# EPA-450/2-77-022 November 1977 (OAQPSNO. 1.2-079)
OAQPS

# GUIDELINES



# CONTROLOFVOLATILE ORGANICEMISSIONS 

# FROM SOLVENT

# METALCLEANING

I 

### U.S.

## ENVIRONMENTALPROTECTION AGENCY Office of

## AirandWasteManagement 1 

## OfficeofAirQuality Planningand Standards 

# a0

- I,\ ResearchTrianglePark,North Carolina 27711 

# 328 1 RADIANLIBRARY I, 

# DURHAM,N.C. II i.This reportisissued by the Environmental ProtectionAgency to report technical data of interesttoa limited number of readers. Copies are availablefreeofchargeto Federal employees, currentcontractorsanc! grantees, and nonprofitorganizations - in limited quantities

- fromthe LibraryServices Office (MD-35). ResearchTriangle Park, NorthCarolina 27711; or, for afee, from the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.

Publication No. EPA-45012-77-022

### PREFACE The purpose of 

### this document is to 

### inform regional, State, and 

### local airpol1 ution control agencies of 

### the different techniques available for reducing organic emissions from solvent metal cleaning (degreasing)

# . Solvent metal cleaning includes the use of equipment from any of three broad categories: cold cleaners

## ,open top 

### vapor degreasers

## ,and conveyorized degreasers. A11 of these employ organic solvents toremove soluble impurities from metal surfaces. The diversity in

### designs and applications of degreasers make an emission 1

### imit 

### approach inappropriate; rather, regulations based 

### on equipment specifications and operating requirements are recomnended. Reasonably available control technology (RACT) 

### for these sources entails implementation of operating procedures which minimize solventbss and retrofit of applicable control devices. Required control equipment 

### can be as simple as amanual cover or as complex
as a carbon adsorption system, depending on 

### the size and design of the degreaser. Required operating procedures include covering degreasing equipment whenever possible, properly using solvent sprays, reducing the amount of solvent carried out of the 

### uniton cleaned work by various means, promptly repairing leaking equipment, and most importantly properly disposing of wastes containing volatile organics. Not all controls and 

### procedures will be applicable 

### to a11 

### degreasers, a1though in general specific operating requirements and control devices will be applicable 

### tothe majority of designs within

### each category of 

### degreasers. Control of open top and 

### conveyorized vapor degreasing is the most cost effective, followed by 

### waste solvent disposal for

### a11 

### degreasing operations, manufacturing cold cleaning and

### maintenance cold 

### cleaning.

iii

### switches are: 

### 1. 

### Vapor level control thermostat, 2. 

### Condenserwater flow switch and thermostat, 3. 

### Sump 

### thermostat, 4. 

### Solvent level control, 5. 

### Spray safety switch. The firstfour safety switches 1

### isted above turn off the sump heat while the fifth turns off the spray. The most important safety switch is the vapor level control thermostat. This device is activated when solvent vapor zone rises above the designed operating level. This can occur if the coolant flow is interrupted, for example. When the hot vapors are sensed, the sump heater is turned off thus minimizing vapor escape. This thermostat should be a manual reset type for manually operated degreasers. For conveyorized degreasers, the vapor level control thermostat should activate 

### an alarm system. These controls should be checked frequently. The condenser water flow switch and thermostat 

### turn off the sump heat when either the condenser water stops circulating or the condenser water becomes
warmer than specified. If the condenser water flow switch and thermostat is properly adjusted, then itwill serve as a back-up for the safety vapor thermostat and 

### also assure efficient operation of the condenser coils. In 

### summer months, the cooling water for condensing coils often becomes too
warm. In this case, the thermostats in a condenser water flow switch can signal a need for improvement, such as increasing the water flow rate. This problem occurred during a test performed for EPA. 

### 16 As oils, greases and 

### other contaminants build up 

### in the solvent, the boiling point of the mixture increases. Both the sump thermostat and solvent 3-15TABLE 1. CONTROL SYSTEMS FOR COLD CLEANING
Control System A Control Equipment: 1. Cover 2. Facility for draining cleaned parts 3. Permanent, conspicuous label. sumnarizing the operating requirements Operating Requirements: 1. Do not dispose of waste solvent or transfer itto another ~arty, such that greater than 20 percent of the waste (by weight) can evaporate into the atmosohere.* Store waste.solvent on1v incovered containers. 2. Close degreaser cover whenever not handling parts inthe cleaner. 3. Orain cleaned parts for at least 15 seconds or until dripping ceases. Control System B Control Equipment: 1. Cover: Same as InSystem A, except if (a) solvent volatility is reater than 2 kPa (15 mn Hg or 0.3 psi) measured at3B°C (10O0F),** 

# 9b) solvent isagitated. or (c) solvent is heated, then the cover must be designed so that i: can be easily operated with one hand. (Covers for larger degreasers may require mechanical assistance, by spring loading, cdunterweiqhtinq or Dowered svsterns.) 2. Drainage facility: Same as inSystem A, except that ifsolvent volatility isgreater than about 4.3 kPa (32 mn Hg or 0.6 psi) veasured at 38°C (lOO°F), then the drainage facility nust be internal. so that oarts are enclosed under the cover while draining. The drainage facilitymay be external for applications where an internal type cannot fit intothe cleaning system. 3. Label : Same as inSystem A 4. Ifused, the solvent spray must be a solid, fluid stream (not a fine, atomized or shower type spray) and at a pressure which does not cause excessive splashing. 5. Major control device for highly volatile solvents: Ifthe solvent volatility is D 4.3 kPa (33 n Hg or 0.6 psi) measured at 38°C (lOO°F), or ifsolvent is heated above 50'C (12O0FJ, then one ofthe following control devices must be used:
a. Freeboard that gives a freeboard ratiow* 20.7 6. Nater cover (solvent must be insoluble inand heavier than water)
c. Other system of equivalent control, such as a refrigerated chiller or carbon adsorption. Operating R~rprirrn~ntq: Sawe as inSystem P
*Water and solid waste regulations must also be comolied with. **Senerally solvents consisting primarily gf mineral :pirits [:?oddard) have tolatilities < 2 CPa. ***Freeboard ratio isdefined ajthe freoocard Aeignt divided by the uidth of the degreaser.Two 

### levels of control for each type of degreaser have been identified here as examples of reasonably avai1 able control technology 

### (RACT)

# . In general, control level A 

### shows proper operating practice and simple, inexpensive control equipment. Control level B 

### consists of level A 

### plus additional requirements to improve the effectiveness of control. The degree of emission reduction forboth individual items and control levels are discussed in

### the text. Specific requirements can be modified to achieve whatever level of control isnecessary. Control systems for cold cleaners
are shown in Table 1, thosefbr open top vapor degreasers in

### Table 2, 

### and those for conveyorized degreasers in

### Table 3. 

### Two exemptions are recommended. First, conveyorized degreasers smaller 2 

### than 2.0 

### m 

### of air/vapor interface should be exempt from a requirement for
a major control device. This would not be cost effective and would tend to
move the small conveyorized degreaser users to open top vapor degreasers which emit more solvent per unit work load. Second, open top vapor degreasers 2 

### smaller than 1

### m of open area should be exempt from the application of refrigerated chi1 lers or carbon adsorbers. Again, requirement for these would not be cost effective.TABLE 3. CONTROL SYSTEMS FOR CONVEYORIZED DEGREASERS
Control System A Control Equipment: None Operating Requirements: 3 2 1. Exhaust ventilation should notexceed 20 m/min per m (65 cfm per ft2) ofdegreaser opening, unless necessary to meet OSHA requirements. Work place fans should not be used near the degreaser opening. 2. Minimize carry-out emissions by:
a. Racking parts for best drainage. b. Maintaining verticle conveyor speed at < 3.3 m/min (11 ft/min) 3. Do not dispose ofwaste solvent or transfer itto another party such that greater than 20 percent of the waste (by weight) can evaporate into the atmosphere. Store waste solvent only incovered containers. 4. Repair solvent leaks imnediately, or shutdown the degreaser. 5. Water should not be visibly detectable inthe solvent exiting the nater separator. Control System B Control Equipment: 1. Major control devices; the degreaser must be controlled by either: a, Refrigerated chiller, b. Carbon adsorption system, with ventilationL 15 m2/min per m 2 (50 cfm/ft2) of air/vapor area (when down-time covers are open), and exhausting <25 ppm of solvent by volume averaged over a complete adsorption cycle, or c. System demonstrated to have control efficiency ?quivalent to or better than either of the above. 2. Either a drying tunnel, or another means such as rotating (tumbling) basket, sufficient to prevent cleaned parts from carrying out solvent liquid or vapor. 3. Safety switches
a. Condenser flow switch and thermostat - (shuts off sump heat if coolant iseither not circulating or too wan). b. Spray safety switch

### - (shuts off spray pump or conveyor ifthe vapor level drops excessively, e.g. > 10cm (4 in.)). c. Vapor level control thermostat 

### - (shuts off sump heat when vapor level rises too high). 4. Minimized openings: Entrances and exits should silhouettework loads so that the average clearance (between parts and the ed~e of the degreaser opening) iseither <10 cm (4 in.) or <I0percent of the width of the opening. 5. Down-time covers: Covers should be provided for closing off the entrance and exitduring shutdown hours. Operating Requirements: 1. to 5. Same as for System A 6. Down-time cover must be placed over entrances and exits ofconveyorized degreasers immediately after the conveyor and exhaust are shutdown and removed just before they are started up.- - TABLE 2. COMPLETE CONTROL SYSTEMS FOR OPEN TOP VAPOR DEGREASERS

Control System A Contrcl Equiwent: 1. Cover that can be opened and closed easily without disturbing the vapor zone. Operating Requirements: 1. Keep cover closed at all times except when processing work loads through the degreaser. 2. Minimize solvent carry-out by the following measures:
a. Rack parts to allow full drainage. b. Move parts inand out of the degreaser atless than 3.3 m/sec (11 ft/min). c. Degrease thework load inthe vapor zone at least 30 sec. or until condensation ceases. d. Tip out any pools of solvent on the cleaned parts before removal. Allow parts to dry within the degreaser for at least 15 sec. or until e. visually dry. 3. Do not degrease porous orabsorbent materials, such as cloth, leather, wood or rope. 4. Work loads should not occupy more than half of the degreaser's open top area. 5. The vapor level should not drop more than 10 cm (4 in)when the mrkload enters the vapor zone. 6. Never spray above the vapor level 7. Repair solvent leaks imnediately, or shutdown the degreaser. 8. Do not dispose ofwaste solvent or transfer itto another party such that greater than 20 percent of the waste (by weight) will evaporate into theatmosphere. Store waste solvent only inclosed containers. 9. Exhaust ventilation should not exceed 20 m3/min per m2 (65 cfm per ft2) ofdegreaser open area, unless necessary to meet OSHA requirements. Ventilation fans should not be used near the degreaser opening. 10. Water should not be visually detectable insolvent exitingthewater separator. Contro: System B Control Equipment: 1. Cover (same as insystem A). 2. Safety switches
a. Condenser flowswitchana tkrmostat- (siurts off sump neat ifcondenser coolant iseither not circulating or too ram). b. Spray safety switch

### - (shuts off spray pump ifthe vapor level drops excessively. about 10 cm (4 in). 3. Major Control Device: Either: a. Freeboar9 ratio reater than or equal to 0.75, and if the degreaser opening is > 1 m (10 ft

## B), the cover must be powered, b. Refrigerated chiller, c. Enclosed design (cover ordoor opens only when the dry part isactually entering or exiting the degreaser.) , d. Carbon adsorption system, with ventilation 2 15 m3/min per m 2 (50 cfm/ft ) of air/vapor area (when cover isopen), and exhausting <25 ppm solvent averaged over one complete adsorption cycle, or e. Control svstem. demonstrated to have control efficiency, equivalent to or betterthan any Of the above. 4. Permanent, conspicuous label. sumnarizing operating procedures #1 to #6. Operating Requirements : Same as inSystem A

### Page



## ............ 3-6 3.1

## .1.3 Refrigerated Chi 11

### ers



## ............. 3-9 3.1

## .1.4 Carbon Adsorption 3.1.1.5 SafetySwitches 

## ............... 3.14 3.1.2' 

### Controls to Miniinize Carry-Out 

## ............ 3-16 3.1.3 Controls for Both Solvent Bath and Carry-Out Emi.ssions Com6ined 

# ............ 3-18 3.1.3.1 Automated Cover-Conveyor System 

# ....... 3-18 3.1.3.2 Refrigeration Condensation 

## ......... 3-20 3.1.4 Control 
of Haste Solvent Evaporation 

# ......... 3-22 3.1.4.1 

### Cuwent Practices 

# .............. 3-22 3.1.4.2 Recommended Practices 

## ............ 3-23 3.1.5 Other Control Dey'i'ces 

# ................ 3-27 3.1.5.1 Incineration 

# ................ 3-28 3.1.5.2 Liqufd Absorption 

# .............. 3-28 3.2 Complete Control Systems 

# .................. 3-29 

### 3.2.1 Cold Cleaning Control Systems 

## ............ 3-30 3.2.2 Control Systems for Open Top Vapor Degreasing 

# ...................... 3-32 3.2.3 Control Systems for Conveyorized Degreasers 

# ..... 3-32 3.3 References 

## ......................... 3-37 Chapter 

### 4.0 Cost Analysis 

# ........................ 4-1 4.1 Introduction 

# ........................ 4-1 4.1.1 Purpose 

# ....................... 4-1 4.1.2 Scope 

# ........................ 4-1 4.1.3 Model Plants 

# ..................... 4-2 

### 4.1.4 Capital Cost Estimates 

## ................ 4-3TABLE OF CONTENTS Page Preface 

## ................................. iii Chapter 1.0 Introduction and Summary 

## ..................1-1 1.1 rieed to Regulate Solvent Metal Cleaning 

## .......... 1-1 1.2 Regulatory Approach 

## ....................1-2 Chapter 2.0 Sources and Types of Emissions 

## ............... 2-1 2.1 Industry Description 

# ....................2-1 2.2 Types of Degreasers and Their Emissions 

## ..........2-4 2.2.1 Cold Cleaners 

# .................... 2-7 2.2.1.1 Design and Operation 

# ............ 2-7 2.2.1.2 Emissions 

# .................2-12 2.2.2 Open Top Vapor Degreasers 

# .............. 2-16 2.2.2.1 Design and Operation 

# ............ 2-16 2.2.2.2 Emissions 

# ................. 2-25 2.2.3 Conveyorized Degreasing 

# ............... 2-33 2.2.3.1 Design and Operation 

# ............2-33 2.2.3.2 Emissions 

# ................. 2-39 2.4 References 

# ........................ 2-45 Chapter 3.0 Emission Control Techno1ogy 

# ................ 3-1 3.1 Emission Control Devices 

# .................3-1 3.1.1 Emission Control Devices 

# .............. 3-1 3.1 1 Improved Cover 

# ...............3-2 3.1.1.2 High Freeboard

# ............... 3-5

### Page 6.1 

### Observation of 

### Control Eqo~Qment and Operating Practices 

# .................... 6-2 

### 6.2 Material Balance 

# ..................... 6-2 

### 6.3 

### Other Emission Tests 

# ................... 6-3 

### Chapter 7.0 Enforcement Aspects 

# .................... 7-1 7.1 

### Regulatory Approaches 

# ................... 7-2 7.1.1 Emission Standards 

# ................. 7-2 7.1.2 

### Equipment Standards 

# ................ 7-3 7.1

# .3 

### Operational Standards 

# ............... 7-4 7.1.4 

### Solvent Exemptl'on Standards 

# ............ 7-5 7.2 Affected Facilities


## .Pri'oriities 

# ............. 5 

### 7.2.1 Definitions of Affected Facilities

# ......... 7-5 

### 7.2.2 Prioritiesof Enforcement 

# ............. 7-5 Appendix A.0 Emission Test Results Appendix 0.0 

### Calculationr

### Page 4.2 Cold Cleaners 

## ........................ 4-4 4.2.1 Model Plant Parameters 

## ................ 4-4 4.2.2 Control Costs 

## .................... 4.0 4.3 Open Top Vapor Degreasers 

## .................. 4-8 4.3.1 Model Plant Parameters 

## ................ 4-8 4.3.2 Control Costs 

## .................... 4-8 4.3.3 Cost Effectiveness 

## .................. 4-14 4.4 Conveyorized Degreasers 

## ................... 4-16 4.4.1 Model Plant Parameters 

## ................ 4-10 

### 4.4.2 Control Costs 

## .................... 4-18 4.4.3 Cost Effectiveness 

## .................. 4-20 4.5 References 

# ......................... 4.24 Chapter 5.0 Adverse Environmental Effects of Applyfng The Technology 

# ........................ 5-1 

### 5.1 AirImpacts 

# ......................... 5-1 5.2 Uater Impacts 

# ........................ 5.1 5.2.1 

### Waste Solvent Disposal 

# ................ 5-1 5.2.2 Steam Condensate from Carbon Adsorpti'on 

## ....... 5-2 5.2.2.1 Chlorinated Solvent ih 

### Steam Condensate 

## ................. 5-2 5.2.2.2 Stabilizers in Steam Condensate 

## ....... 5-3 5.2.3 Effluents from Water Separators 

## ........... 5-4 5.3 

### Solid Waste Impact 

## ..................... 5-4 5.4 Energy Impact 

## ........................ 5-5 5.5 Other Environmental Concerns 

## ................5-6 5.6 References 

## ......................... 5-8 Chapter 

### 6.0 Compliance Testing Methods and Moni'tori'ng Techniques 

## ......................... 6-1

### Figure 2-1 Cold Cleaner 

## ........................ 2-9 

### Figure 2-2 Cold Cleaner Emission Poi.nts 

# ................ 2-13 Figure 2-3 Open 

### Top Vapor Degreaser 

# .................. 2-18 Figure 

### 2-4 Basic Principle for Uater Separator for Yapor Degreaser 

## . . 2-20 Figure 

### 2-5 Open 

### Top Degreaser with 

### Offset Condenser Coils 

## ....... 2-21 Figure 2-6 

### Two Compartment Degreaser with Offset Boili'ng Chamber 

## ... 2-22 Figure 2-7 

### Two Compartment Degreaser 

## ................. 2-23 Figure 2-8 Degreaser with 

### Lip 

### Exhaust 

## ................. 2-24 Figure 2-9 Open 

### Top Vapor Degreaser Emission 

### Points 

## .......... 2-26 LIST 

### OF FI'GURES Page

Figure 2-10 Cross Rod Conveyorized Degrearer 

## .............. 2-35 Figure 

### 2-11 Monorail ConveyorPzed Degreaser 

# .............. 2-36 Figure 

### 2-12 Vibra Degreaser 

# ...................... 2-37 Figure 2-13 Ferris Uheel Degreas.er

# ................... 2-38 Figure 

### 2-14Mesh Belt Conveyorized Degreaser 

# .............. 2-40 Figure 

### 2-15 Conveyorized Degreaser Emission 

### Points 

## ........... 2-42 Figure 3-1 Refrigerated Freeboard Chiller 

# ............... 3-7 Figure 3-2 

### Carbon Adsorber 

## ...................... 3-10 Figure 3-3 Adsorption Cycle 

## ...................... 3-11 Figure 3-4 Desorption Cycle 

## ...................... 3-12 Figure 3-5 Elevator Design 

### of Degreaser

.

### Vapor Type 

# ......... 3-19 Figure 3-6 

### Vapor Pressures 

### of Several Sol~ents

## ............ 3-21 Figure 3-7 External Still 

## ....................... 3-25 Figure 

### 4-1 Cost-Effectivenass of A1ternative Control Opti'ons for Existing Open Top 

### Vapor Degreasers 

## ............. 4-15 Figure 

### 4-2 Cost-Effectiveness of Alternative 

### Control Options 

### for Existing Monorail Degreasers 

## ................ 4-21 Figure 4-3 

### Cost-Effectiveness of Alternative Control Optfons 

### for Existing Cross-Rod Degreasers 

# ............... 4-23

xiii

### LIST OF 

### TABLES Page



# ..............v Table 1 Control Systems for Cold Cleaning Table 2 Control Systems for Open Top Vapor Degreasers 

## ........vi 

### Table 3 

### Control Systems for Conveyorized Degreasers 

## .........vii 

### Table 2-1 Common Metal Cleaning Solvents 

## ................ 2-3 Table 2-2 National Degreasing Solvent Consumption (1974) 

## ........ 2-5 Table 2-3 Emissions from Solvent Degreasers (1974) 

# ........... 2-6 

### Table 3-1 Control Systems for Cold Cleaning 

# .............. 3-31 Table 3-2 Complete Control Systems for Open Top Vapor Degreasers 

## .... 3-33 Table 3-3 Control Systems for Conveyorized Degreasers 

## ......... 3-35 Table 4-1 Cost Parameters forModel Cold Cleaners 

# ........... 4-5 

### Table

### 4-2 Control Costs for Typical Cold Cleaners 

# ........... 4-7 Table 4-3 Cost Parameters forModel Open Top Yapor Degreasers 

# ..... 4-9 Table 4-4 Control Cost for Typi'cal StzeOpen Top Vapor Degreaser 

## .... 4-10 Table 4-5 Control Cost for Small Open Top Vapor Degreaser 

## ....... 4-11 Table 4-6 Cost Parameters forModel Conveyorized Degreasers 

# ...... 4-17 Table 4-7 

### Control Costs for Typical Con~eyorized 

### Degreasers 

## ...... 4-191,0 INTRODUCTION AND SUMMARY
The purpose of EPA's series of control technique guideline documents isto provide guidance on emission reduction techniques which can be applied to existing sources inspecific industries. The documents are to be used to assist States inrevising their implementation plans (SIP'S) to attainand maihtain National Ambient Air Qua1ity Standards (NAAQS)

# . This document discusses volati 1 e organic compound (VOC) emissions and applicable control techniques for organic solvent metal cleaning operations (degreasing with solvents).
1.1 NEED TO REGULATE SOLVENT METAL CLEANING Solvent metal cleaning isa significant source of volatile organic compounds (VOC) and tends to be concentrated inurban areas where the oxidant NAAQS is 1ikely to be exceeded. In1975 solvent metal cleaning emitted about 725 thousand metric tons oforganics. This represents about four percent ofthe national organic emissions from stationary
sources. Presently, solvent metal cleaning isthe fifth largest stationary
source of organic emissions. Although emissions from solvent degreasing (i.e. 

### ,metal cleaning) represent about four percent of nationwide VOC sources, the proportion issignificantly higher inmost urban areas, because of their high concentration of metalworking industries. For example,to upper atmospheric ozone depletion. These reasons and others support the decision to concentrate on positive reduction rather than substitution. Positive emission reduction from solvent metal cleaning should be attained t+ugh use of proper operating practices and retrofit control equipment. Proper operating practices are those which minimize solvent loss to the atmosphere. These include covering degreasing equipment whenever possible, proper use of solvent sprays, various means of reducing the amount of solvent carried out of the degreaser on cleaned work, prompt repair of leaking equipment, and most importantly, proper disposal of wastes containing volatile organic solvents. Inaddition to proper operating practices there are many control devices which can be r e t r o f i t t o degreasers; however, because of the diversity intheir designs, not all degreasers require a11 control devices. Small degreasers using room temperature solvent may require only a cover, whereas a large degreaser using boiling solvent may require a refrigerated freeboard chiller or a carbon adsorption system. Two types of control equipment which will be applicable to many degreaser designs are drainage facilities for cleaned parts and safety switches and thermostats which prevent 1arge emissions due to equipment ma1function. The many degreaser designs along with the emissions characteristic ofthose designs and the factors affecting those emissions are described inChapter 2. Control devices for each type of emission and control systems for each degreaser design are described inChapter 3.

### the Southern California Air QualityManagement District estimates that 14.8 percent of the stationary organic emissions in Los Angeles County are attributable to sol

### vent degreasing. 

### Control technology is available to reduce hydrocarbon emissions from existing solvent metal cleaning operations. However, this techno1ogy has not been broadly applied 1 argely because of unawareness of economic incentives and the absence of regulatory requirements. In 1974, for example, 16 states covered degreasing operations with solvent regulations identical
or similar to Rule 66 of the Los Angeles County Air Pollution Control District. Since then, additional stateand local agencies have adopted the same types of statutes. Generally, 

### up to 3,000 pounds of VOC 

### emissions per day are allowed from sources using solvents considered non-photochemically reactive under Rule 66 criteria. Since solventmetal cleaning operations rarely release
more than that amount, they have usually complied with Rule 66 regulations merely by substitution. Regulatory incentive to institute control technology rather than substitution isnecessary to achieve positive emission reduction.
1.2 

### REGULATORY APPROACH 

### Photochemical oxidant control strategies in

### the past have re1ied heavily
on the substitution of solvents of re1atively low photochemical reactivity to reduce emissions of higher reactivity VOC. 

### Thus, 

### total emissions did not necessarily decrease, only the make-up of those emissions changed. One problem with this approach was that many solvents classed as low reactivity materials have since been found to be moderately and in

### some cases highly reactive. EPA's current direction and the direction of this document is toward positive reductions of all VOC 

### emissions. This isnot only more rational from a standpoint of conservation but 

### some low reactivity solvents are now suspected of contributing2.0 SOURCES AND TYPES OF EMISSIONS

2.1 INDUSTRY DESCRIPTION Solvent metal cleaning describes those processes using non-aqueous solvents to clean and remove soils from metal surfaces. These solvents, which are principally derived from petroleum, include petroleum distil1ates, chlorinated hydrocarbons, ketones, and a1coho1s

# . Organic solvents such as these can be used alone or inblends to remove water insoluble soils for cleaning purposes and to prepare parts for painting, plating, repair, inspection, assembly, heat treatment or machining. Solvent metal cleaning is usually chosen after experience has indicated that satisfactory cleaning is not obtainedwith water or detergent solutions. Availability, low cost and farni: iari1.y combine tomake water the first consideration for cleaning; however, water has several 1 imitations as a cleaning agent. For example, itexhibits low solubility for many organic soils, a slow drying rate, electrical conductivity, a high surface tension and a propensity for rusting ferrous metals and staining non-ferrous metals. All of these limitations can be overcome with the use of organic solvents. A typical industrial degreasing solvent would be expected to dissolve oils, greases, waxes, tars, and insome cases water. Insoluble matter such
as sand, metal chips, buffing abrasives or fibers, held by the soils, are flushed away.Table 2-1 COmN METAL (3LEANING SOLVENTS  Type of Solvent/ Solvent Alcohols Ethanol (958) Isopropanol Methanol Aliphatic Hydrocarbons Heptane Kerosene Stoddard Mineral Spirits 66 Aromatic Hydrocarbons Benzenea**  SC 150 N I Toluene w Turpentine Xylene Chlorinated Solvents Carbon Tetrachloride*** Methylene Chloride Perchloroethylene 1,1,l-Trichloroethans Trichloroethylene Fluorinated SolventsTrichlorotrifluoroethane (PC-113) Ketones Acetone Methyl ethyl ketone Solvency for Metal Working 

# -Soils

Poor poor poor good good good good good good good good good
excellent excellent excellent excellent excel lent

*Federal Register, June 27, 1974, Vol. 39, No. 125. Toxicity (PP~
lOOO*

400* 200*
500* 500 200 200

lo* 200 200' loo* loo*

lo* 500' loo* 350* loo*

lOOO*
lOOO*

200* Flash Point 

## -
60°F 55°F 58°F
<20°F 149°F 105°F 107°F

10°F 151°F

45°F 91°F 81°F

none none none none none

none

<OOP 28°F Water Evaporation Solubility Boiling Point Rate* (8 wt.) (Range) Pounds Per Gal.
6.76 6.55 6.60
5.79 6.74 6.38 6.40
7.36 7.42 7.26 7-17 7.23
13.22 10.98 13.47 10.97 12.14

13.16

6.59 6.71 Price Per Gal.
$ 1.59 $ 1.26 S 1.11 $ 0.86 $ 0.66 $ 0.62 $ 0.62


## -- S 1.06 $ 0.90 S 2.40 $ 0.96 $ 3.70 $ 2.83 $ 3.33 $ 2.7a S 3.13

S 7.84 S 1.45 $ 1.74
**~va~oratioi ate-determined by weight 106s of 50 mls ina 125 ml beaker on an analytical balance (Dow Chemical Co. method). ***Not recommended or sold formetal cleaning (formerly standards inindustry). ****Primary source from The Solvents and Chemicals Companies 'Physical Properties of Comn Organic Solvents' and Price List (July 1, 1975).A 

### broad spectrum of organic solvents is available. Choices among the solvents are based on the solubility of the soil, toxicity, flammability, evaporation rate, effect on non-rtietallic portions of the part cleaned and
numerous other properties. The r~ost important properties of solvents commonly used in

### metal cleaning are summarized in Table 2-1. As would be expected, the metal working industry is the major user of solvent metal cleaning. Eight SIC 

### codes (Numbers 25 

### and 33 

### to 39) 

### cover these industry categories. Examples of industries within these cjassifications
are automotive, electronics, appliances, furniture, jewelry, plumbing, aircraft, refrigeration, business machinery and fasteners. A1

### 1 are frequent
users of organic solvents formetal cleaning. However, the use of solvents formetal cleaning is not limited to these industries; solvent metal cleaning is also used in non-metal working industries such as printing, chemicals, plastics, rubber, textiles, glass, paper and electric power. Often, the function of the organic solvents in

### these industries istoprovide maintenance cleaning of electricmotors, fork lifttrucks, printing presses, etc. Even in 

### non-manufacturing industries, solvent metal cleaning is commonplace. Most autornotive, rai1 road, bus, aircraft, truck and electrictool repai

### r stations
use these solvents. In short, most businesses perform solvent metal cleaning, at least part time, ifnot regularly. The number of companies routinely using solvent metal cleaning operations probably exceeds one million. Furthermore, large scale users may often have over 100 separate degreasing operations at
one plant location. Solvent metal cleaning isbroken into three major categories: cold cleaning, open top vapor degreasing 

### and conveyorized degreasing

# . In cold 

### cleaning operations, all types of solvents are used depending on the type 

### of parts to be cleaned. Vapor degreasing uses halogenated solvents because- - Table 2-2 National Degreasing Solvent Consumption* (1974) Solvent Consumption (10' metric tons) So1 vent Type Cold cleaning Vapor degreasing All degreasing Halogenated: Trichloroethylene 25 128 153 1,1,1 Trichloroethane 82 80 162 Perchloroethylene 13 41 54 Methylene Chloride 23 7 30 Tri chlorotrifluoroethane 10 20 30 

### 153 

### 276 429 A1 iphatics 222 222 Aromatics: Benzene To1uene Xylene Cyclohexane Heavy Aromatics
Oxygenated: Ketones:

Acetone 10 Methyl Ethyl Ketone 8
Butyl 5 Ethers 6

*3 Total Solvents: 450 276+** 726 Range ofAccuracy: (+125) 

## (95 (+I45) *See Appendix B.l for background on the above estimates. 

### **Includes 25,000 metric tone~frorn non boi1ing convevorized degreasers. 

### ***Iqcl udes 75,000 netric tons from conveyorized vapor degreasers.

### they are not flammable and their vapors are much heavier than air. The most recent estimates are that there are 1,300,000 cold cleaning units in the United States, with about 70 percent of these devoted to maintenance or servicing operations and the remainder used for manufacturing operations. There are a1so an estimated 22,000 open top vapor degreasers and 4,000 conveyorized degreasers. Of the estimated 726,000 metric tons per year of solvent used for degreasing, roughly 60 percent is for cold cleaning, 25 

### percent for open top vapor degreasing and 15 percent for conveyorized degreasing. Tables 2-2 

### and 2-3 

### summarize the above information. Emissions are discussed in detail in the next chapter.
2.2 TYPES OF 

### DEGREASERS AND 

### THEIR EMISSIONS There are three basic types of organic solvent degreasers: cold cleaners, open top vapor degreasers, and conveyorized degreasers. Cold 

### cleaners are usually the simplest and least expensive. Their solvent is usually near room temperature, but 

### is sometimes heated. The temperature, however, always remains below the solvent's boiling point. A 

### cold cleaner is a tank of solvent usually including a cover for nonuse periods. Inside is a work surface or basket suspended over the solvent. An 

### open top vapor degreaser resembles a large cold cleaner; however, the solvent is heated to its boiling point. This creates a zone of solvent vapor that iscontained by

a set of cooling coils. Both the cold cleaner and the open top vapor degreaser clean individual batches of parts; thus, they are termed "batch loaded". A 

### conveyorized degreaser is 

### 1oaded continuously by means of various types of conveyor systems, and may either operate as a vapor degreaser as a cold cleaner.

