Air Pollution Training institute
MD20
Environmental Research Center
Research Triangle Park, NC 27711
June, 1982
Cyrrespendence Course 416
Inspection Procedures for
Organic Solvent Metal
Cleaning (Degreasing)
Operations
Guidebook
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United States
Environmental Protection
Agency
Air Pollution Training Institute
MD20
Environmental Research Center
Research Triangle Park, NC 27711
-PA 450/2-82-014
june, 1982
Air
APTI
Correspondence Course 416
Inspection Procedures for
Organic Solvent Metal
Cleaning (Degreasing)
Operations
Guidebook
Prepared into a Correspondence Course by:
David S. Beachler
Northrop Services, Inc.
P.O. Box 12313
Research Triangle Park, NC 27709
Under Contract No.
68-02-3573
EPA Project Officer
R. E. Townsend
United States Environmental Protection Agency
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
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Notice
This is not an official policy and standards document. The opinions and selections
are those of the authors and not necessarily those of the EnVinnurlencaLProt'ection,
Agency. Every attempt has been made to representthe1pr.esentstate ';of the art. as
well as subject areas still under evaluation. Any mention,df "products or organiza-
tions does not constitute endorsement by the UnitetLStates EnviToqmental Protec-
tion Agency.
Availability
This document is issued by the Manpower and Technical Information Branch,
Control Programs Development Division, Office of Air Quality Planning and Stan-
dards, USEP A. It was developed for use in training courses presented by the EP A
Air Pollution Training Institute and others receiving contractual or grant support
from the Institute. Other organizations are welcome to use the document.
This publication is available, free of charge, to schools or governmental air
pollution control agencies intending to conduct a training course on the subject
covered. Submit a written request to the Air Pollution Training Institute. USEPA,
MD 20, Research Triangle Park, NC 27711.
Others may obtain copies, for a fee, from the National Technical Infornlation
Service (NTIS), 5825 Port Royal Road. Springfield, VA 22161.
ii
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Table of Contents
I'. :.. ':J" L' L ~'C: ".J'--' ,:r1~ Page
Lesson 1. Course-.lntmdudion:......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-I
Lesson 2. Degreasers: ;1ntroclucrion and Background. . . . . . . . . . . . . . . . . . . . . . . . .2-1
Lesson 3. Cold Cleaners: :Equipment Description, VOC Emission
Points, Emission Reduction Techniques, and Inspection
Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1
Lesson 4. Open Top Vapor Degreasers: Equipment Description,
VOC Emission Points, Emission Reduction Techniques,
and Inspection Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1
Lesson 5. Conveyorized Degreasers: Equipment Description,
VOC Emission Points, Emission Reduction Techniques,
and Inspection Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Lesson 6. Problem Set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1
Lesson 7. Introduction to Source Testing of Degreasers. . . . . . . . . . . . . . . . . . . . . . .7-1
111
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Lesson 1
Course Introduction
This is a 20-hour correspondence course dealing with inspection procedures for
degreasing operations. The course reviews in detail the inspection and VOC source-
testing procedures for degreasers. Course topics include:
. EP A policy on RACT regulations for degreasers
. Degreaser description for cold cleaners, open top vapor degreasers, and con-
veyorized degreasers
. VOC emission points
. Typical emission control methods
. Inspection procedures
. Emission-testing procedures
Course Goal
This course is designed to familiarize you with degreasing operations, emission
points, control techniques, and source emission testing for compliance.
Course Objectives
Upon completion of this course, you should be able to:
1. recognize the operation and VOC emission points of a cold cleaner.
2. recognize the operation and VOC emission points of an open top vapor
degreaser.
3. recognize the operation and VOC emission points of a conveyorized degreaser.
4. name the work practices and control equipment used to reduce VOC emis-
sions from cold cleaners and briefly describe inspection procedures.
5. name the work practices and control equipment used to reduce VOC emis-
sions from open top vapor degreasers and briefly describe inspection
procedures.
6. name the work practices and control equipment used to reduce VOC emis-
sions from conveyorized degreasers and briefly describe inspection procedures.
7. recognize the EP A policy on RACT regulations for organic solvent metal-
cleaning operations.
8. recognize source-testing methods for compliance purposes.
1-1
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Lesson Titles
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Lesson 6
Lesson 7
Course Introduction
Degreasers: Introduction and Background
Cold Cleaners: Equipment Description,
VOC Emission Points, Emission Reduc-
tion Techniques, and Inspection
Procedures
Open Top Vapor Degreasers: Equipment
Description, VOC Emission Points, Emis-
sion Reduction Techniques, and Inspec-
tion Procedures
Conveyorized Degreasers: Equipment
Description, VOC Emission Points, Emis-
sion Reduction Techniques, and Inspec-
tion Procedures
Problem Set
Introduction to Source Testing of
Degreasers
Trainee involvement
time (hours)
1
2
4
4
4
2
3
Requirements lor Successful Completion 01 this Course
To receive 2.0 Continuing Education Units (CEUs) and a cenificate of course com-
pletion. you must:
1. take one mail.in final examination.
2. achieve a fmal course grade of at least 70% (out of 100%) based on the final
exam.
Reading Materials
. APTI Correspondence Course 416 Inspection Procedures for Organic Solvent
Metal Cleaning (Degreo..sing) Operations: Guidebook. EPA 450/2-82-014.
. EPA 340/1-79-008. June 1979. Solvent Metal Cleaning: Inspection-Source
Test Manual. *
Additional Suggested Readings
The following publications are not included with the course materials and are not
necessary for successful completion of this course. However, they are informative
and are, therefore, recommended readings. You should obtain a copy from your
State or local air pollution agency files. Should these materials not be available
through your agency, contact the Air Pollution Training Institute for assistance.
*This text will be referred to as the Inspection Manual.
1-2
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. Environmental Protection Agency (EPA). 1980. Organic Solvent Cleaners;
Standards of Performance for New Stationary Sources; Proposed Rule and
Notice of Public Hearing. 45 Fed. Reg. No. 114, 39766-39784 Oune 11, 1980).
. Environmental Protection Agency (EPA). 1981. Standards of Performance for
New Stationary Sources; Organic Solvent Cleaners-Amendment for Proposed
Rule. 46 Fed. Reg. No. 76. 22768-22769. (April 21, 1981).
. EPA 905/2-78-001. April 1978. Regulatory Guidance for Control of Volatile
Organic Compound Emissions from 15 Categories of Stationary Sources.
. EPA 450/2-77-022. November 1977. OAQPS Guidelines Control of Volatz"le
Organic Emissions from Solvent Metal Cleaning.
Use 0/ the Guidebook
This guidebook directs your progress through this course. This first lesson
introduces the rest of the course material and explains how to use it. Lessons 2
through 7 are self-paced, giving reading assignments and review exercises for sec-
tions of each lesson. To complete a review exercise, place a piece of paper across
the page covering the questions below the one you are answering. Mter answering
the question, slide the paper down to uncover the next question. The answer for
the first question will be given on the right-hand ponion of the page separated by
a line from the second question (Figure 1-1). All answers for review questions will
appear below and to the right of their respective questions. The answers will be
numbered to match the questions.
Review Exercise
1. Question lellllCl
1111, ellu .,lIcl//IIl/I
2. Question III, null. Answer
II I/IIIClu'l'c II IIIICI
3. Question 1111 leI/ 2. Answer
ICI 1111. ellu "lIcl/'
Figure 1-1. Review exercise format.
Do not write in this guidebook. Please use a piece of paper for answering the
questions. Complete the review exercise for each section in each lesson. If you are
unsure about a question or answer, review the lesson section preceding the exercise,
then proceed to the next section.
1-3
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Lesson Content
Lessons in this guidebook contain the foUowing information:
. lesson goal
. lesson objectives
. reading ~ignx.nent
. review exercises and exercise answers (Lessons 2 through 7)
If supplementary reading material is available, it will be recommended in the
appropriate lesson, but this material is not required for successful completion of
the course.
Instructions for Completing the Course
Contact the Air Pollution Training Institute if you have any questions about the
course or when you are ready to receive ~ copy of the fmal examination.
