particulate and gaseous emissions. For the following discussion
foundry operations are divided into melting operations and nonmelting opera-
tions .
A typical inspection is performed in four steps:
Stack and roof observations;
Data gathering in the instrument control room;
Inspection of control equipment; and
Inspection of process equipment and local exhaust systems.
The steps will vary depending upon the process and control equipment,
but, in general, the checklists are set up in the above order.
Appendix B contains six checklists which cover various combinations
of typical process and control equipment used in foundries. Checklists for
melting operations cover processes and control equipment, while checklists
for nonmelting operations cover only local exhaust systems and control
equipment. Process operating conditions do not typically cause emission
problems in nonmelting operations.
Before you start the inspection, you should have completed "Cover Sheet
for Process and Control Equipment Checklist." To save inspection time, this
can be completed during your file review at the agency. Clearly identify
facility name and address, inspection date and time, type of process, pro-
cess ID, and control equipment ID. Make sure you identify all processes if
the control equipment serves more than one process. Equipment ID is impor-
tant when a facility has more than one process of similar type; e.g., a
61
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large automobile engine block manufacturer may have five to seven cupolas
side by side, and the emissions may be controlled by only two or three
scrubbers.
4.2.1 Melting Operations
In general, there are three typical process-control equipment combina-
tions in foundries: (a) cupola with high energy scrubber; (b) cupola with
gas cooling system, fabric filter; and (c) electric arc furnace or electric
induction furnace, fabric filter.
One area common to all these melting operations is the charge prepara-
tion area. See Appendix B for the checklist covering the charge preparation
area.
4.2.1.1 Inspection of Charge Preparation Area (Checklist I)--
During the preinspection meeting with plant officials, you should get
information on raw material and process weight rate. Compare these num-
bers with the numbers in the foundry's original permit application or the
information in the file. Changes in composition of the charge will affect
the emissions.
During the walkthrough of the charge preparation area:
Check if the scrap is dirty (oily, rusted, fine matter), and note
if any charge preparation is done, for example, cutting big pieces
of scrap, burning off of oil from scrap, or any screening.
Check if raw materials are stored in an enclosed building or out-
doors .
Observe charge loading. Excessive dust dumped with other raw ma-
terials will increase emissions from melting equipment.
Check how charges are weighed. If weight is approximated, find
out how the melting rate or process weight is estimated because
compliance with process weight regulations could be affected.
4.2.1.2 Inspection of Cupola with High Energy Scrubber (Checklist II)--
During the preinspection meeting with plant officials, you should get
information on the melting rate. Make sure the number you are told is the
actual melting rate of that day and not the number submitted previously to
the agency. Ask for the logbook or plant records to verify the melting
rate.
During the walkthrough:
Request to be taken to the roof if possible, or find a location
where you can observe the stacks.
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Look for any VE violations or fugitive emissions.
Look for leakage of gases from the cupola top.
Next, visit the cupola control panel. In many foundries the instru-
ment panel for the scrubber is located in the same room; in some foundries,
however, controls for furnace and control equipment are in different places.
In the latter case, you will have to visit both areas.
Note the data requested in the checklists.
Check when the monitoring instruments were calibrated the last
time.
If the instruments are not functioning, find out and note the
reasons.
Next, visit the scrubber system. A typical type of high energy scrub-
ber used in a foundry is the Venturi scrubber.
Inspect externally the whole scrubber housing, associated duct-
work, fan housing, and pumps for corrosion and leakage.
Any air infiltration will reduce operating pressure of the system and
affect the efficiency of the control system.
Since high energy scrubbers operate with high pressure (40 to 70 in.
wg.) it is not possible to observe the scrubber internally when the system
is operating. If the scrubber is equipped with portholes through which the
spraying nozzles or sump area can be seen, then:
Check whether scrubbing liquid is being sprayed with proper pres-
sure. Low pressure results in an increase in the water spray
droplet size and results in reduced collection efficiency.
Look for plugged or worn nozzles or buildup of scrubbing liquid in
the sump (see Figure 4-1). In most cases you will have to depend
upon the data gathered at the instrument panel. A very high water
pressure indicates a plugged nozzle which should be replaced. A
below average flow rate of scrubbing liquid indicates pumps are
not operating efficiently or that the recirculated liquid contains
suspended solids. If the pump motor is equipped with an ammeter,
then a below average ampere reading indicates plugging of nozzles
or spray bars. It also can indicate pump wear or plugging of the
suction line. An increase in the ampere reading indicates holes
in the spray bar or missing nozzles.
Check the fan system for excessive vibration and audible belt
slippage noise. Causes of fan vibration can be material buildup
on fan blades, cracks in the fan blades or wheel, holes due to
corrosion in the fan housing, or open access doors (Figures 4-2
through 4-4). Fan vibration will eventually cause a breakdown
and severe mechanical damage that can result in a malfunctioning
control system.
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Figure 4-1. Reduction
in spraying action of
worn nozzle.
Replace Worn Spray Nozzles -
to Restore Good Collection Efficiency
WORN FAN HOUSING
Holes or Cracks in
Housing Starve Air
from the System
Figure 4-2
EXCESSIVE FAN VIBRATION
Excessive Vibration is Usually Caused by
Worn Impeller. Replace or Repair Promptly
-FLYING BLADES ARE LETHAL. Use Qual
ified Personnel Only.
Figure 4-3
Source:
Figure 4-4
Inadequate Tension -
Causes Belt Slippage and Wear
Figures 4-2 - 4-4. Typical fan problems.
The Maintenance and Operation of Exhaust Systems in the Hot Mix
Plant, Information Series 52A, National Asphalt Paving Asso-
ciation.
-------
Last, observe the cupola operation.
Check for fugitive emissions at the charge door during the charg-
ing operation.
Check if afterburners are operating. These burners burn off car-
bon monoxide and other oily organic materials. Thus, they help in
complying with opacity regulations and also prevent explosions in
the gas cleaning system. Further, they reduce problems caused by
condensation of organic materials in the primary control device.
Check that the cupola top remains closed at all times during op-
eration. If you find it open, find out the reason.
Check if the cupola system is equipped with a control equipment
bypass system, and note the amount of time control equipment is
bypassed (check plant records). Discuss excessive malfunction
problems with plant personnel. If data from the instruments posi-
tively indicate problems with the scrubbers, set up a time with
plant personnel to inspect the scrubbers internally.
Follow the steps in the checklist.
If time permits, observe the foundry's start-up and shutdown prac-
tices .
4.2.1.3 Inspection of Cupola with Gas Cooling System, Fabric Filter
(Checklist III)--
The initial steps of stack observation and data collection from the
control room are the same as those discussed above for the cupola with high
energy scrubber. After noting the data required (see checklist) from the
cupola control room and/or monitoring instruments for the control equipment:
Inspect the gas cooling system. The three systems most commonly
used in foundries are: cooling by convection columns, by dilution
of exhaust gases by air, or by spray towers. Although the check-
list for the gas cooling system is primarily written for spray
towers, a common but important parameter for any cooling system is
the exit temperature of the gases which enter the fabric filter.
This temperature should be sufficiently low to prevent damage to
the bags in the fabric filter. At the same time, to prevent con-
densation on bags or other fabric filter components, the tempera-
ture should not be lower than the dew point of the entering gases.
Consider the various items in the checklist and whether the indi-
cators show that the cooling system is functioning properly or po-
tential problems exist.
After checking the gas cooling system:
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Examine the fabric filter system externally for corrosion of the
housing, weld seam gaps, and holes. This type of damage will
cause external air infiltration, which reduces operating pressure,
causes condensation on internal surfaces of the fabric filter
housing bags, and promotes bag blinding and corrosion.
Check the proper operation of cleaning cycles by making visual ob-
servations; listening for sound from movement of solenoid valves,
noise of air puffs, or a shaker mechanism in operation; and noting
pressure gauges. Pressure gauges in multicompartment fabric fil-
ters will show lower pressure in the compartment that is going
through a cleaning cycle.
Observe the discharge of solids from screw conveyors or hoppers.
An irregular or erratic discharge indicates solids buildup or
bridging in the hopper. Only an internal inspection will reveal
the definite cause.
Check the fan system for excessive vibration and audible belt
slippage noise.
Compare data noted from the instruments with the average values
(available from the agency's files or fabric filter manufacturers).
Excessive pressure drop across the fabric filter indicates bag
blinding, cleaning system not operating properly, insufficient
cleaning cycle time, or solids removal system not operating prop-
erly. If the pressure drop across the fabric filter is below
average, bag tears or loose or missing bags are indicated.
If during the external inspection you find abnormal values for operating
parameters compared to average values, then an internal inspection may be war-
ranted. With compartmentalized fabric filters you may be able to perform an
internal inspection while the fabric filter is operating. This should be done
only if necessary and a self-contained respirator should be worn at all times
inside the fabric filter. Otherwise you may have to reschedule an internal
inspection when the filter is not operating.