### 2.2.1 Cold Cleaners Cold cleaner operations include spraying

## ,brushing

## ,f

### 1 ushing and imnersion. The solvent occasionally is heated in 

### cold cleaners but 

### always remains we11 below its boiling point. Cold cleaners aredefined here not to include nonboiling conveyorized degreasers which are covered in

### Section 2.3. Wipe cleaning 

### is also not included. Cold cleaners are estimated to result in the largest total emission of the three categories of degreasers. This 

### is primarily because of the extremely large number of these units (over 1million nationally) and because much of the disposed of waste solvent isallowed to evaporate. Itis estimated that cold cleaners emit 380 thousand metric tons of organics per year, this being about 55 

### percent of the national degreasing emissions (seeAppendix B. 

### 1). 

### Cold cleaning solvents nationally account for almost all of the aliphatic, aromatic, and oxygenated degreasing solvents and about one-third of halogenated degreasing solvents. Despite the large aggregate emission, the average cold cleaning unit generally emits only about one-third ton per year of organics, with about one-half to three-fourths of that emission resulting from evaporation of the waste solvent at a disposal site. 2.2.1.1 Design and Operation 

## -Table 2-3 Emissions from Solvent Degreasers (1974)

Estimated National Approximate Averaged Emission Emission No. of Unit6 Rate per

### Unit Type Degreaser (1

### o3~t/yr) Nationally (WY~) Cold Cleaners Open Top Vapor 200

Degreasers Conveyorized 100

Degreasers



### *380 emission = 450 consumption (from Table 2-2) minus 25 for wiping losses, 

### 25 for conveyorized cold cleaning and 20 for non-evaporative waste solvent disposal (incineration and non-evaporating landfill encapsulation).

# EPA-450/2-77-022 November 

# 1977 (OAQPSNO. 1.2-079)
OAQPS

# GUIDELINES



# CONTROL

# OFVOLATILE ORGANIC

# EMISSIONS 

# FROM SOLVENT

# METALCLEANING

U.S.ENVIRONMENTALPROTECTIONAGENCY Officeof

## AirandWasteManagement

- 

## Officeof AirQualityPlanningand Standards 

# 3

# 28 ResearchTrianglePark,North Carolina2771

### 1 

# RADIANLIBRARY



# DURHAM, N.C. IThis report is issued bythe Environmental ProtectionAgency to report technical data of interestto a limited number of readers. Copies are available free ofchargeto Federal employees, currentcontractors and grantees, and nonprofitorganizations - in limited quantities

- from the LibraryServices Office (MD-351, ResearchTriangle Park, NorthCarolina 27711; or, for afee, fromthe National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.

Publication No. EPA-45012-77-022

### PREFACE


### The purpose of this document isto inform regional, State, and local airpol1 ution control agencies of the different techniques available for reducing organic emissions from solvent metal cleaning (degreasing)

# . Solvent metal cleaning includes the use of equipment from any of three broad categories: cold cleaners, open top vapor degreasers

### ,and conveyorized degreasers. A11 of these employ organic solvents to remove soluble impurities from metal surfaces. The diversity in

### designs and applications of degreasers make an emission 1imi

### t approach inappropriate; rather, regulations based on equipment specifications and operating requirements are recorrmended. Reasonably available control technology (RACT) 

### for these sources entails implementation of operating procedures which minimize solventbss and retrofit of applicable control devices. Required control equipment can be as simple as amanual cover or as complex
as a carbon adsorption system, depending on 

### the size and design of the degreaser. Required operating procedures include covering degreasing equiprnent whenever possible, properly using solvent sprays, reducing the amount of solvent carried out of the uniton cleaned work by various means, promptly repairing leaking equipment, and most importantly properly disposing of wastes containing volatile organics. Not all controls and procedures will be applicable to a11 degreasers, a1though ingeneral specific operating requirements and control devices will be applicable to the majority of designs within 

### each category of degreasers. Control of open top and conveyorized .vapor degreasing is the most cost effective, followed by waste solvent disposal fora11 degreasing operations, manufacturing cold cleaning and maintenance cold 

### cleaning.

iiiTwo 

### levels of control for each type of degreaser have been identified here as examples of reasonably available control technology (RACT). 

### In general, control level A 

### shows proper operating practice and simple, inexpensive control equipment. Control level B 

### consists of level A 

### plus additional requirements to improve the effectiveness of control. The degree of emission reduction forboth individual items and control levels are discussed in the text. Specificrequirements can be modified to achieve whatever level of control isnecessary. Control systems for cold cleaners
are shown in Table 1, 

### thosefbr open top 

### vapor degreasers in

### Table 2, 

### and those for conveyorized degreasers in Table 3. 

### Two exemptions are recommended. Fi

### rst, conveyorized degreasers smaller 2 

### than 2.0 

### m 

### of airlvapor interface should be exempt from a requirement for
a major control device. This would not be cost effective and would tend to
move the small conveyorized degreaser users toopen top vapor degreasers which emit more solvent per unitwork load. Second, open top vapor degreasers 2 

### smaller than 1

### m of open area should be exempt from the 

### application of 

### refrigerated chillers or carbon adsorbers. Again, requirement for these would not be cost effective.TABLE 1. CONTROL SYSTEMS FOR COLD CLEANING
Control System A Control Equipment: 1. Cover 2. Facility for draining cleaned oarts 3. Permanent, conspicuous label, summarizing the operatino requirements Operating Requirements: 1. Do not dispose of waste solvent or transfer itto another Darty, such that greater th!n 20 percent of the waste (by weight) can evaporate into the atmosohere. Store waste.solvent onlv in covered containers. 2. Close degreaser cover whenever not handling parts in the cleaner. 3. Drain cleaned parts for atleast 15 seconds or until dripping ceases. Control System 0 Control Equipment: 1. Cover: Same as fn System A, except if (a) solvent volatility is reater than 2 kPa (15mn Hg or 0.3 psi) measured at38°C (lOO°F).** 

# 4b) solvent isagitated, or (c) solvent isheated, then the cover must be designed so that it can be easily operated with one hand. (Covers for lar~er deqreasers may require mechanical assistance, by spring ;oading, countenreiqhtinq or Dowered systems.) 2. Drainage facility: Same as in System A, except that if solvent volatility isgreater than about 4.3 kPa (32mn Hg or 0.6 psi) ~easured at 38°C (10O0F), then the drainage facilitymst be internal, so that oarts are enclosed under the cover while draining. The drainage facilitymay be external for applications where an internal type cannot fitinto the cleaning system. 3. Label : Same as in System A 4. If used, the solvent spray must be a solid, fluid stream (not a fine, atomized or shower type spray) and ata pressure which does not cause excessive splashing. 5. Major control device for highly volatile solvents: If the solvent volatility 1s > 4.3 kPa (33n Hg w 0.6 psi) measured at 38°C (lT)O°F), or if solvent is heated above 50'C C120°F], then one of the following control devices must be used:

a. Freehoard that gives a freeboard ratiof** 20.7 h. Yater cover (solventmust be insoluble in and heavier than water)

c. Other system of equivalent control, such as a refrigerated chiller or carbon adsorption. Operating R~rp~irprnentr : Sane as in System A
%:er and sol'd waste regulations must also be cornolied Kith. **Senerally solvents consisting primarily ~f mineral Ioirits !Z!oddard) have rolatilities c 2 kPa. ***Freeboard ratio is defined as the freeooard heiqnt divided oj the width of :he degreaser.TABLE 2. COMPLETE CONTROL SYSTEMS FOR OPEN TOP VAPOR DEGREASERS

Control System A Contrcl Equipment: 1. Cover that can be opened and closed easily without disturbing the vapor zone. Operating Requirements: 1. Keep cover closed atall times except when processing work loads through the degreaser. 2. Minimize solvent carry-out by the following measures:
a. Rack parts to allow full drainage. b. Move parts in and out of the degreaser atless than 3.3 mlsec (11 ftlmin) c. Degrease the work load in the vapor zone at least 30 s~c. or until condensation ceases. d. Tip out any pools of solvent on the cleaned parts before removal. e. Allow parts to dry within the degreaser for at least 15 sec. or until visually dry.

. - 3. Do not degrease porous or absorbent materials, such as cloth, leather, wood or rope. 4. Work loads should not occupy more than half of the degreaser's open top area. 5. The vapor level should not drop more than 10crn (4 in) when the work load enters the vapor zone. 6. Never spray above the vapor 1 eve1. 7. Repair solvent leaks imnediately, or shutdown the degreaser. 8. Do not dispose of waste solvent or transfer it to another party such that greater than 20 percent of the waste (by weight) will evaporate into the atmosphere. Store waste solvent only in closed containers. 3. Exhaust ventilation should not exceed 20 m3/min per m2 (65 cfm per ft 2) of degreaser open area, unless necessary tomeet OSHA requirements. Ventilation fans should not be used near the degreaser opening. 10. Water should not be visually detectable in solvent exiting the water separator. Contro: System B Control Equipment: 1. Cover (same as in syztem A). 2. Safety switchfs

a. Condenser flowzwitctt ana tfermostat - [snuts off sump neat if condenser coolant iseithernot circulating or too warm). b. Spray safety switch 

### - (shuts off spray pump if the vapor level drops excessively, about 10cm (4 in). 3. Major Control Device: Either: a. Freeboar$ ratio reater than or equal to 0.75, and if the degreaser opening is > 1 m (10 ft 

### 9), the cover must be powered, b. Refrigerated chiller, c. Enclosed design (cover or door opens only when the dry part isactual1 y entering or exiting the degreaser

### .), d. Carbon adsorption system, with ventilation L 15m3/min per m2 (50 cfmlft ) of airlvapor area (when cover is open), and exhausting 45ppm solvent averaged over one complete adsorption cycle, or e. Control svstem. demonstrated to have control efficiency, equivalent to or betterthan any of the above. 4. Permanent, conspicuous label, sumnarizing operating procedures #1 to 116. Operating Requirements : Same as in System ATABLE 3. CONTROL SYSTEMS FOR CONUEYORIZED DEGREASERS
Control System A Control Equipment: None Operating Requirements: 3 1. Exhaust ventilation should not exceed 20 m /min per m 2 (65 cfm per ft2) ofdegreaser opening, unless necessary to meet OSHA requirements. Work place fans should not be used near the degreaser opening. 2. Minimize carry-out emissions by:
a. Racking parts for best drainage. b. Maintaining verticle conveyor speed at < 3.3 m/min (11 ftlmin) 3. Do not dispose ofwaste solvent or transfer it to another party such that greater than 20 percent of the waste (by weight) can evaporate into the atmosphere. Store waste solvent only Incovered containers. 4. Repair solvent leaks imnediately, or shutdown the degreaser. 5. Water should not be visibly detectable inthe solvent exiting the water separator. Control System B Control Equipment: 1. Major control devices; the degreaser must be controlled by either:
a. Refrigerated chiller, b. Carbon adsorption system, withventilation 5 15 m2/min per m 2 (50 cfm/ft2) of air/vapor area (when down-time covers are open), and exhausting <25 ppm of solvent by volume averaged over a complete adsorption cycle, or c. System demonstrated to have control efficiency ?quivalent to or better than either of the above. 2. Either a drying tunnel, or another means such as rotating (tumbling) basket, sufficient to prevent cleaned parts from carrying out solvent 1iquid or vapor. 3. Safety switches
a. Condenser flow switch and thermostat

### - (shuts off sump heat if coolant iseither not circulating or too warm). 6. Spray safety switch

### - (shuts off spray pump or conveyor ifthe vapor level drops excessively, e.g. > 10 cm (4 in.)). c. Vapor level control thermostat - (shuts off sump heat when vapor level rises too high). 4. Minimized openings: Entrances and exits should silhouettework loads so that the average clearance (between parts and the edge of the degreaser opening) iseither ~10 cm (4 in.) or <10 percent of the width of the opening. 5. Down-time covers: Covers should he provided for closing off the entrance and exitduring shutdown hours. Operating Requirements: 1. to 5. Same as for System A 6. Down-time cover must be placed over entrances and exits ofconveyorized degreasers immediately after the conveyor and exhaust are shutdown and removed just before they are started up.TABLE 

### OF CONTENTS 

### Fage Preface 

## .................................iii Chapter 1.0 Introduction and Summary 

## ..................1-1 1.1 Need to Regulate Solvent Metal Cleaning 

## ..........1-1 1.2 Regulatory Approach 

## ....................1-2 Chapter 2.0 Sources and Types ofEmissions 

## ...............2-1 2.1 Industry Description

# ....................2-1 2.2 Types of Degreasers and Their Emissions 

## .......... 2-4 2.2.1 Cold Cleaners 

# .................... 2-7 2.2.1.1 Design and Operation 

# ............ 2-7 2.2.1.2 Emissions 

# ................. 2-12 2.2.2 Open Top Vapor Degreasers 

# .............. 2-16 2.2.2.1 Design and Operation 

# ............ 2-16 2.2.2.2 Emissions 

# ................. 2-25 2.2.3 Conveyorized Degreasing 

# ............... 2-33 2.2.3.1 Design and Operation 

# ............ 2-33 2.2.3.2 Emissions 

# .................2-39 2.4 References 

# ........................2-45 Chapter 3.0 Emission Control Technology 

# ................ 3-1 3.1 Emission Control Devices 

# ................. 3-1 3.1.1 Emission Control Devices 

# ..............3-1 3.1.1.1 Improved Cover 

# ............... 3-2 3.1.1.2 High Freeboard

# ............... 3-5

viii

### Page



## . 

## ............ 3-6 3-1 1.3 Refrigerated Chi1 lers



## ............. 3-9 3.1

## .1

## .4 Carbon Adsorption



## ............... 3-14 3.1.1.5 Safety Switches 3.1.2 ' 

### Controls to Flini'rnize Carry-Out 

## ............ 3-16 3.1.3 Controls for Both Solvent Bath and Carry-Out Emi'ssions Combined 

## ............ 3-18 3.1.3.1 Automated Cover-Conveyor System 

# ....... 3-18 3.1.3.2 Refrigeration Condensation 

## ......... 3-20 3.1.4 Control of Naste Solvent Evaporation 

# ......... 3-22 3.1.4.1 Cum-ent Practices 

# .............. 3-22 3.1.4.2 Recommended Practi.ces

# ............ 3-23 3.1.5 Other Control Dwi'ces 

# ................ 3-27 3.1.5.1 Inci'neration 

# ................ 3-28 3.1.5.2 LiquTd Absorption 

# .............. 3-28 3.2 Complete Control Systems 

# .................. 3-29 3.2.1 Cold Cleaning Control 

### Systems 

# ............ 3-30 3.2.2 Control Systems for Open Top Vapor Degreasing 

# ...................... 3-32 3.2.3 Control Systems for Conveyorized Degreasers 

## ..... 3-32 3.3 References 

## ......................... 3-37 Chapter 

### 4.0 Cost Analysis 

# ........................ 4-1 4.1 Introduction 

# ........................ 4-1 4.1.1 Purpose 

## ....................... 4-1 4.1.2 Scope 

## ........................ 4-1 4.1.3 Model Plants 

# ..................... 4-2 4.1.4 Capi'tal Cost Estimates 

## ................ 4-3 4.1.5 Annualized Costs 

## ................... 4-3

### Page 

### 4.2 Cold Cleaners


## ........................ 4-4 4.2.1 Model Plant Parameters

## ................. 4-4 4.2.2 Control Costs 

## .................... 4-0 4.3 

### Open Top 

### Vapor Degreasers 

## .................. 4-8 4.3.1 Model Plant Parameters


## ................ 4-8 

### 4.3.2 Control Costs


## .................... 4-8 4.3.3 Cost Effectiveness


## .................. 4-14 

### 4.4 Conveyorized Degreasers 

## ................... 4-16 4.4.1 Model Plant Parameters 

## ................ 5-10 

### 4.4.2 Control Costs 

## .................... 4-18 4.4.3 Cost Effectiveness 

## .................. 4-20 

### 4.5 References 

## .........................4-24 Chapter 5.0 Adverse Environmental Effects of Applying 

### The Technology 

## ........................ 5-1 5.1 

### Air Impacts 

## .........................5-1 5.2 

### Water Impacts 

## ........................ 5.1 

### 5.2.1 

### Naste Solvent Disposal 

# ................ 5-1 

### 5.2.2 Steam Condensate from Carbon Adsorpti'on 

## ....... 5-2 5.2.2.1 Chlorinated Solvent ih 

### Steam Condensate 

## .................5-2 5.2.2.2 Stabilizers in Steam Condensate 

## ....... 5-3 5.2.3 Effluents from Water Separators 

# ........... 5-4 5.3 Solid Waste Impact 

## ..................... 5-4 5.4 

### Energy Impact 

## ........................5-5 5.5 Other Environmental Concerns 

## ................ 5-6 5.6 References 

## .........................5-8 

### Chapter 6.0 Compliance Testing Methods and Monitori'ng Techniques 

## .........................6-1

### Page 6.1 Observation of Control EglQment and Operating Practi'ces 

# .................... 6-2 6.2 Material Balance 

# ..................... 6-2 

### 6.3 Other Emission Tests 

# ................... 6-3 

### Chapter7.0 Enforcement Aspects 

# .................... 7-1 7.1 Regulatory Approaches 

# ................... 7-2 7.1.1 Emission Standards 

# ................. 7-2 7.1

# .2 Equipment Standards 

# ................ 7-3 7.1.3 Operati'onal Standards 

# ............... 7-4 7.1.4 

### Solvent Exemptton Standards 

# ............ 7-5 7.2 Affected Facilities 

## .Prtariiies 

# ............. 7-5 

### 7.2.1 Definitions of Affected Facilities 

# ......... 7-51 7.2.2 Priorities of Enforcement 

# ............. 7.5 Appendix A.0 Emission 

### Test Results Appendix B

# .0 Calculations

### v LIST OF TABLES Page Table 1 Control Systems for Cold Cleaning 

## .............. Table 2 Control Systems for Open Top Vapor Degreasers 

# ........vi 

### Table 3 

### Control Systems for Conveyorized Degreasers 

## .........vi

### i Table 2-1 Common Metal Cleaning Solvents 

# ................ 2-3 Table 2-2 National Degreasing Solvent Consumption (1974) 

## ........ 2-5 Table 2-3 

### Emissions from Solvent Degreasers (19741 

# ........... 2-6 Table 3-1 

### Control Systems 

### for Cold Cleaning 

# .............. 3-31 Table 3-2 

### Complete Control Systems for Open Top Vapor Degreasers 

## .... 3-33 Table 3-3 

### Control Systems for Conveyorized Degreasers 

## ......... 3-35 Table 4-1 Cost Parameters forModel Cold Cleaners 

# ........... 4-5 Table 4-2 Control Costs forTypical Cold Cleaners 

# ........... 4-7 Table 4-3 Cost Parameters forModel Open Top Yapor Degreasws 

# ..... 4-9 Table 4-4 Control Cost for Typi'cal Si2e 

### Open Top Yapor Degreaser 

# .... 4-10 Table 

### 4-5 Control Cost 

### for Small Open Top Vapor Degreaser 

# ....... 4-11 Table 4-6 Cost Parameters forPlodel Conveyorized Degreasers 

# ...... 4-17 Tab1

### e 4-7 Control Costs for Typical Con~eyorized Degreasers 

# ...... 4-19

### Figure 2-1 Cold Cleaner 

## ........................ 2-9 Figure 2-2 Cold Cleaner Emission Points 

## ................ 2-13 Figure 2-3 Open Top Vapor Degreaser 

# .................. 2-18 Figure 2-4 Basic Principle for Water Separator forVapor Degreaser 

# . . 2-20 Figure 2-5 Open Top Degreaser with Offset Condenser Coils 

# ....... 2-21 Figure 2-6 Two Compartment Degreaser with Offset Boili'ng Chamber 

# ... 2-22 Figure 2-7 Two Compartment Degreaser 

## ................. 2-23 Figure 2-8 Degreaser with Lip Exhaust 

# ................. 2-24 Figure 

### 2-9 Open Top Vapor Degreaser Emission Points 

# .......... 2-26 LIST 

### OF FIGURES 

### Page

Figure 2-10 Cross Rod Conveyorized Degreaser 

# .............. 2-35 Figure 2-11 Monorail Conveyorized Degreaser 

# .............. 2-36 Figure 2-12 Vibra Degreaser 

# ...................... 2-37 Figure 2-13 Ferris Wheel Degreaser 

# ................... 2-38 Figure 2-14 Mesh Belt Conveyorized Degreaser 

## .............. 2-40 Figure 2-15 Conveyorized Degreas.er Emissi.on Points 

## ........... 2-42 Figure 3-1 Refrigerated Freeboard Chiller 

# ............... 3-7 Figure 3-2 Carbon Adsorber 

## ...................... 3-10

Figure 3-5 Elevator Design 

### of Degreaser


### .Vapor Type 

## ......... 3-19 Figure 3-6 Vapor 

### Pressures of Several Solvents 

## ............ 3-21 Figure 3-7 External Sti:ll 

## ....................... 3-25 Figure 3-3 Figure 3-4 Adsorption Cycle 

## ...................... 3-.11 Desorption Cycle 

## ...................... 3-12

Figure 4-1 Cost-Effectiveness of A1ternative Control Options for Existing Open Top Vapor Degreasers 

## ............. 4-15 Figure 4-2 Cost-Effecti~eness of

### A1ternative Control Options for ExistingMonorail Degreas-ers 

## ................ 4-21 Figure 4-3 

### Cost-Effectiveness of Alternative Control 0pti:ons for Existing Cross-Rod Degreasers 

## ............... 4-23

xiii1,O INTRODUCTION AND SUMMARY
The purpose of EPA's series of control technique guideline documents isto provide guidance on emission reduction techniques which can be applied to existing sources inspecific industries. The documents are to be used to assist States inrevising their implementation plans (SIP'S) to attain and maihtain National Ambient Air QualityStandards (NAAQS). This document discusses volatileorganic compound (VOC) emissions and applicable control techniques for organic solvent metal cleaning operations (degreasing with solvents).
1.1 NEED TO REGULATE SOLVENT METAL CLEANING Solvent metal cleaning isa significant source of volatileorganic compounds (VOC) and tends to be concentrated inurban areas where the oxidant NAAQS is likely to be exceeded. In1975 solvent metal cleaning emitted about 725 thousand metric tons oforganics. This represents about four percent of the national organic emissions from stationary
sources. Presently, solvent metal cleaning isthe fifth largest stationary
source of organic emissions. Although emissions from solvent degreasing (i.e., metal cleaning) represent about four percent of nationwide VOC sources, the proportion issignificantly higher inmost urban areas, because of their high concentration of metalworking industries. For example,the Southern California AirQua1ity Management District estimates that 14.8 percent ofthe stationary organic emissions inLos Angeles County are attributable to solvent degreasing. Control technology isavai1 able to reduce hydrocarbon emissions from existing solvent metal cleaning operations. However, this technology has not been broadly applied largely because of unawareness ofeconomic incentives and the absence of regulatory requirements. In 1974, for example, 16 states covered degreasing operations with solvent regulations identical
orsimilar to Rule 66 ofthe Los Angeles County Air Pollution Control District. Since then, additional state and local agencies have adopted the same types of statutes. Generally, up to 3,000 pounds ofVOC emissions per day are allowed from sources using solvents considered non-photochemicallyreactive under Rule 66 criteria. Since solvent metal cleaning operations rarely re1 ease more than that amount, they have usually compliedwith Rule 66 regulations merely by substitution. Regulatory incentive to institute control technology ratherthan substitution isnecessary toachieve positiveemission reduction.
1.2 REGULATORY APPROACH Photochemical oxidant control strategies in the past have re1ied heavily
on the substitution ofsolvents of relatively low photochemical reactivity to reduce emissions of higher reactivity VOC. Thus, total emissions didnot necessarily decrease, only the make-up ofthose emissions changed. One problem with this approach was that many solvents classed as low reactivity materials have since been found to be moderately and insome cases highly reactive. EPA1s current direction and the direction ofthis document istoward positive reductions of all VOC emissions. This is not only more rational from a standpoint of conservation but some low reactivity solvents are now suspected of contributing

### to upper atmospheric ozone depletion. These reasons and others support the decision to concentrate on positive reduction rather than substitution. Positive emission reduction from solvent metal cleaning should be attained thpugh 

### use of proper operating practices and retrofit control equipment. Proper operating practices are those which minimize solvent loss to the atmosphere. These include covering degreasing 

### equipment whenever possible, proper use of solvent sprays, various means of reducing the 

### amount of solvent carried out of the degreaser on cleaned work, prompt repair of leaking equipment, and most importantly, proper disposal of wastes containing volatile organic sol vents. In addition to proper operating practices there are many control devices which can be retrofit to degreasers; however, because of the diversity in their designs, not all degreasers require a11 control devices. Small degreasers using room temperature solvent may require only a cover, whereas a large degreaser using boiling solvent may require a refrigerated freeboard chi1 ler or a carbon adsorption system. Two types of control equipment which will be applicable to many degreaser designs are drainage facilities for cleaned parts and safety switches and thermostats whi

### ch prevent 1 arge emissions due to equipment malfunction. The many degreaser designs along with the emissions characteristic of those designs and the factors affecting those emissions are described in Chapter 2. 

### Control devices for each type of emission and control systems for each degreaser design are described in Chapter 3.

### 2.0 

### SOURCES AND 

### TYPES OF 

### EMISSIONS
2.1 INDUSTRY DESCRIPTION Solvent metal cleaning describes those processes using non-aqueous solvents to clean and remove soils from metal surfaces. These solvents, which are principally derived from petroleum, include petroleum distillates, chlorinated hydrocarbons, ketones, and a1 coho1s. Organic solvents such as these can be 

### used alone or in blends to remove water insoluble soils for cleaning purposes and to prepare parts for painting, plating, repair, inspection, assembly, heat treatment or machining. Solvent metal cleaning isusually chosen after experience has indicated that satisfactory cleaning is not obtained with 

### water or detergent solutions. Availability, low cost and farni:iaril,y combine to make water the first consideration for cleaning; however, water has several limitations as a cleaning agent. For example, itexhibits low solubility formany organic soils, a slow drying rate, electrical conductivity, a high surface tension and a propensity for rusting ferrous metals and staining non-ferrous metals. A11 of these 1

### initations can be overcome with the use of organic solvents. A 

### typical industrial degreasing solvent would be expected 

### to dissolve oils, greases, waxes, tars, and in some cases water. Insoluble matter 

### such

as sand, metal chips, buffing abrasives or fibers, held by 

### the soils, are flushed away.

### A 

### broad spectrum of organic solvents is available. Choices among the solvents are based on the solubility of 

### the soil, toxicity, flammability, evaporation rate, effect on non-metallic portions of the part cleaned and
numerous other properties. The most important properties of solvents conmonly used in metal cleaning are summarized in Table 2-1. As would be expected, the metal working industry 

### is the major user 

### of solvent metal cleaning. Eight SIC codes (Numbers 25 and 33 

### to 39) 

### cover these industry categories. Examples of industries within these classifications

are autornotive, electronics, appliances, furniture, jewelry, plumbing

### , aircraft, refrigeration, business machinery and fasteners. A11 are frequent
users of organic solvents formetal cleaning. However, the use of solvents formetal cleaning is not limited to these industries; solvent metal cleaning is 

### also used in non-metal working industries such as printing, chemicals, plastics, rubber, textiles, glass, paper and electricpower. Often, the function of the organic solvents in these industries istoprovide maintenance cleaning of electricmotors, fork lifttrucks, printing presses, etc. Even in non-manufacturing industries, solvent metal cleaning iscommonplace. Most automotive, rai1 road, bus, aircraft, truck and electrictool repair stations
use these solvents. In short, most businesses perform solvent metal cleaning, at least part time, if not regularly. The number of companies routinely using solvent metal cleaning operations probably exceeds one mil1 ion. Furthermore, large scale users may often have over 100 separate degreasing operations at
one plant location. Solvent metal cleaning isbroken into three major categories: cold cleaning, open top vapor degreasing 

### and conveyorized degreasing. In cold cleaning operations, all types of solvents are used depending on the type of parts to be cleaned. Vapor degreasing uses halogenated solvents becauseTable 2-1 COMMON METAL CLEANING SOLVENTS**** Solvency for Water Type of Solvent/ Solvent Metal Working



# - Soils Toxicity (PP~ Flash Point Evaporation Rate" Solubility (twt.) Boiling Point (Range) Pounds Per Gal. Price Per Gal. Alcohols Ethanol (959) Isopropanol Poor poor 1000' 400' Methanol poor 200* Aliphatic Hydrocarbons Heptane good 500* Kerosene good 500 Stoddard Mineral Spirits 66 good good 200 200 Aromatic Hydrocarbons Benzene*** good lo* FO w ' SC 150 Toluene Turpentine Xylene good good good good 200 200' loo* loo* Chlorinated Solvents Carbon Tetrachloridee** excellent lo* none 111 <0.1 170-172°F 13.22 $ 3.70 Methylene Chloride excellent SOO* none 363 0.2 104-105.SoF 10.96 $ 2.83 Perchloroethylene 1,1,1-Trichloroethane excellent excellent loo* 350* none none 16 103 <0.1 (0.1 250-254°F 165-194'F 13.47 10.97 $ 3.33 $ 2.73 Trichloroethylene excellent loo* none 62.4 <O.1 188-190°F 12-14 $ 3.13 Fluorinated SolventsTrichlorotrifluoroethane (PC-113) lOOO* none 439 <0.1 117°F 13.16 $7.84
Ketones Acetone lOOO* Methyl ethyl ketone 200' *Federal Register, June 27, 1974, Vol. 39, No. 125. **Evaporation Rate determined by weight lose of SO mlr, in a 125 ml beaker on an analytical balance (DowChemical Co. ~thod). ***Not reconmended or sold for metal cleaning (formerly standards in industry). ****Primary source fromThe Solvents and Chemicals Companies .Physical Properties of Commn Organic Solventsw and Price List (July 1, 1975).they are not flammable and their vapors are much heavier than air. The most recent estimates are that there are l,3OO,OOO cold cleaning units inthe United States, with about 70 percent of these devoted tomaintenance or servicing operations and the remainder used for manufacturing operations. There are a1so an estimated 22,000 open top vapor degreasers and 4,000 conveyorized degreasers. Ofthe estimated 726,000 metric tons peryear of solvent used for degreasing, roughly 60 percent is for cold cleaning, 25 percent for open top vapor degreasing and 15 percent for conveyorized degreasing. Tables 2-2 and 2-3 summarize the above information. Emissions are discussed indetail inthe next chapter.