After completing the final exam, return it and the answer sheet to the Air Pollu-
tion Training Institute. Your fmal exam grade and course grade will be mailed to
you.
Air Pollution Training Institute
Environmental Research Center
MD 20
Research Triangle Park, NC 27711
1-4
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Lesson 2
Degreasers:
Introduction and Background
Lesson Goal
To familiarize you with the scope of the EP A inspection manual for solvent metal
cleaning and EP A's policy on RACT regulations for degreasers.
Lesson Objectives
At the end of this lesson, you should be able to:
1. recall the EP A policy on RACT regulations for degreasers.
2. name four organic solvents used in degreasing operations.
3. list four pieces of field inspection equipment used for inspecting degreasers.
4. recall safety considerations for field inspections.
Reading Materials
. EPA 340/1-79-008. Solvent Metal Cleaning: lnspectz"on-Source Test Manual,
Chapter 1.
Additional Suggested Readings
. EPA 450/2-77-022. November 1977. OAQPS Guidelines. Control of Volatile
Organic Emissionsfrom Solvent Metal Clean%ng, pages 1-1 to 1-3, and 2-1 to
2-6.
Reading Guidance
This lesson will cover EP A policy on RACT regulations for degreasers, degreasing
solventS, inspection equipment used for field inspections, and safety considerations.
You will be instructed to read a short section of material from the lnspection-
Source Test Manual and then answer some review questions. The manual will be
referred to as the lnspect%'on Manual throughout this guidebook.
2-1
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EPA. Policy on RACT Regulations For D~fltISen
R.eading Alaignment
Begin your reading with pages 1.1-1, and 1.2-1 to 1.2-2 of the Inspection Manual.
After completing this reading assignment, answer the following review questions.
Note: Control System A consists of "operating practices and simple, inexpensive
control equipment." Control System A is required as a minimum in all urban
nonattainment area facilities emitting 100 tons per year or less of VOCS provided
attainment is demonstrated by December 51, 1982. Control System B consists of
"Control System A plus additional requirements to improve the effectiveness of con-
trol." Control System B is required in urban nonattainment areas (population
> 200,000) seeking an extension until the 12/51/87 SIP deadline and in all
facilities emitting VOCs in excess of 100 tons per year in other nonattainment
areas.
R.eview Exercise
1. True or False? Control System B consists of operating
practices and simple inexpensive control equipment.
2. True or False? Control System B consists of Control 1. False
System A plus additional requirements to improve the
effectiveness of control.
5. Control System A is required as a minimum in 2. True
a. all attainment areas.
b. urban nonattainment area facilities emitting 100
tons per year or less of VOCS provided attainment
is demonstrated by December 51, 1982.
c. attainment areas emitting 100 tons per year or less
of VOCs.
4. Control System B is required in 5. b. urban non-
a. all attainment areas. attainment
b. nonattainment rural areas emitting 100 tons per area facilities
year or less of VOCs. emitting 100 tons
c. urban nonattainment areas (population> 200,000) per year or less of
seeking an extension until the 12/51/87 SIP VOCs provided
deadline and in all facilities emitting VOCs attainment is
in excess of 100 tons per year in other nonattain- demonstrated by
ment areas. December 31, 1982.
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5. An EPA-recommended exemption to the CTG 4. c. urban non-
regulations is: attainment areas
a. all open top vapor degreasers in urban nonattain- (population
ment areas should be exempt from installing > 200,000)
carbon adsorbers. seeking an exten-
b. open top vapor degreasers with an open area of less sion until the
than 1.0 ml should be exempt from installing 12/31/87 SIP dead-
refrigerated chillers and carbon adsorbers. line and in all
c. open top vapor degreasers with an open area of facilities emitting
greater than 2.0 ml should be exempt from VOCs in excess of
installing refrigerated chillers and carbon 100 tons per year in
adsorbers. other nonattain-
ment areas.
6. EP A will approve exemptions for all cold cleaners 5. b. open top vapor
emitting less than 100 tons per year of VOCs in degreasers with an
areas. open area of less
than 1.0 ml should
be exempt from
installing refriger-
ated chillers and
carbon adsorbers.
7. True or False? A State is permitted to exempt open 6. rural
top or conveyorized degreasers in rural nonattainment nonattainment
areas if the VOC emissions are less than 100 tons per
year on a facility-wide basis.
7. True
Degrea.sing Solvents
Reading Assignment
Continue your reading with pages 1.3-1 through 1.3-5 of the Inspection Manual.
After completing this reading assignment, answer the following review questions.
Review Exercise
1. Degreasing solvents are organic chemicals derived
principally from
2. True or False? Stoddard solvent, kerosene, heptane, 1. petroleum
and cyclohexane are petroleum distillates used fre-
quently in cold cleaners.
2-3
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w
S. Halogenated hydrocarbons are used in vapor 2. True
degreasers because they are and they are
approximately four times
than air.
4. True or False? Evaporative losses in cold cleaners S. nonflammable
increase as the volatility of the solvent used increases. more dense
5. Perchloroethylene has a(n) solvency for 4. True
cleaning metal-working soils.
6. True or False? Benzene and carbon tetrachloride are 5. excellent (see
highly recommended degreasing solvents. Table 1-1)
6. False (see Table
I-I. Benzene is a
hazardous material .
and carbon tetra-
chloride is not
recommended for
metal cleaning.)
Inspection Bquipmmt
R.eading A8aignment
Continue your reading with pages 1.4-1 and 1.5-1 of the Inspection Manual. After
completing the reading assignment, answer the following review questions.
R.eview Exercise
1. A field inspector should wear routine safety equipment
such as a hard hat, steel-toed shoes, and
2. True or False? Field equipment specific to degreaser 1. safety glasses
inspections would include a tape measure, ther-
mometer, Stop watch, and small collecting bottle.
S. Most solvents used in degreasers are not toxic and can 2. True
be inhaled without causing damage to the lungs.
2-4
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4. A field inspector should never put his or her hand 3. False
below the level inside a vapor degreaser.
4. vapor
2-5
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Lesson 3
Cold Cleaners:
Equipment Description, VOC Emission
Points, Emission Reduction
Techniques, and Inspection Procedures
Lesson Goal
To familiarize you with the operation of and inspection procedures for cold
cleaners.
Lesson Objectives
At the end of this lesson, you should be able to:
1. recall how a cold cleaner operates.
2. name the VOC emission points of a cold cleaner.
. 3. recall the work practices and control equipment used to reduce VOC
emissions from cold cleaners. ,
4. recall the inspection procedures for cold cleaners.
Reading Materials
. EPA 340/1-79-008. Solvent Metal Cleaning: Inspection-Source Test Material.
Chapter 2.
Additional Suggested Reading
. EPA 450/2-77-022. November 1977. OAQPS Guidelines. Control of Volatile
Organic Emissionsfrom Solvent Metal Cleaning, pages 2-7 through 2-16, 3-1
through 3-5, 3-18, 3-22, 3-23, 3-30 through 3-32.
Reading Guidance
This lesson will cover cold cleaners: how they operate, the VOC emissions
generated from them, the work practices and control equipment used to reduce
VOC emissions, and the procedures for a field inspection. You will be instructed to
read a short section of material from the Inspection Manual and then answer some
review questions.
3-1
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Process Description
Reading Assignment
Begin your reading with pages 2.1-1 through 2.1-4 of the Inspection Manual. After
completing this reading assignment. answer the following review questions.
Review Exercise
1. Cold cleaners are generally used for
a. low volume workloads of small metal parts.
b. high volume workloads of large metal parts.
c. neither of the above
2. In a cold cleaner. is used to dissolve dirt 1. a. low volume
or grease from the part to be cleaned. workloads of small
a. hot water metal parts.
b. a cold solvent
c. a cold vapor
5. True or False? Cold cleaning is occasionally enhanced 2. b. a cold solvent
by agitating the solvent or by spraying the solvent on
the part.