During an internal inspection:
Make sure you take all safety precautions to guard against heat,
toxic gases, and low oxygen levels. A plant official should accom-
pany you on the internal inspection. Note: Never conduct internal
inspections alone.
Check that the clean side of the fabric filter is clean; if it is
not, there are definitely broken or loose bags.
Check for material deposited on bags or on the floor near the bot-
tom of bags.
Check the condition of the bags. It will indicate improper op-
erations; e.g., burn spots on bags indicate insufficient cooling
of exhaust gases entering the fabric filter or that the wear
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plate is worn out and gases are entering at high velocity. Any
dust buildup or bridging in the hopper or fabric filter indicates
air and moisture leaks in the fabric filter or that the solids
removal system is not functioning properly.
If possible, check the high temperature alarm system and the fab-
ric filter bypass system. If the cooling system fails and the
alarm system or the bypass system is not functioning, the filter
can be damaged severely.
Last, observe the cupola operation.
Check for fugitive emissions at the charge door during the charg-
ing operation.
Check if afterburners are operating. These burners burn off car-
bon monoxide and other oily organic materials. Thus, they help
in complying with opacity regulations and also prevent explosions
in the gas cleaning system. Further, they reduce problems caused
by condensation of organic materials in the primary control de-
vice.
Check that the cupola top remains closed at all times during op-
eration. If you find it open, then find out the reason.
Check if the cupola system is equipped with a control equipment
bypass system, and note the amount of time control equipment is
bypassed (check plant records).
Discuss excessive malfunction problems with plant personnel. If
data from the instruments positively indicate problems with the
scrubbers, set up a time with plant personnel to inspect the
scrubbers internally.
Follow the steps in the checklist.
If time permits, observe the foundry's start-up and shutdown
practices. Obtain process related data (see checklist) prior to
the inspection and observe during the inspection.
4.2.1.4 Inspection of Electric Arc Furnace or Electric Induction Furnace,
Fabric Filter (Checklist IV)--
Since the basic steps to inspect the electric arc furnace (EAF) and the
electric induction furnace (EIF) are the same, one checklist is sufficient.
In general, only clean scrap is melted in the EIF; thus, there are very few
emissions. You may find that an EIF has no controls at all.
For the initial inspection steps of observing visible and fugitive
emissions:
67
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Request to be taken to the roof if possible, or find a location
where you can observe the stacks.
Look for any VE violations or fugitive emissions.
Next is the inspection of the control equipment and fabric filter. The
majority of the emissions from the EAF and EIF are captured through a side
draft or canopy hood. Captured emissions are then taken to the fabric fil-
ter. Since large amounts of air are exhausted with the emissions, a gas
cooling system is not needed.
For inspection of the fabric filter the reader should refer to subsec-
tion 4.2.1.3.
During the inspection of the EAF and EIF, you should observe all opera-
tions: charging, tapping, back-charging, and melting.
Look for fugitive emissions.
Check if the canopy hood or any other type of hood is capturing
emissions properly. In many instances, cross-drafts caused by
open windows and doors will deflect emissions away from the hood.
Many times, the charge is preheated in the EIF and may cause
fugitive emissions.
Check the preheating of the charge buckets or conveyors for emis-
sion problems.
4.2.2 Nonmelting Operations
The nonmelting foundry operations (pouring and cooling, shakeout,
cleaning, and sand handling) which are sources of particulate and organic
vapors can be classified as fugitive emissions sources. They are so de-
fined because, in the absence of auxiliary ventilation systems, the emis-
sions enter the foundry environment and are exhausted to ambient air through
doors, windows, roof monitors, and exhaust vents rather than through a con-
fined stack.
In medium to large mechanized foundries with auxiliary ventilation sys-
tems, problems may be due to malfunctions of the exhaust ventilation system
or operation and maintenance of the control equipment or ductwork. In most
foundries, these emissions are controlled by low energy scrubbers or mechani-
cal collectors (cyclone, multiclone).
As you will note, the checklist for nonmelting operations is for local
exhaust systems and control equipment only, not for processes. Primarily,
therefore, you will be checking the exhaust system (emission pickup points,
hoods, ductwork) and the related control equipment. However, you should
identify any other fugitive emissions that are occurring from the operations.
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4.2.2.1 Local Exhaust System with Low Energy Scrubber (Checklist V)--
The first steps in inspecting any of the nonmelting operations are:
Go up to the roof, if possible.
Look for any visible emissions from stacks or fugitive emissions
through ventilation fans.
Make VE readings if needed.
If you see a large amount of particulate (e.g., sand) on the roof,
inquire about any regular cleaning program. Such particulates can
become windblown and cause fugitive emission problems.
The next step is:
Visit the control equipment area and check the scrubber system
visually. This system will be much smaller and less complex to
inspect than a scrubber system on melting equipment. Most of the
time this type of scrubber will not have many monitoring instru-
ments. If there are pressure gauges or a flow meter, they will
usually be located very close to the control system.
Note the data required in the checklist.
Make visual observation, through the access doors or portholes, of
the scrubbing liquid spraying system for plugged or missing spray
nozzles and buildup of scrubbing liquid in the sump.
Check the fan system for vibration and audible belt slippage. If
you notice a problem, then follow other steps in the checklist to
find the causes. Causes of fan vibration can be material buildup
on fan blades, cracks in the fan blades or wheel, holes due to
corrosion in the fan housing, or open access doors. Fan vibration
will eventually cause a breakdown and severe mechanical damage
that can result in a malfunctioning control system.
Next, visit the process equipment area to observe the local exhaust
system. Usually, this system consists of a hood and exhaust ductwork, and
the emissions are captured by the hood and then transferred through the ex-
haust ductwork to the control equipment. Often there are several hoods col-
lecting different types of emissions, and these hoods are then connected to
one control device.
Check to see if emissions are being captured adequately by the
hood. Emissions or exhaust gases may be deflected from the hood
because of insufficient capture velocities, improper location of
the hood, or the presence of cross-drafts (caused by open windows,
a large opening in the building, or open doors) or thermal drafts.
Large amounts of dust in the ductwork, which plug the exhaust sys-
tem, can result in low flow and poor capture. Common emission
problems at more than one nonmelting operation may indicate poor
operation and maintenance of the control system.
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4.2.2.2 Local Exhaust System with Mechanical Collectors (Checklist VI)--
Initial steps in the inspection of this type of system will be the same
as those discussed above in subsection 4.2.2.1. Perform all external checks
first.
Most mechanical collectors are structurally unified with almost no mov-
ing parts except the solids removal system. Thus, they require very little
maintenance. The first problem associated with mechanical collectors is
holes due to corrosion and wear caused by abrasive dust or a high dust load-
ing. The second problem is associated with the buildup of dust in the ex-
haust ductwork and inside walls of the collector. Holes due to corrosion or
wear in the body of the collector and/or ducts allow outside air to enter,
displacing exhaust gases. This reduces the capacity of exhaust hoods and
affects their collection efficiency (see Figure 4-5).
If visible emissions are observed from the gas outlet tube, then an in-
ternal inspection may be needed.
Take necessary safety precautions before you perform an internal
inspection. (See Section 5 for detailed discussion of possible
hazards.) An internal inspection is done mostly by visual obser-
vations .
Check flop gates, double-tipping gates, or rotary airlocks for air
leakage and wear (see Figures 4-6 and 4-7). If the particulate
discharge valve fails or the collection hopper is clogged, then
material may accumulate in the cyclone to the point that it ceases
to function (Figure 4-8).
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Figure 4-6
CYCLONE - PRIMARY COLLECTOR
Holes in Primary Collectors & Duct
Impair Dust Collection and Steel Air
from Dryer. Make Sure That Repairs
Result in Smooth Inside Surface.
Simple Gravity Valve -Must Swing Freely and
Seal Well When Closed. Replace Seal When Worn.
Figure 4-5. Disturbance in airflow
due to holes in cyclone.
Source:
The Operation and Maintenance
of Exhaust Systems in the
Hot Mix Plant, Information
Series 52A, National Asphalt
PIC
Paving Association.
Figure 4-7
Double Tipping Valve-
Must Operate Freely
ROTARY AIR LOCK
Figure 4-8
Excessive Wear on Rotor Causes
Air Leakage Up Through Valve
Figures 4-6 - 4-8.
Various types of valve related problems found in mechanical
collectors.
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SECTION 5.0
HEALTH AND SAFETY GUIDELINES FOR FOUNDRY INSPECTORS25'26
5.1 INTRODUCTION
There are several measures an inspector should consider taking in order
to protect his or her personal safety and health when conducting foundry in-
spections. Appropriate protective equipment should be worn, and the inspec-
tor should be familiar with potential safety or health problems before en-
tering a foundry.