2.2 TYPES OF DEGREASERS AND THEIR EMISSIONS There are three basic types of organic solvent degreasers: cold cleaners

## ,open top vapor degreasers

## ,and conveyorized degreasers

# . Cold cleaners are usually the simplest and leastexpensive. Their solvent is usually near room temperature, but issometimes heated. The temperature, however, always remains below the solvent's boiling point. A cold cleaner isa tank of solvent usually including a cover for nonuse periods. Inside isa work surface or basket suspended over the solvent. An open top vapor degreaser resembles a large cold cleaner; however, the solvent is heated to itsboiling point. This creates a zone of solvent vapor that iscontained by
a set of cooling coi1s. Both the cold cleaner and the open top vapor degreaser clean individual batches of parts; thus, they are termed "batch loaded". A conveyorized degreaser is 1 oaded continuously by means of various types of conveyor systems, and may either operate as a vapor degreaser as a cold cleaner.- - Table 2-2 National Degreasing Solvent Consumption* (1974)

9 Solvent Consumption (lo3 metric tons) Solvent Type Cold cleaning Vapor degreasing A11 degreasing Halogenated:

Trichloroethylene 25 128 153 1,l ,1 Trichloroethane 82 80 162 Perch1 oroethylene 13 41 54 Methylene Chloride 23 7 30 Trichlorotrifluoroethane 10 2 0 30 

### 153 

### 276 429 A1 iphatics Aromatics: Benzene To1uene Xylene Cyclohexane Heavy Aromatics
Oxygenated: Ketones:

Acetone 10 Methyl Ethyl Ketone 8
Butyl 5 Ethers 

## *-* Total Solvents: 450 276*** 726 Range ofAccuracy: (+125) (225) (+145) *See Appendix B.l for background on the above estimates. 

### **Includes 25,000 metric tone5from non boi1ing convevorized degreasers. 

### ***Iqcludes 75,000 metric tons from conveyorized vapor degreasers.

### Table 2-3 

### Emissions from Solvent Degreasers (1974)

Estimated National Emi

### ssion Approximate No. of Units Averaged Emi

### ssion Rate oer Unit Type Degreaser Nationally

### Cold Cleaners Open Top Vapor 200

Degreasers Conveyorized 1

### 00



### Degreasers

*380 

### emission = 

### 450 

### consumption (from Table 2-2) minus 25 forwiping losses, 

### 25 forconveyorized cold cleaning and 20 

### for non-evaporative waste solvent disposal (incineration and non-evaporating landfill encapsulation).2.2.1 Cold Cleaners Cold cleaner operations include spraying, brushing, flushing and imnersion. The solvent occasionally is heated incold cleaners but always remains well below its boiling point. Cold cleaners are defined here not to include nonboiling conveyorized degreasers which are covered inSection 2.3. Wipe cleaning isalso not included. Cold cleaners are estimated to result inthe largest total emission of the three categories of degreasers. This isprimarily because of the extremely large number of these units (over 1 millionnationally) and because much ofthe disposed ofwaste solvent isallowed to evaporate. It is estimated that cold cleaners emit 380 thousand metric tons of organics per year, this being about 55 percent of the national degreasing emissions (see Appendix B. 1)

# . Cold cleaning solvents nationally account for almost all of the aliphatic, aromatic, and oxygenated degreasing solvents and about one-third of halogenated degreasing solvents. Despite the large aggregate emission, the average cold cleaning unit generally 

### mits only about one-thirdton per year oforganics

## ,with about one-half tothree-fourths ofthat emission resultingfrom evaporation of the waste solvent at a disposal site. 2.2.1.1 Design and Operation 

## -Typical Model 

## - A typical cold cleaner isshown inFigure 2-2. The dirty parts are cleaned manually by spraying and by soaking inthe dip tank. The solvent inthe dip tank isoften agitated to enhance the cleaning action. After cleaning, the basket of cleaned parts may be suspended over the solvent to allow the parts to drain, or the cleaned parts may be drained on an external drainage rack (not shown) which routes the drained solvent back into the cleaner. The cover is intended to be closed whenever parts are not being handled inthe cleaner. The cold cleaner described and shown inFigure 2-1 is most often used for maintenance cleaning of metal parts. A typical size 

### 2 of sbch a maintenance cold cleaner isabout 0.4 m (4 ft

### 2) of opening and 

### 3 about 0.1 

### n (30 gallon) capacity. Applications 

# - The two basic types of cold cleaners are maintenance cleaners and manufacturing cleaners

# . The maintenance cold cleaners are usually simpler, less expensive, and smaller. They are designed principally for automotive and general plant maintenance cleaning. Manufacturing cold cleaners usually perform a higher qua1ityof cleaning than do maintenance cleaners and are thus nore specia1ized. Manufacturing cold cleaning isgenerallyan integral stage inmetalworking production. Manufacturing cold cleaners are fewer innumber than maintenance cleaners but tend to emit more solvent per unit because ofthe larger size and work load. Manufacturing cleaners use a wide variety ofsolvents, whereas maintenance cleaners use mainly petroleum solvents such as mineral spiri ts (petroleum di sti11 ates

### , and Stoddard solvents)

# . Some cold cleaners can serve both maintenance and manufacturing purposes and thus are difficult toclassify. The type of cold cleaner to be used for a particular application depends
on two main factors: (1) the work load and (2) the required cleaningFigure 

### 2-1 COLD CLEANER



### Cleaner

### effectiveness. Work load is a function of tank size, frequency of cleaning, and type of parts. Naturally, the larger work loads require larger degreasers. The more frequently the cold cleaner isused, the greater the need to automate and speed up 

### the cleaning process ;

### more efficient materia1s hand1ing 

### systems help automate, while agitation speeds cleaning. Finally, the type of parts to be cleaned is important because more thorough cleaning and draining techniques are necessitated formore complexly shaped parts. The required cleaning effectiveness establ ishes the choice of solvent and the degree of agitation. For greater cleaning effectiveness, more powerful solvents and more vigorous agitation are used. Senerally, emissions will increase with agitation and with higher solvency. Equipment Design 

## - A1though classif.ying cold cleaners according to maintenance or manufacturing application is a convenient initial approach, manufacturing cold cleaners vary so widely in design that 

### no one typical design can adequately describe them. Thus, a more specific classification of manufacturing cold cleaners must also co~nsider the equipment design. The most important design factors are tank design, agitation technique, and the material handling of parts to be cleaned. The two basic tank designs are the simple spray sink and the drip tank. The sinple spray sink is usually less expensive. It ismore appropriate for cleaning applications that are not difficultand require only a relatively low degree of cleanliness. The dip tank provides more thorough cleaning through soaking of dirty parts. Dip tanks also can employ agitation, which improves cleaning efficiency. Agitation is generally accomplished through use of pumping, compressed air, vertical motion or ultrasonics. In the pump 

### agitated cold cleaner, the solvent is rapidly circulated in the soaking tank. Air agitation involvesdispersing compressed air from the bottom of the soaking tank; the air bubbles providing a scrubbing action. Inthe vertically agitated cold cleaner, dirty parts move up and down while submerged inorder to enhance the cleaning process. Finally, inthe ultrasonically agitated tank, the solvent isvibrated by high frequency sound waves. Ultrasonically agitated 1 iquids often need to be heated to specific temperatures to achieve optimum cavitation. Cavitation isthe implosion ofmicroscopic vapor cavities within the liquidsolvent. The implosions, which are caused by pressure differentials of the sound waves inthe solvent, break down the dirtfilmon the parts. The designs for material hand1ing incold cleaning systems are almost endless, but they are generally divided intomanual and batchloaded conveyorized systems. (Continuously loaded conveyorized systems are described separately in Section 2.3). Manual loading isused for simple, small-scale cleaning operations and is self explanatory. Batchloaded conveyorized systems are for use inthe 11lorecomplex, larger-scale cleaning operations. These systems may include an automated dip, which automatically lowers, pauses, and raises the work 1 oad. They may also include systems, such as a rollerconveyor, to transfer the work load toother operations. Inanother variation, two or more dip tanks may be used inseries. These tanks may contain increasingly pure solvent ina "cascade" cleaning system. The consecutive dip tanks may also contain different cleaning solutions for more complex operations and may even be combined with vapor cleaning and aqueous systems. The materials handling technique can be important inreducing emissions from cold cleaning. Regardless of the system, the work loads need to be handled
so that the solvent has sufficient time to drain from the cleaned parts into an appropriate container. Drainage facilities are described inSection 3.1.2.

### 2.2.1.2 

### Emissions 

## - Solvent evaporates both directly and indirectly from the cold cleaners. The emission rates vary widely; nevertheless, the average emission rate, calculated from national consumption data, is estimated to be about 0.3 metric ton per year. Maintenance and manufacturing cold cleaners are estimated to emit approximately 0.25 

### and 0.5 metric tons per year, respectively (seeAp~endix 8.2.2). Data from the Safety Kleen Corporation reports only 0.17 

### metric tons per year for thier cold cleaner. However, their emissions
are expected to be lower than others because most of the waste solvent from Safety Kleen units is distilled and recycled by the company. Emissions from a cold cleaner occur through: (1) bath evaporation, (2) 

### solvent carry-out, (3)agitation, (4) 

### waste solvent evaporation, and (5) 

### spray evaporation. These are depicted in Figure 2-2 and discussed in thp 

### following sections. Bath Evaporation 

## - Bath evaporation can be greatly reduced through use of
a cover. Generally, the cover should be closed whenever the parts are not being handled in the cold cleaner. Although covers are standard equipment on most cold cleaners,keeping 

### the cover closed requires conscientious effort on the part of the operator and his su~ervision.

### As will be discussed in

### Section 3.1.1, there

are various means of inducing the operator to close the cover more frequently. Where solvents much more volatile than mineral spirits are used, adequate freeboard height is important to reduce evaporation. Freeboard height is the distance from the solvent to the top edge of the cold cleaner. The 

### requirement for freeboard height 

### ismost commonly expressed as freeboard ratio, with freeboard ratio being defined as the ratio of freeboard height to degreaser width (not length). Excessive drafts in the workshop can significantly increase solvent bath evaporation. Thus, room and exhaust ventilation should be no greater than is

### 1. 

### use of a manual cover; 2. 

### use of a manual or powered cover in combination with extended freeboard; 3. 

### refrigerated chiller; 4. 

### carbon adsorber; As in the case of cold cleaners, incremental costs for housekeeping controls on open top vapor degreasers are not presented because they appear to be negligible. With regard to conveyorized vapor degreasers, control cost estimates will be presented for facilities that primarily use trichloroethylene or perchloroethylene solvents. The control cost estimates will reflect the use of the following techniques:
a. carbon adsorber b. 

### refrigerated chi11ers Again, incremental costs for housekeeping are 

### not presented because they. appear 

### tobe negligible. 4.1.3 Model Plants Control cost estimates are presented for typical model degreasers in the metal cleaning industry. Specificmodel plant parameters will be presented in the subsequent portions of this chapter. Admittedly, control costs may vary from one installation 

### toanother, perhaps even appreciably from the costs described for the models in this chapter. However, the difficulty of obtaining actual plant control costs requires use of model plants. To the extent possible, EPA 

### has incorporated actual plant cost information into the cost analysis.necessary to provide safe levels for the operator's health and plant's protection. Agitation Emissions 

### - Agitation increases emissions. The rate of emission depends upon: ( 1) use of the cover, (2) aqitation system adjustments and (3) volatility of the solvent. Ifthe cover is kept closed durinq aqitation, then emissions usually are insignificant. However, agitation emissions can increase dramatically with the cover open. This isespecially true with ultrasonic agitation of solvents heated to their optimum cavitation temperature. The bath should also be agitated for
no longer than necessary to complete the cleaning. Poor adjustment of the agitation system may also increase emissions. Inparticular, the airflow into airagitated 3 cleaners should be about 0.01 to 0.03 m per minute per square meter ofopening. EPA tests on cold cleaners indicate that the volatility of the solvent greatly affects emissions due to agitation. Emissions of low volati1ity solvents increase significantly with agitation; however, contrary towhat one might expect, agitation
causes only a small increase inemissions ofhigh volatility solvents. This is believed to be due tothe already high unagitated evaporation rateof high volatility solvents (see Appendix A). Littledifference was found between the eftects ot pump agitation and air agitation. Carry-3ut Emissions

## - Carry-out emissions depend on the existence and use of a drainage faci1ity. Drainage faci1 ities are racks or she1ves used for draining excess solvent off cleaned parts. The drainage facility isstandard equipment for some cold cleaners and iseasily and inexpensively retrofittedfor most other cold cleaners. Drainage facilities are described further inSection 3.1.2. Although installation of a drainage facility isusually no problem, itwill sometimes require a special effortto fully use the facility. As recommended from ASTM 0-26, cleaned parts should drain at least 15 seconds

# .' For rapid pace work, such as automotive repair, this time may be perceived as toodelaying; nonetheless, the 15 second drain time should be adhered to. Waste Solvent Evaporation

## - Waste solvent evaporation isthe greatest
source of emissions from cold cleaning. The amount of waste solvent disposed of depends on the size of the cold cleaner and on the frequency of disposal. When the cleaning job removes large quantities of oil and other contaminants,
or requires a high degree of cleanliness, the solvent will be disposed of
more frequently. Conversely, ifthe cold cleaner isequipped with an effective fi lter, as many cold cleaners present are, then solidirnpurities are removed and disposal is required less frequently. Waste solvent evaporation depends not only upon the amount but also upon the method of disposal. Acceptable methods of handling waste solvent include proper incineration, disti 1 1 ati on, and chemical landfi1 ling

### , where the waste solvent is buried inenclosed containers and encapsulated by impermeable soi1. Disposal routes that result intotal emission to the environment include flushin5 into sewers, spreading waste solvent for dust control, such as on dirt roads, and landfillingwhere the solvent can evaporate or leach into the soil. Waste solvent evaporation isdiscussed further inSection 3.1.4. Spray Evaporation 

### - Evaporation from solvent spraying wi11 increase with the pressure of the spray, the fineness of the spray, and tne tenaency iu >p;a>;r and overspray out of the tank. Evaporation is also greater when the spray is used constantly and when volatilesolvents are used. Preferrably, the spraying pressure should be less than 10 psig, and the spray should be a solid, fluid stream.* The solvent loss from overspraying and splashing can usually be elirninated by sensible design and careful operation. Solvent Type- The type of solvent isa factor that greatly affects the emission rate from the cold rleanpr. The volatility of the solvent at the o~eratina temerature isthe sinale :,lost inoortant variable.More toxic organics are rarely used indegreasers, butwhen they are they tend to be much better controlledto protectworkers and to comply with OSHA regulations. These include carbon tetrachloride, benzene and methyl ethyl ketone. The priceof the solvent influences the care that istaken to conserve it. Thus, more expensive solvents are emitted less. Inaddition, the higher the price of the solvent, the more likely that the wastes will be recovered, and the more economical control wi11 become.
2.2.2 Open TODVa~or Deqreasers Vapor degreasers clean through the condensation of hot solvent vapor on colder metal parts. Open top vapor degreasers are batch 1 oaded, i,e., they clean only one work load at a time. Open top vapor degreasers are estimated to result inthe second largest emission of the three categories of degreasers. Itisestimated that open top vapor degreasers emit 200 thousand metric tons oforganics peryear, this being about 30 percent of the national degreasing emissions (see Appendix B.3). 2.2.2.1 Design and Operation 

## - The Cleaning Process 

## - Inthe vapor degreaser, solvent vapors condense on the parts to be cleaned until the temperature ofthe parts approaches the boilin( point 

### of the solvent. The condensing solvent both dissolves oils and provides a washing action to clean the parts. The selected solvents boil atmuch lower temperatures than do the contaminants; thus, the solvent/soil mixture inthe degreaser boils to produce an essentially pure solvent vapor. The simplest cleaning cycle involves lowering the parts into the vapor zone so that the condensation action can begin. When condensation\ceases, the parts are slowly withdrawn from the degreaser. Residual liquidsolvent on theparts rapidly evaporates as the parts are removed from the vapor zone. The cleaning action isoften increased by spraying the parts with solvent (below the vapor level) or by immersing them into the liquidsolvent bath. Basic Design

## - A typical vapor degreaser, shown inFigure 2-3, isa tank designed to produce and contain solvent vapor. At least one section of the tank is equipped with a heating system that uses steam, electricity, or fuel combustion to boil the solvent. As the solvent boils, the dense solvent vapors displace the airwithin the equipment. The upper level of these pure vapors iscontrolled by condenser coils located on the sidewalls of the degreaser. These coils, which are supplied with a coolant such as water, are generally located around the entire inner surface of the degreaser, although for some smaller equipment they are limited to a spiral coil at one end of the degreaser. Most vapor degreasers are also equipped with a water jacket which provides additional cool ing and prevents convection of solvent vapors up hot degreaser walls. The cooling coils must be placed at some distance below the top edge of the degreaser to protect the solvent vapor zone from disturbance caused by air movement around the equipment. This distance from the top of the vapor zone

CL- LL, .+a#L tup 

### ~f the degreaser tat-~kib called the freeboard and isgeneraliy established by the location of the condenser coils. The freeboard iscustomarily 50 to 60 percent of the width of the degreaser for solvents with higher boiling points, such as perch1oroethylene, trichloroethylene, and 

### l ,l,l -trichloroethane. For solvents with lower boiling points, such as trichlorotrifluoroethane and rnethylene chloride, degreasers have normally been designed with a freeboard equal to at least 75 percent of the degreaser width. Higher freeboards than those recomnended will further reduce solvent emissions; however, there comes a point where difficulty associated with moving parts into and out

. +Figure 2-3 OPEN TOP DEGREASER
Safety Thermostat

# \

Condensing Coils

Water Jacket ondensate Trough

ater Separator

Indicator Cleanout Door

Solvent Level Sight

## c lass/ 

# \ Heating Elements Work RestAnd ProtectiveGrateof a degreaser with a high freeboard outweighs the benefit of increased emission control. Nearly all vapor degreasers are equipped with a water separator such as that depicted inFigure 2-4. The condensed solvent and moisture are collected ina trough below the condenser coils and directed to the water separator. The water separator isa simple container which allows the water (being immiscible and less dense than solvents) toseparate from the solvent and decant from the system while the solvent flows from the bottom of the chamber back into the vapor degreaser. Variations inDesign

## - Figure 2-5, 2-6 and 2-7 show the most popular open top vapor degreasers inuse. These units range insize from table top models with open top dimensions of 1 foot by 2 feet up to units which are 110 feet long and 6 feet wide. A typical open top vapor degreaser isabout 3 feet wide by 6 feet long. Historically, degreasers of the typical size and smaller have been supplied with a single piece, unhinged, metal cover. The inconvenience of using this
cover has resulted ingeneral disuse or, at best, use only during prolonged periods when the degreaser would not be operated, for example on weekends. More recently, small open top degreasers have been equipped with manuallyoperated roll -type plastic covers, canvas curtains, or hinged and counter-balanced metal
covers. Larger units have been equipped with segmented metal covers. Finally, most of the larger open top vapor degreasers (200 &quare feet and larger) and
some of the smaller degreasers have had manually controlled powered covers. Lip exhausts such as those shown inFigure 2-8 are not uncommon although inuse on less than half of the existing open top vapor degreasers. These exhaust systems are designed to capture solvent vapors escaping from the degreasers and carry them away from the operating personnel. To the extent

### Figure 2-4



# BASIC PRINCIPLE 

# FOR WATER SEPARATOR 

# FOR VAPOR DEGREASER

WATER 

# =-- OUT WET 

### SOLVENT 

# 1- FROM CONDENSER 

### (SOLVENT)

JENT 

### OUT-- Figure 2-5 OPEN TOP DEG~~WITH OFFSETCONDENSER COILS



### water

### /\ Jacket- - Figure 

### 2-6 TWO COMPARTMENT DEGREASER WITH OFFSET BOILINGCHAMBER



# \ Solvent Overflow arm Solvent Dam ImmersionChamberFiqure 2-7 TWOCOMPARTMENTDEGREASER

ImmersionChamberFigure 

### 2-8 DEGREASERWITH LIPEXHAUST

haust c

### t

### that they disturb the vapor zone, they increase solvent losses.) For properly designed exhaust systems, the covers blose below the 1

ip exhaust inlet level. Applications 

## - Open top vapor degreasers are usually 1 ess capital intensive than conveyorized systems, but

### more capital intensive than cold cleaning equipment. They are generally located near the work which isto be 

### cleaned at convenient sites in the plant, whereas conveyorized vapor d 

### legreasers tend to be located at central cleaning stations requiring transport of parts for cleaning. Open top degreasers operate manually and are generally used for only a small portion of the workday or shift. Open top vapor degreasers are found primarily i~ 

### metal working plants,
as described previously. Furthermore, the larger the plant the more likely itwill use vapor degreasers instead of cold cleaners. Vapor degreasers are generally not used forordinary maintenance cleaning of metal parts, because cold cleaners can usually do this cleaning ata lower cost. An 

### exception may be maintenance cleaning of electrical parts by means of vapor degreasers because
a high degree of cleanliness is needed and there is ntricacy of design. 2.2.2.2 

### Emissions 

# - Unlike cold cleaners, open top vapor degreasers lose a relatively small proportion of their solvent in 

### the waste material an as 1 iquid carry-out. Rather, most of the emissions are those vapors that diffuse out of the degreaser. As with cold cleaning, open top vapor degreasing emissions depend heavily on the operator. The major types of emissions from open top vapor degreasers
are depicted in

### Figure 2-9. 

### An average open top vapor degreaser emits about 2.5 

### kilograms per hour per 

### m2 

### of opening (0.5 

### pounds per hour f t

### 2)

# . This 

### estimate isderived fromnational consumption data on vapor degreasing solvents and from seven EPA emission tests summarized inAppendix A. Assuming an average open top vapor degreaser would have an open top area of about 1.67 2 m 2 (18 ft 

### ), a typical emission ratewould be 4.2 kilograms per hour or 9,500 kilograms per year (9 pounds per hour or 10 tons per year). Diffusion Losses 

## - Diffusion isthe escape ofsolvent vapors from the vapor zone out of the degreaser. Solvent vapors mix with air at the top of the vapor zone. This mixing increases with drafts and with disturbances from cleaned parts being moved tnto and out of the vapor zone. The solvent vapors thus diffuse into the room air and into the atmosphere. These solvent losses include the convection ofwarm solvent-laden air upwards out ofthe degreaser. Diffusion losses from the open top vapor deg-reaser can be minimized by
mefoll owing actions:
a. Closing the cover, b. Minimizing drafts,
c. Providing sufficient cooling by the condensing coi1 s

## , d. Spraying only below the vapor level,
e. Avoiding excessively massive work loads, f. Maintaining an effective water separator, g. Promptly repairing leaks. The cover must be closed whenever the degreaser is not inuse. This includes shutdown hours and times between loads. Cover design isalso important. Improved designs for the cover can make iteasier to use thereby facilitating
more frequent closure. Covers should also be designed to be closed while a part isbeing cleaned inthe degreaser. Drafts can be minimized by avoiding the use ofventilation fans near thedegreaser opening and by placing baffles on the windward side of the degreaser. A baffle issimply a vertical sheet of material placed along the top ofthe degreaser to shield the degreaser from drafts. Sufficient cooling by the condensing coils should be attained by following design specifications for the degreaser. Cooling rate isa function of solvent type, heat input rate, coolant temperature and coolant flow. If the vapor level does not rise above the midpoint of the cooling coils, then the cooling 4 rate is probably adequate. The solvent must not be sprayed above the vapor level because such spraying will cause solvent vapors to mix with the airand be emitted. When this occurs, the operator should wait for the vapor level to return to normal and then should cautiously operate the spray wand only below the vapor level. A massive work loadwill displace a large quantity of solvent vapor. The work load should not be so massive that the vapor level drops more than about 10 

### cm (4 inches)5 as the work load is removed from the vapor zone. Otherwise, excessive quantities of solvent vapors will mix with the airas the vapor level falls and rises. The water separator should be kept properly functioning so that water does not return tothe surface ofthe boiling solvent sump. Water can combine with the solvent to form an azeotrope, a constant boiling mixture ofsolvent and water that has a lower vapor density and higher volatility than does pure solvent 

### 6 vapor. Lastly, it isimportant for any leaks to be repaired properly and promptly. Special attention should be paid to leaks ofhot solvent because hot solvent evaporates quickly. These leaks may be greater than they appear or go completely unnoticed. Carry-Out Emissions 

## - Carry-out emissions are the liquidand vaporous solvent entrained on the clean parts as they are taken out ofthe degreaser. Crevices 2-28and cupped portions of the cleaned parts may contain trapped liquids or vapors even after the parts appear to be dried. Also, as the hot cleaned part iswithdrawn from the vapor zone, itdrags up solvent vapors and heats solvent-laden aircausing ittoconvect upwards out ofthe degreaser. There are seven factors which directly effect the rate of carry-out emissions: a. Porosity or absorbency ofwork loads, b. Size ofwork loads inrelationto the degreaser's vapor area,
c. Racking parts for drainage, d. Hoist or conveyor speed,
e. Cleaning time inthe vapor zone, f. Solvent trapped incleaned parts, g. Drying time. Porous orabsorbent materials such as cloth, leather, wood or rope 

### will absorb and trap condensed solvent. Such materials should never enter a vapor zone.The work load preferably should not occupy more than one-half ofthe degreaser's working area.7 Otherwise, vapors will be pushed out of the vapor zone by means of a piston effect. Proper racking of parts is necessary tominimize entrainment (cupping) of solvent. For example, parts should be positionedvertically with cups or crevices facing downw'ard. A maximum hoist speed of 3.3 meters per minute (11 feet per minute) has been generally accepted as reasonable by the degreasing industry. Rushing work loads into and out of the degreaser will force solvent vapors out into the air and leave liquidsolvent on the cleaned parts which can subsequently evaporate intothe air.Cleaning time isthe period the work load remains inthe vapor zone. If this isnot long enough to allow the work load to reach the temperature of the condensing vapor, the parts 

### will not dry properly when removed from the vapor zone. The work load should remain inthe.vapor zone until the vapors
no 1 onger condense on the parts. Usually30 seconds issufficient; 10 howe;er, massive work loads may require 1 onger periods. Before the cleaned parts emerge from the vapor zone, they should be tipped and/or rotated to pour out any collected liquidsolvent. The work load should be removed from the vapor zone slowly (at a vertical speed not to exceed 11 11 feet per minute). Drying time is critical. Itshould be long enough toallow the solvent tovaporize from the clean part but not significantly longer. When a hot dried part rests just above the vapor level

## , itcauses solvent-1aden air to 12 heat up and rise. Typically a work load can dry in15 seconds. Waste Solvent Evaporation

## - Solvent emissions may also result from disposing of waste solvent sludge inways where the solvent can evaporate intothe atmosphere. The volume of waste solvent insludge from vapor degreasers ismuch less than that from cold cleaners for equivalent work loads for two
reasons. First, the solvent inthe vapor degreaser sump can be allowed to become much more contaminated than the solvent used ina cold cleaner because the contaminants, with high boiling points, stay inthe sump ratherthan vaporize intothe vapor zone. Second, vapor degreasing solvents are halogenated and as such are generally more expensive; thus, they are more often distilledand recycled than cold cleaning solvents. A1though the waste solvent evaporation from vapor degreaser sludge is usually less than the diffusion and carry-out losses, itstill contributes about 5 to 20 percent of the degreaser's total solvent emissions. l3 When

### the solvent in the sump accumulates too much oil and other contaminants problems can occur. The most serious iscoating of the heater surfaces, leading to overheating and subsequent chemical degradation of the solvent. Thus, the solvent sludge must be cleaned out of the degreaser periodically and replaced with fresh solvent. There are four practices that can reduce and nearly eliminate the atmospheric evaporation from waste solvent disposal;

a. Boi1 -down, b. 

### Use of in-house distillation,

c. Use of contract reclamation services, d. 