4. A typical size of a colc:i cleaner is 5. True
a. a 20-ftl opening and a 200-gallon solvent capacity.
b. a 4-ftl opening and a 50-gallon solvent capacity.
c. neither of the above
5. True or False? Pumping. compressed air vertical 4. b. a 4-ftl opening
motion. or ultrasonic vibration may be used to agitate and a 50-gallon
liquid solvent in a cold cleaner. solvent' cap-acity.
5. True
5-2
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VOC Emissions and Control Methods
Reading Assignment
Continue your reading with pages 2.2-1 through 2.2-5, and 2.3-1 through 2.3.3 of
the lnspectz'on Manual. After completing the reading assignment, answer the
following questions.
Review Exercise
1. VOC emissions can be emitted from a number of points of a cold cleaner. From
Figure 3.1, what are the five VOC emission points?
. 'K;;(J';~~~~;~ 0
(0
Figure 3-1. Cold cleaner emission points.
3-3
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Answers for question 1.
Spray
:::/:::::, G?,:~ath evaporation
,::,j;f~;li:::j!~;t2}~:;
," '.,. (;\
,',:;' .. "'. i '..' \!..I
}'~?~;f~~;!); C~'out
o
Waste solvent
Figure 3-2. Cold cleaner emiuion poinu (answen).
2. True or False? Bath evaporation emissions from the
cold cleaner are increased by air movement caused by
drafts and plant ventilation fans near the degreaser.
3.
for a cold cleaner is defined
as the distance from the solvent level to the top of the
cold cleaner.
2. True
4. True or False? Freeboard ratio is defined as the ratio
of freeboard length to freeboard width of the
degreaser.
3. Freeboard height
5. Bath evaporation emissions can be reduced by keeping
a(n) closed during degreasing operations
except when pans are removed.
4. False
6. True or False? The solvent in a cold cleaner is some-
times heated to help the degreasing action.
5. cover
3.4
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7. Carry-out emissions occur when pans are 6. True
removed from the degreaser and
evaporates in the surrounding area.
8. Waste solvent emissions are generated by the 7. wet
of waste solvent. solvent
9. Carry-out emissions can be minimized by allowing 8. improper disposal
wet metal pans to sit on a( n)
for at least 15 seconds.
10. In a cold cleaner, more VOC emissions are usually 9. drying rack
generated from than any other operation.
a. carry-out
b. bath evaporation
c. improper disposal of waste solvent
d. agitation of solvent
11. True or False? Spray emissions can be reduced by 10. c. improper
keeping the spray fluid pressure less than 10 psig. disposal of waste
solvent
12. If a highly volatile solvent is used in a cold cleaner 11. True
(>4.3 kPa at 38°C) what control methods would be
required for RACT Control System B?
a. a freeboard height giving a freeboard ratio of ~ 0.7
b. a water cover
c. a refrigerated chiller
d. Any of the above methods is acceptable.
12. d. Any of the
above methods is
acceptable
3-5
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Inspection Procedures for Cold Cleaners
R.eading Assignment
Continue your reading with pages 2.4-1 through 2.4-8 of the 11UPection Manual.
After completing the reading assignment. answer the following questions.
Note: "It should be stressed that EPA has exempted cold cleaners with remote
solvent reservoirs from operating requirements to cover the degreaser during non-
use periods. In addition. the units can be exempted from equipment specifications
which require each cold cleaner to have a closable cover. Also. a separate drain
rack is unnecessary." (EP A Memo).
Vapor pressures of various cold cleaning solvents can be difficult to determine if
the cleaning solvent is a blend of a number of different solvents. If the relative sol-
vent concentrations are known. the vapor pressure of the cleaning solvent can be
calculated. Vapor pressures are commonly written in units of mm of Hg. One nun
Hg is equal to 1 SS Pa.
R.eview Exercise
1. During a field inspection. the inspector should observe
both the and the of the
degreaser.
2. The degreaser cover should be whenever 1. control equipment
there are no parts in the cold cleaner. operating
procedures
S. If the freeboard height is 2 ft. and the width of the 2. closed
degreaser is 2.5 ft. what is the freeboard ratio?
a. 1.25
b. 5.0
c. 0.8
d. 0.67
4. If the solvent used in a cold cleaner having dimensions S. c. 0.8
as in question S has a solvent volatility of 5. S kPa
measured at S8°C. is the freeboard ratio large
enough?
a. Yes
b. No
*EP A Memo from David Beck to Robert T. Walsh. "Recommended Changes to a Control
Techniques Guideline for Organic Solvent Cleaning." June 5, 1979.
S-6
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5. True or False? External drainage racks can be used for 4. a. Yes
drying wet parts if the drainage is routed back to the
solvent bath.
6. The cover must be easily operated with one hand if 5. True
a. the solvent volatility is ~ 2 kPa (measured at 38°C).
b. the solvent is agitated.
c. the solvent is heated.
d. all of the above
6. d. all of the above
3-7
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Lesson 4
Open Top Vapor Degreasers:
Equipment Description, VOC Emission
Points, Emission Reduction
Techniques, and Inspection Procedures
Lesson Goal
To familiarize you with the operation of and inspection procedures for open top
vapor degreasers.
Lesson Objectives
At the end of this lesson, you should be able to:
1. recall how an open top vapor degreaser operates.
2. name the VOC emission points of an open top vapor degreaser.
3. recall the work practices and control equipment used to reduce VOC emis-
sions from open top vapor degreasers.
4. recall the inspection procedures for open top vapor degreasers.
Reading Materials
. EPA 340/1-79-008. Solvent Metal Cleaning: Inspection-Source Test Manual.
Chapter 3.
Additional Suggested Reading
. EPA 450/2-77-022. November 1977. OAQPS Guidelines. Control of Volatile
Organic Emissions from Solvent Metal Cleaning, pages 2-16 through 2-33, 3-5
through 3-29, 3-32 through 3-3~.
Reading Guidance
This lesson will cover open top vapor degreasers: how they operate, the VOC emis-
sions generated from them, the work practices and control equipment used to
reduce VOC emissions, and the procedures for a field inspection. Open top vapor
degreasers are also commonly called open top degreasers. Open top degreasers can
be designed to use vapor only or a combination of vapor and liquid solvents for
4.1
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degreasing metal components. You will be instructed to read a shon section of
material from the Inspection Manual and then answer some review questions.
Process Description
Reading Assignment
Begin your reading with pages g .1-1 through g .1-12 of the Inspection Manual.
After completing this reading assignment, answer the following questions.
Review Exercise
1. In an open top vapor degreaser, cleaning is a result
of the condensation of on
the cool surface of the metal pan being cleaned.
a. liquid solvent
b. solvent vapors
c. water vapor
2. True or False? In an open top vapor degreaser, no 1. b. solvent vapors
more cleansing action occurs after the metal pan ~
reaches the temperature of the solvent vapors.
g. solvents are used in' open top vapor 2. True
degreasers.
4. True or False? Open top vapor degreasers can be 3. Nonflammable
designed to use vapor only or a combination of vapor
and liquid for degreasing metal pans.
4. True
4-2
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5. What are the "numbered" components of a typical open top vapor degreaser as
shown in Figure 4-1?
o
Cleanout door
o
Water separator
Figure 4-1. Typical open top vapor degreaser.
4-3
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Answers for question 5.
o Condensing coils
Cleanout door
o
Water jacket
Water separator
o
Condensate trough
o Heating elementS
o Work rest and protective grate
Figure 4-2. Typical open top vapor degreuer (answers).
4-4
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6. True or False? Open top vapor degreasers are usually
smaller than cold cleaners.
7. Some larger open top vapor degreasers are equipped 6. False
with a(n) that draws air
laterally across the top of the degreaser and vents this
air to the roof or to a carbon adsorber.
8. Heating elements in an open top degreaser can be 7. lip exhaust
a. electric heating coils.
b. steam pipes and steam jackets.
c. natural gas burned in an immersion tube.
d. all of the above
9. True or False? Halogenated solvents are used in 8. d. all of the above
vapor degreasers because they are nonflammable and
their vapors are denser than air.
10. The freeboard of a vapor degreaser is the ponion of 9. True
the degreaser extending
a. above the liquid solvent.
b. above the work rest grate.
c. above th~ cooling coils.
d. none of the above
11. are used to limit the vapor 10. c. a bove the
space of a vapor degreaser. cooling coils.