The personal protective equipment that should be considered prior to
entry includes a hardhat, safety glasses, safety shoes, hearing protection,
and protective work clothing (e.g., heavy long-sleeved shirt and jeans).
Loose clothing which can get caught in machinery is not suitable. The need
for these safety items should be discussed with foundry personnel.
The inspector should also determine during the preinspection conference
with foundry personnel if there are any areas that have restricted access,
are particularly hazardous, or if there are any specific precautions to be
taken in any area of the foundry. The inspector should always be accompa-
nied by an employee of the plant who is familiar with the plant's operation.
Someone should be assigned to accompany the inspector.
5.2 FOUNDRY PROCESSES AND ASSOCIATED SAFETY AND HEALTH HAZARDS
Although no two foundries are alike, they all basically melt metals and
cast them into useful shapes called castings. Therefore, the processes are
similar. The basic foundry processes and hazards associated with them are
discussed in this section. These processes are:
• Sand preparation • Melting and pouring
' c°re making . Shakeout
• Molding . Cleaning of castings
5.2.1 Sand Preparation
The major potential health hazard associated with the preparation of
sand for coremaking and molding is exposure to airborne dusts. Most foun-
dry sands contain crystalline-free silica which, if breathed in excessive
amounts, can result in silicosis. Proper use of a NIOSH- or MESA-approved
single use dust mask or a dust respirator with a mechanical filter should
provide adequate protection to inspectors who are transiently exposed to
high dust levels.
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5.2.2 Coremaking, Molding, Melting, and Pouring Operations
Potential exposure to mineral and silica dusts occurs in the core room
and is associated with automatic core molding, core sand mulling, and core
finishing. Exposure to resins, solvents, and chemicals also presents poten-
tial hazards. Many of these resins, solvents, and chemicals are potential
skin and respiratory irritants, and skin contact should be avoided. If the
inspector plans to spend considerable time (2 to 8 hr) in the area, proper
OSHA-recommended respirators should be worn. The physical hazards which
might be present include noise and nonionizing microwave radiation. Ap-
proved earplugs or earmuffs and protective clothing should be worn.
If the inspector intends to spend considerable time (2 to 8 hr) in
the melting and pouring area, hazards posed by hot environments should be
considered, and appropriate measures such as protective clothing or staying
behind a heat shield (highly reflective material) should be considered. The
inspector should be aware of the potential presence of carbon monoxide
around the top of the cupola and at the tapping station. Appropriate res-
piratory protection is recommended. Core binders and additives thoroughly
decompose during pouring and molding operations and can pose potential
health hazards.
5-2.3 Shakeout, Cleaning, and Grinding Operations
The separation of a casting from the sand (shakeout) and the core from
certain castings results in potential exposure to silica dust, metal dust,
and fumes. As in many other areas of the foundry, noise is a potential haz-
ard in the shakeout, cleaning, and grinding area. Approved earplugs or ear-
muffs should be worn. Metallic fumes such as iron oxide, zinc oxide, lead,
silica dust, and metal dust can result from chipping, rough grinding, sand
and shot blasting, finish grinding, sprue cutting, and other cleaning opera-
tions. Proper respiratory protection is recommended.
5.2.4 Other Miscellaneous Operations
Ionizing radiation may present a hazard if X rays are used to inspect
large castings. Potential exposure can be avoided by maintaining a safe
distance from any energized or seal source. Nonionizing radiation (ultra-
violet and infrared) is given off during burning operations. Use of special
dark tinted glasses and protective clothing (long sleeves and gloves) can
help prevent exposure to these potential hazards.
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SECTION 6.0
REFERENCES
1. Dietert, H. W. Foundry Core Practice. American Foundrymen's Society,
1966.
2. Sylvia, J. G. Cast Metals Technology. Addison Wesley, Reading, PA,
1972.
3. Design of Sand Handling Ventilation Systems. American Foundrymen's
Society, Des Plaines, IL, 1972.
4. Roberts and Lapidge. Manufacturing Processes. McGraw-Hill, New York,
NY, 1977.
5. Danielson, J.A. Air Pollution Engineering Manual. Los Angeles County
Air Pollution Control District, National Center for Air Pollution
Control, 1967.
6. Bates, C. E. and L. D. Scheel. Processing Emissions and Occupational
Health in the Ferrous Foundry Industry. American Industrial Hygiene
Association Journal, August 1974.
7. Molding, Coremaking, and Patternmaking. American Foundrymen's Society,
Des Plaines, IL, 1972.
8. Envirex, A Rexnord Company. Air Evaluation of Occupational Health
Hazard Control for the Foundry Industry. National Institute for
Occupational Safety and Health, Cincinnati, OH, October 1978.
9. Metals Handbook, Vol. 5. American Society for Metals, 1970.
10. Cupola Handbook, 4th Edition. American Foundrymen's Society,
Des Plaines, IL, 1976.
11. CEA Carter-Day Company. Carter-Day Filters Control Smoke, Iron Oxide
Fumes. No. 8.5M 3-73 Bruce, Minneapolis, MN.
12. Fennelly, P. F. and P. D. Spawn. Air Pollutant Control Techniques for
Electric Air Furnaces in the Iron and Steel Industry. EPA-450/2-78-024,
U.S. Environmental Protection Agency, Research Triangle Park, NC,
June 1978.
75
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13. Georgieff, N. T. Addendum to Standards Support and Environmental
Impact for Electric Arc Furnaces in the Gray Iron Foundry Industry.
U.S. Environmental Protection Agency, December 1976. Unpublished,
14. U.S. Environmental Protection Agency. Electric Arc Furnaces in
Ferrous Foundries-Background Information for Proposed Standards-
Draft EIS. U.S. Environmental Protection Agency, Research Triangle
Park, NC, April 1980.
15. Wallace, D. and C. Cowherd. Fugitive Emissions from Iron Foundries.
EPA-600/7-79-195, U.S. Environmental Protection Agency, Research
Triangle Park, NC, August 1979.
16. Modi, E. K. Comparing Processes for Making Ductile Iron. Foundry,
July 1970.
17. Matter, D. Modularizing Methods Quality Ductile Iron-Today and
Tomorrow. In: Proceedings of a Joint AFS/DIS Conference, October 14
through 16, 1975.
18. A. T. Kearney Company. Systems Analysis of Emissions and Emissions
Control in the Iron Foundry Industry, Vol. II, Exhibits. PB-198 349,
U.S. Environmental Protection Agency, February 1971.
19. Melting and Pouring Operations. American Foundry-men's Society,
Des Plaines, IL, 1972.
20. Cleaning Castings. American Foundrymen's Society, Des Plaines, IL,
1977.
21. Committee on Industrial Ventilation. Industrial Ventilation, A
Manual of Recommended Practice, 16th ed. American Conference of
Governmental Industrial Hygienists, Lansing, MI, 1980.
22. Modern Casting, August 1972.
23. The Midwest Research Institute. Summary of Factors Affecting Compliance
by Ferrous Foundries, Volume 1 - Text Final Report. EPA-34011-80-020,
U.S. Environmental Protection Agency, Washington, D.C., 1981.
24. Warda, R. D. and Buhr, R. K. "A Detailed Study of Cupola Emissions"
AFS Transactions. Vol. 81, 1973.
25. Bates, C. E. and L. D. Scheel. Processing Emissions and Occupational
Health in the Ferrous Foundry Industry. American Industrial Hygiene
Association Journal, August 1974.
26. Health and Safety Guide for Foundries, DHEW Publication No. (NIOSH)
76-124, U.S. Dept. of Health, Education, and Welfare, National Insti-
tute for Occupational Safety and Health, Division of Technical Ser-
vices, Cincinnati, Ohio, April 1976.
76
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27. Midwest Research Institute. Summary of Factors Affecting Compliance by
Ferrous Foundries, Volume II - Appendices A-E Final Report. EPA Con-
tract No. 68-01-4139, Task No. 15, U.S. Environmental Protection Agency,
Washington, D.C., 1981.
77
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APPENDIX A
GLOSSARY OF TERMS USED IN FOUNDRY INDUSTRY
A-l
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ACFM
Acid Lining
Additive
Aerosol
Afterburner
Agglomeration
Air Furnace
Anneal
Back Charge
Baked Core
Basic Lining
Bed
Bentonite Clay
Actual cubic feet per minute; refers to the
volume of gas at the prevailing temperature
and pressure.
A refractory furnace lining made essentially
of silica.
A substance added to another in relatively small
amounts to impart or improve desirable qualities,
or suppress undesirable qualities.
Small liquid or solid particles dispersed in a
gaseous medium (dust, fog, smoke, for example).
A device for burning combustible materials that
were not oxidized in an initial burning process.