### Transfer to acceptable disposal facilities. Boil-down is a technique of distilling pure solvent from the contaminated mixture in the deg~easer. As the contaminated solvent is boiled in the sump pure solvent vaporizes and condenses on the cooling coils where itis routed to

### and stored in a holding tank. Boi1-down can usually reduce the solvent content in the contaminated material 

### to less than 40 to 45 percent by volume. When production schedules permit 

### further boi1

### -down time,considerably 1 ower 14 levels can be achieved. In-house aistillation can be an 

### erricient and often profitabie methoa of treating waste solvent. Distilled solvents can nomally be reused although additional stabi1

### izers must be added sometimes. Disti11

### ation systems vary from centralized centers to relatively mall external stills for one ormore vapor degreasers. Through distillation, the solvent content of the waste solvent sludge can be reduced 

### toabout 20 

### percent by weight (12-15 percent by volume) in most operations.l5 Additional steam stripping can reduce this further. Presently most vapor degreaser operators do 

### not use in-house disti11ationbut 

### transfer theirwaste solvent to another system or company. Even if the waste solvent is distilled, there are oils and contaminants, called still bottoms, that require disposal. The preferable disposal methods, for minimizing solvent evaporation into the atmosphere, are disti1 lation plants and special incineration plants. Disposal in landfi11s afterevaporation is also used but 

### is less desirable. Waste solvent disposal is discussed in greater detail in Section 3.1.4. Exhaust Emissions 

## - Exhaust systems are often used on larger than average open top vapor degreasers. These systems are called lipor lateral exhausts and they draw in 

### solvent-laden air around the t9p 

### perimeter of the degreaser. Although a collector of emissions, an exhaust system can actually increase evaporation from the bath, particularly Sf the exhaust rate is excessive. Some exhaust systenls include carbon adsorbers to collect the exhaust solvent for reuse; thus, exhaust emissions can be nearly eliminated if the adsorption system functions properly. In some poorly designed exhaust systems, the ventilation rate can be too high. If the air/vapor interface isdisrupted by high ventilation rates, more solvent vapors will mix with air and be carried out by the exhaust system. A 

### rule of thumb 

### used by manufacturers of degreaser equipment and control systems isto set the exhaust rate at 50 

### cubic feet per minute per square foot of 16 degreaser opening (15

### m3 

### per minute

# - m2). 

### The primary objective of exhausting is to assure that the threshold limit value (TLV) as adopted by 

### OSHA 

### is not exceeded. The exhaust level recomended above is

### satisfactory for 

### OSHA requirements on ventilation except when the qualof operation of

### the degreaser 

### is rated as "average" or "poor." Poor operation noted by OSHA 

### to include excess carry-out of the vapor and liquid solvent, contamination of the solvent, or improper heat balance. In these cases, andfor solvents with a 

### TLV 

## - < 100 ~pm, the minimum OSHA ventilation requirement is 75 or 100 cubic feet per minute per square foot of degreaser opening, Consequently, atmospheric emissions from poorly operated degreasers are fncreased even further.
2.2.3 Conveyorized Degreasing There are several types of conveyorized degreasers, operating both with cold and vaporized solvents. An average conveyorized degreaser emits about 25 metric tons peryear of solvent; however, because of their 1imi ted numbers they contribute only about 15 percent ofthe total solvent degreasing emissions. Because oftheir 1 arge work capacity conveyorized degreasers actual1 y emit less solvent per part cleaned than either open top vapor degreasers or cold cleaners. Controls discussed inChapter 3 can reduce this amount still further.
2.2.3.1 Design and Operation

## - Inconveyorized equipment, most, and sometimes all, of the manual parts handling associatedwith open top vapor degreasing has been eliminated. Conveyorized degreasers are nearly a1 ways hooded or covered. The enclosure of a degreaser diminishes solvent losses from the system as the result ofair movement within the plant. Conveyorized degreasers are used by a broad spectrum ofmetalworking industries but are most often found inplants where there isenough production toprovide a constant stream of products to be degreased. There are seven main types ofconveyorized degreasers: monorai1

## ,cross-rod

## , vibra, ferris wheel, belt, strip, and circuit board cleaners. While most ofthe
seven types of conveyorized degreasers may be used with cold or vaporized solvent, the first four are almost always vapor degreasers.The cross-rod degreaser (Figure 2-l0)obtains itsname from the rods between the two power driven chains from which parts are supported as they
are conveyed through the equipment. The parts are contained inpendant baskets or, where tumbling of the parts isdesired, perforated cylinders. These cylinders are rotated by a rack and pinion design within the solvent and/or the vapor zone. This type of equipment lends itselfparticularly well tohandling small parts which need to be immersed insolvent to obtain satisfactory cleaning or requires tumbling to provide solvent drainage from

L cavities inthe parts. A monorai1 vapor degreaser (~igure 2-11) isusually chosen when the parts to be cleaned are being transported between manufacturing operations using a monorail conveyor. This design lends itselfto automatic cleaning with solvent spray and vapor. The parts can be moved inone side and out the other, as illustrated, orthey can turn 180' while inthe vapor orspray portions ofthe equipment and exitthe equipment through a tunnel parallel to the entrance. Ina vibra degreaser (Figure 2-12) dirty parts are fed through a chute which directs them into a pan flooded with solvent. The pan isconnected to a spiral elevator. The pan and spiral ele~ator are yi'hrated, causing the parts tomove from the pan up the spiral to the exit chute. The parts condense solvent vapor as they are vibrated up the spiral and dry as soon as they leave the vapor zone. These degreasers are capable ofprocessing quantities of small parts. Since the vibratory action creates considerable noise, acoustical insulationof the equipment is needed or the system must be enclosed ina noise-control booth. Three other typkal units are the ferris wheel, be1t, and strip degreasers. The ferris wheel degreaser (Figure 2-13) isone of the least expensive andFigure 

### 2-10 CROSS-RODCONVEYORIZED DEGREASERFigure2-1 1 MONORAIL CONVEYORIZED DEGREASER

Conve Path

JacketFigure 2-12 VlBRA DEGREASER f


# 1 Workload Discharger Chute 

# I

# I Ascending 

# 1 '1 Vibrating Trough 

### - 

### 1 Workload 

# I Entry Chuter Distillate Return Steam Coils

### 4 CFigure 2-13 FERRISWHEEL DEGREASER

Work Baske
Gear to tumble 'baskets



### oil

### ihg Chamber

### sr,iallest conveyorized degreasers. It

### generaliy uses perforated baskets : 

### as does the cross-rod degreaser. The be1

### t degreaser is designed to enable

f~ 

### simple and rapid loading and unloading of parts (see Figure 2-14). strip degreaser resembles a belt degreaser, except that the strip itself is being cleaned. The strip degreaser is an integral step in

### the fabrication and coating of some sheet metal products. Circuit board cleaners are conveyorized degreasers which use one of the previously described designs specifically in the production of printed circuit boards. There are three types of circui

### t board cleaners: 

### developers, strip~ers, and defluxers. In the production of circuit boards, ultraviolet rays
are projected through a film of an electrical circuit pattern tc create an image on a copper sheet covered with resist. The developer degreaser dissolves off the unexposed resist. This copper covered board is then dipped in an acid bath to etch away the copper that is not covered by the hard, developed resist. Next, the stripper degreaser dissolves off the developed resist. Then a wave of solder passes over the bare copper circuit and bonds to it. Lastly, the defluxcr degreaser dissolves off the flux 

### left after the solder hardens. Because of the nature of the materials being cleaned, circuit board cleaners can use cold (room temperature) solvents, as well as vapor degreasing processes. 2.2.3.2 

### Emissions 

## - About 85 

### percent of the conveyorized degreasers are vapor types, leaving 15 percent as conveyorized non-boi 1 ing degreasers. Circui

### t board cleaners represent most of 

### the non-boii ing 

### ccnveyorized degreasers. An average emission rate from a conveyorized vapor degreaser is about 25 

### metric tons per year, while that 

### for non-boiling conveyorized degreasers is almost 50 Iflet

### ri

### c tons per year. However, most new designs for non-boi 1

### ing 

### conveyorizedFiaure 2-14 MESH BELTCONVEYORIZED DEGREASER

Conveyorpath

# /

### degreasers are far mcrs e--ficientthan the older designs.le 

### It is estimated that the vapor types presently ccntribute about 75 

### percent of 

### the conveyorized degreaser ercissions nat? cnally 

### and the non-Soi 1

### ing 

### types ccntribute the reniaining 25 percent. 3n the national scale, about 75,000 metric tons/year
are emitted from conveyorized vapor degreasers, and about 25,000 metric tons/ year are from conveyorized non-boiling degreasers (seeA~pendix 6.4). 

### The major types of etnissions from conveyorized desreasers are depicted in Figure 2-15. Bath Evaporation 

## - For an equivalent work load, the diffusion and convection of solvent vapors from the solvent bath are considerably less for conveyorized degreasers than for open top degreasers. This is because the conveyorized degreasers are normally enclosed except for a relatively small entrance and exit. Because conveyorized degreasers are generally automated, operatins practice is a minor factorwhile design and adjustment are major factors affecting emissions. Proper adjustment of the degreasing systern primarily affects bath evaporation and exhaust emissions, while operation and degreaser design affect carry-out and waste solvent evaporation. The main adjustment affecting the bath evaporation rate is the heating and cooling balance. Basically, the cooling supplied by the primary condensing coi1 s should be suff i cient to condense a11 

### the vaporized solvent. Also, the heating rate needs to be large enough 

### to prevent the vapor level from dropping as cold parts enter the vapor zone. With regard to equipment design, bath evaporation can be reduced by ginimizing the entrance and exit areas and by regulating the spray system.19 

### Naturally the smaller the area of opening, the lower the loss of solvent vapors. Partial covers can be placed over the openings which silhouette the parts to be cleaned yet give enough margin for safe passage. Sprays should be designed or adjusted so that they do 

### not cause turbulence at the air,/vapor interface. Spray pressure should the minimum necessary for proper perfor~ance

### One we71 designed system uses the high pressure spray in a contained and partia1ly subrilerged chamber. Poor operation can increase convective losses frmtne s~l.dellt 

### bath. For instance, if work baskets are overloaded the vauor zone may collapse increasing air vapor mixins and, 

### tkus, emissjons. This can be avoided by following the manufacturer's specificaticn for a1lowable work load in tons per hour, which is determined thrcugh an enerSLtbalance of 

### the syster;,, The heating cauacity of the sclj~ent boiler must be 

### greater than the heat loss due to solvent condensation cn the work 

### :oad. ti~aporat!ve losses from the bath 

### also increase when there is delay in solvent leak repair. Carry-Out Enlissions 

### - Carry out of vapor and liquid solvent is usually the major emission from conveycrized degreasers. It

### is difficult to reduce carry-out eriiczions, because the amoant of 

### work lead 

### is inherently large.

ds

### was discussed for opeK top vapor degreasing. Racking is especially critical 

### in conveyor1zed dcr

### reasers

### , because there is 1 1

### ttle an operator can do 

### to reduce c3r 

### :-oux -FYF s pr~clly

### 5esigned systei~.. The 

### dcgineaser design s?o~la 

### allo:. s~fficiert cn?ce .?+ fire 

### =orthe 

### cleaned ;avLz 

### t - 

### drj r,m~:etc;y 

### Tone desi~rlsinclcde 2 si-r~ud 

### ertercciing -F ciii the ex't to 

### forn;2 dsy7nc

### t~nr,e!. 4?&7n 

### the conveyor speed should not exceed 2 3 

### n:eters ner

### ~inute (1

### 1 feet per 

### minute) vertical rise.

### 20 Exhaust Emissions 

## - In 

### some cases the eniissions can be nigh because of
cn 

### excessive ventil~~ion rzte. As v~ith open top :,a,)ordegre2sers the ventilaticn rate should not be 

### much greater 

### tlan 15 n

### 3!min-rn2 

### (50 

### cfm/ft

### 2) 

### of airjsolvent interface.21

### Waste Solvent Evaporation 

## - Evaporation from waste solvent disposal is the sniallest emission from conveyorized degreasers. Most conveyorized 

### degreasers are designed to distill their own solvent. An 

### external still is attached tothe conveyorized degreaser so that used solvent can be constantly pumped out, distilled and returned. Thus, the wastes will usually consist only of still bottoms. Still, because of the high volume, waste solvent emissions fro^ 

### conveyorized degreasers are significant, typically equal1

### ing 10 to 20 percent of the total emissions from a conveyorized degreaser.22 

### As was discussed earlier, the method of

### disposal of the still bottoms
or undistilled waste solvent will determine the amount of solvent that evaporates into the atmosphere.REFERENCES 1. T. J. Kearney, "Reply toJ. C. Dollinger letter ofSeptember 3, 1976," letter of Cctober 1976. 2. American Society forTesting and Materials (ASTM) Comrnittee D-26, "Recornmended Practice for New Source Performance Standards to Control Solvent Metal Cleaning Emissions." 3. Surprenant, K. S. and Richards, D. W. of Dow Chemical Company, "Study to Support New Source Performance Standards for Solvent Metal Cleaning Operations

### ,"Uo1ur;e 2, Appendix C-72, prepared for Emission Stan~ards and Engineering Division (ESED)

### , under Contract # 68-02-1329, Task Ordei* #9, ;:ne 30, 1976. 4. Information provided by K. S. Surprenant by telephone toJ. C. iB~?lingei. EPA, Flarch 3, 1977. 5. DON Chemlcai Company, 

### "Modern Vapor Degrecsing

### ,"operating 1;12vL!a-, 

### tcrr G 100-5185-72. ASTM, D-26., "Handbook of Vapor Degreasing," ASTM Special Tcc5r'c~' Fu~ii catlor. 31C 

### A, Philadelphia, April, 1976. Detrex Chemical Ind., 

### Inc., Detroit, "Todays' Concepts ofSolvent Degreasing ,'I operating manual

# .

C-8. r rr .:,I,, --LC, d~. >:L. Ibi d. Surprenant

### ,OD. Ci t. hericznSociety for Testing and Materials Op. Lit. Surprenant, Op. Cit. "Trip Report 

### - Meeting of ASTM Cornittee D-26 on Halogenated Organic Solvents, Gatlinburn, Tenn.", EPA mernorandur~from 

### J. L. Shumaker to D. R. Patrick, June 30, 7977.

### 3.0 EMISSION CONTROL TECHNOLOGY


### This chapter describes individual emission control devices applicab1e to solvent degreasers, and then shows how these can be combined to form complete control systems. Estimates are also provided of the control efficiency (i

# .e.

### ,percent emission reduction) of individual control devices along with a range of control efficiency for the complete control systems. It is important to keep in mind 

### that optimum control systems will not be equivalent for each degreaser design or even each application of a particular design. All of the major devices discribed in this chapter will yield optimum control in certain instances; however, because degreaser designs and applications vary, one or more of these devices could be completely unsuitable for a given degreaser. Processes must be evaluated individually to determine the optimum control system. The individuality of systems is such that control efficiencies estimated in this chapter are not directly comparable and should not be used to rate one device against another. They are given only as general levels of control which one could expect from appropriately applied technology.
3.1 EMISSION CONTROL 

### DEVICES 3.1.1 Solvent Bath Emissions There are five main devices that can reduce emissions from the solvent bath:1. Improved cover, 2. 

### High freeboard,

### Information provided by Detrex Chemical Industries, Inc., Letter from 

## L. Schlossberg toJ. L. 

### Shumaker, June 28, 1977. Surprenant

### , Op. Ci 

### t. ASTM, D-26, Op. Cit. Bollinger, J. C., 

### "Maximum Impact of

### NSPS on 1985 National Degreasing Emissions," December, 1975. Information provided by Bob Porter of Holl

### is Engineering Company, Nashua, 

### N. H. by 

### telephone toJ. C. 

### Bollinger, EPA, March 28, 1977. American Society, Op. Cit. 

### ASTM, 

### D-26, Op. Cit. 

### Information, 

### K. S. 

### Surprenant, Op. 

### Cit. Ibid.

### halogenated solvent. The water cover cannot be used in manv applications. however because the water may corrode the metal surface 

### of the cleaned Parts or may
cause chemica1 degradation of halogenated solvent. Covers 

### on cold cleaners which use flamnable solvents generally have a fusible link in the support arm. This link is designed 

### toopen if the solvent catches fire, thus a1lowing the cover 

### to close and smother the flames. Unfortunately, some designs require disassembly of the mechanism for normal closing of the cover. These designs cause unnecessary emissions and should be avoided. Not all cold cleaner designs include a soaking feature. Some of the smaller maintenance units are designed with an enclosed sump from which solvent is pumped to a sink for cleaning parts. The sink drains back 

### tothe sump, minimizing the time during which solvent can evaporate. A1though the solvent is contained, these units generally include 

### a cover on the sink as a fire prevention feature. It

### is doubtful that closing this cover can effect a significant additional emission reduction. Even though conveyorized degreasers are basically covered by design, additional cover related control can be achieved by minimizing the openings and 

### covering the openings during shutdown hours. ASTM has recommended 

### that there 

### notbe more than 6 

### inches (15 cm) clearance between the parts on the conveyor and the sides of the opening.' This clearance can be specifically defined as the average distance between theedge of the openings and the part, and termed the "average silhouette clearance." Average silhouette clearance
can be appreciably less than 6 

### inches (15 cm) for parts that are 

### not unusually large. EPA 

### recommends an average silhouette clearance of 4 

### inches (10 cm) or 10 percent of the opening's width.

### 3. 

### Refrigerated chi1

### lers

## , 4. 

### Carbon adsorption, 5. 

### Safety switches. 3.1.1.1 Improved Cover

# - The cover is the single most important control device for open top vapor degreasers. Although covers are normally provided on open top degreasers
as standard equipment, they can usually be made more easy touse, and hence
more frequently used, if they are mechanically assisted, powered or automated. For vapor degreasers the cover should open and close in a horizontal motion, so that the air/vapor interface disturbance isminimized. These types of covers include roll type plastic covers, canvas curtains and guillotine covers. Itis usually advantageous on larger open top vapor degreasers to power the cover. This may be done pneumatically or electrically, usually by manual control with an automatic cut off. The most advanced covering systems are automated in coordination with the hoist or conveyor. The cover
can be designed so itwi1 l 

### close while the parts are being cleaned and dried. Thus, the cover would only be opened for a short period of time when the parts
are actually entering or exiting the degreaser. This isfurther described in Section 3.1.3.1. 

### On cold cleaners, covers are frequently mechanically assisted by means of spring loading or counterweighing. A 

### pedal operated or powered system
can make the cover even more convenient to use. 

### For specific applications, two additional types of covers can be used; these are the submerged cover and the water cover. The submerged cover (comercia1ly termed "turbulence baffle") is a horizontal sheet of material submerged about two inches below the surface of the 1

### iquid solvent that is vigorously pump 

### agitated. The water cover is simply 

### a layer of water about two to four inches thick over a

### 4 

### The effectiveness of a down-time cover on conveyorized degreasers should 

### be significant, although itis difficult to quantify. One test found that about 18 percent of the total emissions was due to evaporation during down-time. Itisexpected that most of this loss could be eliminated by a down-time cover. 3.1.1.2 High Freeboard 

## - The freeboard primarily serves to reduce drafts near the air/solvent interface. An acceptable freeboard height isusually determined by the freeboard ratio, the freeboard height divided by the width (not length) of the degreaser's air/solvent area. Normally the freeboard ratio is0.5-0.6 for the open top vapor degreasers, except for very volatile solvents, such as methylene chloride or fluorocarbon solvents, where a minimum freeboard ratio of 0.75 is used. In fact, the American Society forTesting and Materials has recomnended that a minimum freeboard ratio of 0.75 be an alternative control for open top degreasers using a11 sol vents.5 For an open top vapor degreaser that is idling (has no work load), the emission reduction from raising a freeboard ratio from 0.5 to 0.75 may typically be 25-30 percent. In fact, an increase in

### ratio from 0.5 

### to 1.0 may yield about a 50 

### percent reduction in

### emissions. These are EPA 

### estimates based on a test by 

### Dow Chemical .6 The total emission reduction due to the freeboard will generally be less for open top vapor degreasers under normal work load, because the freeboard isless effective in reducing the carry-out emissions than solvent bath emissions. The freeboard height seems tohave littleeffect on cold cleaners using solvents with low volatilities, such as mineral spirits, but

### provides significant benefits for cold cleaners using higher volatility solvents, such as the ha1ogenated ones. OSHA 

### requires at least a 6 

### inch (15 cm) freeboard for cold cleaners.7Covers can be easily made for the entrance and exit tothe conveyorized degreaser so that they can be closed immediately after shutting down the degreaser. These covers can be made of any material that impedes drafts into the degreaser and should cover at least 80 to 90 percent of the opening. Closing these covers ismost important during the hours imnediately after shutdown, because the hot solvent iscooling and evaporation continues. Even after the solvent sump has cooled, the down-time cover may be significantly effective for more volatile vapor degreasing solvents. A cover on an open top vapor degreaser has been shown to reduce total emissions by approximately 20-40 percent depending upon the frequency of 

### 2 its use. It is impossible to estimate a single control efficiency for the cold cleaning cover, because the emission reduction varies too greatly with respect tothe solvent volati1ity, draftvelocity, freeboard ratio, operating temperature and agitation. However, itcan be estimated that bath evaporation ratevaries directlywith the solvent volati1ity atoperating temperature. A1though a closed cover can nearly eliminate the bath evaporation, the cover can do nothing to reduce the carry-out orwaste solvent emissions. Thus, a normally closed
cover becomes effective only when bath evaporation accounts for an appreciable portion ofthe total emission. More specifically, when solvent volatility is moderate tohigh (approximately > 0.3 psi at 100°F (2.1 kPa at 38°~~), it is significantly effective to close the cover atall times when parts are not being cleaned manually inthe cold cleaner. It isespecially important that the cover be closedwhen the bath isagitated or heated. Ifnone of these conditions apply, then the cover should at least be closed during long periods of cold cleaner disuse, such as during shutdown hours and idle periods > 112 hour.3,

### Figure 3-1 REFRIGERATED FREEBOARDCHILLER

Primary 

### Coils



### ter Jacket3.1.1.3 Refrigerated Chi1 lers 

## - The vapors created within a vapor degreaser are prevented from overflowing the equipment by means of condenser coils and a freeboard water jacket. Refrigerated freeboard chillers add to this basic system a second set of condenser coils located slightly above the primary condenser coils of the degreaser (see Figure 3-1)

# . Functionally

### ,the primary condenser coi1 s control the upper limitof the vapor zone. The refrigeratedfreeboard chilling coils on the other hand impede the diffusion of solvent vapors from the vapor zone into thework atmosphere by chilling the air immediately above the vapor zone and creating a cold airblanket. The cold airblanket results ina sharper temperature gradient. This reduces the mixing of airand solvent vapors by narrowing the air/vapor mixing zone. Finally, the chillingproduces a stable inversion 1 a,yer which decreases the upward convection of solvent lad~n air. Fkeboard chillers operat@ with refrigerant temperatures inthe range of 

## * -30 to 5OC. Although there isa patent on unitswhich operate below O°C, most major manufacturers of vapor degreasing equipment offer both above and below freezing freeboard chi1lers. The recomnended operating temperature for below freezina chi11 ers is -30 to-25°C. Because of these low temperatures, designs must include a timed defrost cycle to remove the icefrom the coils and restore the heat exchange efficiency. Although the liquidwater formed during the defrost cycle is directed tothe water separator, some water contamination of the vapor degreasing solvents isnot uncomnon. Water contarnination

### of vapor degreasing solvents can have an adverse effect on water soluble stabilizer systems, a1though major stabi1izer depletions from this are rare. Water, however, contributes to equipment corrosion and can diminish the working life of the equipment significantly. 'US Patent 3,375,177 issued toAutoSonics Inc.

## , March 

### 26, 1968, 

### 3-

### 6

### energy consumption may be too greatwhen used on larger open top vapor degreasers. The refrigerated condenser coil offers portability of the open top vapor degreaser by excluding the need for plumbing to cool condenser coils with tapwater. Tests have been performed for EPA 

### on three below freezing refrigerated freeboard chillers. Emission reductions of 16, 43, and 62 

### percent were measured.1° The chiller which achieved only a 16 percent reduction in

### emissions
was installed around 1968 and the design was not representative of present designs. This degreaser also had a low "uncontrolled" emission rate of 0.14 lb/hr ft2, partly due to the use of a cover. The units which achieved 43 

### and 62 percent reduction in emissions are thought to be more representative of present designs

## . EPA 

### has not performed tests on above freezing freeboard chillers or refrigerated condensing coi7

### s. However, tests are planned whi

### ch should he1p 

### quantify the effectiveness of these controls. Chillers are not normally used on cold cleaners. While it

### iscertain that a chillerwould reduce emissions, especially from units using the more volatile solvents, this control is generally too expensive for 

### a normal cold cleaner. A 

### chiller on a cold cleaner should have about the same effectiveness
as a normally closed cover, but 

### itwould cost considerably more. In fact, a chiller could well cost more than the cold cleaner itself. Still, some manufacturing cold cleaners with unusually high emission rates could find
a chi11 erappropriate. 3.1.1.4 Carbon Adsorption 

## - Carbon adsorption systems arewidely used to capture solvent emissions from metal cleaning operations. 

### On appropriate degreasing processes, these devices can achieve high levels of emission control. Equipment design and operation (as illustrated in Figures 3-2, 3-3, and 3-4) 

### are fairlywell 3-9

### Refrigerated freeboard chi1 lers are normally sized by specifying the cooling capacity per length of perimeter. The above freezing refrigerated freeboard chiller is normally designed to achieve a minimum of 500 Btu/hr



## - (865 W/m.OK) 

### cooling capacity per foot of air/vapor interface perimeter, while the below freezing refrigerated freeboard chiller is normally designed to the following specifications: Minimum Cooling Capacity Degreaser Width 

### (Btu/hr ftof perimeter)

< 

### 3.5 ft. (1.1 

### m)

> 

### 3.5 ft. (1.1 

### m) 300

> 

### 6 

### ft. (1.8 

### m) 400

> 

### 8 

### ft. (2.4 

### m) 500

> 

### 10 ft. 

### (3.0 

### m) 600 rr 

### Normally each pass of finned cooling coil is expected toremove 100 Btu/hr ft 

### (1 73 

## ~/n The previous speci f ications are typical design 

### standards OK). 

### used by manufacturers of chillers. €PA

### test data indicate that these design standards wi11 provide satisfactory emission control, but 

### atpresent data are insufficient to confirm that they yield optimum emission control. In addition tothese, a third type of refrigerated chiller, known as the refrigerated condenser coil, 

### is available. Refrigerated condenser coils do not provide an extra 

### setof chi11ing coi1s as the freeboard chi1 lers do, but replace the primary condenser coi1s. If the coolant in the condenser coi1s isrefrigerated enough, it

### wi

### 11 create a layer of cold airabove the air/vapor interface. DuPont and Rucker Ultrasonics have recomnended that the cooling rate of refrigerated condenser coils be equal to 100-120 percent of the heat input rate in

### the boiling 

### sump, in order to give optimum emission i 

### control

# .' The refrigerated condenser coils are normally used only on small open top vapor degreasers (especiallywith fluorocarbon solvent), because 3-8Figure 

### 3-3 ADSORPTION CYCLE

t-Laden nlet

Activated Carbon Bed



# - CleanAir Exhaust

### standardized and described in

### detai1 in general 1 iterature,in the Dow 12 ~e~ort" and in

### the report by JACA Corporation. A 

### well designed and maintained carbon adsorption system will normally capture in excess of 95 

### percent of the organic input to the bed. Carbon adsorption systems for solventmetal cleaning normally wi11 achieve about 40-65 

### percent reduction of the total solvent emission.l3 One reason for the difference between the theoreti'cal and actual is.that tk 

### ventilation apparatus of the control system cannot capture all of the solvent vapors and deliver them to the adsorption bed. As has been discussed earlier, major loss
areas are drag-out on parts, leaks, spills, and disposal of waste solvent, none of which are greatly affected by the ventilation system. Improved ventilation design can increase an adsorber

### 's overall emission control efficiency. Higher ventilation rate alone, however, wi11 not necessarily be advantageous, since increased turbulence could disrupt the airlvapor interface causing an increase in

### emissions, all of which would not be captured by the collection systems. The effectiveness of the ventilation system can also be improved through use of drying tunnels and other devices which decrease losses due to dragout. Poor operation has been found to decrease the control efficiency of carbon adsorption systems. Examples are dampers that do not open and close properly, use of carbon that does not meet specifications, poor timing of the desorption cycles, and excessive inlet flow rates. Desorption cycles must be frequent enough to prevent breakthrough of the carbon beds, but 

### not so frequent as to cause excessive energy waste. The degreaser's airlvapor interface may be disturbed as a result of excessive adsorber inlet flow. This
can increase losses due to low adsorber inlet collection efficiency. GoodFigure 3-4 DESORPTIONCYCLE

Condenser

vated on Bec

Recovered Solvent



### Steam Inlet Ui 

### operating practice and proper maintenance will eliminate all of the above problems. Carbon adsorption systems can effect the highest achievable level of emission control for many degreasing operations. Its positive aspects are we11known. There are, however, a few negative aspects that should be mentioned. F i

### rs

### t, where solvent mixtures are used, the col1

### ected solvent emissions will be richer in the more volatile components. Thus, the recovered solvent mixture is rarely identical to that used in the cleaning system. Second, there are solvent components that are water soluble. Examples
are acetone or ethyl alcohol used as co-solvents with 

### t~~chlorotrifluoroethane and stabilizers added to tllany solvents to inhibit decomposition. Theyatei

### soluble components wi11 be selectively extracted by the stearn during the desorption process. In 

### these cases, fresh solvent, stabilizers and/or co-solvents must be added to the recovered solvent before itis reused. Tests performed on carbon adsorption systems control1ing an open top vapor degreaser and a conveyorized non-boiling degreaser, measured 60 

### and 65 

### percent emission reduction respectively.14 These levels of control are typical of properly designed,adjusted and maintained adsorption systems on degreasing operations which are suitable for this type of control. Three other carbon adsorption systems were tested and found to have low control efficiencies. 

### Two of these systems achieved 21 percent and 25 

### percent emission reductions. A 

### third was found 

### toactually increase emissions by 8 

### percent. 15 

### These tests exernplify the need for proper application, design, operation, and maintenance of carbon adsorption systems. 3.1.1.5 Safety Switches 

## - Safety switches are devices used on vapor degreasers to prevent emissions during malfunctions and 

### abnormal operation. The five main types of safetyswitches are: 1. Vapor level control thermostat, 2. Condenser water flow switch and thermostat, 3. Sump thermostat, 4. Solvent level control, 5. Spray safety switch. The firstfour safety switches listedabove turn off the sump heat while the fifth turns offthe spray. The most important safety switch isthe vapor level control thermostat. This device isactivatedwhen solvent vapor zone rises above the designed operating level. This can occur ifthe coolant flow isinterrupted, for example. When the hot vapors are sensed, the sump heater isturned off thus minimizing vapor escape. This thermostat should be a manual reset type for manually operated degreasers. For conveyorized degreasers, the vapor level control thermostat should activate an alarm system. These controls should be checked frequently. The condenser water flow switch and thermostat turn off the sump heat when either the condenser water stops circulating or the condenser water becomes
warmer than specified. Ifthe condenser water flow switch and thermostat is properly adjusted, then it

### will serve as a back-up for the safety vapor thermostat and also assure efficient operation of the condenser coi1s. Insummer months, the cooling water for condensing coils often becomes too
warm. Inthis case, the thermostats ina condenser water flow switch can signal a need for improvement, such as increasing the water flow rate. This problem occurred during a test performed for

### EPA.16 As oils, greases and other contaminants build up inthe solvent, the boiling point of the mixture increases. Both the sump thermostat and solvent

### level control prevent the sump from becoming too hot, thus causing solvent decomposition. The sump thermostat cuts off the heat when the sump temperature rises signif

### icantly above the solvent's boi1 ing point. The solvent level control turns off the heat when the liquid level of the boiling sump drops down 

### tothe height of the sump heater coi1s. Without these controls, excessive heat could decompose the solvent, emitting such things as hydrochloric acid

# .The spray safety switch is not used as often as the other safety switches, but 

### itcan offer a 

### significant benefit. Specifically, if the vapor level drops below a specif

### ied level

### ,then the pump 

### for the spray application wi11 be cut off until the normal vapor level is resumed. Thus, the spray safety switch prevents spraying above the vapor level which causes excessive 17 emissions

# . The effectiveness of 

### the five safety switches cannot be quantified because their operati

### on results from poor degreaser maintenance and use. Nevertheless, considering the factthat vapor degreasers do 

### not always receive proper attention and maintenance, itisexpected that the safety switches wi11 provide a significant reduction in emissions for typical vapor degreasing operations. 3.1.2 Controls to Minimize Carry-out Carry-out emissions are the solvent emissions that resultwhen clean parts sti11 containing liquids or vapors are extracted from the vapor degreaser. As described in chapter 2, 

### good operating practices are the primary method of reducing carry-out emissions. Furthermore, there are devices that can help minimize the carry-out from cold cleaners and 

### conveyorized degreasers, but 

### not generally from open top vapor degreasers.The main control device for carry-out emissions from cold cleaners is a simple drainage facility. The two types of drainage facilities are the external and internal drainage racks (or shelves). The external drainage rack is attached to the side of the cold cleaner at the top. The liquid solvent from the cleaned parts drains into a trough and is returned to the cold cleaning bath. This control is inexpensive and easily retrofitted. An internal drainage facility is located beneath the cover. Itmay be a basket that is suspended over the solvent bath, or a shelf from which the solvent drains. Particularly with solvents of higher volatilities (i .e. 