12. is usually used as the cooling medium for 11. Cooling coils
the cooling coils.
a. Liquid nitrogen
b. Freon
c. Methylene chloride
d. Water
13. Most vapor degreasers are equipped with a(n) 12. d. Water
to help prevent solvent from
mixing with water and possibly causing corrosion of
degreaser and piping.
4-5
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14. Occasionally, vapor degreasers are equipped with Ig. water separator
to help prevent convection of
vapors up degreaser walls.
a. protective grates
b. water jackets
c. water separators
14. b. water jackets
VOC Emissions and Control Methods
R.eading Assignment
Begin your reading with pages g.2-1 through g.2-4, and 3.3-1 through 3.3-4 of the
Inspection Manual. Note: On page 3.3-2 under Control System B (#3), the major
controls for Control System B should read:
Either: a. freeboard ratio greater than or equal to 0.75
b. refrigerated chiller
c. enclosed design (cover or door opens only when the dry part is
actually entering or exiting)
d. carbon adsorption system, with ventilation greater than 15 mJ/min per
ml (50 cfm/ftl) of air/vapor area (when the cover is open), and
exhausting less than 25 ppm solvent average over one complete
adsorption cycle, or .
e. control system demonstrated to have a control efficiency equivalent to
or better than any of the above.
The confusing point is that according to Control System B, if the oPening of the
open top vapor degreaser is greater than 10 ftl, then the cover must be powered.
This is true whether the freeboard ratio is greater than or less than 0.75.
In addition to the material written on page 3.2-4, the following comments
should be made concerning "water in the solvent." Some solvent inhibitors are also
soluble in water. The presence of water in the solvent mixture (vapor) may remove
these inhibitors from the solvent. Inhibitors are used to slow or prevent a chemical
reaction.
4-6
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Review Exercise
1. VOCs can be emitted from a number of operations in an open top vapor
degreaser. Refer to Figure 4.3 and list the five emission points.
Retractable cover
~;. 0
.: ~..::::~::{;i~:::)
Potential adsorber
8
;,,/::,/,
Lip exhawt
Condensing coils
.0
:':', .:~
,.:", ..... ...: . :::
'::_J'.j,~;Jt;
:: .--
. .'. '-.
Figure 4-5. Typical open top vapor degreaaer emission points.
0,....:..::::::.
:<:::.~~:?::/\/
: -.1/ ': j': .~ ::,:
4-7
-------
Answers to question 1.
, .
.::\..:~~:j:,:.(D Roof vent
.1 '.': . ;'.'
.;:..:~':~ ~: ....:~
:'~::. :: :
.Q)piffuaion and convection
:::":':::,?'.:"':?"::~;~:; i\~ Lip exhaust
Potential adsorber
Retractable cover
Wute solvent 0:::. '.:X}:~': .
:/~";:~{~}~t~/:
Condensing coila
./". .:.::. :.{~; Carry-out
;:11;
I'ipre 4-4. Typical o~ top npor degreuer l!Ini_ioD poinu (aDIWen).
2. True or False? The size of the workload and the
speed with which anicles are moved in and out of the
degreaser does not affect the VOC emission rate.
s. If liquid solvent is sprayed in an open top vapor
degreaser, the spray should be aimed
a. below the lip exhaust.
b. above the condensing coils.
c. below the condensing coils.
4. The use of during idle and down times
will help reduce diffusion and convection of VOC
eID1SS10ns .
4-8
2. False
!L c. below the con-
densing coils
-------
5. If the degreaser is equipped with a lip exhaust, the
ventilation rate should be
a. > 50 ftS / min per ftZ of degreaser opening.
b. < 100 ftS / min per ftZ of degreaser opening.
c. < 50 fts/min per ftZ of degreaser opening.
6. True or False? Refrigerated chillers are located below
the primary condensing coils.
7. Below-freezing refrigerated chillers must be
a few minutes each hour to melt the
accumulated ice and slush on the chiller. The water
is collected in the and sent
to the water separator.
8. To reduce carry-out emissions, parts should be
allowed to dry for
a. 30 seconds above the freeboard area.
b. 15 seconds in the freeboard area.
c. 2 minutes in the freeboard area.
9. True or Faise? Porous or absorbent materials such as
cloth, leather, wood, and rope make good hoisting
straps in open top vapor degreasers.
10. In an open top vapor degreaser, if water is allowed to
accumulate in the boiling sump. emissions may be
increased since
a. the water/solvent vapor mixture has a lower
density than pure solvent vapor and thus has
a greater tendency to be lost by diffusion.
b. water combines with the solvent to form a low
boiling azeotrope that results in a higher
vaporization rate.
c. water is corrosive to degreaser surfaces and
piping, thus making leaks a serious problem.
d. all of the above
4-9
4. covers
5. c. < 50 fts/min
per ftZ of
degreaser
opening.
6.
'alse
7. defrosted
condensate trough
8. b. 15 seconds in
the freeboard
area.
9. False
10. d. all of the above
-------
Inspection Procedures for open Top Vapor DegrmstJrs
Reading Aasignment
Continue your reading with pages 3.4-1 through 3.4-8 of the Inspection Manual.
After completing this reading assignment, answer the foUowing questions.
Note: On page 3.4.3, "a. freeboard ratio of greater than 0.75" and "b. If the
degreaser area is greater than 1.0 ml the cover must be powered" should be con.
sidered as a single major control device.
Also, number 5 under "operating requirements" has been rescinded by EPA and
should no longer be considered as an operating requirement.
Review Exercise
1. The vapor level control thermostat is a safety switch
that
a. turns off the sump heat if the vapor zone
temperature rises above the design level.
b. turns on the sump heat if the vapor zone
temperature falls below the design level.
c. causes the refrigerated coils to go through a defrost
cycle.
2. An open top vapor degreaser has a width of 3 feet
and a length of 6 feet. The height from the top of the
primary coils to the top of the degreaser is 2 feet.
What is the freeboard ratio?
a. 0.33
b. 0.5
c. 1.5
d. 0.667
3 . Would a degreaser with the dimensions given in
question 2 be required to have major control devices
such as a refrigerated chiller or carbon adsorber for
Control System B? (1 m = 3.048 ft)
a. Yes
b. No
4-10
1. a. turns off the
sump heat if the
vapor zone tem-
perature rises
above the design
level.
2. d. 0.667
-------
4. To minimize carry-out emissions, the inspector should 3. a. Yes.
make sure that The open area of
a. the parts are moved in and out at a speed of less the unit is 18 ft!.
than 11 ft/min. For Control Sys-
b. pans dry within the freeboard area for at least 15 tem B, the free-
seconds. board ratio must
c. pans are degreased in the vapor zone for at least be > 0.75 or the
30 seconds or until condensation stops. unit must be
d. all of the above equipped with a
major control
device such as a
refrigerated
chiller carbon
adsorber, or
must be an
enclosed design.
5. If a degreaser is 2 ft wide and 4 ft long, metal parts 4. d. all of the above
should have a surface area
a. greater than 1 ft2.
b. less than 4 ft2.
c. greater than 8 ft2.
d. less than 2 ft2.
5. b. less than 4 ft2.
(see item 4 page
3.4-4)
4-11
-------
Lesson 5
Conveyorized Degreasers:
Equipment Description, VOC Emission
Points, Emission Reduction
Techniques, and Inspection Procedures
Lesson Goal
To familiarize you with the operation of and inspection procedures for conveyor.
ized degreasers.
Lesson Objectives
At the end of this lesson, you should be able to:
1. recall how a conveyorized degreaser operates.
2. name the VOC emission points of a conveyorized degreaser.
3. recall the work practices and control equipment used to reduce VOC emissions
from conveyorized degreasers.
4. recall the inspection procedures for conveyorized degreasers.
Reading Materials
. EPA 340/1-79-008. June 1979. Solvent Metal Cleaning: Inspection-Source
Test Manual. Chapter 4.