Gathering together of small particles into larger
particles.
A reverberatory-type furnace in which metal is
melted by heat from fuel burning at one end of
the hearth, passing over the bath toward the
stack at the other end.
A heat treatment which usually involves a slow
cooling for the purpose of altering mechanical
or physical properties of the metal, particularly
to reduce hardness.
Second charge added to the molten initial charge
as soon as sufficient volume is available in the
furnace. Back charging produces a violent erup-
tion of emissions.
A core which has been heated to produce the
desired physical properties attainable from its
oxidizing or thermal setting binders.
The inner lining and bottom of a melting furnace
composed of materials that have a basic reaction
in the melting process; usually either crushed
burned dolomite, magnesite, magnesite bricks, or
basic slag.
Initial charge of fuel in a cupola upon which the
melting is started.
A widely distributed, peculiar type of clay
which is considered to be the result of denitci-
fication and chemical alteration of the glassy
particles of volcanic ash or turf. Used in
foundry to bond sand.
A-2
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Binder(s)
Blast
Blast Volume
Blind Filter Bags
Borings
Briquette
Burden
Burned Sand
Canopy Hood
Cantilever Hood
Capture Velocity
Cast Iron
- Material to hold the grains of sand together in
molds or cores. May be cereal or clay, resin,
pitch, etc.
- Air driven into the cupola furnace for combus-
tion of fuel.
- The volume of air introduced into the cupola
for the burning of fuel. This volume governs
the melting rate of the cupola.
- A buildup of water, oil, or similar materials
on filter bags that restricts the flow of gases
through the filter.
- Metal in chip form resulting from machining
operations.
- Block of various shapes formed of finely divided
materials by incorporation of a binder, by pres-
sure, or by both. Materials maybe ferroalloys,
metal borings or chips, silicon carbide, coke
breeze, etc.
- A collective term of the component parts of the
metal charge for a cupola melt.
- Sand in which the binder or bond has been removed
or impaired by contact with molten metal.
- A metal hood over a furnace for collecting gases
being exhausted into the atmosphere surrounding
the furnace.
- A counterbalanced hood over a furnace that can
be folded out of the way for charging and pour-
ing the furnace.
- The air velocity at any point in front of a hood
or at a hood's opening necessary to overcome op-
posing air currents and to capture the contami-
nated air at that point by causing it to flow
toward a hood.
- A generic term for the family of casting alloys
composed of iron, carbon, and silicon in which
the carbon is present in excess of the amount
that can be retained in solid solution in the
austenite that exists in the alloy at the
eutectic temperature. This family of ferrous
alloys includes chilled iron, pig iron, gray
cast iron, white cast iron, mottled cast iron,
malleable cast iron, and ductile iron.
A-3
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Cereal
Channel Induction
Furnace
Charge
Charging Door
Coke
Coke Breeze
Cold Box Molding
Control at the Source
Convection
- A binder used in core mixtures and molding sands,
derived principally from corn flour.
- In this type of induction furnace, the metal
charge surrounds the transformer core, thereby
forming a loop or channel.
- The total ore, ingot, metal, pig iron, scrap,
limestone, etc., introduced into a melting fur-
nace for the production of a single heat.
- An opening in the cupola or furnace through which
the charges are introduced.
- The product resulting from the destructive distil-
lation of suitable coal in which the volatiles have
been driven off by heating in the absence of air;
used as a fuel in cupola furnaces.
- Fines from coke screenings.
- A core making or molding process in which cold
set binders (urethane resins) are used and cure
(hardened) by passing a catalyst gas [usually
triethylamine (TEA) or dimethyl ethylamine
(DMEA)] through the mold.
- Exhaust capture close enough to the point of
generation of air contaminants to prevent the
contaminants from entering the general atmos-
phere.
- The motion resulting in a fluid from the dif-
ferences in density and the action of gravity
due to temperature differences in one part of
the fluid and another. The motion of the flui.d
results in a transfer of heat from one part to
another.
Cope
Core
The upper or topmost section of a flask, mold.
or pattern.
A separate part of the mold which forms cavities
and openings in castings which are not possible
with a pattern alone. Cores are usually made of
a different sand from that used in the mold arid
are generally baked or set by a combination of
resins.
Core Binder
Any material used to hold the grains of core sand
together.
A-4
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Core Blower
Coreless Induction
Furnace
Core Oven
Core Sand
Cross Draft
Crucible
Cupola
Cupola, Hot Blast
Cupola Stack
Cyclone
Cyclonic Scrubber
Desulfurizing
Direct Arc Furnace
Direct Shell Evaluation
Downdraft Hood
- A machine for making cores by blowing sand into
the core box by means of compressed air.
- In this type of induction furnace, the metal
heated by both the core and secondary coil.
Furnace coils are water cooled to prevent heat
damage.
- Specially heated chambers for the drying of cores
at low temperatures.
- Sand for making cores, generally a silica sand,
bonded with one or more organic binders that is
made into the desired shape and hardened to form
a core.
- A current of air that acts to disrupt or change
the direction of streams of air before they can
enter an exhaust hood.
- A vessel or pot made of a refractory such as
graphite or silicon carbide with a high melting
point and used for melting metals.
- A vertical, cylindrical furnace usually lined
with refractories, for melting metal in direct
contact with coke by forcing air under pressure
through openings (tuyeres) near its base.
- A cupola supplied with a preheated air blast.
- The overall top column of the cupola from the
charging floor to the spark arrester.
- A device with a control descending vortex created
to spiral objectionable gases and dusts to the
bottom of a collector cone for the purpose of
collecting particulate matter from process gases.
- Radial liquid (usually water) sprays introduced
into cyclones to facilitate collection of
particulates.
- The removal of sulfur from molten metal by the
addition of suitable compounds.
- An electric arc furnace in which the metal being
melted is one of the poles.
- See Fourth Hole Ventilation.
- An exterior hood in which the exhaust enters in
a downward manner.
A-5
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Drag
Ductile (or nodular)
Iron
Duplexing
Dust Loading
Electric Arc Furnace
(EAF)
Electric Induction
Furnace (EIF)
Enclosing Hoods
Endothermic Reaction
Equivalent Opacity
Exothermic Reaction
External Hood
The lower or bottom section of the mold, flask,
or pattern.
Ferrous metal in which the graphite is present in
spheroidal shape. The graphite in this shape does
not greatly affect the inherent ductility of the
metal matrix. Also called nodular iron or spheroi-
dial-graphite iron.
A method of producing molten metal of desired
analysis. The metal being melted in one furnace
and refined in a second.
The concentration of dust in the gas entering or
leaving a collector.
The direct arc electric furnace consists of a
refractory lined, cup shaped, steel shell with
a refractory lined roof through which three
graphite or carbon electrodes are inserted. The
shell is arranged for tilting to discharge the
molten metal.
The induction furnace is a cup or drum shaped
vessel that converts electrical energy into heat
to melt the charge. No electrodes are used in
EIF. The induction furnace converts electrical
energy into heat by utilizing the transformer
principle in which a magnetic field is set up
when the primary coil of the transformer is
energized. The magnetic field at a high flux
density induces eddy currents in the charge
which are converted to heat by the electrical
resistance of the charge itself.
A local exhaust hood where the generation point
for air contaminants is within the confines of
the hood.
Designating, or pertaining to a reaction which
occurs with the absorption of heat from the
surroundings.
The determination of smoke density by comparing
the apparent density of smoke as it issues from
a stack with a Ringelmann Chart.
Chemical reaction involving the liberation of
heat, such as burning of fuel.
A hood that does not confine the process or
equipment emitting contaminants; functions
by inducing a flow of air from the source or
release toward the hood opening.
A-6
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Fabric Filter
Face (of a hood)
Facing Sand
Flask
Fluxing agent
Forehearth
Foundry Effluent
Foundry Returns
Fourth Hole Ventilation
(Direct Shell Evacuation)
- A particulate control device using filters made
of synthetic, natural, or glass fibers within a
large chamber for removing solid particulate
matter from the air or gas stream.
- An opening through which air flows into the hood.
- Specially prepared molding sand mixture used in
the mold adjacent to the pattern to produce a
smooth casting surface.
- Metal or wood frame without top or a fixed bot-
tom, used to retain the sand in which a mold was
formed; usually consists of two parts, cope and
drag.
- Material or mixture of materials, limestone,
dolomite, fluorspar, calcium carbonate which
causes other compounds with which it comes in
contact to fuse at a temperature lower than
their normal fusion temperatures.
- Brick-lined reservoirs in front of and connected
to the cupola or other melting furnaces for re-
ceiving and holding the melted metal.
- Waste material in water or air that is discharged
from a foundry.
- Cast iron scrap, gates, risers, and scrap castings,
used as one of the raw materials for the production
of cast iron.