### ,much greater than that of mineral spirits), an internal drainage facility can prevent a significant sol vent emission. The internal drainage faci1 ity sometimes cannot be reasonably retrofitted, because theremay not be enough room inside the cold cleaner todrain parts while cleaning other parts. The main control devices for carry-out emissions from conveyorized degreasers are a drying tunnel and rotating baskets. A drying tunnel is simply an extension from the exit of the conveyorized degreaser. This tunnel extension gives cleaned parts more time to dry completely. The drying tunnel should work particularly we11 in combination with carbon adsorption. Drying tunnels can be retrofitted, ifthere is adequate space. Rotating baskets may be used on cross-rod degreasers and ferriswheel degreasers. A rotating basket is a perforated cylinder containing parts to be cleaned that is slowly rotated through the cleaning system, so that the parts cannot trap liquid solvent. Rotating baskets are designed into the conveyorized system and hence
are not easily retrofitted. Conveyors themselves can contribute to carry-out emissions. Some designs cause less emissions than others. In general, these emissions are directly proportional to the surface area entering and leaving the cleaning

### zone. One design, uses small pushers to move parts along fixed rods which support the work. This design is advertised to carry-out 70 

### percent less solvent than conventional wire mesh conveyors. The effectiveness of control devices that he1pminimize carry-out emissions cannot be quantified. The amount of carry-out depends too much

on the type of work loads (shape and crevices) and the qua1ity of operation. Nevertheless, it

### isobvious that if the exiting cleaning parts visibly show 1

iquid sol vent, then carry-out emissions wi11 be substantia1

# . 3.1.3 Controls for Solvent Bath and Carry-out Emissions Combined Two 

### contr;? systems reducc both sc?*;e:t 53th 2nd 

### carry-out emissions. They are the automated cover-conveyor system and a refrigeration condensation system. Both systems are relatively new designs and infrequently used in practice. They are somewhat complex and expensive in relation to most other control devices. 3.1.3.1 Automated Cover-Conveyor Sys

### tem 

## - The purpose of an automated cover-conveyor system is to close the
cover of an open top vapor degreaser when parts are being cleaned and dried. Thus, the cover is open only forthe short period of time when dry parts are actually entering or exiting. (Itispossible to use this system
on a cold cleaner but 

### the solvent volatility and losseswould generally have tobe very high tojustify the expense of such a system.) 

### The automated
cover must be capable of closing while 

### the part 

### is inside the degreaser. If the part is conveyed by means of a cable and hoist, then the cover can close horizontally and be split into two parts so that itcloses atthe center where the cable is located. If the parts are conveyed by means of a shelf that automatically lowers and rises, then the vapor degreaser can be covered by a permanent enclosurewith

### a vertical door, (See Figure 3-5).Automated conveyor systerns 

### include adjustab1 e timing delays for cl eaning and drying and automatic cut-offs topositionthework load for cooking and drying. Because emissions could occur only for the short period of time when dry parts are entering or exitingthe automated degreaser, itisexpected that an automated cover-conveyor systemwould provide highly effective control

# . 3.1.3.2 Refrigeration Condensation

# - Direct condensation of solvent vapors from exhaust airstreams isa possible a1though perhaps difficult means of recovering solvent. Sulllr insight intothe problem isgained by examining Figure 3-6. 20 Condensation 

### wi11 occur when an air/vapor stream is refrigeratedto
a temperature where the solvent's equilibriumvapor pressure is less than itsactual vapor pressure. The actual vapor pressure iscalculated by mu1tiplying the percent solvent vapor concentration (by volume) by the total pressure (usuallyatmospheric). For example, 1000 ppm of perch1 oroethylene atatmospheric pressureyields an actual vapor pressure of 0.76 

### mm Hg (0.1 percent concentration multipliedby 760 

### m Hg). Extrapolating from the graph, 0.76 mm Hg intersects curve 

### #9 at-25OC; thus, condensation
occurs below -25°C for perchloroethylene at 1000 ppm and 1 atmosphere. A1though solvent concentrations may reach 1000 ppm momentarily

## , the average concentration of chlorinated solvent vapors from typical operations isabout 300 ppm (0.23 

### mi11irneters HCJ)

# . Consequently, direct cond~nsati on of perchloroethylene would not usually occur until the temperature of the air/vapor streamwas reduced to at least -40'~. There are two major problems with refrigeration condensation. First, at these low temperatures, ice forms rapidly on the hkat exchange surfaces, reducing the heat exchange efficiency. The iceformation also requires the remova 3-20Figure 3-6. Vapor Pressures otjeveral Solventsof a large amount of heat (1300 Btu's per pound) which will add significantly tothe cost of this control, Second, when condensation occurs a fine mist of liquidsolvent isformed. The problem is inremoving this mist from the air stream. This analysis indicates that itwould be difficult to control emissions from degreasers with refrigeration condensation, However, this rests on two assumptions: (1

### ) 1 atmosphere pressure ismaintained and (2) vapors cannot be collected inhigher concentrations, Still

## ,this does not preclude its successful use. An example isone design which was reported after the initial EPA test program had been completed. The equipment manufacturer, Autosonics Inc., reported successful emission control using a prototype of their desig!~, called the "Zero-Emission" vapor degreaser. This system employs refrigeration condensation along with carbon adsorption and isreported to be able to capture solvent vapors with unusually high efficiency. EPA tests on this degreaser are planned. 3.1.4 Control of Waste Solvent Evaporation 3.1,4,1 Current Practices 

## - Emissions from waste solvent occur through a number of diverse routes,
none of which can be easily monitored or quantified. Based on the 1

### imi ted information currently available (see Appendix B.5), it isestimated that about 

### 280 thousand metric tons of waste solvent were disposed of from metal degreasing operations in1974. This isapproximately one-third 

### of the total metal degreasing emissions, Most of thiswaste isdisposed of ina manner such that itcan evaporate intothe atmosphere. A large fraction isindiscriminately dumped into drains or onto the grounds surrounding the using facility. Some waste solvent isstored inopen containers and evaporates. 

### A small amount of waste solvent finds itsway tomunicipal or chemical landfills that make noattempt to encapsulate the solvent. Some larger companies have used deep well injection, but overall this isconsidered an insignificant disposal route for waste solvent from degreasing. Ithas been estimated that these four disposal routes account for %35 percent of the total waste solvent 1

oad. Itisconvenient for automotive maintenance facilities to dispose of theirwaste solvent a1ong with theirwaste crankcase oi1. Perhaps as much
as 15 percent of the total waste solvent load (or s33 percent of the waste solvent from maintenance cold cleaners) enters this route. Crankcase oi1 is reprocessed, rerefined, used for dust control on unpaved roads or handled inother ways, none ofwhich pay significant attention tothe solvent fraction. Properly controlled incineration isone of the few disposal routes which does not result inorganic emissions to the atmosphere. However, only a small fraction (-5 percent) ofwaste solvent isbelieved to be disposed of inthis manner. Solvent reclamation isthe most environmentally acceptable route for waste solvent. Itisbelieved that -45 percent of thewaste solvent load is being reclaimed through disti11ation.22923 Primarily

### , ha1ogenaied solvents are distilled; petroleum related solvents, such as mineral spirits,
are more difficult and less profitable to distill, because such solvents
are flammable and inexpensive, compared to halogenated solvents. 3.1.4.2 Recomnended Practices

# - Reclamation Services

## - Reclamation services collectwaste solvent, disti11 it, and return the reclaimed portion to the solvent user. Charges vary but
are roughly equal to one half the market value of the solvent. In industrial
areas where large numbers of users are present, solvent scavenging and reclamation isbeing practiced profitably. Inrural areas, where users are1 

### separated by large distances, collection and transportation is a 1imi 

### ting factor. HoWever, suitabl, collection systems could be devifed and reclamation service could be expanded beyond the industria1 areas. 

### For example, it

### would be possible for the rural user to store waste solvent insealed containers unti1sufficient volume isacquired tomake collectioneconomical. Another a1ternative isoffered by 

### the Safety Kleen Corporation. This firm provides a 

### service of supplying both the solvent and cold cleaning equipknt to usei-s. The solvent used isperiodically collected and replaced with fresh solvent by 

### the company and the used solvent isdistilledat central locations. The firm operates inindustrial areas throughout the U.S. 

### In-House Reclamation

# - Many large users practice in-house reclamation. Invapor degreasing, the use of stills isfairly comnon. For instance, nearly a1

### 1 conveyorized vapor degreasers and 1 arge open top degreasers are equipped

### wi th sti

### 11s. (see Figure 

### 3-7). These sti

### 11s have been customarily used because they reduce the maintenance cost of cl eaning the vapor degreas

### ing system, enable the systern to remove soi

### 1s collected

### wi thout interrupting the cleaning process and recover valuable quantities of solvent. The Dow Report estimated that the total yearly cost of in-house reclamation of chlorinated solvents can be recovered from the first 

### 350 gallons distilled. Nonchlori nated solvents, because of thei

### r f

### 1 amnabi1

### ity 

### and 1 ower recovery value, would require 

### 6 to 12 times this quantity. Bottoms from all disttllation columns are of a hazardous nature, containing metals, sludge, residual solvent, etc. 

### They must be disposed of properly 

### inchemical landfills or preferably through a properly controlled high temperature incinerationfacility. Each solvent 

### class exhibits its

### own pecullarproblems indisti1 lation. Chlorinated solvents are part1 a1lystripped 

### of their stabi1

### izers duringdistiilation. These must be replaced toavoid chemical decom7-:i tion of the recovered solver^t

## . Nonchlori nated solvents are quite flammab' and require equipment designed to prevent fires and explor'ons. Solvent blends usually consist of solvents of different boiling points; thus, the solvent initial 1y recovered has a higher portion o - lower boiling poini; solvents. Certain contaminates can also greatly increase the difficulty of disti11ing any solvent. For example, azeotropes can form betdeen contaminates and sol~~.?nts during distillation, making separatfon difficult. Also, adverse chemical reactions can occur. For these reasons disti11ation service companies generallyanalyze waste solvent. The company using in-house disti11ation
can often eliminate analysis and avoid many of the problems encountered by services which distil1 a mixture ofsolvents from different users, because the solvents and the contaminants are known. Direct Incineration

### - Direct incineration ina properly controlled

-.- 

## - P. faci1ity isanother environrnentallyacceptable disposal route forwaste solvent. Incineration does not, however, produce a useable product and often requires significant amounts of supplementary fuel. For these reasons, itisnot as attractive as reclamation. Nonchlorinated solvents are fuel oil grade waste and after simple filtration of hazardous contaminates could provide the heat value necessary for incineration of chlorinated compounds. However, their fuel value will be considerably less than their solvent value. There are approximately 25 to 50 faci

### I ities inthe 

### UnSted States capable of acce~tahly incineraticg chlorinated solvents. Such facilities require high t~n!peratures ( J1230"Sj, ;dfficient 

### rx!der.ce tine (about L seconds), and sop+:sticate:: e~h39:t gas s i

### eani73 equ

### ip~nt 

### tu rerzove ha1qsnated compoucds [primalilyHCl:, riarticulates, 2nd other csntamindnts- Ca~i tal investment to

### Luiid t: 

### is LIC~~f 

### ;ncinera~~r ir 

### c-$;It,car;t [I..

### t~ 

### 5 ;7, 10 (o

# . .,dr capacity). 

### ~Cpe~~ti-,, 6 

### gailo:! cf :2cte 

### per ~in~te ccstr, hc

### /e ~eeF ect.rated 

### 24 at 

### lecc th~n 2Q/lt;~f s;iw-it iri:il;c?ratcd.

1 

### ,Ilt:n:ca; Lacdf?: i

- - ;tllr+c-ni-.ik 

### trier: are rPclrica1 iand'i"r ;.r ica~c' 3

### tion

c 

### pro.zer; ?s

### appraved 12;- th* 

### disixza' c9waste zo'venf., hour;^.!.. c

# -
- ' i :, :hi ;



### - Rannsr could result iii 

### losr of

### vclat~leorganfc:, ~hese f 

### ciliti~;-2 

### :rt~ent emissions if extrm~ 

### Lare 

### is 'aKcn 

### to e-imiraz~ c:apcraf,'s.~ ar;a pefi i-q. 

### One method has been to seal the haste solvent in

### lined drum and surb ;und the 

### drums FS 

### th

### 4 ic 

### 23 ft, 

### of pzckej :lay. 

### No 

### testirg has beon don^ tc; 

### ,_-rn 

### that even this method will contrcl vrganic emissions. Ir

### isbe: ieved tndt 

### most chemical landfjlls are not ddequate for the disposal of waste sclvm;t. 

### Itis 

### not the purpose of 

### this report to evaluate waste solvent disposa; facilities in depth, rather only to show that they are available, even though the degree of 

### their excessibilit; varies geograpnica-iy. EFc's (: ?f

.'c-~ C 

### Solid kiteManagemen: Programs is

### currently preparing rcgulatinns. the Resource Conservation and Recovery Act of 1976, 

### to cover transportacion,

-8 

### storage, 

### treatment and 

### disposcl of

### hazardcliz waste. I11ece

### recuiat

### roils are targeted for promigatiirn in dprf1 94: i97E 

### and hcp&ul ly wi! 

### 1apply '

. -': 

### waste ~olvents frm 

### d~greasing. 3.1.5 Cther Control Devices Two other control devices could conceptually be used 

### to reduce solvent bath em

### iss.ions: 

### incineration and 1

### iquid absorption. Generaily

### , incineration appears to be too expensive and energy intensive, and liquid absorption presents specia1 

### technical problems and could even cause increased atmospher:~ emissions.

### 3.1.5.1 IpsinerstiOP

## - incineration ha; been used formany 

### years to control emissions of organics 

### to the atmosphere. For degreasing operations, it

### could be 

### applied most easily to systerns using petroleum hydrocarbons and oxygenated solvents which readily 

### combusi 

### to carbon dioxide and water. App! 

### ication to syste~ns using halogenated hydrocarbons would be more difficult. A1though halogenated hydrocarbons 

### are non-f1

### arrnnable under normal conditions

### , they can be pyrolyzed attemperatures ;n 

### the incinerafion range. The 

### pyrolytic 

### decomposition of cblorindted hydrocarbons, for example, wi

### 11 release chlorine, hydrochloric
6 :id, 

### ad 

### phosgene depending upon the conditions of oxidation. These product; would have tobe removed from the off-gas stream of the incinerator using sophisticated gas cleaning equi~nent before exhausting to the atmosphere. 75: 

### cost of incineration could also be high. First, capital requirements
are generally large, particularly in comparison to the 

### relatively low zest 

### of most 

### degreasers. F~rthermore, costs would be significantly increased with the addition of gas cleaning equipment, were that needed. Next, solvent c~ncentrations in exhast streams are frequently below the range required 

### to sustain combusti

### on; thus, supplemental fuel would be required. Scarce fuel
resources would 

### make this 

### a limiting factor. 3.1.5.2 

### Liquid Absorption 

## - Liquid absorption is a well known process that has been investigated for
use in solvent metal cleaning. For example, trichloroethylene vapors in

### air could he 

### substantia1ly reduced by absorption in

### mineral o i

### 1. 

### However, at anChi1lingthe absorbing fluidwould reduce itsconcentration 

### inthe exhaust air. However, cooling to a temperature below 0°C (32°F) would cause iceformation inthe column sincewater is insoluble inmineral oil. Although this could be avoided by prerefrigeration ofthe airstream, the use of refrigeration would greatly increase energy consumption. Finally, the energy requiregent for recovering the solvent from the mineral oil isgreat. Thus, itappears that this method of emission control is impractical except for the recovery of (1) high concentrations of solvent vapors inair, (2) very valuable vapors or (3) highly toxic chemical vapors. 19

3.2 COMPLETE CONTROL SYSTEMS A complete emission control system utilizes both contrcl equipment and ~3erating procedures. Although controls can be combined inmany ways toform 3~1ydifferent control systems, twc 9as-i~ control 

### syzterz for each type -:gl :c3er are presented 

### here. Generally

### , control system A consis ts of proper czerating practices and simple, inexpensive control equipment. Control -ystc~; 0 consists ofsyste~ A plus other devices that increase the effectiveness

f xrtxl. The details of contml system A or B can be modified to arrive



# - love1 of contrcl needed. 

### T?e smission control efficiency of reasonably we11 designed and maintained 

### cz-troi systems isestimated from the present test data base. Control systems wh-ch are seriously defective are not uncomnon. 

### A few such systems were even recomended unintentionally by contrcl system vendors to EPA as being exemplary; itrequired close inspection and sometimes etnission measurements to discover that the systems were defective.3.2.1 

### Cold Cleaning Control Systems The most important emission control for cold cleaners is the controS of waste solvent. The waste solvent needs to be reclaimed or disposed of 

### so that a minimurn evaporates into the stnosphere. Next in 

### importance are the operating practices of closing the cover and draining cleaned parts. Severa7 other control techniques becme significant only in

### a small fraction of applications. The control devices and operating practices for control systems A 

### and B 

### are summarized in

### Table 3-1. There is not 

### a 1

### arge difference in effect between systern A and 6, 

### because most of tne cold cleaning emissions iire 

### controiyeci in

### systern 

### A. if 

### the requirements qf 

### systmA 

### were followed conscienti~usly by 

### nearly a1' of the cold cleaning operators, there would be littleneed for the acidit1

### .,:I; 1 

### system B 

### requiremen

### ts. However, because cold cleani

### n~ cqerators can tend to be 

### lax in keeping the cwzr closed, equipment requirements 

### #1 and #4 

### in systarn R 

### are added. 

### Sinilarly, the nodifications for #2 

### and the equipzwt requirements in #3 

### v:ouid effect significant emiszion reductions in a few 

### applications. Although t7e 

### effectiveness of the control systems depends greatly on the qua7ity of operation, average cases have been approximated, (seeAppendix B.

### 1j 

### Syste~ A 

### could reduce cold cleaning emissions by 

### 50 (90)

### percent and system B 

### may reduce itb~y

### 53 (+20) 

### percent. The lower end of the ratiqe

- 

### rqresents thz emission reductim projected for poor compliance, and the nigher end represents excellent compliance. As can be readily seen from these estimates, the expected benefit from system B 

### is only slightly better than that for system A 

### for an average cold cleaner, assuming low volatility solvents. This difference is small because the additional devices required in system B 

### generally control only bath evaporation, which represents aboutTABLE 3-1. CONTROL SYSTEMS FOR COLD CLEANING
Control SyrtmA Control Equipment: 1. Cover 2. Facility for draining cleaned parts 3. Permanent. conspfcuous label, surmariz:ng the operating requirements Operating Requirements: 1. Do not dispose ofwaste solvent or transfer it to another part:/, such that greater th$n 20 percent of the waste (by weight) can waporate into the atmosDhe?e. Store waste.solvent on.lv incovered containers. 2. Close degreaser cGver whenever not handling parts inthe cleaner. 3. Drain cleaned parts for at least 15 seconds or until dripping ceases. Control System 8 Control Equipment: 1. Cover: Same as inSystem A, except if (a) solvenf volatility is 

## Tre2 ter than 2 kPa (15 m Hg or 0.3 psi) veasured at 28°C ,lOO°F\ ,**

b) soivent isagitated, or (c) solvent isheated. then the cover must be designed so :hat 1: car be easilv 3pera:ed with one hand. 'Covers for ;drqer Geqreasers may recuire mechanicai assistance. by ;orin5 !oadin~, raunterweiqhtinq or lowered svstems. ! 2. 3rainage facility: Same as inbystem h, except that if so:vent volatility isgreater than about 4.3 kPa (32mn Hp or 0.6 psi) measured at 38'C (lOO°F), then the drainage facility muzt be iqternal, SG that parts ?re enclosed under the cover while draining. The drainage facility mybe externai for aoplications where an internal type cannot fit lntothe cleaninq svstem. 3. Label : Same as in System A 3. If used, the so:vent spray must be a solid, fluid stream (not ti fine. atomized or shower tvoe soravl and ata Pressure which does not czuse excessive splashing. 5. Major control device for highly volatile solvents: Ifthe solvent volatility is > 4.3 kPa (33 m Hg or 0.6 psi measured at 38°C (13C°F), 3r jf solvent is heated above 50°C (12O0F), then one ofthe following control devices must be used:
a. Freehoard that gives a freeboard ratiof** 20.7 b. Water cover (solvent must be insoluble inand heavier than water)
c. Other systems of equivalent control, such as a refrigeratedchiller or carbon adsorption.

Same as inSystem A
%ater and solidwaste regulations must a1 so be cmpliedwith. **Generally solvents consisting primarily ofmineral spirits (Stoddard) have volatilities

# .2 kPa. ***Freeboard ratio isdefined as the freeboard height divided by the width of the degreaser.

### --



### -- -- 20 

### to 30 

### perc-nt of the total emission from an average cold cleaner. For cold cleaners with high volatility solvents, bath evaporatisn may contribute ~50 

### percent of the total emission; 

### tt is estimated that system 6 

### may achieve 69 (220) 

### percent control efficiency, whereas system A 

### might experience only 55 (+20) 

### percent control.

- 

### 3.2.2 

## - Control Systems for Open Tcp 

### Vapor Degreasin9 The basic elements of a control system for 37en top vapor degreasers
zre proper operating practices and 

### use of control equipment. There are about ten main operating practices. The 

### control eqgipment includes a cover, safe", y;;i teks 3rd 

### a major control device, ef

### ther h?

### gh 

### freebaard, refriyerated c$iiler, enclosed design or carbon adsorption. Two control systems for open top vapor degreasers are out1ined in Table 3-2. 

### The 

### vapor level thermostat isnot included 

### because itis aiready required by 

### OSHA 

### on "o?en surface vapor degreasing 

### tanks.

### " -he 

### sump thermostat and solvent level cmtrol are used primarily to prevent sc!vec5 ieyad3tion and protect the equipment and thus are also not included here. The 

### emizsicn reduction by these controls is a secondary effect in 

### any event. The two

. . 

### safety switches presented serve primarily to reduce vapor solvent emissions. System A 

### may reduce open top vapor degreasing emissions by 45 

### (t15)percent, and system E my

### reduce them by 60 (+15)percent. For an average size open top vapor degreaser, system A 

### and S 

### would reduce emissions from 9.5 

### rn tons/year dowr! to about 5.0 

### and 3.8

### rn tons/year, respectively. It isclear that systein B 

### is appreciably more effective than system A. 3.2.3 

## - Control Systems for Convgorized gegreasers 2mtrol devices tend towork most effectively on conveyorized degreasers

## , mainly beca~;ethey are enclosed. Since these cmtrol devices can usually result in solvent savings, they often will net an annualized profit.TABLE 3-2. COMPLETE CONTROL SYSTEMS FOR OPEN TOP VAPOR DEGREASERS

. Control System A Control Equipment: 1. Cover that can be opened and closed easily without disturbing the vapor zone. Operating Requirements: 1. Keep cover closed at all times except when processing work loads through the degreaser. 2. Minimize solvent carry-out by the followlng measures: a. Rack parts toallow full drainage. b. Move parts inand out of the degreaser at less than 3.3 m/sec (11 ft/min) c. Degrease the work load inthe vapor zone at least 30 sw. or until condensation ceases. d. Tip out any pools of solvent on the cleaned parts before removal. e. Allow parts to dry within the degreaser for at least 15 sec. or until visually dry. 3. Do not degrease porous or absorbent materials, such as cloth, leather, wood or rope. 4. Work loads should not occupy more than half ofthe degreaser's open top area. 5. The vapor level should not drop more than 10 cm (4 in) when the

- work load enters the vapor zone. 6. Never spray above the vapor level. 7. Repair solvent leaks imnediately, or shutdown the degreaser. 8. Do not dispose ofw? solvent or transfer itto another party such that greater than 20 percent of the waste (by weight) will evaporate into the atmosphere. Store waste solvent only inclosed containers. 9. Exhaust ventilation should not exceed 20 m3/min per nz (65 cfm per ft2) of degreaser open area, unless necessary tomeet OSHA requirements. Ventilation fans should not be used near the degreaser opening. 10. Water should not be visually detectable insolvent exiting the water separator. Contro: System B Control Equipment: 1. Cover (same as insystem A]. 2. Safety witches
a. Condenser flowswitch ana tnennostat

### - (snuts off sump neat ifcondenser coolant iseither not circulatingor too warm). b. Spray safety switch- (shuts off spray pump ifthe vapor level drops excessively. about 10 cm (4 in). 3. Major Control Device: Either: a. Freeboar9 ratio reater than or equal to 0.75, and if the degreaser opening is > 1 m (10 ft

### 9), the cover must be powered, b. Refrigerated chiller, c. Enclosed design (cover ordoor opens only when the dry part is actually entering or exiting the degreaser.), d. Carbon adsorption system, with ventilation , 15 m3/min per mZ (50 cfm/ft2) of airlvapor area (when cover isopen), and exhaustinq -25 Dpm solvent averaged over one complete adsorption cycle, or e. Control svstem. demonstrated to have control efficiency, equivalent to or betterthan any Of the above. 4. Permancnt, conspicuous label. sumnarizing operating procedures ff1 to 16. Operating Requirements

, Same as in System b

### Two recommended control systems for conveyorized degreasers are shown in Table 3-3. 

### Control system A 

### requires only proper operating procedures which
can be implemented, inmost cases, without large capital expenditures. Control system B, 

### on the other hand, requires a major control device. Major control devices can provide effective and economical control for conveyorized degreasers. A 

### refrigerated chillerwill tend tohave 

### a high control efficiency, because room drafts generally do not disturb the cold air blanket. A carhon adsorber also tends toyield a high control efficiency, because collection systems aremore effective and inlet streams contain hi

### gher sol

### vent concentrations, for conveyorized degreasers than for open top vapor degreasers. Small scaleconveyorized degreasing applications can resul

### t in significantly high annualized costs from using a major control device. Consequently, many operators may be motivated touse the less expensive open top vapor degreaser in place of a conveyorized one, even though more solvent isemitted for an equivalent work load. Thus, itisreasonable toexempt conveyorized degreasers wit 

### less than 2.0 

### m2 

### of air/vapor interface from requirement of a major control device. The remaining three control devices recommended in 

### system B 

### should entail nominal expense in

### relation to their potential solvent savings. Because of thewide diversi

### ty of applications for conveyorized degreasing

## ,there may be
a few 

### applications where thedrying tunnel or a minimized opening may be 

### impractical; thus, occasional exceptions may have tobe made for these two requirements. For example, a plant might not have enough space available to permit 

### use of a drying tunnel; also, hanging partsmay occasionally swing from a conveyor 1 ine more than the clearance a1lowed by the control requirement. The control efficiency for system A 

### is estimated at25 

### (+5) percent and 

### - for system B, 

### 60 

### (+lo) percent. Emissions from a typical conveyorized degreaser 

### -TABLE 3-3. CONTROL SYSTEMS FOR CONVEYORrZED DEGREASERS
Control System A Control Equipment: None Operating Requirements: 3 2 1. Exhaust ventilation should not exceed 20 m /min per m (65 cfm per ft2) ofdegreaser opening. unless necessary to meet OSHA requirements. Work place fans should not be used near the degreaser opening. 2. Minimize carry-out emissions by:
a. Racking parts for best drainage. b. Maintainingverticle conveyor speed at c 3.3 m/min (11 ft/min). 3. Do not dispose ofwaste solvent or transfer ittoanother party such that greater than 20 percent of the waste (by weight) can evaporate intothe atmosphere. Store waste solvent only Incovered containers. 4. Repair solvent leaks imnediately, or shutdown the degreaser. 5. Water should not be visibly detectable inthe solvent exitingthe water separator. Control System B Control Equipment: 1. Major control devices; the degreaser must be controlled by either:
a. Refrigerated chiller, b. Carbon adsorption system, with ventilation > 15 m2/min per m2 (50 cfm/ft2) ofair/vapor area (when down-time cove& are open), and exhausting <25 ppn of solvent by volume averaged over a complete adsorption cycle, or c. System demonstrated to have control efffciency ?quivalent to or better than either of the above. 2. Either a drying tunnel, oranother means such as rotating (tumbling) basket, sufficient to prevent cleaned parts from carrying out solvent liquid or vapor. 3. Safety switches
a. Condenser flow switch and thennostat - (shuts offsump heat if coolant iseither not circulatingor too warm). b. Spray safety switch

### - (shuts off spray pump or conveyor ifthe vapor level drops excessively, e.g. > 10cm (4 in.)). c. Vapor level control thermostat

### - (shuts off sump heat when vapor level rises too high). 4. Ilinimized openings: Entrances and exits should silhouettework loads so that the hveraye clearance (betweell partsand the edge of the degreaser opening) iseither <locm (4 in.) or .10 percent ofthe width of the opening. 5. Down-time covers: Covers should be provided for closingoff the entrance and exit during shutdown hours. Operating Requirements

. 1. to 5. Same as for System A 6. Down-time cover must be placed over entrances and exits of conveyorized degreasers imnedistely after the conveyor and exhaust are shutdown and removed just before they are started up.

### may decrease from 27 

### to ~20 and 

### .~ll (metric) tonsjyr for systems A and 

### B, 

### respectively. Thus, system B 

### offers a much greater emission reduction per degreaser for conveyorized degreasers than for 

### cold cleaners or open top 

### vapor degreasers.

### 3.3 REFERENCES 

### 1. American Society for Testing and Materials (ASTM)

## , Committee D-26, "Recommended Practice for New Source Performance Standards to Control Solvent Metal Cleaning Emissions." 2. Surprenant, K. S. and Richards, D. Id. of Dow Chemical Company, "Study to Support New Source Performance Standards for Solvent Metal Cleaning Operations," Yo1

# . 2, prepared for Emission Standards and Engineering Division (ESED), under Contract # 68-02-1329, Task Order #9, June 30, 1976. 3. Ibid. 4. Ibid, Appendix C-9. 5. American Society for Testing Materials, Op. Cit. 6. Surprenant, K. S., Op. Cit, Appendix C-12. 