Additional Suggested Reading
. EPA 450/2-77-022. November 1977. OAQPS Guideline. Control of Volatile
Organic Emissions from Solvent Metal Cleaning, pages 2-33 through 2-44, 3-9
through 3-36.
Reading Guidance
This lesson will cover conveyorized degreasers: how they operate, the VOC emis-
sions generated from them, the work practices and control equipment used to
reduce VOC emissions, and the procedures for a field inspection. You will be
instructed to read a short section of material from the Inspection Manual and then
answer some review questions.
5-1
-------
Process Description
Reading Assignment
Begin your reading with pages 4.1-1 through 4.1-11 of the Inspection Manual.
After completing this assignment. answer the following questions.
Review Exercise
1. True or False? Conveyorized degreasers can use either
cold or vaporized solvents.
2. In a conveyorized degreaser using a vapor solvent. the
"cold pan" being degreased must the
vapor to condense the solvent on the pan.
a. be at a lower temperature than
b. be at a higher temperature than
c. be at the same temperature as
1. True
3. Conveyorized degreasers are generally
automatic units designed to handle a lot of work
pieces.
2. a. be at a lower
temperature
than
3. large
4. What are the "numbered" components of a typical monorail (conveyorized)
degreaser as shown in Figure 5-1?
o
Figure 5-1. Typical monorail degreuer using vaporized and liquid solvents.
5-2
-------
Answers to question 4.
. 0 (2) Condensing coils
Boiling sump
Figure 5-2. Typical monorail degreaser using vaporized and liquid solvents (answers).
5. Conveyorized degreasers do not require access to the
pan while it is in the degreaser. Therefore, they are
generally units with a and
system.
6. Cross-rod conveyorized degreasers are generally used
for cleaning small or irregular pans. Cross-rod
degreasers use
a. spiral vibrating elevators to vibrate the pans while
the pans sit in a bath of cold solvent.
b. a mesh belt to transpon the pans through a vapor
chamber and a liquid solvent bath.
c. suspended pendant baskets or perforated cylinders
to hold pans while they move through the vapor
and liquid zones of the degreaser.
7. True or False? Monorail degreasers can be designed
to bring a part into the unit, carry it to the other
end, turn 1800, and exit through the same end
through a parallel adjacent opening.
5-3
5. enclosed
hood
exhaust
6. c. suspended
pendant baskets or
perforated
cylinders to hold
pans while they
move through the
vapor and liquid
zones of the
degreaser.
-------
8. Condensing coils are installed inside the conveyorized 7. True
degreaser. The coils control the
a. number of pans that can enter the unit.
b. amount of liquid condensed on the diny pan.
c. vaporS from moving into the top of the degreaser
and define the air/vapor interface. .
9. True or False? The water jacket is used to separate 8. c. vapors from
the solvent vapors from water/solvent mixtures. moving into the
top of the
degreaser and
define the
air/vapor
interface.
10. The freeboard in a conveyorized degreaser is 9. False
a. a chiller used to prevent convection of solvent
vapors up the walls of the degreaser.
b. the area above the cooling coils extending to the
top of the conveyorized degreaser.
c. the area between the boiling sump and the cooling
coils.
10. b. the area above
the cooling coils
extending to the
top of the
conveyorized
degreaser
5-4
-------
VOC Emissions and Control Methods
Reading Assignment
Continue your reading with pages 4.2-1 through'4.2-g, and 4.3-1 through 4.3-3 of
the Inspection Manual. Mter completing this assignment, answer the following
questions.
Note: The conveyor speed under "operating requirementS" is a vertical speed
limitation only. 0
Review Exercise
1. There are a number of VOC emission points for a conveyorized degreaser. Refer
to Figure 5-3, and list the "numbered" pointS.
',::.;'. .
" f:\
:/;;.:::\?$.\.'}-J
" ;,~. ;", ::'::..- ,~:
..
.;W>{,ir~ CD
G:Y!.'Oi
Figure 5-3. VOC emission pointS from a typical conveyorized degreaser.
5-5
-------
Answers to question 1. Note: There will also be some VOC emissions coming
from the exit-of the degreaser in addition to those from the entrance.
. '.~:.i,'~(,; f2'\ Roof vent
:.'!, :::~~'~?:f;f
'.' .
; .'
0"::':."o'~
Carry-out . ~
o 0
o ::~;.:;:~J/
Waste solvent
,"..' "".
lJg~~;~'~n
"""':".~:.'~: and convection
Figure 5-4. VOC emission poinu from a typical coDveyorized degreaaer (answen).
2. Carry-out emissions are the result of that
has not totally dried or dripped off the part(s) while
they are in the degreaser.
a. solvent vapor
b. waste solvent
c. liquid solvent
3. In a conveyorized degreaser, if the exhaust rate is too
high, a greater amount of VOC emissionS will be pro.
duced because a high exhaust rate disturbs the
air/vapor interface. However, the exhaust rate must
be high enough to prevent
a. the solvent from condensing too early.
b. vapor from diffusing and convecting out the
degreaser entrance and exit.
c. the carbon adsorber from becoming too saturated.
4. True or False? The conveyor speed has little or no
effect on degreaser emissions because the unit is com-
pletely enclosed.
5.6
2. c. liquid solvent
3. b. vapor from dif-
fusing and con-
vecting out the
degreaser entrance
and exit.
-------
5. The function of the
upper level of the vapor zone.
a. adsorber
b. enclosure
c. condensing coils
is to control the
6. True or False? Once the solvent's boiling temperature
has been achieved. increasing the heat input to the
boiling sump will not affect the emissions from a con-
veyorized degreaser because the unit is enclosed.
7. When degreasing materials that have pockets or cups
that can trap solvent, a should be used
so that parts can be rotated to prevent solvent
drag-out.
a. cross-rod degreaser
b. mesh belt degreaser
c. monorail degreaser
8. True or False? One way to reduce carry-out emissions
from a conveyorized degreaser is to keep the conveyor
speed greater than 11 ft/min.
9.
should be placed over degreaser
entrances and exits immediately after the degreaser
has been shut down to help reduce diffusion and con-
vection emissions.
a. Work place fans
b. Metal bars
c. Down-time covers
10. True or False? Overloading work baskets in a convey-
orized cross-rod degreaser may reduce the vapor tem-
perature and collapse the vapor zone, thereby increas-
ing the air/vapor mixing and subsequent emissions.
5-7
4. False
5. c. condensing coils
6. False
7. a. cross-rod
degreaser
8. False
9. c. Down-time
covers
10. True
-------
Inspection Procedures for Conve:yorized Degreasers
Reading Assignment
Continue your reading with pages 4.4-1 through 4.4-10 of the Inspection Manual.
After completing this reading assignment, answer the following questions.
Review Exercise
1. True or False? Safety switches should be installed and
working for condenser flow and thermostats, sprays,
and vapor level control thermostats.
2. The entrances and exits of a conveyorized degreaser 1. True
should have a clearance between the part being
degreased and the degreaser opening of
a. greater than 10% of the width opening.
b. less than 10% of the width opening ~
c. at least 15 inches.
3. A long will help reduce carry. 2. b. less than 10% of
out emissions from a conveyorized degreaser. the width opening.
4. For a subzero chiller the temperature should not 3. drying tunnel
exceed
a. 40 of
b. OOF
c. - 13 OF
5. True or False? For above-freezing chillers the cooling 4. c. - 13 OF
capacity should be at least 500 Btu/hr per ft of the
degreaser perimeter.
6. True or False? In conveyorized degreasers that have 5. True
their down-time covers open, the ventilation rate
should be ~ 50 cfm per ft of air/vapor area. These
units should be controlled by using carbon adsorbers
or refrigerated chillers.
7. should not be visually detectable in solvent 6. True
exiting the water separator.
5-8
-------
8. The waste solvent should not be disposed of or trans- 7. Water
ferred to another party if of the waste (by
weight) can evaporate into the atmosphere.
a. greater than 40%
b. greater than 20%
c. less than 10%
8. b. greater than 20%
5.9
-------
Lesson 6
Problem Set
Lesson Goal
To familiarize you, by using a problem set, with the inspection procedures for a
typical degreaser.