In regard to air pollution control, the using of
a fourth hole in the roof of an electric furnace
to exhaust fumes.
Fugitive Emissions, Total -
Fugitive Emissions
Full Anneal
Fume
All particles from either open dust or process
fugitive sources as measured immediately adja-
cent to the source.
Emissions not orginating from a stack, duct, or
flue.
A heating-and-cooling process applied to either
gray or ductile iron castings to reduce the hard-
ness, improve the ductility, and relieve residual
stresses.
Fine, solid particles dispersed in air or gases
and formed by condensation, sublimation, or
chemical reaction.
A-7
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Gate
General Ventilation
Graphitizing Anneal
Gray Iron
Green Sand
Griffin System
Hawley Close Capture
Hooding System
Heel
Holding Furnace
Hood
Hood Leakage (or Loss)
Hot Blast
Hot Box Cores
The end of the runner in a mold through which
molten metal enters the mold cavity.
Dilution method of ventilation achieved by reduc-
ing pollutant concentrations and by supplying
fresh, tempered air.
A heating-and-cooling process that serves to trans-
form, wholly or in part, the combined carbon in
cast iron to graphitic or free carbon.
Ferrous metal that contains a relatively large por-
tion of its carbon in the form of flake graphite,
and substantially all of the remainder of the
carbon in the form of eutectoid carbide. Such
metal has a gray fracture. These irons have
very little ductility.
A naturally bonded sand or a compounded molding
sand mixture which has been tempered with water
and additives for use while still in a damp or
wet condition.
A method operating in two stages, to recoup and
preheat air by using the latent heat of cupola
gases.
A commercially patented close-capture hooding
system for electric arc and electric induction
furnaces which control emissions during charging,
melting, slagging, and tapping operations.
Metal left in ladle after pouring has been com-
pleted. Metal kept in induction furnaces during
standby periods.
A furnace for maintaining molten metal, from a
larger melting furnace, at a proper casting
temperature.
Projecting cover above a furnace or other equip-
ment for purpose of collecting smoke, fume, or
dust.
Emissions which are carried by air currents past
the capture zone of a hood.
Blast air which has been heated prior to entering
into the combustion reaction of a cupola.
• Hot box resins include furan and phenolic resins.
The liquid resin is mixed with the core sand and
formed in conventional equipment and heated in
core boxes.
A-8
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Indirect Arc Furnace
Indraft Velocity
Induction Furnace
Inlet Volume
Inoculant
Inoculation
Ladle
Ladle Addition
Latent Heat
Lining
Magnesium Treatment
Malleable Iron
(sometimes called
white)
Melting Rate
Mold
Muller
- An electric arc furnace in which the metal bath
is not one of the poles of the arc.
- Linear flowrate of contaminated air through the
face opening of a hood.
- A melting furnace which utilizes the heat gener-
ated by electrical induction to melt a metal
charge.
- The quantity of gas entering a collector from
the system it serves.
- Any of a number of materials usually magnesium
that modify the microstructure of cast irons when
small amounts are added to the molten metal just
before pouring.
- The addition to molten metal substances designed
to form nuclei for crystallization.
- Metal receptacle lined with refractory for
handling molten metal. Ladles are used for iron
inoculation, transport, and pouring metal into
molds.
- The addition of alloying elements to the molten
metal in the ladle.
- Thermal energy absorbed or released when a sub-
stance changes state, such as from solid to
liquid or from one solid phase to another.
- Inside refractory layer of firebrick, clay,
sand or other material in a furnace or ladle.
- The addition of magnesium to molten metal to
form nodular iron.
- Ferrous metal obtained by heat treatment of white
cast iron which converts substantially all of
the combined carbon into nodules of graphite.
- The tonnage of metal melted per unit of time.
- The form, generally made of silica sand, which
contains the cavity into which molten iron is
poured to produce a casting of the desired shape.
- A type of foundry sand mixing machine.
A-9
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No Bake Molding
Nodular Iron
Normalizing
Off Gas
Oven Bake Cores
Oxidizing Atmosphere
Oxidation Losses
Oxygen Lancing
Parting Compound
Pattern
Pig Iron
- A core making molding process where no bake
resins (polymers) are catalyzed while mixing
with sand and harden over a relatively short
period of time but sufficiently long to enable
the sand to be packed into a pattern to make a
mold.
- (See Ductile Iron)
- Gray or ductile iron is normalized by heating
to 885° to 927°C and cooling in still air.
- Gas emitted from an industrial operation, in-
cluding the forced ventilation of an area or
operation.
- Oven baked core resins are one of four types:
oleoresinous, urea-formaldehyde, phenol formal-
dehyde, cereal. The resin and core sand are
mixed and formed in a pattern. The cores are
then baked in an oven for curing.
- An atmosphere resulting from the combustion of
fuels in an atmosphere where excess oxygen is
present, and with no unburned fuel lost in the
products of combustion.
- Reduction in the amount of metal or alloy through
oxidation. Such losses usually are the largest
factor in melting loss.
- It is a process of injecting oxygen with the help
of long steel pipe or tube usually covered with
refractory. It is used mainly for adjusting of
the chemistry of the steel, but may also be used
for speeding up of the melting process and for
superheating the bath.
- A material dusted, brushed or sprayed on patterns
or mold halves to prevent adherence of sand and
to promote easy separation of cope and drag part-
ing surfaces when cope is lifted from drag.
- A form made of wood, metal, or other material
around which molding material is placed to make
a mold for casting metals.
- The crude iron product of a blast furnace that is
produced by the reduction of iron ore and is cast
into small bars (pigs); often used as a raw ma-
terial for the production of cast iron.
A-10
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Pit Molding
Plume
Polynuclear Aromatic
Hydrocarbons (PAH)
Pour-Over Inoculation
Method
Preheater
Push-Pull Ventilation
Recuperator
Reducing Atmosphere
Refractory
Reverbatory Furnace
Riser
Rotary Furnace
Runner
Molding process for large castings in which
lower portions of mold are made in a suitable
pit or excavation in foundry floor.
A visible, elongated column of mixed gases,
partially condensed vapors, gas-born particu-
lates, and smoke emitted from a stack.
Hydrocarbons with fused-ring systems, with or
without aliphatic side chains.
In this technique of inoculation, hot metal is
poured over to an empty laddie containing inocu-
lant.
A device used to preheat the charge before it is
charged into a furnace. It is used primarily
with induction furnaces.
Local exhaust control where a receiving hood
induces a flow of air toward it while a "push"
toward the hood is achieved by mechanical means
or prevailing ventilation patterns. Also called
blow and exhaust systems.
Equipment for transferring heat from hot gases
for the preheating of incoming fuel or air for
hot blast cupolas.
An atmosphere resulting from the incomplete com-
bustion of fuels.
Heat resistant material, usually nonmetallic and
used for furnace linings.
A large quantity furnace with a vaulted ceiling
that reflects flame and heat toward the hearth
or the surface of the charge to be melted.
A reservoir of molten metal connected to a cast-
ing to provide feeding of additional metal to the
casting as it contracts during solidification.
A furnace using pulverized coal, gas, or oil; of
cylindrical shape with conical ends mounted so as
to be tipped at either end to facilitate charging,
pouring, and slagging.
A channel through which molten metal flows from
the downgate (sprue) of a mold into the casting
cavity or from the casting cavity to the riser.
A-ll
-------
Sandwich Inoculation
Method
SCFM
Schumacher System
Sea Coal
Shakeout
Shell Molding
Shotblasting
Side Draft Hood
Slag
Spark Arrester
Sprue
Standard Air
Storage Pile Activities
In this method of inoculation, inoculant is
covered with 1 to 2% steel punching or plate
or ferrosilicon. Hot metal is poured over.
This allows more hot metal to be poured before
the reaction starts and results in greater mag-
nesium recovery.
Standard Cubic Feet per minute. The volume of
gas measured at standard conditions, usually one
atmosphere of pressure and 70°F.
In this patented sand handling system, an over-
sized muller is used to produce excess moist sand.
This moist sand is mixed with the dry sand leav-
ing the shakeout hopper to reduce dust emissions
during spent sand handling.
Pulverized, high-volatile, bituminous coal fre-
quently added to green molding sand for making
molds for the production of iron castings.
The operation of removing castings from a sand
mold.
A process for forming a mold from thermosetting
resin bonded sand mixtures brought in contact
with preheated metal patterns, resulting in a
firm shell with a cavity corresponding to the
outline of the pattern.
Casting cleaning process employing a metal abra-
sive propelled by centrifugal force.
A receiving hood into which exhaust enters
laterally.
Nonmetallic covering which forms on the molten
metal as a result of the flux action in combin-
ing impurities contained in the original charge.
Device over the top of the cupola to prevent
the emission of sparks.
The channel, usually vertical, connecting the
pouring basin with the runner to the mold cavity.