### 7. Information provided by H. A. Rowan of Magnus Division of Economics Lab. Inc., S. Plainfield, N. J., by telephone toJ. C. Bollinger, EPA March 

### 28, 1977. 8. Information provided by J. Picorney of Baron Blakeslee Inc., Chicago, by telephone to J. C. Bollinger

### , EPA, November 18, 1976. 

### 9. "Trip Report

# - Collins (now Rucker Ultrasonics) Inc., Concord, Calif

# ." EPA memorandum from J. C. Bollinger to D. R. Patrick, November 5, 1976. 10. Surprenant, K. S., Op. Cit., Appendices C-3, C-5, and C-7. 11. Ibid, pg. 4-5. 12. JACA Corp., Fort Uashington, Pa., "Air Pollution Control of Hydrocarbon Emissions 

## - Solvent Metal Cleaning Operations

## ,"prepared for EPA, Office of Technology Transfer, Seminar : "Upgrading Metal Machining, Fabricating, and Coating Operations to Reduce Pol1ution

## ." 13. Surprenant, K. S., Op. Cit., pg. 4-59. 14. rbid, Appendices C-10 and C-11

# .

### Ibid, Appendices C-4, 

### C-5, and C-8. 

### Ibid, Appendix C-7. 

### Kearney, T. 

### J., Detrex Chem. 

### Inc., letter to J. 

### F. Durham, EPA, February 17, 

### 1976. Surprenant, 

### K. S., 

### Op. Ci

### t. Ibid. Ibid, 

### pg. 

### 4-16. Ihid, pg. 

### 4-18. Information provided by 

### F. X. 

### Barr, Graymil1

### s Co. 

### ,Chicago, by telephone to

### J. 

### L. Shumaker, EPA, 

### January 13, 

### 1977. Information provided by K. S. 

### Surprenant, Dou Chemical

### ,Midland, Michigan by telephone to J

# . L. Shumaker, EPA, 

### January 11

### , 1977. Information provided by Hydroscience, Inc., Knoxville, Tennessee by telephone to 

### J. L. 

### Shumaker, 

### EPA, March 24, 1977.

### 4.0 COST 

### ANALYSIS

4.1 

### INTRODUCTION 4.1

### .1 

### Purpose The purpose of this chapter is 

### topresent estimated costs for applying alternative emission control techniques in the metal cleaning, or degreasing industry. Cost data 

### will be provided for hydrocarbon controls 

### on cold cleaners, open top vapor degreasers, and 

### conveyorized vapor degreasers. These cost data will be presented for model new facilities as well as for model existing p1

### ants. 4.1.2 

### Scope With regard to cold cleaners, control cost estimates will reflect the
use of the following techniques: 1

# . drainage faci1

### ity; 2. 

### mechanically assisted cover (spring 1 oaded)

# . The scope of this section includes both low volatility solvents, such 

### as mineral spirits, and high volatility solvents such as 1,l

### ,I- trichloroethane. Costs will be presented for only one size cold cleaner facility. 

### No incremental costs for housekeeping controls are presented in this chapter. A 

### reasonable judgment is that such costs are negligible, particularly considering that they are offset by savings in 

### recovering additional solvent from improved housekeeping. With regard 

### toopen top vapor degreasers, control cost estimates will be presented for two sizes of facilities 

### that primarily use trichloroethylene solvent or 1,l,l-trichloroethane solvents. The control cost estimates wi11 reflect the following techniques:

### 1. 

### use of a manual cover; 2. 

### use of a manual or powered cover in combination with extended freeboard; 3. 

### refrigerated chiller; 4. 

### carbon adsorber; As in the case of cold cleaners, incremental costs for housekeeping controls on open top vapor degreasers are not presented because they appear to be negligible. With regard to conveyorized vapor degreasers, control cost estimates will be presented for facilities that primarily use trichloroethylene or perchloroethylene solvents. The control cost estimates will reflect the use of the following techniques:
a. carbon adsorber b. 

### refrigerated chi11ers Again, incremental costs for housekeeping are 

### not presented because they. appear 

### tobe negligible. 4.1.3 Model Plants Control cost estimates are presented for typical model degreasers in the metal cleaning industry. Specificmodel plant parameters will be presented in the subsequent portions of this chapter. Admittedly, control costs may vary from one installation 

### toanother, perhaps even appreciably from the costs described for the models in this chapter. However, the difficulty of obtaining actual plant control costs requires use of model plants. To the extent possible, EPA 

### has incorporated actual plant cost information into the cost analysis.

### Cost information ispresented both for typical new model degreasers as well as for typical existing model facilities. Model degreasers depicting size, design, and solvent usage have been developed. The purpose of this is to show the relative variation in control equipment costs with these factors. Although the degreaser models chosen for the analysis are believed to be representative of degreasers used throughout the industry, no attempt has been made to span the range of existing degreaser designs and sizes. 4.1.4 Capital Cost Estimates Control cost estimates comprise installed capital costs and annualized operating costs. The installed capital cost estimates reflect 

### the cost of designing, purchasing, and installing a particular control device. These estimates include costs for both major and auxiliary equipment, rearrangement
or removal of any existing equipment, sitepreparation, equipment installation and design engineering. No attempt has been made to include costs for lost production during equipment instal1 ation or start-up. For degreasing operations, most of the controls discussed will take 

### a matter of hours for installation which should minimize delays in production. All capital costs reflect first quarter 1977 costs. In general, information for capital costs has been developed through contacts with degreaser equipment manufacturers. In addition,
an EPA 

### contractor study1 

### and EPA 

### in-house files have been used to develop the capital costs. 4.1.5 Annualized Costs Annualized cost estimates include costs for operating labor, maintenance and utilities, credits for solvent recovery, depreciation, interest, administrative overhead, property taxes, and insurance. Operating cost estimateshave been developed on the basis ofthe EPA contractor study cited above. The number ofannual operating hours was assumed tobe 2250 hours. The cost of electricity isassessed at4 cents per kilowatt-hour.' Solvent prices used were $0.20 per kilogram for mineral spirits, and $0.43 for trichloroethylene and $0.41 for the chlorinated blended solvent used incold cleaning. These solvent prices are based on recent quotations from the Chemical Marketing ~e~orter. Maintenance costs for a11 controls (except housekeeping)
were estimated to be 4 percent ofthe purchase cost of the equipment. Estimates of depreciation and interest costs have been developed by EPA based on the use of the capital recovery factor, an interest rate of 10 percent, and an equipment lifeof 10 years. Inaddition tocosts for depreciation and interest, other capital charges include a 4 percent charge for administrative overhead, property taxes, and insurance.

- 4.2 COLD CLEANERS 4.2.1 Model Plant Parameters The model parameters that were used indeveloping control costs for cold cleaners are shown inTable 4-1. These parameters are based on industry contacts and EPA studies of the solvent degreasing industry. The most comnon type of cleaning isrepresented by low volatile solvent cleaning. Also shown ishigh volatile solvent cleaning, which 

### isimportant from the standpoint of higher emission rates. The emission rates inTable 4-1 represent typical values. The recovered solvent values and the cost of solvent are used to estimate solvent creditswhich 

### will reduce the annualized control costs. The assumed composition for the high volatility solvent blend is60 percent 1

### ,I,1 -trichloroethane, 20 percent xylene, and 20 percent mineral spirits.I Table 4-1. COST PARAMETERS FOR MODEL COLD CLEANERS

Working Area, 

### rn2 Solvent Used Uncontrolled Emission Rate, metric tons per year Emission Rate with Housekeeping Requirements

### , metric tons per year
P cn

### ' Solvent Recovered by Control System, metric tons per year Solvent cost, 

### $ per kg Low Volatility High Volatility Solvents Solvents 0.5 0.5 Mineral Spirits Blended Solvent 0.25 0.40

Source: EPA assumptions based on industry contacts, contractor studies and in-house files.

### 4.2.2 Control Costs Costs for control of emissions from cold cleaners have been developed for the following cases formodel new and existing cold cleaners: 1. drainage facility for low volatility solvent cleaning 2. drainage facility plus a mechanically assisted cover for high volatility solvent cleaning. The drainage facility consists of an external rack equipped with a drain line to return recovered solvent to the storage tank, which supplies the solvent for cleaning. The mechanically assisted cover consists of a spring loaded plunger which helps the operator to easily open and close the cover. The costs for these equipment features are presented in

### Table 4-2. Estimates arepresented for installed capital costs, annualized costs, and the cost per kilogram of hydrocarbon controlled. The capital costs forthe drainage facility arethe same for an existing cleaner as for a new one because of 

### the ease with

### which itcan be retrofitted. The capital costs for the cover are for the spring loaded plunger which can be retrofitted onto the cover of an existing cleaner. These costs were provided to EPA 

### by
a manufacturer of cold cleaning One hour of labor isassumed
as the requirement for installing the spring loaded plunger. The cost of hydrocarbon control per kilogram of recovered solvent is quite sensitiveto the value of the recovered solvent. Note that the low volatility solvent cleaner in

### Table 4-2 incurs a cost of $0.021 per kilogram

:.I 

### whereas the high volatility solvent cleaner saves $0.31 per kilogram forthe
new facility and $0.267 per kilogram forthe existing facility.

### 4.3 

### OPEN TOF 

### VAPOR 

### DEGREASERS 4.3.1 

### - Model Plant Parameters The model parameters that were used in developing control costs for two sizes of open top vapor degreasers are displayed in Table 4-3. The two sizes represented are characterized by 

### working area and solvent emissions. These parameters were selected as a rosult of industry contacts and EFA stL: 5; 

### of the industry. The emission rates in Table 4-3 

### represent typical vafue-. 

### The working are2 isused to determine costs for covers, refrigerdted ck,ii:ers, and frwboard extensions. The assumption used to estimate costs is t:ic\+ tr+ 

### length of the workin9 area istwice the width. The recovered solvent vclucs 

### and the cost of solvent are used ta estimate solvent credits \:F.ich a-e 

### der!l~:-?a 

### from the annualized costs of the control devices. 4.3.2 Control Costs Costs for control of emissions from open top 

### vapor degreasws nave 

### been developed for the following cases formodel new and existing degrsjsers: 1. manual cover; 2. 

### manual 3r 

### powered cover forworking area exceeding 1.0rr,' in 

### combinati3n 

### with 

### extended freeboard; 3. refrigerated chi11

### er; 4. 

### carbon adsarber. Table 4-4 

### presents the costs for these controls on the average sized 

### degreaser, and Table 4-5 

### presents costs for the smaller degreaser. Costs
are presented in terms of installed capital costs, annualized costs, and 

### the cost per kilograr 3f hydrocarbon contrclled.Table 4-3. COST IIRIZAMFTERS 

### rr)Rt.1ODtL OPEN TOP VAPtlR @t.GkEASERS

---_ _ -_ ___ 

## _ __ - -_ 

## -- Working Area, 

### m2 

### Uncontrolled Fmission Pate

, 

### metric tons per yezr 

### Emission rate with housekeepin7 

### requirements, metric ton:, 

### per year Solvent recovered by 

### -ontrol 

### sys

### tern, metric tons per year a) Manual cover b) 

### High freeboard and 

### powered cover c) Chiller d) 

### Carbon adsorber

Solvent Cost

### ,$ 

### per kg 

### Manual cover and high freeboard.

\ I 

### SOURCE: EPA 

### assumpf-innsbased 

### on indu:;-". rr~ntact,

### contrirctor studies, and in-house fi

### les.

### With regard to Tables 4-4 

### and 4-5, the installed capital for the carbon adsorber in the existing facility represents the worst retrofit situation to be encountered for this control device. This would occur if no steam capacity is available for solvent desorption, and space is limited. Retrofit capital would include a small steam boiler and an elevated platfom to provide space. For most retrofit situations, the installed capital would be somewhere between the costs for a new facility and the ?stirnates shown for the existing facilities. The retrofit factor for carbon adsorbers applied to existing degreasers
was developed from an actual facili

### ty.6The cost of the carbon adsorber for the facility was $13,990; the boiler, $4,000; and the platform above ground level in the plant to house both the boiler and the adsorber, $3,300. The ratio of the boiler an3 platfom,costs to the carbon adsorber costs is approximately 0.50. The retrofit factor for the refrigerated chillers is also approximately 50 percent, or in other words, retrofit costs are 50 percent more for existing degreasers than for new units. The basis for this is the study cited earlier (see reference 

### 13. Retrofit costs for freeboard extensions, 

### or high freeboards, and covers
are difficult.

### todetermine in

### some situat-ions. Based on contacts with two

manufacturers of these devices, approximate instal1 ation 

### r~nl~ir~rneqts 10 man-hours for manual 

# cover^,^ 16 man-hours for freeboards, and 16 man-hours for powered covers.8 

### The installed capital in Table 4-4 for the powered cover with extended freeboard in an existing facility includes $5,5009 for digging a concrete pit. The purpose of the pit is tocallow room for a hoist or 

### a conveyor

### bringing parts to the cleaner. Such a problem most likely would not exist for small degreasers. Consequently, a provision for this type of retrofit penalty is provided in Table 4-4 but 

### not in Table 4-5. Another difference to be noted in capital costs for the powered coverextended freeboard design is that the powered cover is required only for this degreaser with working area in excess of 1.0

### rn2



## . Otherwise, the degreaser would be required to install only a manual cover. Note the difference in capital between the manual cover-extended freeboard design in Table 4-5 and the powered cover design in Table 4-4 for new facilities. In both Tables 4-4 and 4-5, the costs of hydrocarbon control per kilogram of recovered solvent are reported. These values will be used todevelop the cost-effectiveness curves later in this chapter. As these tables indicate, the costs of hydrocarbon control vary considerably depending upon the size of the degrease;-, the type of control, and the amount of recovered solvent. As an illustration, carbon adsorber costs range from $0.091 per kilogram (Table4-4) in a new facility for the typical degreaser to $0.583 per kilogram (Table 4-5) for the small degreaser. This is an indication that carbon adsorbers should be much less expensive for larger open top vapor degreasers. Conversely, the extended freeboard and manual cover combination is less expensive for the smaller degreasers than the similar combination with the powered
cover on larger degreasers. This 

### conclusion isshown by the difference in 

### savings between $0.234 per kilogram for the typical degreaser in a new facility (Table4-4) and $0.363 per kilogram for the small degreaser (Table 4-5).4.3.3 Cost-Effectiveness The purpose of this section isto provide a graphical analysis of the
ccst-effectiveness of a1ternative control options for various types of open top vapor degreasers. This analysis will attempt to relate the annualized cost per kilogram of hydrocarbon removal with degreaser size for each control option. Figure 4-1 isa presentation of the typical relationship for control of hydrocarbon emissions from open top vapor degreasers. Curves are shown for carbon adsorbers, refrigerated chillers, powered covers with extended freeboards, and manual covers. The size range shown inFigure 4-1 represents the approximate range ofmost degreasers (0.8 square meters to 18 square meters) based on EPA data, contractor studies, and contacts with degreaser manufacturers. The efficiencies of the control devices shown represent the capabilityofthe control device for reducing emissions from a well maintained degreaser (which has carried out a11 good housekeeping practices). A1though detai1 ed costs
are presented for two model degreasers inSection 4.3, several more estimates
were derived inorder todefine the curves with reasonable precision. The curves represent the retrofit costs for existing facilities. However, this constraint was somewhat relaxed for the powered cover optionwhich does not include the cost of the concrete pit shown inTable 4-4. The reason for this isthat the powered cover option with a lower control efficiency may be an acceptable option inthose situations where the concrete pitisnot necessary. On the other hand, 

### ifthe pitwere required, then the refrigerated chi11 er with a higher control efficiency (45 percent) becomes more attractive.

### Far example, Table 4-4 shows for the degreaser with 

### 1.57 square meters a cost of $0.928 

### per kilogram for the chiller and $0.115 f9r the powered cover with

### the concrete pit. An 

### important concept for contr~l of 

### 3egresser enissions isthe fact that credits for recovered xlvsnt ~ffset o some extent the annualized costs of installing, operating, and maintaining 

### a control device. In 

### reviewing Figwe 4-1, the reader will observe the extmt towhich solvent credits can more than affset the 

### annuelizec! costs of the control device. This isgraphically illustrated by 

### the horizontal dashed 1

### ine of $0. 

### per kilogram. This dashed line indicates that applicaticn of carbon adsorbers will result in

### an out-of-the-pocket expense to the o?eratw ~f

### the degreaser for a sizebelow an approximate 6 

### square meters in

### working area. Similarly, refrigerated chillers will do 

### the same fordegreasers smaller than approximatc!! 2 

### square meters. 4.4 

### CONVEYORIZED DEGREASERS 4.4.1 

### Model Plant Parameters

- 

### The model plant parameta-s thatwere used in developing control costs fcf cmveyorized degreasers are displayed in Table 4-6 farmonorail and cross-rod designs. These parameter selections arebased on industry contacts and EPA 

### studies cf the industry, in the same manner as cold cleaners and open 

## tw vapor degreasers. The emission rates in

### Table 4-6 

### represent typical values. The working area isused todetermine costs for refrigerated chillers. The assumption used to estimate chiller costs is that length of 

### the working are;,
or interface, is 2.7 

### times the width. The basis for this isan emission test study performed on a monorail degreaser.' The recovered solvent values and the cost of solvent areused to estimate solvent creditswhich will reduce the annualized control costs of the control devices.--- Table 4-6. COST PARAMETERS FOR MODEL CONVEYORIZED DEGREASERS

Monorai 1 Cross-Rod

- - Working Area, m 

### L

Uncontrolled emission rate, metric tons per year
Emission rate

### with housekeeping requirements, metric tons per year P I 4 Solvent recovered by control system, metric tons per year Solvent cost, $ per kg 0.43 0.43

Source: EPA assumptions based on industry contacts, contractor studies and in-house files.

### 4.4.2 

### Control Ccsts Costs for control of emissions from cmveyorized degreasers have been developed for the fol1

### owing control devices: 

### 1. 

### carbon adsorbers 2. 

### refrigerated chillers. Table 4-7 

### presents the cc~sts for the mdel conveyorized degreasers. Costs are ?resented in terms of installed capital ccsts, annualized costs, 2nd 

### the c~st per kilogram of hydrocarbon controlled. The installed capital for the carbon adsorber in the existing facilityrepresents the worst retrofit situatim 

### tobe encountered. This would occur if no 

### stea~ capacity is available for regeneration of adsorbed solvent and space is limited. Retrofit capitzl ir.ciudes a 

### small steam boiler and an elevated platform for the carbon adsorber. The rztrofit factor applied to the new source costs fwthe carbon adsorber isthe same as the retrofit factor used for open tcp vapor degreasers. 

### Most existing facilities already have steam raising capacity to operate
a stiY 

### toreclaim dirty solvent. These facilities could possibly schedule their stean boiler to desorb the carbon bed during periads when the still is not used. For most retrofit situations, the installed capital would lie somewhere between the costs shown for new and existing facilities. The figure of $8,550 shown for the existing facility on the monorail degreaser compares reasonably well with a figure of $8,294 

### (1975 

### dollars) 

### on
an actual facility.'' The latterwould be $9,123 in 1977 

### dollars based 

### on the
use cf the Chemical Engineering Plant Index. The retrofit factor used to estimate costs for chillers is the same as the one used for the chillers 

### on open 

### top vapor degrsasers.

### The cost of hydrocarbon control pzr kilogram shol~n in Table 3-7 

### for the carbon adsorber on 

### a new faciljty costs $0.10 ?er kilogram for the cross

### rod degreaser. On 

### the other hand, the application of a carbon adsorber results in a saving of $0.201 for the monorail degreaser. On 

### the retrofitted facility, 

### the application of the carbon adsorber costs $0.289 

### per kilogram for thc crcisrod degreaser but 

### results in a 

### savings of $0.125 for the monorail degreaser. Itmust be noted that the difference in cost for the 

### two degreaser models is sensitive to the emission rate and potential solvent recovered because the annualized costs of instailing an3 operating a carbon adsorber are assumed +o 

### remain approximately the same in both cases. This is an important consideration in the i~pact of control upon the owner of the degreasers. The refrigerated chi1ler appears to be inexpensive to the user regardless of the type of degreaser and the degree of retrofit. This isdemonstrated by 

### the savings shown for all cases in

### Table 4-7. 

### 4.4.3 

### Cost-Effectiveness This section provides a graphical analysis of the cost-effectiveness for alternative control options on conveyorized degreasers. This analysis will relate the annualized cost per kilogras of hydrocarbon control to degreaser size for each control option. figure4-2 

### shows a relationship of cost versus size for carbon adsorbers and refrigerated chillers on monorail degreasers. The assumptions regarding the size range and control efficiencies are similarto those outlined for open top degreasers. The size range of most monorail degreasers is 1.9 to 18 square meters. As shwn in Figure 4-2, 

### the application of carbon adsorption results 

### in an out-of-the-pocket expense for degreasers smaller than approximate1 2 

### square meters in working area. 3y 

### the same token, carbon adsorbers can

### be quite cost-effective for degreasers with 

### large airto vapor working areas. Figure 4-3 

### shows 

### a siniilar relationship for cross-rod degreasers. There

are two important differences between Figure 4-3 

### and Figure 4-2 

### for the monorail degreasers. First, the sizerange isnarrower for the cross-rod degreasers. The range formost xoss-rod degreasers is 1.9 square meters to 4.8 

### square meters. For monorail degreasers the range is 1.9 to 18 

### square meters. Second, controls are generally more expensive for cross-rod degreasers than for monorail degreasers. In 

### particular,the cost of carbon adsorption appears to be 

### mcre than offsetting solvent credits along the entire size range. This is shown by the position of the carbon adsorption curve in relation to the horizontal 1

### ine of $0. 

### per kilogram control in Figure 4-3. 

### The information depicted in 

### the two figures formonorail and cross-rod degreasers demonstrates the variation in costs with

### degreaser design that can be anticipated for conveyorized degreasers.

### 3.6 

### REFERENCES Surprenant,

### K.S. 

### ,and Richards,

### D.W. 

### , "Study to Support New Source Performance Standards for Solvent Metal Cleaning Operations

### " prepared for the Environmental Protection Agency, Contract No. 68-02-1329, Dow Chemical Company,Midland, Michigan, June 30,

### 1976. Anon., "Typical Electric Bills 1976," Federal Power Commission. Chemical Marketing Reporter, Schnell Pub1ishing 

### Co. ,March 7,1977. Private communication, Frank L. 

### Bunyard, OAQPS, Environment21 Pr~tectior Agency, to Jerry Shields,Vanager of

### Marketing, Graymills, Chicago, August, 1976. Private communication,Frank L. 

### Bunyard,OAQPS, Environmental Protection Agency, to Jerry Shields,Manager of Marketing, Graymills, Chicago, August, 1976. Surprenant and Richards,

# x.cit., Appendix C-4. 

### - Private communication,Frank 

### L. Bunyard,OAQPS,Environmental Protection Agency to Parker Johnson,Vice President of Sales, Baron Blakeslee Corp., Cicero, Illinois,March 16, 1977. Private communication, Frank L. 

### Bunyard, OAQPS, Environmental Protection Agency to Dick Clement, Detrex Chemical, Detroit,Michigan, March 21, 1977.. Surprenant and Richards,OJ. 

### cit., page 4-97.


## - Surprenant and Richards, 

### 9. cit., Appendix C-7.


## -

'

### Ibid page 10.CHArTEF! 5. FDVERSE ENVIRONMENTAL EFFECTS 0' AFPLYING THE TECHNOLOGY


### 5.' AIR IMPACTS 

### No significant adverse airimpacts should result from solvent degreas4r1g 

### regulations, a1though gross ,:eel

### icence wjth

### maintenance and operatic- 2r' 

### control devices could increase emissions in

### individual cases. Examryes are carbon adsorotion systems operating with 

### spent or saturated adscrbent, maladjusted refriger?.tion sycterns and excessive vent;lation rates. 'r3per maintenance and o?eration of these controls will eliminate increases and 

### effect significa~t reduciicns in enissions. Improper incineration cf 

### waste solvent is another possfble area ,"here emissions could increase. If 

### chlorinated waste solvents are incinerated without subsequent 

### gas cleaning, hydrcchlor'c acid, chlorine, phosgene and cther potentia1ly harmfulIy emissions could result. Scpkisticated ga, cleaning equipment iz 

### req~ii red 

### t~ccctrol these e~i ssions. Eciler eaissqons r,lay increase due to the stearr required tc?

### distiyl waste solsrentand recjenerate carbon ~eds, b lt iri 

### general these increa~es tviii be 

### insigificant compared tc the 

### emission reductions obtained cy this eqirio ieqt.
5.2 MTER IlzlPACTS 5.2. 

### I Waste Solvent Disposal The major potential water pollutants from solvent degreasers are waste

### solvents. Waste solvent can enter natural water systems through sewer disposal or as leachate from landfi11s. Additional airpollution controls

are not expected to allow sewer or improper landfill disposal because much of 

### the solvent would eventually evaporate. Thus, water pollution would probably be diminished by additional air pol1 ution control. 5.2.2 

### Steam Condensate from Carbon Adsorption The largest impact on water quality resulting from the control of solvent r~reta;cleaning comes from the use of carbon adsorption. Steam used to desorb the solvent is condensed with the solvent and separated by gravity. Water 

## * soluble stabilizers and some solvent will remain with the water and eventuall: enter the sewer system. Stabilizers are organic chemicals added in

### very small quantities to chlorinated solvents to protect them from decomposition. Stabilizers evaporate from the degreaser as does the chlorinated solvent and both are amenable to collection by adsorption. Furthermore, many stabilizers are water miscible and thus will be removed almost completely from the process during steam desorption. Chlorinated solvents are only slightlywater miscible but 

### small quantities wi11 

### remain with 

### thewater. 5.2.2.1 Chlorinated Solvent i

### n Steam Condensate 

# - Solvent discharge into the sewer can typically reach 190 kg (0.13 rn

### 3 

### or 35 gallons) per year. This assumes solvent at

### a concentration of 900 ppm 

### in the condensate and a total of about 40,000 gallons per year of steam condensat 

## *Stabilizers may also be referred to as inhibitors oradditives. Some

-

### stabilizers are normally lost into the water of the degreaser's water

separator, but the quantity of this water is negligible compared to that from steam 

### stripped adsorption systems.In 

### comparison, the reduction in atmospheric 

### emissions from the degreaser by 

### 3 

### using the carbon adsorber wouId 

### typically be 14,000 kcj (10 n 

### or 2500 gallons) per year. Therefore, in this case potential sewer emissions 

### of solvent (before evaporating) are less than about 1.5 percent 

### of the degreaser emissions prevented by the carbon adsorber. The above estimates are based on two tests which measured the solvent content in waste water from adsorbers used on chlorinated solvents.132 

### 5.2.2.2. Stabilizers in Steam Condensate 

### - In addition 

### to chlorinated compounds, steam condensate wi11 contain small amounts of solvent stabilizers. Nhen the condensate is disposed of most of these stabilizers, because of their volatile nature, will eventually evaporate The highest sewer stabilizeremission would probably occur with 1,1,1- trichloroethane which requires considerable amounts of water soluble stabilizers. Assuming a solvent recovery rate of 10

### m' per year (2500 gallons per year), 5 

### percent stabilizers in the 1

### ,l,l-trichloroethane blend and 40 percent of the stabilizer being water soluble, the stabilizereffluent to the sewer would be 3 

### 0.2 m 

### per year (50 gallons per year). This would be the worst case; however, and itmay not be representative of any actual degreasing processes. The captured solvent vapor does not necessarily contain as high a precentage of stabilizers as does the original liquid solvent. For this reason even systems using 1,l,l

### -trichloroethane may not emit this amount. Furthermore, other major solvents contain less water soluble stabi1izers than 1

### ,l,1-trichloroethane; therefore, the average stabilizeremission would be less than 0.2 m 3 

### per year. A 

### method for assessing the impact of the stabilizers would be to analyze the toxicity, water solubi1

### ity, percent composition, volatility

### ,and BOD 

### (relates to the decomposition rate) for each stabilizer. Unfortunately, percent compositions are generally considered trade secrets by solventmanufacturers. However. a litersture search yielded some data which isgiven iri Appe,:dix B 

### 6 ? After studyina the effects of some of the more toxic substances, itwas concluded that only diisobutylene and triethylamine. which are used in trichloroethylene, present any significant potential problem with regard to i'sh toxicity.' Two other stabi1 izers of possible concern are acrylonitrile and epichlorohydrin, although the data on them are not vet conclusive. If the quantity of stabilizers and solvent dissolved inthe steam condensate were found to be significant, then air sparging could dramatically reduce the levels of a11 these compounds. During sparging itmay be advantageous to vent the off-qas back into the adsorber. Thus, atmospheric emission of the sparge off-gas would be controlled. Furthermore, more stabilizer would tend to remain inthe recovered solvent. Although sparging appears tobe an inexpensive means of treating the waste water, the data thus far have not indicated a significant environmental need. 5.2.3 Effluents from Water Separators Water separators on vapor degreasers and distillation units collect a small amount of contaminated water. This isgenerally less than a gallon or two per day per degreaser, and should not create a significant impact on water qua1 ity. De-icing of refrigerated control systems which operate below 32O~, will increase this, but probably not enough to create a problem. Steam stripping of still bottoms indistillation units to reduce solvent content will also increase this amount, but again probably not enough to create a problem.


### 5.3 SOLIDWASTE IMPACT There appears to be no significant solidwaste impact resulting from control of solvent degreasers. The quantity ofwaste solvent would not increase
as a result of controls but should decrease because of increased practice

### ofdistillation and incineration. Carbon used in carbon adsorber beds isdiscarded periodically. Vendors and users have estimated the life of carbon at

### up to 30 years but replacement is generally recommended every 10 to 15years. Assuming there are up to 7,000 degreasers, using 50 kg of carbon each and averaging a 10 percent annual replacement rate, disposal of carbon from adsorbers could reach 35,000 kg annually for the nation. This amount would never be realized, however, because spent carbon can easily be reactivated. Most major activated carbon manufacturer:

are equipped for this task.
5.4 

### ENERGY IMPACT Carbon adsorbers, refrigerated chillers and distillation units are the principal energy consuming control devices used for controlling degreasing emissions. 

### A carbon adsorber consumes the areatest amount of enerav because of st.~arn required for desorption; however, this energy expenditure is far less than the energy required to manufacture replacement solvent. 

### A typical carbon adsorption system on a degreaser may consume 35 

### kw (120,000 

### Btu per hour) of energy and

recover 7 kg per hour (15 pounds per hour) of solvent. This energy consumption estimate is based on the following assumptions: 4 kw per kg solvent for steam production, 

### 3 to 12 

### kw (10,000 to 40,000 

### Btu per hour) for fan power. 

### A carbon adsorber may typically increase the energy consumption of a vapor degreasing 

### 4 system by 20 percent. A typical refrigerated freeboard chi1lermay increase 

### a degreaser

### 's energy consumption by 5 percent. The chi1lerwould consume 0.7 to 2.2 kw (2500 to 

### 7500 

### Btu per hour) if itran at 100 percent output. The above values are derived from assuming an average of 1 to 3 horsepower for compressor ratings. 

### A chiller

### may reduce emissions by about 1.5 kg 

### per hour (3 1

### bs per hour) 

### on a typical 2 

### open top vapor degreaser having a 1.7 m 

### (18 square feet) opening. Thus, roughly 0.5 kw


### . hr may be spent to save 1.5 kg of solvent.5 

### Solvent distillation requires about 0.1 

### to0.2 kw 

### hr/kg of recovered solvent (150 to 300 Btu/pound). Assuming a steam cost of 0.78 

### centsjkw-hr (2.30 $/lo

### 6 

### Btu), then the energy costs 0.08 to 0.15 $/kg of distilled solvent (0.035 to 0.07 

### t/lb). Considering that chlorinated solvent costs about 45 

### $/kg (20 $/lb), the cost of 

### the distillation energy appears to be an insignificant expenditure.6 

### Other vapor control devices are the powered cover and powered hoist. Their energy consumption isinsigificant because the electric motors are small and are used only for short durations. The energy value of the solvent saved ismuch greater than the energy expended to conserve the solvent. The energy value of the solvent iscomposed of the solvent manufacturing process energy plus the 

### heat of combustion lost when the processed petroleum feedstock is not used as fuel, plus other energy consumed to replace the lost solvent. The heat value of the feedstock alone is greater than the energy required to recover the solvent. Without doubt control of solvent emissions, by any method, would have a favorable impact on energy consumption.
5.5 OTHER ENVIRONMENTAL CONCERNS The only other consideration might be blower noise associated with carbon adsorbers. This noise does not affect the environment external to the plant, although itwould be noticeable inside the plant near the adsorber. Noise levels have not been measured because they have not appeared significantwhen compared to the normal noise level in machine shops and other manufacturing areas where

### carbon adsorbers are found. While noise does not seem to present a significant environmental problem, it is worthy of consideration when choosing the in-plant location for a carbon adsorber. This problem could be resolved by utilizing existing noise suppression technology.REFERENCES 

### 1. Sc,iei1

### , George 'X. 

### , Mio:,est Research Institute. "Source Test Trichloroethylene Degreaser Adsorber

## ." EPA Project Report No. 76-DEG-1. 2. Schei1, George !,I. "Test of Industrial Dry Cleaning Operation," EPA Report No. 76-DRY-2. 3. Surprenant, K..S. and Richards, D.!d., Dow Chemical. "Study to Support New Source Perfornlance Standards for Solvent Metal Cleaning Operations," Prepared for 

### EPA, Contract No. 68-02-1329, Task Order 

### No. 9. 

### 4. IBID. pg. 7-8. 5. IBID. pg. 7-9. 

### 6. IBID. pg. 7-9.

### CHAPTER 6. 

### COMPLIANCE TEST 

### METHODS AND 

### MONITORING TECHNIQUES
It is not expected that emission testing will play a significant part in a compliance program for degreasers. This results from the difficulty in measuring emissions and in enforcing emission standards, as discussed in Chapter 7. 