Lesson Objectives
At the end of this lesson, you should be able to:
1. determine, by reviewing the design plans of an open top degreaser, if the unit
meets RACT guidelines.
2. recognize the control equipment that must be used and the operating prac-
tices that must be observed during a field inspection.
Reading MateriaLr
. EPA 340/1-79-008. June 1979. Solvent Metal Cleaning: Inspection-Source
Test Manual. Chapter 4.
. EPA-42. Supplement 12, ComPilation of Air Pollutant Emission Factors. April
1981, pages 4.6-1 through 4.6-7.
Additional Suggested Readings
. Environmental Protection Agency (EPA) 1980. Organic Solvent Cleaners;
Standards of Performance for New Stationary Sources; Proposed Rule and
Notice of Public Hearing. 45 Fed. Reg. No. 114, 39766.39784 Qune 11, 1980).
. Environmental Protection Agency (EPA) 1981. Standards of Performance for
New Stationary Sources; Organic Solvent Cleaners-Amendment for Proposed
Rule. 46 Fed. Reg. No. 76, 22768-22769 (April 21, 1981).
Reading Guidance
This lesson contains an example of the procedures for an office review and a field
inspection, by an air pollution control agency inspector, of a typical open top
vapor degreaser. This example is designed using the topics covered in previous
lessons. You should refer to the appropriate lessons in this course as you complete
this exercise.
6-1
-------
In addition to writing the review exercise, you will be reading a short section
concerning emission factors of degreasers. That section was taken from EP A
AP.42, ComPilation of Air Pollutant Emission Factors, Supplement 12, April
1981, pages 4.6-1 through 4.6-7.
The United States Environmental Protection Agency (EP A) proposed New Source
Performance Standards (NSPS) for Organic Solvent Cleaners on June 11, 1980.
These rules set standards of performance for all new degreasers. You should be
aware that a promulgated rule may be published very soon and that you should
refer to the Federal Register for this information. Any new source must comply
with the NSPS set for that source category. When reviewing the design plans for
the installation of a new degreaser, you should make sure that the unit complies
with the NSPS regulations.
lleading Assignment
Begin by reading the following pages reprinted from AP-42. Then review Chapter
4, pages 4.4-1 through 4.4.10. After completing this reading assignment, complete
the review exercise that begins on page 6-10.
6-2
-------
4.6
SOLVENT DEGREASING
1 2
General'
4.6.1
Solvent degreasing (or solvent cleaning) is the physical
process of using organic solvents to remove grease, fats, oils, wax
or soil from various metal, glass or plastiC items. Th8 types of
equipment used in this method are categorized as cold cleaners,
open top vapor degreasers, or conveyorized degreasers. Nonaqueous
solvents such as petroleum distillates, chlorinated hydrocarbons,
ketones and alcohols are used. Solvent selection is based on the
solubility of the substance to be removed and on the toxicity,
flammability, flash point, evaporation rate, boiling point, cost
and several other properties of the solvent.
The metalworking industries are the major users of solvent
degreasing, i.e., automotive, electronics, plumbing, aircraft,
refrigeration and business machine industries. Solvent cleaning is
also used in industries such as printing, chemicals, plastics,
rubber, textiles, glass, paper and electric power. Host repair
stations for transportation vehicles and electric tools use solvent
cleaning at least part of the time. Many industries use water
based alkaline wash systems for degreasing, and since these systems
emit no solvent vapors to the atmosphere, they are not included in
this discussion.
Cold Cleaners - The two basic types of cold cleaners are maintenance
and manufacturing. Cold cleaners are batch loaded, nonboilinS
solvent degreasers, usually providing the simplest and least
expensive method of metal cleaning. Maintenance cold cleaners are
smaller, more numerous and generally using petroleum solvents as
mineral spirits (petroleum distillates and Stoddard solvents).
Manufacturing cold cleaners use a wide variety of solvents, whiGh
perform more specialized and higher quality cleaning with about
twice the average emission rate of maintenance cold cleaners. Some
cold cleaners can serve both purposes.
Cold cleaner operations include spraying, brushing, flushing
and immersion. In a typical maintenance cleaner (Figure 4.6-1),
dirty parts are cleaned manually by spraying and then soaking in
the tank. After cleaning, the parts are either suspended over the
tank to drain or are placed on an external rack that routes the
drained solvent back into the cleaner. The cover is intended to be
closed whenever parts are not being handled in the cleaner. Typical
manufacturing cold cleaners vary widely in design, but there are
two basic tank designs, the simple spray sink and the dip tank. Of
these, the dip tank provides more thorough cleaning through
immersion, and often is made to improve cleaning efficiency by
agitation. Small cold cleaning operations may be numerous in urban
areas. However, because of the small quantity of emissions from
each operation, the large number of individual sources within an
urban area, and the application of small cold cleaning to industrial
4/81
Evaporation Loss Sources
4.6-1
6-3
-------
4>-
0-
I
N
0\
~
~
~
In
In
H
~
~
~
o
~
".
....
CD
....
lATH
EV APCIIIA TIO.
I
WASTE
SOlVE.T
COlO CUA.ER
, ,
I :'
. .
(i?
6
. . .
. .
.
caRRV OUT
CIIMPREIIE 0
AIR
RnRAC"'IU
COVER
,
OlffUSIO. A.O .
CO.VECTIO.
I
~I-+-:--
~ (AIR 8
;T~diTF\iF
..' .,. '.~'I'I"l ~.I.. ~I.
;.-:: ,.a.I:-...: ~ .: -.I:.i ::-.1-:. ,1:
...'. ,,&, " .~. ..~ '~';..J.t:.'.
---- - .-- - --
lIOUIO
OPE. TO' VAPOR OESRUSER
Figure 4.6-1. Degreaser emission pointL
'Ii
\ ,'.
. .
I
CARRV OUT
CO.OE.SER
COlli
-------
uses Got directly associated with degreasing, it is difficult to
identify individual small cold cleaning operations. For these
reasons, factors are provided in Table 4.6-1 to estimate emissions
from small cold cleaning operations over large urban geographical
areas. Factors in Table 4.6-1 are for nonmethane VOC and include
25 percent 1,1,1 - trichloroethane, methylene chloride and
trichlorotrifluoroethane.
TABLE
4.6-1. NONMETHANE VOC EMISSIONS FROM
COLD CLEANING DEGREASING OPERATIONSa
EMISSION FACTOR RATING: C
SMAL L
Operating period
Per capita
emission factor
Annual
1 . 8 kg
4.0 Ib
Diurnal
5.8 g
0,013 Ib
a
bReference 3.
Assumes a 6 day operating week (313 days/yr).
Open Top Vapor Systems - Open top vapor degreasers are batch loaded
boiling degreasers that clean with condensation of hot solvent
vapor on colder metal parts. Vapor degreasing uses halogenated
solvents (usually perchloroethylene, trichloroethylene, or l,l,l-tri-
chloroethane), because they are not flammable and their vapors are
much heavier than air.
A typical vapor degreaser (Figure 4.6-1) is a sump containing
a heater that boils the solvent to generate vapors. The height of
these pure vapors is controlled by condenser coils and/or a water
jacket encircling the device. Solvent and moisture condensed on
the coils are directed to a water separator, where the heavier
solvent is drawn off the bottom and is returned to the vapor degreaser.
A "freeboard" extends above the top of the vapor zone to minimize
vapor escape. Parts to be cleaned are immersed in the vapor zone,
and condensation continues until they are heated to the vapor
temperature. Residual liquid solvent on the parts rapidly evaporates
as they are slowly removed from the vapor zone. lip mounted exhaust
systems carry solvent vapors away from operating personnel. Cleaning
action is often increased by spraying the parts with solvent below
the vapor level or by immersing them in the liquid solvent bath.
Nearly all vapor degreasers are equipped with a water separator
which allows the solvent to flow back into the degreaser.
Emission rates are usually estimated from solvent consumption
data for the particular degreasing operation under consideration.