Air with a density of 0.075 pounds per cubic
foot, generally equivalent to dry air at 70°F
and 14.7 psi.
Load-in, vehicular traffic around storage piles,
wind erosion from storage piles, and load-out.
A-12
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Superheating
Tapping
Thermal Draft
Threshold Limit Value
(TLV)
Tramp Metal
Tuyere
Wet Cap
Wet Scrubber
Wind Box
- Heating of a metal to temperatures above the
melting point of the metal to obtain more com-
plete refining or greater fluidity.
- Removing molten metal from the melting furnace
by opening the tap hole and allowing the metal
to run into a ladle.
- Air currents set in vertical motion by heat.
A concentration in air or an exposure or dose
rate felt to be safe for repeated exposure to
workers. A set point for control of a hazard.
A metallic element present as an impurity,
usually in insignificant amounts.
The nozzle openings in the cupola shell and
refractory lining through which the air blast
is forced.
A device installed on a cupola stack that col-
lects emission by forcing them through a cur-
tain of water. The device requires no exhaust
fan but depends upon the velocity pressure of
the effluent gases.
An air pollution control device, a liquid spray
device, usually water for collecting pollutants
in escaping foundry gases.
The chamber surrounding a cupola through which
air is conducted under pressure to the tuyeres.
A-13
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APPENDIX B
CHECKLIST FORMS FOR VARIOUS PROCESS
CONTROL EQUIPMENT SYSTEMS IN FOUNDRY
B-l
-------
i
N3
COVER SHEET FOR CONTROL EQUIPMENT CHECKLIST
Facility Name: Inspection Date and Time:
Facility Address: Inspector Initials:
Facility Contact: Phone No.:
Name Title
Type of Process (check) Type of Control Equipment (check)
D Charge Preparation area D Fabric Filter
Q Cupola d High Energy Scrubber System
D Electric Arc Furnace D Low Energy Scrubber System
D Electric Induction Furnace D Gas Cooling System
D Other (describe) D Local Exhaust System
D Mechanical Collector; (circle one)
Cyclone, Multiclone, Setting Chamber
Process Equipment ID No. Control Equipment ID No.
Is the process system operating? Yes No Is the Control System operating? Yes_ No
(This can often be confirmed by noticing vibration of equipment or fan noise).
If control system or process(es) is not operating, then conclude the inspection after finding out
the reasons.
Check exhaust stack of the control equipment for any visible emissions (VE)
Note percent opacity Color (Take VE readings if in violation
of opacity regulations; follow
your agency's procedures).
-------
I. CHECKLIST FOR CHARGE PREPARATION
What To Look For
Where To Look
I
OJ
Total charge (Ton/hr) Plant records
Coke (Ib/hr)
Flux (Ib/hr)
Scrap composition
Percent steel scrap
Scrap-appearance
(Amount of oil, rust,
fine matter, sand,
moisture)
Any charge preparation
(describe screening,
sizing cutting, and
reheating)
Raw material storage
covered or outdoor
Charge loading method
Same as above
Same as above
Plant records in
plant official's
office
Same as above
Scrap pile or at
charge floor
Near materials
storage area or
charge floor.
Same as above
Charge floor
Fugitive emissions Same as above
How charges are weighed Same as above
When To Look
Preinspection meet-
ing
Same as above
Same as above
Preinspection,
before starting
plant walk-through
Same as above
During plant walk
through
During inspection
Same as above
During charging
operation
Same as above
Same as above
Additional Comments
(How)
Compare these numbers
with numbers in agency
files.
Same as above (for
Cupola only)
Same as above (for
Cupola only)
Company should have
daily records of
raw materials usage.
Same as above
Observations
(Your Comments)
Describe
If approximate,
describe.
-------
II. CHECKLIST FOR CUPOLA-HIGH ENERGY WET SCRUBBER
What To Look For
Monitoring instru-
ments
Calibration of moni-
toring equipment
Additional Comments
Where To Look
Instrument panel
or at various
locations on the
system.
When To Look
Same as above
Observations
(Your Comments}
Request plant official
to show you scrubber
system instrument panel.
Find out last time
instruments were calibrated
W
I
Note following data
if available:
(scrubber)
Pressure drop across
scrubber (in. of
H20).
Scrubber liquid flow
rate (gpm)
Scrubbing liquid
pressure (psi)
Inlet Tempera-
ture (°F)
Pressure drop
across mist
eliminator (in.
of H20).
Makeup liquid
flow rate
Nozzle operating
pressure (psi)
Inlet and outlet
static pressure of
fan system
Instrument panel
or instruments
located at various
locations on system
Same as above
Note this information
if available. If in-
struments are not
operating, find out why
and for how long.
-------
td
Ln
(continued)
What To Look For
Note following data:
(Cupola)
Melting rate (T/hr)
Coke metal ratio
Blast rate (acfm)
Blast temperature (°F)
Exhaust gas temper-
ature (°F)
SCRUBBER SYSTEM
Corrosion, leakage
scaling
Where To Look
Plant records
Same as above
When To Look
Preinspection meeting
Same as above
Cupola control panel During blasting
operation
Same as above Same as above
Fugitive emissions
Cupola or control
device instrument
panel
Outside scrubber
system
Ductwork
Fan housing
Pumps and valves
Demister
Inside scrubber
Shell
Trays
Demister
Ductwork
Control system
During melting
operation
While system is
operating
While system is
off
While system is
operating
Additional Comments
(How)
Note where the
temperature is
measured
Draw diagram of system
and show point of
point of corrosion on
back of this form or
describe.
Describe
Draw diagram and
show point of emis-
sions on back of this
form.
Observations
(Your Comments)
-------
I
ON
(contj nued)
What To Look For
Scrubbing liquid
spraying system for
plugging or insufficient
pressure
Buildup of scrubbing
liquid in sump.
Fan
Vibration
Audible belt slip-
page noise
Material buildup or
caking on fan blades
Stress mark, cracks
in fan blades or wheel
Open inspection doors,
holes, open portholes
Where To Look
Spray nozzles
When To Look
While system is
operating.
Sump (liquid reser-
voir at bottom
of the scrubber
vessel).
Around fan
housing
Around fan
housing
Fan blades
Fan blades, fan
wheel
Fan system,
ductwork
Same as above
While fan system
is running
Same as above
While fan system
is off
Same as above
Anytime
Additional Comments
(How)
This can be indicated
by poor flow or
poor spraying action
by observing through
portholes, if possible
Large amount of
liquid buildup will
indicate this situation.
This can be checked
by observing through
portholes or open access
doors.
Visual observation
Noise from housing
Through access door
or opening in fan
housing
Same as above
Visual observation
around control system
Observations
Ofour Comments)
-------
w
I
(continued)
What To Look For
CUPOLA
Emissions leakage
Charge door kept open
or closed during the
operation
After-burner operating
Also note the tempera-
ture if available
General housekeeping
Startup and shutdown
practices
Control equipment by-
passing
Where To Look
Cupola top
Charge door
Other places
Charge floor
Fuel gauge on
control panel or
actual burner flames
if accessible
Around melting
operation
Obtain description
from plant official.
Plant records
and control panel
When To Look
Same as above
During charging
operation.
During operation
During inspection
Obtain information
prior to inspec-
tion and observe
during inspection
During control
equipment bypass
operation
Additional Comments
(How)
Observations
(Your Comments)
Not location and
configuration of A.B.
Describe bad house-
keeping practices
which will have effect
on emissions (e.g.,
dust laden floor)
Perform this activity
if time permits. If
shutdown is observed.
note blast rate, exhaust
rate, and exhaust temperature.
Note amount of time
control equipment by-
passed.
-------
III. CHECKLIST FOR CUPOLA-GAS COOLING SYSTEM - FABRIC FILTER
W
oo
What To Look For
Monitoring instruments
Calibration of moni-
toring instrument
Note following data
if available: (Gas
cooling system)
Where To Look
Instrument panel or
instruments located
at various locations
on system
Instrument panel or
instrument located
at various loca-
tions on the system
Flue gas velocity (rpm)
Flue gas inlet temperature. (°F)
Flue gas outlet temperature. (°F)
Cooling water rate (gpm)
Water spray pressure (psi)
Outlet gas temperature
indicator with warning
device operational.
Instrument panel
When To Look
While system is
operating
While system is
operating during
external inspec-
tion
While system is
operating
Additional Comments
(HowJ_
Request plant official
to show you instrument
panel.
Find out last time
instruments were
calibrated.
Note this data if
available. If instru-
ments are not operating,
find out why and
for how long
Observations
jYour Comments)
Some facilities might
not have this device.