### Instead, equipment and operating practice standards appear to be

more realistic options. In 

### these, compliance relies principally upon observation 

### to determine if control equipment isdesigned and functioning properly and to ensure that operating practices, as observed under normal conditions, are being properly followed. Although the compliance emphasis should be on equipment and operating practice standards, the emission rate of a degreaser system may be useful supplementary information. For example, if emissions are greater than average for a system of a certain size, itisan indication that the system is inadequately or improperly controlled. Emission rates can be estimated roughly with an analysis of solvent purchase and inventory records and more accurately with a material balance test. Other emission tests that could be useful in compliance programs are tests for leaks and tests of carbon adsorption off gas streams. The costs of these tests will often be offset by solvent savings from reduced emissions. An investigator with some familiarity with degreasers and carbon adsorption systems can frequently identify defective systems with a brief inspection and,thus, avoid the expense of emission testing.

6.1 OBSERVATION OF CONTROL EQUIPMENTAND OPERATING PRACTICES Ifthe degreasing regulation specifies equipment and operating standards, the compliance test isbasically one of visual observation. The observation control equipment and operating practices mainly involves checking throuqh a listof requirements; however, 

### a basic understanding of degreasing systems isnecessar.~. The details to observe are described inSections 3.1 and 3.2 of this report.
6.2 MATERIAL BALANCE A material balance test seeks toquantify the amount of solvent input into a degreaser over a sufficiently long time period so that an average emission rate can be calculated. The major advantages of the material balance method are: (1) the total system ischecked, (2) the test issimple and does not require expensive, complicated test equipment, and (3) records
are usually kept of solvent use, and generally all solvent added ismake-up for solvent emitted. The disadvantage of the material balance method isthat it istime consuming. Because many degreasers are operated intermittently and because there is inaccuracy indetermining liquid levels, an extended test time is needed toensure that calculated emission rates are true averages. Inorder to perform a material balance test, the following general procedure should be followed: 1. Fi11 the solvent sump (or bath) to a marked level. 2. Begin normal operation of the degreaser, recording the quantity of make-up solvent and hours of operation.3. Conduct the test for about four weeks, or until the solvent loss is great enough to minimize the error inmeasurement. 4. Refill the solvent sump to the original, marked level, recording the volume of solvent added. The total volume of solvent added during the test period approximately equals the solvent emitted. Although a highly accurate material balance isnot usually necessary, the following modifications will improve the accuracy of the test. 1

## . Clean the degreaser sump before testing

## . 2. Record the amount of solvent added to the tank with a flow meter. 

### 3. Record the weight and type ofwork load degreased each day. 4. At the end of the test run, pump out the used solvent and measure the amount with a flow meter. Also, approximate the volume of metal chips and other material remaining inthe emptied sump, if significant. 

### 5. Bottle a sample of the used solvent and analyze ittofind the percent that isoil and other contaminants. The oil and solvent proportions
can be estimated by weighing samples of used solvent before and after boiling off the solvent. Calculate the volume of oils inthe used solvent. The volume of solvent displaced by this oil along with the volume ofmake-up solvent added during operations isequal to the solvent emission. Proper maintenance and adjustment should be performed on the degreaser and control system before the test period.

6.3 OTHER EMISSION TESTS An emission measurement test on the off-gas stream from a carbon adsorber may occasionally be necessary. However, this has value only inevaluating the adsorption efficiency not the control efficiency of the system. This test will give no indication of the effectiveness of the adsorber's collection

### system; neither will itguantify emissions from waste solvent evaporation, leakage losses, carry-out or sump evaporation. The better sampling systems for organic solvents use gas chromatography (GC). 

### Techniques for using GC 

### are discussed in

### EPA-450/2-76-028, "Control of Volatile Organic Emissions from Stationary Sources. Volume 1: 

### Control Methods for Surface Coating Operations." A 

### specificmethod for perchloroethylene isalso detailed as EPA 

### Method 23: 

### "Determination of Total Non-Methane Hydrocarbons as Perch1oroethylene from Stationary Sources.

### " Finally

### , a method for another chlorinated hydrocarbon isEPA 

### Method 106: "Determination of Vinyl Chloride from StationarySources." For stack measurments, velocity and flow rate can be determined using EPA 

### Methods 1 and 2. 

### One EPA 

### emission testmeasured carbon adsorber inlet and outlet concentrations both with

### a flame ionization detector and with 

### a gas chromatograph, using integrated gas-bag samples. The methodology and test results are detai1 ed 

### in EPA 

### Project Report No. 76-DEG-1. Useful tools in locating leaks and otherpointsof

### emission are the ha1ide torch and the Drager tube. The halide torch isuseful as a locating device that will detect sources of halogenated hydrocarbon vapors. The Drager tube will quantify the vapor concentration in

### ppm and 

### is useful in survey work. These should be useful and relatively inexpensive means to locate sources and quantify by magnitude the hydrocarbon loss. They would allow a maintenance check of control equipment operation and prevent inadvertent losses.CHAPTER 7. ENFORCEMENT ASPECTS
Emission standards are generally not practical toenforce for solvent degreasing for three reasons: (1) there isan extremely large number of solvent degreasers, (2) emission tests are time consuming, and (3) there are complexities inspecifying acceptable emission rates. Inorder to avoid use ofemission standards and to provide quick, inexpensive compliance testing, equipment and operational standards are recommended. Even though visual inspection isrelativelyquick and inexpensive, it
can not easily determine whether or not the equipment and operation is in compliance. For example, on cold cleaners itmust be determined whether
or not it ispractical to install an internal drainage facility. Also, for highly volatile solvents incold cleaners, one must decide whether or not the cover can be classified as easily operable. Another example i s i n deciding what issignificant liquidcarry-out. Even though Chapters 3 and 6 give background on making decisions for visual inspection, the inspector still needs an adequate background knowledge of degreasing operations todeal with some ofthe less definite aspects ofenforcement. Because most emission controls serve to reduce the emissions inside the plant, itis reasonable to consider combining enforcement by OSHA and EPA for control of solvent degreasers. The possibi1ities ofa cooperative enforcement program with OSHA and EPA are being explored.7.1 REGULATORY APPROACHES There are four types of regulations which can be considered for solvent r8ietalcleaning: (1) emission standards, (2) equipment specification standards, (3) operational requirement standards, and (4) solvent exemption standards. Equipment and operational standards appear to be superior to either emission standards or solvent exemption standards. Each of these approaches is discussed inthe following sections. 7.1.1 Emission Standards Emission standards require an emission measurement. A material balance isthe most accurate measurement method for compliance testing but could require over a month for one test. Ifsolvent consumption records kept by the degreasing operator are accurate and complete, they could satisfy the requirement for a material balance test. Ifenforcement were only to determine whether or not degreasing systems
are designed properly, then one emission test would be sufficient for each degreaser model. However, adjestment, maintenance, and operation of degreasers varies so greatly that the actual level of emission control cannot be expected to be sinii1 ar, even for identical degreaser models. Thus, individual degreasers rather than models must be evaluated. An emission standard may be a simple emission rate or itmay be related to another variabie, such as work load tonnage, heat input, idlingmode emission or uncontrolled emission rate. The three most reasonable alternatives for emission standards are: (1) simple emission rate, (2) emission rate per open area of degreaser and (3) emission rate per work load tonnage. These alternatives are briefly discussed below. The simple emission ratestandard provides a conventional regulationthat isreadily understood. However, different values of acceptable emission rates would have to be provided for each type of degreaser. 

### Itwould also not be reasonable to require the same emission ratefor large degreasers as for small degreasers; this would require an emission rate based on the open area of the degreaser. A1though eniission rate is related to the area of the air/vapor interface,
an important consideration isthe amount ofwork load processed. Thus, possible improvement toan eniission standardwould be to relate itto the work tonnage, for example, a specified amount of solvent emission could be allowed per ton of work load cleaned. This type of standardwould be particularly useful if the work loads were consistent intheir surface-to-wei ght ratioand their tendency toentrain solvent; however, this is rarely the case. For example, degreasing a ton of hollow rivetswould result inmuch greater solvent emissions than would degreasing a ton of cannon balls. Generally, for an emission standard toapply fairly to all degreasing applications, itmust relate to the amount and type ofwork load. Preferably, the emission standard should also consider the type ofdegreaser and itssize. Even ifan emission standard could be devised to satisfy these requirements

### , itwould be d i f f i c u l t t oenforce and very burdensome for degreasing operators to have to record quantities and types of pir t s c l eaned

# . 7.1.2 Equipment Standards Equipment standards can be easily enforced and fairly applied tothe larse variety ofdegreasing applications. Equipment standards would not require the same performance by a degreasing operation with a largework load as that with a small work load. The equipment requirement must be specific enough toensure effective control but not so restrictivethat itwould discourage new control technology.

### For example, the high freeboard, refrigerated chi1

### ler, and carbon adsorption venti1

### ation rate can be specified 

### to ensure sufficient emission control. The specifications usually represent an engineering judgement by experts in the degreasing fields and could be revised as new test data are collected. Another type of specification for control gquipment is the exemption of degreasers that are too small for control equipment to be economically reasonable. Particularly in the case of refrigerated chi1

### lers and carbon adsorbers

### , installation could 

### be too expensive for snal1 degreasers and could


### even cost more than the degreaser itself, thus, a lower level cut-off of approximately 1 

### m2 

### for open top vapor degreasers isrecommended. Because 

### of the continuing developments in emission control for solvent degreasing, provision must be 

### made to approve control systems that do not satisfy the requirements specified in this document but may still be effective. Section 3.2 

### describes equipaent and operational standards that can be formulated. Operational Standards As with equipment standards, operational standards can apply to almost all degreasing applications, regardless of their size and type of work load. Operators will play a key role in achieving emission control ;

### however, they will have little incentive to follow complex standards. 

### Thus, the standard must be simple, understandable, and precise. The numerous operational requirements can be more easi ly remembered by the operator if a permanent, conspicuous label is attached to the degreaser summarizing them. The difficulty of enforcement may be minimized by educating the supervision and the operator to the fact that proper operation and control equipment maintenance will usually provide a net profit from solvent savings.7.1.4 Solvent Exemption Standards There is very littleflexibility inconverting from non-exempt to exempt solvents. A recent EPA notice (42 FF. 35314) has suggested that the only materials that should be a1lowed exemptions are methane, ethane, 1 ,I,Itrichloroethane, and trichlorotrifluoroethane. This choice isfurther 1imi ted because of differences insolvency

## , fl ammabi1ity

### , cost, chemical stabi1ity and boi1 ing temperature. Ingeneral

### , the exempt solvent approach to reg.ulating solvent metal cleaning isnot recommended, because itdoes not achieve positive emission reduction. The rationale for this isdiscussed further inChapter 1.
7.2 AFFECTED FACILITIES

# - PRIORITIES Since there isa wide diversity of solvent degreasers, the definition of faci1

### ities affected by degreasing regulations must be accurate. A1though a11 solvent degreasers may be subject to potential regulations, there are
an extremely large number of degreasers; thus, those with greater emissions should be given higher priorityfor enforcement. 7.2.1 Definitions ofAffected Facilities The following defines the three types ofsolvent degreasers that can be regulated. 1. Cold cleaner: batch loaded, non-boiling solvent degreaser 2. Open top vapor degreaser: batch loaded, boiling solvent degreaser 3. Conveyorized degreaser: continuously 1oaded, conveyorized solvent degreaser, either boiling or non-boiling. 7.2.2 Priorities of Enforcement Individual degreasers thatyieldthe greatest emission reduction at reasonable cost should have the highest p r i o r i t y f o r enforcement. Within

### that grouping, priority operations are vapor degreasing 

### and waste solvent disposal from all degreasing operations. The lowest priority is assigned to cold cleaners

### ,especia1ly niaintenance type with 

### 1

### ow volati1

### ity solvents, such
as those used with automotive repair. An 

### emission reduction of 5 to 15 tons per year can be achieved by control1ing 

### a typical open top vapor degreaser or conveyorized degreaser. In comparison, emissions from individual cold cleaners usually cannot be reduced by more than 0.1 tons per year (seeAppendix B). 

### Even though conveyorized degreaser emissions can be reduced more than open top vapor degreasing 

### emissions on the average, regulation of conveyorized degreasers before open top vapor degreasers is not recommended, because-conveyorized degreasers emit significantly 1

### ess solvent than do open top vapor degreasers for an equivalent work load. Thus, itwould not be advantageous to encourage degreaser operators to choose open top vapor degreasers in order to avoid regulations on conveyorized degreasers. Waste solvent is a high priority area forcontrol. Controls could be directed towards solvent users, solvent producers, and/or solvent disposal facilities. It is the reeponsibility of the solvent user to properly dispose of his waste. Facilities which accept waste solvent must use disposal methods which minimize evaporation. It is recommended that solvent producers 1

### abel new solvents to indicate regulations on waste disposal. For example, a label could read that waste solvent should not be 

### disposed of so that itcan evaporate into the airor pollute the waters. In addition to regulating degreasing waste solvent disposal a more comprehensive enforcement program which would cover disposal of all waste solvent and similar volatile organic materia1s should 

### be considered,.

### Although enforcement of regulations on cold cleaners ismade difficult by 

### their large numbers, itcan be practical when enforcement trips are combined with 

### other purposes, or if there are numerous cold cleaners and other solvent degreasers at a particular plant.APPENDIX A. TEST RESULTSAPPENDrX A: TEST RESULTS CONTENTS Page 

### A. 1 Test 

### results

### from Dow Report 

# . . . 

# . . . 

# . . . . 

# . . . . . 

# . . 

# . . A-1 A.2 EPAColdCleanerTest Report. 

## . . 

# . . 

# . . . 

# . . . . 

# . . 

# . . . 

# . . A-3

### A.l TEST RESULTS 

### FROR TtlE DON REPORT Under contract to the EPA the Dow Chemical Company tested eleven solvent metal cleaners. Detailed reports of each test are contained in the Appendices to the document: "Study to Support 

### New Source Performance Standards for Solvent Metal Cleaning Operations," prepared under EPA contract no. 68-02-1329 by K. 

### S. 

### Surprenant and 

### D. W. 

### Richards and dated April 30, 1976. 

### A summary of the

### results is

### given inTable A-1

# .- TABLE A-!. TEST RESULTS FROW OOH REPORT SATISFACTORY CONTROL SYSTEM5 Lbw Report' Uncontrolled Emission Rate Contrllled Ernis~ion Controlled Appendixl User oegreaser* vapor Area Solvent (gal/unit) (lb/ft2-hr) (galjunit) (lb/ftz.hr) Efficiency Control System Cments C-5 Pratt Yhitney OTW 65" 110" l.!,l 97.5 galjwk 0.16 58.4 galiwk 0.10 40; Cover-pneumatically Uncovered to1 24 1' and 49.6 ft2 ijowerid 7 da,,/wi C-2 Eaton OTVD Tri. lblton 99 Iblton 239 Cover jmanua:) iio much infarnation on the test. .>, I , III ibiton 80 lbiton 289 C-12 Dm Lab OW0 24.2"x22" 1.1.1 0.373 0.373 0 TR = 0.5 Idle (no work lc?dc,),moderate draft 3.7 ft2 0.373 0.273 27% = 0.75 0.373 0.167 552 = 1.0 24.2"x22" 1 .I.1 0.955 FR = 0.5 idle, quipt ?lr 3.7 ft2 0.955 0.051 46a 0.75 0.955 0.054 43% 1.O C-3 Hamilton OTYO 15 ft2 llethylene i.5 gal opday 0.186 4.53 gallopday 0.112 >40% Cold Trap Work loadwhen CT on was 50%more than when Standard (1203) Chloride 6.43 gal/day 3.67 gal/day ,43% FR = 0.83 (covered CT off +fb40Z. during disuse) OTVD 11.1 ft2 kethylene 3.63 gallopday 0.450 2.60 gal/opday 0.322 28% Cold Trap Inaccurate results. The ObR deg is expected to (OhR) Chloride 2.9 qallday 1.73 gallday 40% FR = 0.75 have a higher n, due to being uncovered. OLR had (never covered) 1 % wo loa s per operating day whereas X203 had $1!o i3WCtdiopiay. P C-10 ' Vic OW0 12'x4.5' Tri. 108 gal/wk 0.605 38 galiwk 0.213 65% Carbon adsorpt:on Yentilation rate of 10: i:m;ft?. Accuracy of record-keepinq N 54 ft2 is reported by Ocw to be poor. Thus. accuracy of results would be poor. C-7 Schlage Lock CVD- 41.3 ft2 Perc. 19.5 gal/wday 0.79 7.5 gallwday 0.304 62% Chiller Range of n 1s 45 to 65*. knorail C-11 Y. Electric CNO Tri. 0.063 gal/ft2 of - 0.025 gal/ft2 - 60% Carbon adsorption Hawthorne defluxer clrcui t board 23.8 gallwday 10.4 gal/wday UNSATISFACTORYCOITROL SYSTEKS C-5 Pratt Uhitney OTVD 5Vx90" 1.1.1 58 gal/wk 0.138 49 galiwk 0.117 16% Cold Trap FR = 59%. Cold Trap desion tested here was reported as an 35 ft2 obsolete model. tovered during disuse. C-8 Super Radiator OTVO 6'xlZ' Perc. 49 gal/day 1.53 37 gal/day 1.14 -8% Carbon Adsorption Defective adsorption system- bre kthrough; insufficient 1 72 ft2 FR 0.04 ZFR- 0.1. Only 37 cfmlft C-4 Hewlette MD 214 Carbon Adsorption LOW contml efflclency of the adsorption system isthought Packard Monorail to be because of poor ventilation design. Developer C-9 J. L. CVO Tri 1.4 gallhr 1.06 gal/hr 25% Carbon Ad~orption Materia: Falance results Thonpson Crossrod 50.5 gal/wk 49.5 gallwk 50% Carbon Adsorption Resulcs from purchase records mreviations: OTVD = Open Top Vapor Oegreaser, CVD = Conveyorized Vapor Degreaser, CND = Conveyorized Non-boiling Degreaser, Opday = Day degreaser is inoperation, wday = work~ng day, CT = ColdTrap, FR = Freeboard Ratio lb/tov = pounds of solvent emitted per ton ofparts degreased, WKLD = work toad, 1 .I.l = mthyl chloroform, Tri. = trichloroethylene, Perc.

# - perchlorwthylen~. '7he appendix of the Dow Report describes each test indetail.A.2 EPA COLD CLEANER TEST REPORT

### TEST 

### REPORT 

### EVAPORATIVE EMISSIONS STUDY 

### ON 

### COLD CLEANERS



### Walter Pel

### 1etier Peter R. Westlin

U.

### S. 

### ENVIRONMENTAL PROTECTION AGENCY 

### Office of Air 

### Qua1 i

### ty 

### Planning 

### and Standards Research Triangle Park, North Carol ina 

### 2771

### 1 May, 1977A.2 EPA COLD CLEANER TEST REPORT

### TEST REPORT EVAPORATIVE 

### EM1SSIONS STUDY ON COLD 

### CLEANERS

Walter Pel1etler Peter R. 

### Westlin



### U.S. ENVIRONMENTAL PROTECTION AGENCY Office 

### ofAir 

### Qua1ity 

### Planning and Standards Research Triangle Park, North Carolina 27711 May, 

### 1977

### SUMMAKY A 

### preliminary study of coid 

### c1eaner solvent kn~i ssions was undertaken, the purposes of which were to quantify hydrocarcon solvent evaporation 1

### osses from typical air-agitatea, 

### p~iiipagi ttiteci, iind 

### unac;i

### tatxi ccld c1eaners ;

### and to establish relationships between eviiporation rates and several controlled test parameters. These parameters included solvent volati1 ity, room draft velocity, freeboard ratio, and cold cleaner opeiat'on. desults of these tests indicate that i-,ighly volati1e solvents, such as .~orcnloroethyIene, used in different types of ~oici 

### cleaners with different types of solvent agitaticn produce conparable evaporation rates. Solvents EK-;;ions from air-agitated, purng-agitated, and unagitated urlits showed similar
as the solvent. Mi

### th

### less volatile test 

### results ~ith 

### perchl~roet~lylene sc;vents, such as Minerai Spirits, agitated ccld cleaners showed significantly 2 

### 3ater solvent emissions than did the una~itated. In addition, these test resuits

### demonstrate a tendency for solvent emis.sions to iricrezse as the room *raft 

### velocity 

### is increased. Closing the cover on 

### a cold cleaner drastically reduces solvent emissions as is also shown in these tests. An 

### increase in

### solvent emissions with a decrease in freeboard ratio in unagitated units is indicated by 

### these test rerults. Also indicated is an effect ori 

### sol>sntemissions caused by the shape of the solvent-to-air interface area ~f 

### unag;tzted tanks. For these tests, a square solvent-to-air interface surface reshi

### ted in

### greater solvent emissions than did a rectangular one. This result may be 

### affected by the orientation of the tank 

### lothe room draft airmovement. "he effect of solvent volatility on evaporatioc rates isshown as increased

* 

### o;atility produces increased solvent emissions. The largest difference between sdl

### ~ent emisbion rates isshown between tests with the highly volatile, relatively pure perchloroethylene and the mineral spiritsmixtures.TABLE OF CONTENTS Page Kc:

. I

# . INTRODUCTION

# ................... 1

11

# . EQUIPMENTAND SOLVENTS 

# .............. 1

I11

# . TESTPROCEDURES

# .................. 2



### IV

# . DISCUSSIONOF RESULTS

# ............... 5 Appendix A: Test Data

# ............ 16 Appendix B: Solvent Analyses 

# ........ 21

### I. 

### INTRODUCTION The Emission Measurement Branch of the Emission Standards and Engineering Division undertook, a laboratory study of cold cleaners used for parts degreasing. The Furpose 

### of the study was twofold: first, to quantify hydrocarbon solvent evaporation losses from typical ai r-agitated, punp-agitated, and unagitated cold cleaners; and second, to establish relationship between evaporation rate and several test parameters including sol vent volati1i

### ty,
room draft velocity, and free-board ratio. In this preliminary study, a minimum number of data have been collected. In most cases, each data value represents only one test 

### run, the curves are plotted with only two or three points, and comparisons aremade based on only two or three test runs. The results included in

### this report should be regsrded
as preliminary and, atbest, only indications of trends that can occur with cold cleaner solvent emissions. The tests were conducted atthe IRL laboratory under controlled corditioiqs. Four different cold cleaner models were used for this study: 

### an aii-osi

### Wed Kleer-Flo model 90 unit, a pump-agitated Gray Mil1 s model 500 

### cleaner, 

### a KlzerFlo model A-15 unagitated unit, and a Gray Mil1s 

### model SL-32 unagitated cleaner. The four different solvents used for these testswere perchloroet:;: --7.2, ,0? 

### mineral spirits, 112mineral spirits, and 140mineral spirits. The results areexpressed in

### milliliters of solvent lost per hour per square meter of surface area (ml/hr 

# .m2) 

### and in grams of solvent ;ost per hour per square meter of surface area (g/hr 

# .m2)

# . These data are used to develop
curves displaying the re1ationships between evaporation rate and the test parameters. 11. 

### EQUIPMENTAND SOLVENTS A 

### schematic of the Kleer-Flo model 90, an air-agitated co:d cleaner, is

### 2 

### shown in

### Figure 1. The airfor agitation was supplied by 

### an industrial compressor, and the rate of air injection was setat

### a relatively constant 4 

### to 5 

### litersper minute with the use of a calibrated orificemeter. A1though 

### not used in any calculations, the airinjection temperature was monitored with


### a dial thermometer. The pump-agitated cold cleaner used in these tests was the Gray 

### Mills model 500 

### unit. 

### This unit was connected to a timer-switch set to

### run the pump 

### agitator for 20 

### minutes out of 

### every 65 

### minutes in a repeating cycle for all test runs. This was done to avoid over-heating the solvents and to more realis tically represent the operation of the cleaner

# . Tests of unagitated cold cleaners were performed using two different sized units. One was a Kleer-Flo model A-15 shown in Figure 2. 

### The other cleaner
was a 

### Gray Mills model SL-32. 

### Calibrated thermocouples were used to measure solvent temperature and ambient temperature for these test runs as well as for the other test runs. 111. TEST PROCEDURES 

### The measurements made foreach test included solvent volume, 

### room and 

### solvent temperatures, room draft velocity, and solvent density

# . Temperatures
were measured with chrome1-a1umel thermocouples cali

### brated atthe water-ice point and atwater boiling temperature corrected forbarometric pressure. Recorders were used to monitor these temperatures over an extended period of time. The temperatures reported in

### this report represent runs averages that 

### have ranges of about

# - + 

### 5'~. Accuracy of the measured values isestimated at

Room draft velocity was measured with 

### an A1

### nor thermo-anemometer he7d 

### 30 

### cm above the top of the tank. The measurements are estimated to have a



## - + 10

### percent accuracy for draft velocities above 30 

### m/min while below this

### 5 

### level, the accuracy falls to about - + 

### 20 

### percent. Solvent density was determined gravimetrically before and aftereach test run. Solvent volumes were measured with calibrated containers. Accuracy of these measurements is estimated to be about 

### - + 2 

### percent. Samples of solvents
were collected for analysis of distillation characteristics and volati1 ity. These data are shown in

### Appendix 6. 

### Prior to initiation of the test, the cold cleaner units were partially filledwith solvent and operated, if applicable, for a short period. This conditioning step filled any reservoirs with 

### solvent. After the cleaner was drained, a measured amount of solvent was placed in the cleaner and the test conditions were set as desired. Draft velocity was maintained with a laboratoryhood exhaust fan and small, caged, portable fans. At

### the end of the test period, the solvent was drained from the cold cleaner in the same manner as was completed earlier


## . The volumes were measured with

### calibrated containers and t~e volumes
were recorded. Test conditions such as solvent temperature, ambient temperature and humidity, and other test parameters were recorded. IV. DISCUSSION 

### OF RESULTS 

### Tables 1 and 2 

### show the results of tests with the air-agitated and pumpagitated cold cleaners, respectively. The test data for the two un~si tated units
are shown in Tables 3 

### and 4. 

### Figure 3 

### shows a plot of the relationship between evaporation rate of perch1oroethylene and room draft velocity for these clcaners. The scatter in the results shown on this figure indicates that the Type of cold cleaner and the agitation method have littleeffect on the evaporation rate of

a highly volatile solvent such as perchloroethylene. One 

### result that isevident isthat the evaporation rate of solvent increases with an increase in room draft velocity for all types of cleaners. The data show that for the air-agitated unit,

### TABLE 

### I. EVAPORATION 

### XATE TEST RESJLTS FOR 

### THE AIR-AGITATED COLD CLEA;.lIriGUYIT

Cover Room Draft Evapsration Rate Evrlpoimat:on Ra:e Solvent

tcrchloroethylet~e Opon 27 cl.5 99: Percnloroethylene Cpen 85 ;756 2846 ??rchloroethylene Closed 83 143 23:
-' _: Minera'l S,ji 1-its Open 140 Minera'l Spirits Open ;4C Mineral Spirits Open

### TABLE 

### 2. EVAPORATION RATE TEST RESULTS FOR THE PUMP-AGITATED COLD 

### CLEANING UNIT

Solvent Room 

### Draft (n/iiii

### n) Evaporation Rate jmljhr 

## . m ) 

### 2 

### Evaporatfon Rate (g/hr 

# . m 

### ) 2


### Perchloroethylene 64 

### 1167 1891

Perch1oroethylene 28 464 

### 751

Perch1oroethylene N

### o 27 

### Agitation
102Mineral Spiri

### ts

140 Mineral Spi

### ri

### tsTABLE 3. EVAPORATION RATE TEST RESULTS FOR AN UNAGITATED COLE CLEANING UNIT GRAY MILLS M03EL 5L-32 (3irnensions: 81 cix x 41 crn x 25 cm 3eep)

(Freeboard Ratio = Freeboard Height, 41 I

Solvent Freeboard 2atio Room Draft (r/rni n) Evaporation Xate (ml/hr 

## .rn2) Evaporation Rate &/nr 

## .m ) 2 Perchloroethylene 6-27 1873 Perchloroethylene 0.50 1311 Perchloroethylene 0.29 89 Perchloroethylene 0.92 12 102 Mineral Spirtts 0.5G 109 102Mineral Spirits C.25 

### 7 102 Mineral Spiri

### ts 0.50 6 140 Mineral Spirits 2.25 8 140Mineral Spirits 0.53 3

### TABLE 4. EVAPORATION RATE 

### TEST RESULTS FOR 

### AH UNAGITATED COLD 

### CLEANER

KLEER- FLO 

### MODEL A- l5 

### (Dimensions: 33 

### cm x 

### 33 cm x 

### 32 

### cm Deep)

(Freeboard Ratio = 

### Freeboard Height) 

### 3

### 3 Evaporation Evaporation Room Rate Rate Freeboard Draft Solvent Ratio (m/mi

### n) 

### (m1/hr 

# . rn2)

Perch1oroethylene 0.20 58 1508 Perchloroethylene 0.42 53 1210 Perchloroethylene 0.20 3 

### 88 

### Perchloroethylene 0.42 3 20 Perchloroethylene 0.74 3 27 102 Mineral Spi

### ri

### ts 102Mineral Spi

### ri

### ts 102 Mineral Spirits 0.42 3 

### 27 102 Mineral Spi

### rits 0.74 3 24 140 Mineral Spi

### ri

### ts 0.20 

### 3 140 Mineral Spi

### ri

### ts 0.42 140 Mineral Spi

### ri

### ts 0.74

### the evaporation rate of perchloroethylene increases from about l00C g/hr 

# .m2
ata 

### room draft velocity of 

### 27 

### m/inin to over 2300 

### g/hr 2



# . K 

### at85 

### m/min. Tests wi

### tn the other models showed simi1 arresults

# . A 

### third test 

### run was made with the $erchlcroethylene in the air-agitated cold cleaner with 

### the lid closed. At

### a draft velocity of about 85 

### mjmin, the evaporation ratewith the cover ;pen was over 2800 

### g/hr 

# . K?, 

### while with the
mver closed, the evaporat-ianratewas reduced to about 230 g/hr 

# .m2



# . This -?presents Settwthan 3 93 

### percent reduction in

### e~issions. Results of

### tests with less volatile minerals spirits showed somewhat (lifferatt

### relations hi?^. At

### roor draft vei~ci ties below 5 

### m/min, the agitated :cl

### a cleaners showed siyi ficantly greater evaporation rates of mineral spirits 5.nm sid 

### the unsgitated nodeis. 

### For example, under similar test conditions and *oi.lls 

### d:aft veiocities mder 5 m/min, 

### the emissions fro%the air-agitated c~ld .i.-.~

### wzre about 25 

### g/hr 

# . n

### 2 

### of 140 

### ~ineral spirits, the pump-agitated unit 

### ?m% ;-ns were about 50 g/hr 

# . K', 

### while the unagitated unit emissions were less

,,. 