4/81
Evaporation Loss Sources
4.6-3
6-5
-------
Solvents are often purchased specifically for use 10 degreasing and
are not used 10 any other plant operations. In these cases, purchase
records provide .the necessary 1Dforaat ion , and an emission factor
of 1,000 kg of volatile organic emissions per metric ton of solvent
purchased can be applied, based on the assumption that all solvent
purchased 18 eventually emitted. When inforaation on solvent
consumption is not available, emission rates can be estimated if
the number and type of degreasing units are known. The factors in
Table 4.6-2 are baaed on the number of degreasers and emissions
produced nationwide and ..y be considerably in error when applied
to one particular unit.
The expected effectiveness of various control devices and
procedures is listed in Table 4.6-3. As a first approximation,
this efficiency can be applied without regard for the specific
solvent being used. However, efficiencies are generally higher for
more volatile solvents. These solvents also result 10 higher
emission rates than those computed from the "average" factors
listed 10 Table 4.6-2.
Conveyorized Degreaaers - Conveyorized degreasers may operate with
either cold or vaporized solvent, but they 8erit separate
consideration because they are continuously loaded and are almost
always hooded or enclosed. About 85 percent are vapor types, aDd
15 percent are nonboi1ing.
4.6.2 Emissions and Contro1sl-3
Emissions fro. cold cleaners occur through (1) waste solvent
evaporation, (2) solvent carryout (evaporation from wet parts),
(3) solvent bath evaporation, (4) spray evaporation, and (5) agitation
(Figure 4.6-1). Waste solvent loss, cold c1eaninl's greatest
881ssion source, can be reduced through distillation and transport
of waste solvent to special incineration plants. .Draining cleaned
parts for at least 15 seconds reduces carryout emissions. Bath
evaporation can be controlled by using a cover relu1arly, by allowing
an adequate freeboard height and by avoiding excessive drafts in
the workshop. If the solvent used is insoluble in, and heavier
than, water, a layer of water two to four inches thick covering the
halogenated solvent can also reduce bath evaporation. This is
known as a "water cover". Spraying at low pressure also helps to
reduce solvent loss from this part of the process. Alitation
..issions can be controlled by using a cover, by agitating no
longer than necessary, and by avoiding the use of agitation with
low volatility solvents. Emissions of low volatility sc1vents
increase significantly with agitation. Rowever, contrary to what
one might expect, agitation causes only a small increase in emissions
of high volatility solvents. Solvent type is the variable which
most affects cold cleaner emission rates, particularly the volatility
at operating temperatures.
4.6-4
EMISSION FACTORS
4/81
6.6
-------
TABLE 4.6-2. SOLVENT LOSS EMISSION FACTORS FOR DEGREASING OPERATIONS
~ EMISSION FACTOR RATING: C
-
011
...
Type of degreasing Activit~ measure Uncontrolled orgsuic
emission fsctor
AUb Solvent consumed 1,000 kg/Kg 2,000 lb/ton
Cold cleaner c Units in 0.30 Kg/yr /unit 0.33 tons/yr/unit
Entire unit operation
~ Waste solvent loss 0.165 Kg/yr/unit 0.18 tons/yr/unit
I\) Solvent carryout 0.075 Kg/yr/unit 0.08 tons/yr/unit
'0 Bath and spray
0
P1 evaporation 0.06 Kg/yr/unit 0;07 tons/yr/unit
I\)
.. Ent ire unit Surface area and duty
.... 2 0.08 lb/hr/ft2
o cycled 0.4 kg/hr/m
::I
Q') !""
, 0 Open top vapor
" III
1/1 Entire unit Units in operation 9.5 Kg/yr/unit 10.5 tons/yr/unit
II) Entire unit Surfase area and duty
0 2 2
c cycle 0.7 kg/hr/m 0.15 1b/hr/ft
P1
n
/D
III Conveyorized, vapor
Ent ire unit Units in operation 24 Kg/yr/unit 26 tons/yr/unit
Conveyorized, nonbolling
Ent ire unit Units in operation 47 Mg/yr/unit 52 tons/yr/unit
:-
a-
I
V1
a
blOO% nonmethane VOC.
Solvent consumption data will provide much more accurate emission estimates than any
of the other factors presented.
cEmissions generally would be higher for manufacturing units and lower for maintenance
dun its .
Reference 4, Appendix C-6. For trichloroethane degreaser.
eFor trichloroethane degreaser. Does not include waste solvent losses.
-------
'IABLE 4.6-3.
PROJECTED E'MISSION REDUCTION FACTORS lOR SOLVENT DEGREASINGa
Cold Vapor CO..Y8yor1zed
cla....r da.r....r da.r....r
5y.t.. " I " . " I
Co..trol dav1"..
C0Y8r or .Del0..d d..1,m X X I: I: I: I:
Dra1Aap fadUty I: X X X
Vat.r "0Y8r. r.fr1J.rated c:h1Ll.r. c:ar\)oo
MaDe, t 1011 or h1.h frnlltard I: I: I:
loUd. nllu .pray .tr- I: X
Saf.ty ..1tc:h.. aDd ~har.o.tat. I: I:
181..1011 redllCtloa frG8 "o..trol d..1".. (%) 13-38 IlAd 20-40 30-60 40-60
Operat1D. proc:edlln.
Proper \1M of ..u1,-t I: I: I: I: I: I:
0.. of 111'- .olae111ty ...lv...e X
V..ca _l....e ncl-tloa X I: I: I: I: I:
IecIlICed .xII...e ....tUatloa I: I: I: I:
I8
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vapor degreasers as it is with cold cleaners, because the halogenated
solvents used are often distilled and recycled by solvent recovery
systems.
Because of their large workload capacity and the fact that
they are usually enclosed, conveyorized degreasers emit less solvent
per part cleaned than do either of the other two types of degreaser.
More so than operating practices, design and adjustment are major
factors affecting emissions, the main source of which is carryout
of vapor and liquid solvents.
References for Section 4.6
1.
P.J. Marn, et al., Source Assessment: Solvent Evaporation -
Degreasing, EPA Contract No. 68-02-1874. Monsanto Research
Corporation, Dayton, 08, January 1977.
2.
Jeffrey Shumaker, Control of Volatile Organic Emissions from
Solvent Metal Cleaning, EPA-450/2-77-022, U.S. Environmental
Protection Agency, Research Triangle Park, NC, November 1977.
3.
W.8. Lamason, '~echnical Discussion of Per Capita Emission
Factors for Several Area Sources of Volatile Organic Compounds",
Office of Air Quality Planning and Standards, U.S. Environmental
Protection Agency, Research Triangle Park, NC, March 15, 1981,
unpublished.
4.
K.S. Suprenant and D.W. Richards, Study To Support New Source
Performance Standards for Solvent Metal Cleaning Operations,
EPA Contract No. 68-02-1329, Dow Chemical Company, Midland,
MI, June 1976.
4/81
Evaporation Loss Sources
4.6-7
6.9
-------
R.eview Exercise
The Cheeps Fabricating Company has 10 open top vapor degreaaers for cleaning
small metal parts. This facility is located in an urban nonattainment (for ozone)
area with a population greater than 250.000. The peninent data is given below.
1. According to the RACT guidelines, which control system should be applied?
2. Do the installed degreaaers at the Cheeps Fabricating Company meet the
RACT guidelines for the control system identified in question I?
5. During a field inspection, what control equipment and operating practices
must be observed by the inspector?
Degreaser Information
Number of open top vapor degreaaers: 10
Solvent used: perchloroethylene
Operating schedule: 24 hours per day; 7 days per week; 45 weeks per year
Degreaser dimensions (see Figure 6-1): length = 6 ft
width = 5 ft
height = 5 ft
freeboard height = 2 ft
..
6 ft
..
Figure ~1. Dimemiona of an open top vapor degreuer.
6-10
-------
-
Solution
1. The necessary control system can be determined by referring to pages 1.2-1 and
1.2-2 of the Inspection Manual. From AP-42, the emissions can be estimated by
a number of methods. If possible, the emissions should be estimated from yearly
solvent conswnption. This information was not supplied; therefore, the average
emission factor is 10.5 tons per year per unit. There are 10 degreasers emitting
approximately 10.5 tons per year. The total VOC emissions are 105 tons per
year. Since the fabricating plant is located in an urban nonattainment area with
a population greater than 250,000, Control System B must be applied.