-------
(continued)
What To Look For
Note following data
if available: (fabric
filter)
Where To Look
Instrument panel or
instruments located
at various loca-
tions on the
system
Pressure drop across
fabric filter (in. of
H20)
Gas inlet temper-
ture (°F)
Differential
static pressure (in. of
H20) between clean and
dirty side
Dew point of gases
Get the following infor-
mation (Cupola)
Melting rate (T/hr)
Coke metal ratio
Blast rate (acfm)
From plant officials
Plant records
Same as above
Cupola control
panel
Blast temperature (°F) Same as above
Exhaust gas temper-
ature (°F)
Cupola or control
device instrument
panel
When To Look
While system is
operating during
external inspec-
tion
Preinspection meeting
Same as above
During blasting
operation
Same as above
During melting
operation
Additional Comments
(How)
Note this data if
available. If in-
struments are not
operating find out
why and for how long.
Observations
(Your Comments)
-------
(continued)
What To Look For
Corrosion, holes, wear
points
Fugitive emissions
Excess scaling
Plugged or missing
nozzles
FABRIC FILTER
Corrosion, weld seam
gaps, holes, wear
points, physical dam-
age
Where To Look
Around cooling
system, pumps
Around cooling
system
Internal surfaces of
cooling system
Inside cooling
system
When To Look
During external
inspection
During external
inspection while
system is oper-
ating
During internal
inspection when
system is off
While spray system
is operating
Fabric filter
housing near doors
Ductwork
Hoppers
During external
inspection
Additional Comments
(How)_
If large enough damage
from corrosion, you
will sen fugitive
emissions.
Draw diagram of system
and show point of
emissions on back of
this form.
Take safety precautions
and get plant official's
approval before opening
any access doors.
This can be checked by
looking through open
access doors or port-
holes. If these are not
available, you might have
to skip this activity.
Draw diagram of system
and show point of
corrosion on back of
this form or describe.
Observations
(Y our^ Comments )
-------
(continued)
What To Look For
Fugitive emissions
Damaged or missing
seals and proper air-
tight closing
Proper operation of
cleaning cycles
Where To Look
Around control sys-
tem and related
ductwork
Around access
doors, joints,
ductwork
When To Look
During external
inspection when
system is oper-
ating
During external
inspection; system
can be on or off
During external
inspection while
system is operating
Additional Comments
(How)
Draw diagram of system
and show point of
emissions on back of
this form.
Take safety precautions
and get plant official
approval before opening
any access doors.
See text for further
clarification
Observations
(Your Comments)
Proper operation of
solids removal system
Fan vibration
Audible belt slip-
page noise
Material buildup or
caking on fan blades
Sere conveyors,
bottom of hoppers
Around fan housing
Around fan housing
Fan blades
While system is
operating
During external
inspection while
fan system is run-
ning
Same as above
While fan system
is off
In some type of FF
normal operations will
show regular discharge
of solids from hopper or
collecting equipment.
Visual observation
Noise from housing
This activity is necessary
only if fan is upstream
from fan filter.
-------
td
I
(continued)
What To Look For
Corrosion, abrasion
stress mark, cracks
in fan blades or fan
wheel
Material deposits on
bags
Condition of bags
Bag tears
Oily Bags
Dropped bags
Burnspot on bags
Bag deterioration
Improper bag connection
Dampness
Collar wear
Bag tension
Condition of wear plate
Dust buildup, material
bridging
Temperature protection
device or baghouse
bypass system
Where To Look
Fan blades, fan
wheel
Inside fabric
filter
Inside fabric
filter
Inside fabric fil-
ter wear plate is
located where ex-
haust ducts enter
fabric filter.
Inside the fabric
filter hoppers
inlet ducts
This system usually
is integrated with
fabric filter oper-
ation.
When To Look
While fan system
is off
During internal
inspection of
fabric filter
when system is
off
During internal
inspection of
fabric filter when
system is off
Same as above
Same as above
The system ideally
should be checked
when fabric filter
system is operating.
Additional Comments
(Hoy)
Through access door or
opening in fan housing
during internal inspection
Consider all safety
factors before entering
fabric filter or opening
access doors.
Consider all safety
factors before entering
fabric filteror opening
access doors.
Observations
(Your Comments)
Same as above
Same as above
Also it can be
identified by tapping
hoppers with pipe or
hammer
This system may
not be checked due to
operational conditions.
-------
M
OJ
(continued)
What To Look For
Fabric filter preheater
operational
CUPOLA
Emissions leakage or
fugitive emissions
Charge door kept open
or closed during the
operation
After-burner operating
General housekeeping
Startup and shutdown
practices
Control equipment by-
passing
Where To Look
Cupola top
Charge door
Other places
Charge floor
Fuel gauge on
control panel or
actual burner flames
if accessible
Around melting
operation
Obtain description
from plant official.
Plant records
and control panel
When To Look
While system is
operating or shut
down
Same as above
During charging
operation.
During operation
During inspection
Obtain information
prior to inspec-
tion and observe
during inspection
During control
equipment bypass
operation
Additional Comments
(How)
This activity may be
hard to inspect due
to physical location of
heaters.
Observations
(Your Comments)
Describe bad house-
keeping practices
which will have effect
on emissions
Perform this activity
if time permits. If
shutdown is observed.
note blast rate, exhaust
rate, and exhaust tempera-
ture
Note amount of time
control equipment by-
passed
-------
IV.
(F.AF)^^KI.ECTKlC INDUCTION^ RIRNACE_(EJF) -
" " " ' ~
^
FABRIC KILTER
td
I
What To Look For
Monitoring instruments
Calibration of moni-
toring equipment
Note following data
if available:
(Fabric Filter)
Where To Look
Instrument panel or
instrument located
at various locations
on system
Instrument panel or
instruments located
at various loca-
tions on the
system
When To Look
While system
operating
While system is
operating during
external inspec-
tion
Pressure drop across
fabric filter (in. of
H20)
Gas inlet temper-
ture (°F)
Differential
static pressure (in. of
H20) between clean and
dirty side in compartmen-
talize FF
Additional Comments
(Jlow)
Request plant official
to show you control system
instrument panel.
Find out the last time
instruments were cali-
brated.
Note this data if
available. If in-
struments are not
operating find out
why and for how long.
Observations
(Your Comments)
Dew point of gases
From plant officials
-------
(cootinued)
What To Look For
Note following data:
(EAF OR EIF)
Melting rate (Ib/hr)
Power rate
Temperature in
furnace (°F)
Oxygen lancing:
Rate (cfm)
(EAF only)
Duration
FABRIC FILTER
Corrosion, weld seam
gaps, holes, wear
points, physical dam-
age
Fugitive emissions
Damaged or missing
seals and proper air-
tight closing
Where To Look
Plant records
Control board
Control panel
Same as above
When To Look
Preinspection meeting
During inspection
During lancing
operation
Same as above
Additional Comments
(How)
Observations
(Your Comments)
Fabric filter
housing near doors
Ductwork
Hoppers
Around control sys-
tem and related
ductwork
Around access
doors, joint in
ductwork
During external
inspection
During external
inspection when
system is oper-
ating
During external
inspection; system
can be on or off
Draw diagram of system
and show point of
corrosion on back of
this form or describe.
Draw diagram of system
and show point of
emissions on back of
this form.
Take safety precautions
and get plant official
approval before opening
any access doors.
-------
(continued)
What To Look For
Proper operation of
cleaning cycles
Proper operation of
solids removal system
Fan vibration
Audible belt slip-
page noise
Material buildup or
caking on fan blades
Stress mark, cracks
in fan blades or
fan wheel
Material deposits on
bags
Where To Look
Screw conveyors,
bottom of hoppers
Around fan housing
Around fan housing
Fan blades
Fan blades, fan
wheel
Inside fabric
filter
When To Look
During external
inspection while
system is operating
While system is
operating
During external
inspection while
fan system is run-
ning
Same as above
While fan system
is off
While fan system
is off
During internal
inspection of
fabric filter
when system is
off
Additional Comments
(How)
See text for further
clari f ication
In some type of FF
normal operations will
show regular discharge
of solids from hopper or
collecting equipment.
Visual observation
Noise from housing
This activity is necessary
only if fan is upstream
from fan filter.
Through access door or
opening in fan housing
during internal inspection
Consider all safety
factors before entering
fabric filter or opening
access doors.
Observations
(Your Comments)
-------
(continued)
What To Look For
Where To Look
When To Look
Additional Comments
(Mow)
Observat ions
(Your Comments)
Condition of bags
Bag tears
Oily Bags
Dropped bags
Burnspot on bags
Bag deterioration
Improper bag connection
Condition of wear plate
Inside fabric
filter
Inside fabric fil-
ter wear plate is
located where ex-
haust ducts enter
fabric filter.
During internal
inspection of
fabric filter when
system is off
Same as above
Consider all safety
factors before entering
fabric filteror opening
access doors.
Same as above
Dust buildup, material
bridging
Inside the fabric
filter hoppers
Same as above
Same as above
td
I
Fabric filter preheater
operational
While system is
operating or shut
down
This activity may be
hard to inspect due
to physical location of
heaters.
(EAF OR EIF)
Visible fugitive emis-
sions during:
Charging
Tapping
Backcharging
Melting
Oxygen lancing
Around EAF
During furnace
inspection
Describe exhaust
system and show
points of leakage
-------
I
H-1
00
(concluded)
What To Look For
Charge clean and dry
(EIF only)
Preheating of buckets
or conveyors and Fugi-
tive emissions from
them. (F.IF only)
Where To Look
Charging area
Same as above
When To Look
During charging
operation
Same as above
Additional Comments
(How)
Observations
(Your Comments)
-------
V. CHECKLIST LOCAL EXHAUST SYSTEM - LOW ENERGY FOR WET SCRUBBERS
What To Look For
Monitoring instru-
ments
Calibration of moni-
toring equipment
Where To Look
Instrument panel
or at various
locations on the
system.
When To Look
Same as above
Additional Comments
(How)
Request plant official
to show you scrubber
system instrument panel.
Find out last time
instruments were calibrated
Observations
(Your Comments)
W
I
Note following data
if available for
scrubber
Pressure drop across
scrubber (in. of
H20).
Scrubber liquid flow
rate (gpm)
Instrument panel
or instruments
located at various
locations on system
Same as above
Note this information
if available. If in-
struments are not
operating, find out why
and for how long.
-------
I
N3
O
(continued)
What To Look For
SCRUBBER
Corrosion, leakage
Fugitive emissions
Scrubbing liquid
spraying system for
plugging or insufficient
pressure
Buildup of scrubbing
liquid in sump.
Fan
'Vibration
Where To Look
Outside scrubber
system
Ductwork
Fan housing
Demister
Inside scrubber
Shell
Trays
Demister
Ductwork
Around control
system
Spray nozzles
Sump (liquid reser-
voir at bottom
of the scrubber
vessel).
Around fan
housing
Additional Comments
(How)
Draw diagram of system
and show point of
point of corrosion on
back of this form or
describe.
Describe
Draw diagram and
show point of emis-
sions on back of this
form.
While system is
operating.
Same as above Large amount of
liquid buildup will
indicate this situation.
This can be checked
by observing through
portholes or open access
doors.
When To Look
While system is
operating
While system is
off
While system is
operating
Observations
Of our Cpmme n t s)
This can be indicated
by poor flow or
poor spraying action.
While fan system
is running
Visual observation
-------
td
I
ho
(continued)
What To Look For
Audible belt slip-
page noise
Material buildup or
caking on fan blades
Stress mark, cracks
in fan blades or wheel
Open inspection doors,
holes, open portholes
EXHAUST SYSTEM
Note the type of hood:
Enclosures
Receiving hoods
Exterior hoods
Canopy hoods
Movable Hoods
Fugitive emissions
Exhaust gases drawn
adequately into the
hood
Capture velocities
Where To Look
Around fan
housing
Fan blades
Around process
equipment and hood
Same as above
Around hood
When To Look
Same as above
While fan system
is off
Fan blades, fan
wheel
Fan system,
ductwork
Same as above
Anytime
While process is
operating
Same as above
Same as above
Additional Comments
(How)
Noise from housing
Through access door
or opening in fan
housing
Same as above
Visual observation
around control system
Draw diagram of system
and show point of emissions
on back of this form.
Visually observe
adequacy of captive
velocities; if inade-
quate, emissions will
not be drawn into hood.
Observations
Ofour Comments)
-------
w
I
ro
[S3
(concluded)
What Jo LookJTor
Location of hood
Cross-drafts or thermal
drafts
Dust buildup or
obstruction in
ductwork
Flaps being used
around canopy hoods
Where To Look
Around process.
equipment and hood
Same as above
Ductwork associ-
ated with hoods
Around process
equipment
When To Look
Same as above
Same as above
Anytime
When process is
operating
Additioun1 Comments
_ (How)
If visual observation
hood is improperly located,
exhaust gases will not
be captured.
If cross- or thermal
drafts are present,
they will deflect
exhaust gases and will
not be captured by hood.
Conduct this activity
only if accessible and
safe.
If flaps are not used
properly, some emissions
will escape from hood.
Observat ions
(Your Comments)
-------
VI. CHECKLIST FOR LOCAL EXHAUST_SYSTKH-MECHANXCAL COLLECTORS
What To Look For
MECHANICAL COLLECTORS
Corrosion, holes, wear
points
td
I
Solids removal systems
for proper operation
Dust buildup and plug-
ging or foreign mat-
ter restriction
Where To Look
Main shell of col-
lector
Ductwork
Hoppers
Inside walls of
shell and hoppers
Gas outlet tube
Skimmer plate
Solids removal
system such as
screw conveyor,
settling chamber
Inside walls of the
collector
Dust outlet
Ductwork
When To Look
During external
inspection
While system is
off, during in-
ternal inspec-
tion of the
equipment.
While system is
operating
While system is
off
Additional Comments
(How)
Draw diagram of system
and show point of
corrosion on back of
this form or describe.
In some cases you
will not be able
to do this activity
because of inaccessi-
bility to area.
If system is operating
correctly you will see
solids removal from
control equipment also.
This can be checked through
access door, portholes.
In some cases you will not
be able to do this because
of inaccessibility to area.
Observations
(Your Comments)
Proper operation,, air
leakage and wear
Flop gates or in-
ternal vanes
Gravity valve
Rotary air lock
Seal between hoppers
and cyclone
Body of collector
During external
inspection while
system is running
or during internal
inspection while
system is off
-------
(continued)
What To Look For
LOCAL EXHAUST SYSTEM
Note the type of hood:
Enclosures
Receiving hoods
Exterior hoods
Canopy hoods
Movable hoods
Where To Look
When To Look
Additional Comments
(How)
Observations
(Your Comments)
Fugitive emissions
Around process
equipment and hood
While process is
operating
Draw diagram of system
and show point of emissions
on back of this form.
Exhaust gases drawn
adequately into the
hood
Same as above
Same as above
tt)
to
Capture velocities
Location of hood
Cross-drafts or thermal
drafts
Around hood
Around process
equipment and hood
Same as above
Same as above
Same as above
Same as above
Visually observe
adequacy of captive
velocities; if inade-
quate, emissions will
not be drawn into hood.
If visual observation
hood is improperly located,
exhaust gases will not
be captured.
If cross- or thermal
drafts are present,
they will deflect
exhaust gases and will
not be captured by hood.
-------
M
Ul
(concluded)
Additional Comments Observations
What To Look For Where To Look When To Look (How) (Your Comments)
Dust buildup or Ductwork associ- Anytime Conduct this activity
obstruction in ated with hoods only if accessible and
ductworks safe through access
doors or portholes.
Flaps being used Around process When process is If flaps are not used
around canopy hoods equipment operating properly, some emissions
will escape from hood.
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
340/1-81-005
I. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Ferrous Foundry Inspection Guide
i, REPORT DATE
January 1982
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R. Shah, A. Trenholm
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAMt AND ADDRESS
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-6314, Task No. 2
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Protection Agency
Division of Stationary Source Enforcement
13. TYPE OF REPORT AND PERIOD COVERED
Task Final, 1/81-1/82
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
DSSE Project Officer is Robert L. King, (202) 382-2814
16. ABSTRACT
This inspection guide has been written and organized for use by state and local
enforcement field inspectors and entry-level engineers whose familiarity with foundry
operations may be limited. It describes ferrous foundry processes and emissions
control systems. It explains in layman's terms foundry emission problems and causes.
It details step-by-step inspection procedures for process and control equipment, and
is supplemented by inspection checklists. Health and safety guidelines for foundry
inspectors are also listed.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Foundries
Iron and Steel Industry
Manual
Emissions
Air Pollution Control Equipment
Operation and Main-
tenance
Inspection Procedures
13. DISTRIBUTION STATEMENT
19, SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
131
Unlimited
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
-------
U.S. Environmental Protection Agtnqr
Region 5, Library (PL-12J)
77 West Jackson Boulevard, 12th Fkw
Chicago. IL 60604-3590
-------
11 .oH 5»»t°s nffirn of Air Noise and Radiation Enforcement
EnviranmVntal Protection Division of Stationary Source Enforcement
Agency Washington DC 20460
Postage and
rw,r\,\ Rainess Publication No. EPA-340/1-81-005 Fees Paid
KS-SS.U- -ronmenta,
SJO° Agency
EPA 335
If your address is incorrect, please change on the above label,
tear off, and return to the above address
If you do not desire to continue receiving this technical report
series, CHECK HERE D , tear off label, and return it to the
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------- |