2. The installed degreasers at the Cheeps Fabricating Company do not meet the
RACT guidelines for Control System B. From page 3.3-2 of the Inspectz'on
Manual, the degreaser must have "a cover that can be opened and closed easily
without disturbing the vapor zone. It A description of covers for open top
degreasers is given on page 3.1-12 of the Inspection Manual. The agency should
require the plant to install a cover and then observe the operation of the cover
to make sure the degreaser is covered at all times except when the parts are
actually entering and exiting. In addition, since the degreaser opening is 18 ft2,
the cover must be powered. See page 3.4-3 of the Inspection Manual.
S. The degreaser must have safety switches:
a. condenser flow and switch thermostat
b. spray safety switch
The major control device must be any of the following:
a. freeboard ratio greater than or equal to 0.75,
b. refrigerated chiller,
c. enclosed design (cover or door opens only when the dry part is actually enter-
ing or exiting the degreaser),
d. carbon adsorption system, with ventilation> 15 mS/min per m2 (50 dm/ft2)
of air/vapor area (when cover is open), and exhausting < 25 ppm solvent
averaged over one complete adsorption cycle, or
e. control system demonstrated to have control efficiency equivalent to or better
than any of the above.
The freeboard ratio is 2/3 or 0.67. Therefore, the plant must install a
refrigerated chiller, an enclosed design, a carbon adsorption system, or another
control system.
The inspector must make sure that the degreaser is operated according to those
practices listed on page 3.3-2 of the Inspectz'on Manual.
6-11
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Lesson 7
Introduction to Source Testing
of Degreasers
Lesson Goal
To familiarize you with the source testing procedures. used for measuring emissions
from degreasers.
Lesson Objectives
At the end of this lesson, you should be able to:
1. recall the screening procedure used for determining emission concentration
for identifying sources that are above and below the emission limitation.
2. briefly describe the proposed source testing method for determining emission
concentrations from degreasers.
Reading Materials
. EPA 340/1-79-008.june 1979. Solvent Metal Cleanz'ng: lnspectz'on-Source
Test Manual. Chapter 5.
Additional Suggested Reading
. Environmental Protection Agency (EPA). 1980. Orgaru'c Solvent Cleaners;
Standards of Performance for New Statz'onary Sources; Proposed Rule and
Notz'ce of Publz'c Hean~~~_45- Fed. ~eg:. No. }~4_, 39766-39784 Qune 11, 1980). -
Reading Guidance
This lesson briefly covers the screening method used by a field inspector to identify
those degreasers that are well above or well below the emission concentration
limitation. This screening can be performed by the inspector during a routine
inspection. This screening method provides an instantaneous reading of solvent
concentration of the stack gas emitted from a degreaser using a carbon adsorption
control system. The inspector uses a portable organic analyzer that is battery
powered and is safe for use in explosion-hazard areas.
This lesson also briefly covers the proposed source test method for determining
stack emissions. This is EPA Reference Method 23, "Determination of Halogenated
7-1
-------
Organics from Stationary Sources." This proposed method specifies the use of a
Tedlar or Mylar bag to collect an integrated sample. This bag sample is then
analyzed in the lab by using a gas chromatograph equipped with a flame ionization
detector (FID). The proposed method was published in the Federal Register,
Volume 45. on June 11. 1980.
Screening Method
Reading Aasignment
Begin your reading with pages 5.1.1 through 5.1-5. and pages 5.2.1 through 5.2.16
of the Inspectz'on Manual. Mter completing this reading assignment. answer the
following questions.
Review ExerciJe
1. The screening method is used to
a. give. for compliance purposes. the exact VOC con.
centration from a stack.
b. indicate the apparent compliance status of a
source.
c. measure paniculate matter from a source.
d. none of the above
2. For the screening method. the inspector uses a(n) 1. b. indicate the
that is safe for apparent com-
use in explosion-hazard areas. pliance status of a
source.
5. True or False? Two instrumentS that can be used for 2. ponable organic
the screening method are the Bacharach TL V Sniffer analyzer
and the Century Systems FID-QVA analyzer.
4. The ponable analyzer should be both 5. True
before and after sampling.
a. leak checked
b. zeroed and calibrated
c. both a and b, above
4. c. both a and b,
above
'-2
-------
!
Proposed Source Testing Method
Reading Assignment
Continue your reading with pages 5.3-1 of the lnspectz'on Manual.
The remainder of this section, 5.3-16, is optional. (See also Federal
Register, June 11, 1980.) This section should be read by those
individuals who are responsible for performing source tests for com-
pliance purposes.
After completing this reading assignment (page 5.3-1), answer the following questions.
Review Exercise
1. The proposed source testing procedure specifies that
samples are collected in
a. a Tedlar or Mylar bag.
b. a cold trap.
c. an evacuated cylinder.
d. all of the above
2. The laboratory analysis of this proposed method uses a 1. a. a Tedlar or
with a flame ionization detec- Mylar bag.
tor that can separate a mixture of solvent vapors and
determine the concentration of each component.
2. gas ch~omatograph
7-3
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TECHNICAL REPORT DATA
(Pletlst rttld bl~rriQIIS on tht rtl.trst btfort complttinlJ
1 I'IE"ORT 1110 12. 3. RECIPIENT'S ACCESSIO~NO.
EPA 450/2-82-014
4. TITL.E AND SUBTlTL.E 5. REPORT DATE
APTI Course CC:416 June 1982
Inspection Procedures for Or~anic Solvent Metal e. PERFORMING OFIGANIZATION CODE
Cleaning (Degreasing) Operations--Guidebook
7 AUTHORIS) 8, PEFlFOFlMING OFIGANIZATION FIEPOFIT NO.
David S. Beachler
.
II. PEFlFOFlMING OFl-ANIZATION NAME AND ADDRESS 10. PROGRAM EL.EMENT NO.
Northrop Environoental Training
Northrop Services, Inc. 11. CONT"ACT/~..ANT No.
P.O. Box 12313 .
Research Triangle Park, NC 27709 68-02-3573
12. SPONSORING AGENCY NAME AND ADDRESS 13, TYPE OF REPORT AND PEFlIOO COVERED
U.S. Environmental Protection Agency Guidebook
~~npower and Technical Information Branch 14. SPONSORING AGENCY CODE
Research Trian~le Park, NC 27711
15. SUPPL.EMENTARY NOTES
EPA Project Officer for this Guidebook is R. E. Townsend, EPA-ERC, MD 20, RTP,
XC 27711
1.. ABSTRACT
This Guidebook is a correspondence course, APTI Course CC:416 "Inspection
Procedures for Organic Solvent Metal Cleaning (Degreasing) Operations". This
course is designed for engineers, inspectors and other technical personnel
responsible for inspecting degreasing facilities. The course reviews in detail
the inspection and VOC source testing procedures for degreasers. Course topics
include: EPA policy concerning RAC! regulations; descriptions of cold cleaners,
open top vapor degreasers, and conveyorized deRreasers; VOC ernissiun points,
typical control methods, inspection procedures, and emission testing procedures.
17. KEY WORDS AND DOCUMENT ANAL. YSIS
a. DESCRIPTORS b.IOENTIFIERS/OPEN ENDED TERMS C. COSATI Fleld'Gtoup
Air Pollution Control Correspondence Course 13B
VOC Emission Control Guidebook for Inspectiol1 51
De~reasers of Degreasers 68A
Solvent Metal Cleaning Operations
Training Manual
~: ::STP'BUT,Ofll S'!'ATEMEN1 un11:nltec 19 SECURITY CL.ASS rTlllsRepo"j i 21."'C _c~ i'..GES -
:'3 t iona 1 Technical :nfor~ation Service unclassified " ~~;
52&5 Po~t Royal Road 20. SECUFlIT'I' CL.ASS ,'TlIIS p;J.~J - -._-
i:: =-~ Ie::
SDrindield. \'A 22161 unclassifif'C: I -.1
(PA ~~r'" 2220 1 It 731
7-4
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