### tk? iO

### g,'hr 

# . m

### 2



# . Data fron; tests athigher draft velocities are limited, but


### a lirila; result can be shown for the evaporaticn rates of 102 mineral spirits at 

### :,C to 60 m/mir, drzft velocity front the puriip-agitated unit and from the two unasitated mode: s

# . For these tests freebcard ratio isdefined as the 

### height from the surface of :he 

### s~lvent tc the 

### top of 

### the tank (freebardheicht) divided by the length of the shorter side of the 

### tank. Figure 4 

### shows the relslionship of the evapor~tion rate of perchloroethylene versus freeboard ratio. The figure demonstrates the tendency for solvent einissions to decrease as the freeboard ratio is increased.

### 13 Figure 5 

### displays the relat<onshipbetween evaporation rate of variws srades 3f 

### Mineral Spirits solvents and freeboard ratio. Solvent l~sses fcr tness tests were extremely small and the inherent imprecision in measuring thsesmall differences ?robably account for the lack of clear trends OR 

### this figure. One notable result demonstrated is that the Kleer-Flo A-1

### 5 cold 

### cleaner showed greater evaporation losses under the same conditions tha? dfd 

### the Gray Mi71s cold cleaner. This difference may be due to the differenc~ in

### tnc shape 

### of thc two clnits. The Kleer-Flo model has a square solvent-toair interface area, while the Gray Mills 

### unit has a rectangular 

### (22:1 

### length to 

### wfdtt-fi ratio) interface area. These data are normalized as to the solvent area, arid the conditions under which these data were conducted were identical,
so any difference between test results from the two tanks may 

### be because of the shage 

### difference. In 

### addition, the Gray Mills tank was oriented the same way 

### fwa11tests; that is, the room draft direction was para11el with 

### the short sides of 

### the tank. Turning 

### the tank so that the room draft direction is para7 1e: with 

### the 

### long sides of the tank would 1

### ikely produce differen: Y* 

### ulis. 

### The effect of solvent volatility, in term of solvent initial boilSr5 temperature, an evaporation rate isdemonstrated in Figure 

### 7. For this fiqure,


### an increase in in2tial boiling temperature corresponds to a decrease in

### sclvent volatility. The slopes of the three curves on Figure 

### 7 indicate that evaporation rates decrease WI

### th

### decreasing solvent volati1

### ity. 

### The Kleer-Flo A-i5 

### ,me1

### cold cleaner was used for these tests. It

### is not apparent that the square surface shape of 

### this unit had any effecton these results.P,P?ENJIX A TEST GATATABLE A. EVAPORATIONTEST RESULTS FOR THE KLEER-FLO MODE1 90 AIR-AGITATEDCOL.) CLEAIIER (SurXaceArea of Agitated Section = 0.398 m2, Total Solvent Surfr.ce Area 2 = 0 974 m) Ave. Ave. Ave. Ave. Room Ave. Solvent lnjected Air Injected A1r Injected A1r Ave Room Solvent Test Run Vo1u:ne Evaporat'on Evaporbtlon Run Solvent Temp. Moisture (x) Rate (l/min) Draft (m/min) Density (glml) Time (i,rs:min) Loss (1) Rate (ml/hr . m2) Rate (glhr . m )

A Perchloroethylene Open 2-A Pr.rchloroethy1ene Open 3-A Perchloroethylene Closed 4-A 112 Mineral Open Spirits 5-A 1:O Yineral Open Spirits 6 A 140 Mine.-a1 Open SpiritsE (n a (n- 

# - a, os- > 0 ,l-a E In 3 In- 

# - 3- 0 -I- 'z-- TABLE D. EVAPORATION TEST RESULTS FOR THE KLEER-FLO MODEL A-15 UNAGITATED COLD CLEANER (Surface Area = 0.109 m2)

Ave. Ave. Ave. Room Solvent Room Freeboard Solvent Test Run Volume Evaporation Eva?orati011 Temp. Temp. Draft Ratio Density Time Loss Rate Rate 2, Run Sol vent (OK) (OK) (m/min) (g/ml) (hr:min) (1) (ml/hr

. m ) (g/h13 

### . m 

# ,

- - - Perchloroethylene Perchloroethylene Perchloroethylene Perchloroethylene Perchloroethylene 102 Mineral Spirits 102 Mineral

Spirits 102 Mineral Spirits 102 Mineral

Spirits 140 Mineral

Spirits 140 Mineral Spirits 140 Mineral Spirits

### APPENDIX 

### B SOLVENTANALYSESUNITED STATES ENVIRONMENTAL PROTECTIONAGENCY DATE: Nay 4, 1977
SUBJECT: Analysis of Mineral Spirits and Perch1 orethylene

FROM: R. 3. Jungers, Chief

# %;ys Source, Fuels, & Molecular Chemistry Section, ACB (MD-78) TO: R. Shigehara, OAQPSIEMB (MD-13) W. Pel1 itier, OAQPS/EMB (MD-13)

Seventeen samples were submitted to this laboratory on a Sample Request and Report Form dated April 21, 1977. Reid Vapor Pressure and Distillationanalysis was requested. Distillations
were runon all but one sample where a specific request was made that itnot be run. Reid Vapor Pressurewas requested and attempted oli all samples but only 

### three samples had enough pressure for positive
measure. This analysis was conducted using theASTM Method D-323.

EPA Form 1320-6 (REV 3 76

### Samp1es of 

### Mineral Spiri

### ts and Perch1oroethylene From 

### EMB

# .

Distillation OF 

### Sample 

### No. IBP 10% 50% 90% EP 

### RVP LBS. S-77-002-602 326 330 352 383 415 -603 332 333 353 386 428 -604 339 340 353 383 423 -605 332 333 351 384 423 -606 327 328 351 382 409 -607 245 245 

### 245 245 286 0.0 

### -608 Disti1 lation 

### Not Requested 0.5 -609 322 325 333 359 388 -610 325 325 333 357 392 S-77-002-639 330 330 342 370 409 S-77-002-656 369 372 378 393 417 -657 317 327 342 371 411 -658 368 371 379 395 423 -659 364 371 379 395 423 -660 369 372 380 394 420 -661 246 244 245 246 286 -662 246 

### 245 245 246 290- -

-- - 3;:

- Q!"

-

### tQ 1:: SA!APLI:IG DATE

1- 0': FIRSTIDENT.

8 -. 0': NO.USED

.-. 0:

.*- tpz INDUSTRY-ET.~~~>J,%A~;I?-

- (USE TABLE

# 3 Q '



## G- COhrPANY o,: ADDRESS 

# OF 01;

- SA16P;ItIG METHOD
DESCRIPTION OF IDENT NO SAMPLE OR SAMPLE FRACTION

SAMPLI::G CONTRACTOR (IF APPLICABLE) DATE OF REQUEST EPklDU91245 SOURCESAYPLE REQUESTL REPORT (UUST BE FILLED OUT FOP ELCY TEST 9UR) TEST NO-_-- 3-71-Q02.~b\ RUN NO--- -
UNIT PROCESS OPERATION AIR POLLUTION CONTROL - FUEL USED 0 INLET LjOUTLET GAS VOLUME SAMPLED--

. -
. ---- ---- -- (METER VO; IN FT~)
SAMPLE ANALYSIS RFGUESTED
- GE',EQAL C,7:".'E'iTS WT (APPROX C0NCE:TRATIO'IS POSS BLE I:4TtFCE'L',2:S 

# I (SOLID) (LIQUID) ETC) (IN3ICA:E SFtCcFICA',ALYSIS 0'; BACnT'D:,

MG ML

REQUEST

L, PROJECT

## OFFICER~S~N-TAL. REVIE;';ED BY- - DATEANALYSIS REQUESTED OAT€Of REQUEST

- (TOBi FILLED I'i 2--- - - - AIR POLLUTIONCONiROL

- _ --- .- -

DESCRIPTIONOF SAMFLE OR SAMPLE FRACTIOPAPPENDIX B. CALCULATIONSAPPENDIX B CALCULA'TIONS CONTENTS Page B.l Degreasing Emission Summary 

## ...................................... B-1 8.2 Cold Cleaner Emissions 

## .......................................... B-3 8.2.1 National Cold Cleaner Emissions (1974) 

## ....................B-3 0.2.2 Emission Rate Per Cold Cleaner 

## ............................ B-4 8.2.3 Projected Emission Reductions 

## ............................. B-5 B.3 Open Top Vapor Degreaser Emissions 

## ............................... B-7 8.3.1 National Open Top Vapor Degreaser Emissions (1974) 

## ........ 8-7 B.3.2 Emissions Per Average Unit 

## ................................ B-7 B.3.3 Projected Emission Reductions 

## ............................. B-7 8.4 Conveyorized Degreaser Emissions 

## ................................. B-9 8.4.1 National Conveyorized Degreaser Emissions (7974) 

## .......... 8-9 B.4.2 Emissions Per Average Unit 

## ...........................,'....B-9 B.4.3 Projected Emission Reductions 

## .......................'...... 8-9 B.5 Degreasing Waste Solvent Disposal 

## ................................ B-11 B.6 Calculations Relating toAdverse Environmental Affects


## ........... B-13 9.6.1 Increased Boiler Emissions 

## ................................ B-13 B.6.2 Sta~ilizers inChlorinated Solvents 

## ....................... 13-14 B.6.3 Utilities Consumption of Carbon Adsorbers 

## .................B-16 0.6.4 Fuel Costs of Incineration for Manufacturing Cold Cleaners


## .......................................... 8-17 8.7 References


### ...................................................... B-18

### 3 B.l DEGREASING EMISSION SUMMARY, 1974 (All units = 10 metric tons/yr) 1. Total Organic Emissions from Degreasing 

### 700 Cold Cl eaning 380 Open Top Vapor Degreasing 200 Conveyorized Degreasers 100 (14%) (25 CND & 75 CVD) Wiping Losses 20 (3%) 2. Contribution to National HC Emissions Degreasing Emissions (1974)

- 700 

### - 

# - = 2.5% National HC Emission (1975) 28000 Degreasing Emissions 

### - 700 National HC Emissions from 

### - 

## 17000 = 4.1% Stationary Sources (1 975) 3. Solvent consumption data were collected from several sources and tabulated inTable B-1. The consumption estimates were averaged to estimate the solvent consumption of each type ofdegreaser. These data were the basis for our emission estimates.----- 

### B.2 COLD CLEANER 

### EMISSIONS B.2.1 National Cold Cleaner Emissions (1 974) Given: (a) Gross cold cleaning solvent consumption = 

### 450 Gg/yr* 1974 (b) 

### about 5%

### of this isfrom wiping operations, which are not considered cold cleaner (CC) emissions (c) about 25 

### Gg/yr of this is 

### from conveyorized non-Soilin? 

### degreasers (CND)

## . (See subsection B.4.1) 

### (d) Waste solvent disposal (WSD) amounts to 

### 280 Gg/yr. Approximately 7%of this is incinerated or landfilled in

### such
a manner that no emissions occur. (See Section 3.1.4) Calculate: Cold Cleaner Emissions Estimate 450 = 

### Gross cold cleaning solvent consumption



## - 25 = 

### for wiping losses



## - 25 = 

### CND 

### losses



# - 400 = 

### Cold cleaner emissions ifall 

### WSD evaporates



## - 20 = 

### controlled emissions due to proper waste solvent disposal



### - 380 

### (+loo)Gg/yr = 

### estimated emissions from cold cleaners-1974
*Gs = 

### lOJ metric tons

### B.2.2 Emission Rate Per Cold Cleaner Given: (a) 880,000

### Maintenance cold cleaners (1974) 340,000Manufacturing cold cleaners 

### (1974) 

### 1.22 x 

# lobTotal cold cleaners 1974 (b) 

### A manufacturing cold cleaner has twice the average emission of amaintenance cold cleaner. Calculate: Individ~alcold cleaner emission rates 

### (a) 380 

### (L1OO' Gglyr = 

### 0.31 (+0.08)

### Mgjyr per unit



### - 1.22 

### x 10b 

### units

= 

### 660 

### Ib/yr per unit 2 

### 100 (+20) 

### gal/yr per unit



### - (b) IF: X = 

### average maintenance cold cleaner emission 2X = 

### average manufacturing cold cleaner emission Ta, = 

### national maintenance cold cleaner emissions Ta2 = 

### national manufacturing cold clecmer emissions THEN: 

### X x 880 (~10~) = 

### Tal

. 2X 

### x 340 (~103) = 

### Tap Tal 

### + ia2 = 

### 380 

# (+loo)(x103 metric tonlyr) in 

### 1974 

## - AND: 

### Tai = 

### 21

### 5 (~10' metric tonlyr) 3 Ta2 = 

### 165 (x10 metric tonlyr)



### X = 

### 0.24 metric tonlyr = 

### (490

### 1b/yr) 2X = 

### 0.48

### metric ton/yr = 

### (980

### ?b/yr) (c) "Safety Kleen" maintenance cold cleaners and 

### others: 

### Let XSk = 

### 3tlerage emission from a Safety Kleen cleaner



### - - 

### aperage emission from othermaintenance cold cleaners 0 

### Then: 'sk

- - 

### 24 r 103 

### netric tonjyr 0.17 metric ton jsk c1zansr140,000 = 

### 3813 1

### h!vr Y, = 

### 203-L4

0 

### 880-1 40 = 

### 0.24 metric ton= 530 

### lblyrB.2.3 Srojected Emission Reductions* A. Cold Cleaner System A Assumptions & Estimations: 1. Average typical cold cleaner emits about 0.3 metric tonslyr. 2. An average of 55%of cold cleaning emissions isdue to evaporation of waste solvent. This could be reduced to 10%with excel 1 ent compliance 30%with average compliance 40%

### withpoor cornpliance. 3. 45%of the emissions occur directly from the cold cleaner. 20%isthrough bath evaporation (including agitated & spray evaporation) and 25%isthrouqh carr.y out. Cover closing can reduce bath evaporation from 20%to4%with excellent compliance 9%with average compliance 18%with poor compliance. Drainage practice could reduce cavy-out 

### from 25%to 5%with excellent compliance 11%with average compliance 18%with Poor com~liance. Conclusion: With excel 1 ent compliance system 

### A could reduce emissions by 100-1 0-4 80%. With average compliance, emissions could be reduced by 100-30-9-1 1 = 50%, With poor compliance, emissions could be reduced by 100-40-14-18= 28%.

*The previous and the following projected estimates representthe best engineering judgement that can be made aiven the limiteddata-base. These estimates are not to be interpreted as test data; thus., a wide range isgiven for most estimates. 8-

### 5B. Cold Cleaner System B Note that excellent compliance would not vary much between systems A and 

### B. Assumptions & Estimations--same as for system A except: 1. Mechanically assisted covers, the "major control device" and spray specifications and agitation restrictions are estimated to reduce bath evaporation from 20%to 2%with excellent compliance 6%with average compl iance 10%with poor compliance
Conclusion: With excellent compliance system B could reduce emissions by 100-10-25= 

### 83%. With average compliance, emissions could be reduced by 100-30-6-11= 53%. With poor compliance, emissions could be reduced by 100-40-10-18=



### C. Cold Cleaners Using High Volatility Solvent Recommended controlswould effect higher emission reductions on units using highlyvolatile solvents. It isestimated that with average compliance emission reduction would increase to 55%for system A and to 69%for system B. Note: Table 3-14 inthe Dow Report estimates emissions from a typical, maintenance cold cleaner. Although the overall emission rates are on the high side, the percentage of emissions fromwaste solvent evaporation (refi

### 11ing)

### , carry-out and bath evaporation calculateto58%, 28%, and 16%respectively. This compares reasonably with the previous estimates of 55%, 

### 25%and 20%for a11 types of cold cleaners

### , (considering that manufacturing, cold cleaners tend to have a higher proportion of bath evaporation than do maintenance cleaners).

## - - 8.3 OPEN TOP VAPOR DEGREASER EMISSIONS 6.3.1 National Open Top Vapor Degreaser Emissions (1 974) Gross vapor degreasing solvent consumption is275 (225) Gg*/yr. Approximately 200 (+20) Gg/yr of this isfrom Open Top Vapor Degreasing (OTVD)

- and 75 Gg/yr isfrom Conveyorized Vapor Degreasing (CVD). These estimates are similar to previous estimates that CVD emit about 65 Gg/yr and OTVD, 210 ~~/~r.' 8.3.2 Emissions Per Average Unit 1. If there are 21,000 OTVD (1974), an average OTVD would emit about



## - 200 (+20) Gg/yr I 21,000 = 9.5 MT/yr

# . 2 

### 2. If an average OTVD has an open area 18 (+3) ft2= 1 

### .67 (+0.3) 

### m then emission per area would average 5,7 ~~/~r.m' (These averages probably
are within

## - + 25 percent accuracy.) 

### B.3.3 Projected Emission Reductions Estimates have been made of the total control efficiencies 

### ( + the cont efficiencies from improved operating practices 

### () and control efficiencies from control equipment (qe) for control systems A and 

### B. 

# I System A 

### I System B % poor average excel1ent -poor average excel 1 ent 15 25 3 5 20 30 40 qo

Approx. 

### n+ 

# 1 30 45 60 

# 1 45 60 75

Note: (1

# - n+) = (1 

## - no) (1

# - ve)

- *Gg = 103 metric tons2. 

### Given 

### 9.5 mT/yr per average OTVD, 

### Emission Per



# - uncontrolled unit poor Erni

### ssion per controlled 

### u average excel1

### ent nit (mT/yr) 

### System A 

### 9.5 6.5 5.2 

### 3.7 

### System B 9.5 

### 5.3 3.8 2.4

### ------------- 8.4 CONVEYORIZED DEGREASER EMISSIONS B.4.1 National Conveyorized Degreaser Emissions (1974) Given: (a) Emissions from conveyorized vapor degreasers (CVD) is

(b) It isestimated that between 25 to 35 percent of the conveyorized degreasers are Conveyorized Non-Boiling Degreasers (CND) .8 This estimate appears somewhat high, thus choose 25 percent which ison the lower end of the range, Calculate: (a) CND emit 25 Gg/yr (b) CVD emit 75 Gg/yr (c) Total conveyorized degreaser emission are 100 Gg/yr. B.4.2 Emissions Per Average Unit 1, Estimate that there are about 3170 CVD and 530 CND nationally in 1974.~''~ 2. An average emission ratefor a CVD would be 75 000 M 

### ,23.7 ,,,T/yr 

# 3hAE 3, Average emission from a CND would be

## .-&- 25 000 = 47.2 MT/yr. 9.4.3 Projected Emission Reductions Estimates have been made of total control efficiencies (n,), the control efficiencies from improved operating practices (so) and the control efficiencies from control equipment for control systems A and B.

operation Improved 

# I 20 25 30 Control 

# I System A Efficiencies Compliance: 

## (d(%) ) poor average excellent

# 1 System B Compliance: poor avg. excl

## .

Control

equipment Total

approximated Note: (1-n+) = (1-no) (1-ne) *~g = 

### lo3 MT B-9

### 2. 

### Emission control for typical units:

Emission rate (MT/yr) Control1ed with 

### Control1ed with 

### Uncontrolled 

### System 

### A System 

### B Conveyorized Vapor Deg. Con. Non-boiling Deg. Average CD 

# I 2

### 7 120 (19 to 21) 

# 1 10 

### (7.5 to 13)-- B.5 DEGREEING WASTE SOLYENT DISWSAL It has been estimated that 280 (+go) thousand metric tons/yr of waste solvent are disposed of by the solvent metal cleaning industry in 1974. The calculation isbased on the following assumptions and estimates.* Assumptions 1. Percent virgin solvent that becomes waste solvent for each category of degreasers. (EPA and Dow Chemical estimates)
a. Degreasing industry collectivel y 30%to 50% b. Cold cleaners collectively 45%

### to 70%
c. Maintenance cold cleaners 50%to 75% d. Manufacturing cold cleaners 4G%to 60%

, e. Conveyorized vapor degreasers 10%to2rl% f. Open top vapor degreasers 20%to25%

2. Virgin solvent consumption. (EPA estimates)
a. Cold cleaners (excluding 10% as wiping losses) Maintenance (56%) 215,000 Mtlyr Manufacturing (44%)" 165,000 Mtlyr b. Open top vapor degreasers 200,000 Mtlyr
c. Conveyorized degreasers (vapor and cold) 100,000 Mtlyr Waste Solvent Estimates 1

## . Maintenance cold cl eaners = 134,000 Mt/yr (or 215,000 x .625 = 134,000 Mtlyr) 2. Manufacturing cold cleaners = 83,000 Mtlyr (165,000 x .50) 3. Conveyorized vapor degreasers = 15,000 Mtlyr (100,000 x .15) *me accuracy of the estimates is not expected to be better than + 30%.


## -4. Open top vapor 

### degreasers = 

### 45,GOG Mt/yr (200,000 x .225) Total wastc s~lvent= 277,0@0Mt/yr(~85,00CMt/~r)E.6 CALCULATIONS RELATING TQ ADVERSE ENVI2ONMENTAL EFFECTS 8.6.1 Increased 6011 er Emissions-Computation
The objective istc determine the magnitude of increased boiler emissigns caused by use of a carbon aosorber. The carbon adsorber generally has the highest energy consumption compared to that of other control devices. A typical carbon adsorber could be a Vic #536 AD. According to the J. L. Thom?son test report by Dow, the steam usage may be 113 lb. per desorption cycle which converts tc 113,000 Btulcycle. Taking an averaTe of two desorption cycles per day, the consumption becomes about 225,000 Ptulday or 28,000 Btulhr. Assume that high sulfur fuel oilwere to be used t o f i r ethe boiler. Take residual fuel oil with 2%sulfur content. According to "Compilation ofAir Pollution Emission Factors" (AP 42) such fuel combustion would emitthe followinq 3 pollutants per 10 gal. fuel oil: 310 lbSO2, 23 lb particulates 60 lb

### NG,, 4 1 b CO and 3 lbHC (hydrocarbons) ; Relate the emissions to an hourly emission rate. To produce at 75%conversion efficiencywould require 37,000 Btu/hr of fuel. Choosing

. would-=. 1t #5 fuel oil

## ,we have 148,000 Btu/gal

# . Thus

### ,; increased fuel consumptian

### -. be about 0.25 gal/hr.* Increased pollutant emission would then be 0.08 1t/hr (0.036 kglhr) SO2, 0.005 1b/hr (0.002 kg/hr) particulates, 0.008 lb/hr (0.00035 kg/hr) NOx, 0.0005 lb/hr (0.0002 kg/hr) CO and 0.0004 1b/hr (0.0002 kg/hr) HC. Com~are the increased e~issions to the enissim reduction caused by the carbon adsorber. A typical adsorber system that isproperly designed and maintained may save 50 gal/wk 

### 5 15 lb/hr = 6.8 kg/hr. Thus, the total increased hileremissions equals ~b.out 0.6% of the mission reduction caused by a typical carbon adsorber.

### E.6.2 

### Stabilizers in Chlorinated S~lvents

Trichloroethylene Epichlorohydrin Butylene Oxide Gl.yci do1 Acrylonitriie Dii

### soprop.ylamine Triethylmine Ethyl Acetate Diisobutylene Thymoi 

### N-Methyl Pyrrole Acetaldehyde

Dimethyl Hydrazone Tetrahydrofuran Sec. Butanol N-Propanol 

### 1

### ,I ,I Trichloroethane 1,2 Butylene Oxide 

### Butylene 

### Nitroethane N

### i t.rome 

### thane 3-&thoxy

Propronitrile 1,3-Dioxolane 1,4-Dioxane N-Methyl-Pyrrole To1uene Methyl Ethyl

Ketone Isobutyl Alcohol Tertiary Butanol Sec. Butanol Acrylonitrile Acetonitrile 

### Isopropyl Nitrate Tertiary Amy1



### A?cohcl l,3,5 Trioxane 2: ;O 

### Fish Solubility Toxicity BOD-2C Boilinq Point CP

L s 

### in water P

### Pm % of

### Theory

1C 

### ncn-rnisc. 10


### 1C)G 

### 100 S 

### 27-37

10 s2G



### 13 190 

### partia11y 

### S

= 

### slihtlyd

### s. = 

### soluable 'concentraticn giving 50% fatality to rats



### - o r

# 9 human when feed orally, i.e. 

### LD 5C. 

## i

## -- % 

### Fish Solubili.ty Toxicity BOD-2Q 

### Soilinq Point



### inwater PPm 

# ----. % 

### of Theory "C 

### Methylene Chloride Propylene Oxide Butylene Oxide 

### Amy1ene Cyclohexane Methylene Chloride Perch1oroethylene 

### Thymo

### 1 S1.S 

### 4-Methyl

Morpholine 100 2700' P-Tertiary Amvl

Phenol 3-N-Fropoxy partially 31 00'

Propionitrfle Isopropyl A1coho1 Epichlorohydrin niallylamine

Estimated Stabilizer Emissions into Sewer

.-- % 

### Stabilizers in 

### Approximate Solubility Sewer Erission Rat. 

### Solvent blend % 

### gal/wk +/wk 

### Worst 

### Case: 5'% 

### 40% 1.C) 

### 0.004

nversge Case: Atmcspheric Ernissi~nReducti 

### Typical 

### Emiss'on Control : 

### 50 galiwk 0.2 3 

### n /w6.6.3 UTILITIES CONSUMPTION OF CARBON ADSORBERS
Reference to Model Ventilation Rate Solvent Water Steam

Dow Report Adsorber Both Beds Adsorbinq Recovered Consumption Consumption El ec ricity Appendix: Test Site Vic # (cfd (qal/wk) (103 gal/yr) (106 Btulyr) (10

# 5 kw) C-10 Vic Manuf. Co. 572AD 5500 70 630 310 30 C-8 Super Radiator Co. 554AD 23000 

## * 1380 380 30 

### C-9 J. i.Thompson Co. 536AD 940 25 to 50* 230 54 4 C-11 W. Electric Co. 536AD 21300 85 1380 520 13 Average 2700 900 320 19

*Defective control systems

### B.6.4 Fuel Cost of 

### Incineration for Manufacturing Coid 

### Cleaners 

# I Assume a ventilation rate of 50 cubic ft/rninute/ft2 of

### open top area,
an average tank area of 6 ft2, 8 

### hours of operation per 

### weekday and 2 

### 112 dollars/million BTU 

### fuel cost. Using an air density of 0.075 1 bslft 2

### ,a specific heat of 0.25 BTU/lbs°F for ai'r, and a maximum temperature of 800°F,

an approximate annual fuel cost would be 

### about $1200/year, as sumarized be1ow. Exhaust volume = 

### 30

# S cfm 

### x 60min/hr 

### x 8 hrlday 

### x 240 day/yr = 

### 35 

### x 10

### 6 ft

### /yr Heat required = 

### 35 

### x lo6 ft3x 

### 0.075 1b/ft3 

### x 0.25 BTU/lb°F 

### x 740°F = 

### 485 x 

### lo6 BTU/yr Annual fuel cost = 

### 485 x 

### lo6 BTU/yr 

### x 2.50 

### $11

## o6 BTU = 

### 1215 1200 $/yrB,7 REFERENCES 1. Information provided by Tom Hoogheem, Monsanto Research Corp. 

### ,Dayton, Ohio, by telephone to J. C, Bollinger, EPA, on December 1 and 6, 1976. 2. Surprenant, K. S. and Richards, D. W. of Dow Chemical Company, "Study to Support New Source Performance Standards for Solvent Metal Cleaning Operations," 2 vol., prepared for Emission Standards and Engineering Division (ESED), under Contract # 68-02-1329, Task Order #9, June 30, 1976, pp. 7-3. 3. Ibid, 4. Kearney, T, J,, Detrex Chemical Ind., letter toJ. C. Bollinger, EPA, January 9, 1976. 

### 5. Information provided by J. S. Gunnin, Shell Chemical Co., Houston, by telephone to J, C, Bollinger, EPA, September 16, 1976. 6. Op. Cit., Surprenant, K, S., pp, 7-3, 7. Bollinger

## ,John C. 

### ,"Trip Report

## - ASTM, Consultant and Two Waste Solvent Plants," memo to David R. Patrick reporting on triptoASTM D-26 meeting of January 26, 1977. 8. Bollinger, J. C., "Maximum Impact of NSPS on 1985 National Degreasing Emissions," December 1975. 9. Ibid. 10. Surprenant, K. S., Op. Cit. 11. Ibid. pp. 7-3.-- - TECHNICALREPORTDATA (Plcose read Irtwcliot~s 011 llrrrevcrsrbeforecornplc~rrr~)

. REPORT NO. 12. 13. RECIPIENT'S ACCESSIONNO. EPA450/2-77-022 

# I

. TITLE ANDSUBTITLE 15.REPORT DATE Control of Volatile Organic Emissions from November 1977 6. PERFORMINGORGANIZATIONCODE Solvent Metal Cleaning

.AUTHOR(S) 8. PERFORMINGORGANIZATIONREPORT N John C. Bollinger* Jeffrey L. Shumaker, ESED OAQPS 1.2-079 PERFORMING.ORYANIZATl0N NAMEANDADDRESS 10. PRClGRAM ELEMENTNO. U. S. Environmental Protection Agency Office ofAir and Waste Management 11. CONTRACT/GRANT NO. Office of

### Air QualityPlanning and Standards Research Triangle Park, North Carolina 27711
2. SPONSORING AGENCY NAMEANDADDRESS 13.TYPE OF REPORTANDPERIODCOVERE

14. SPONSORING AGENCY CODE 

# t---

1 5.SUPPLEMENTARY NOTES *No longer with EPA

6. ABSTRACT This report provides the necessary guidance to control emissions of volatile organic compounds (VOC) from solvent metal cleaning operations. Emissions are characterized and reasonably available control technology (RACT) isdefined for each of the three major categories of solvent metal cleaners: cold cleaners, open top vapor degreasers, and conveyorized degreasers. Information on the cost of control, environmental impact and enforcement issues isalso included.

7. KEYWORDS AN0Dl CUMENT ANALYSIS DESCRIPTORS I ~.IDENTIFIERS/OPEN ENDED TERMS

- 9ir Pollution Air Pollution Controls Solvent Metal Cleaning (Degreasing) Stationary Sources Emissions and Controls Organic Vapors qegulatory Guidance Degreasing

3. DISTRIBUTION STATEMENT 19.SECURITY CLASS(TllisHrporr) 21. NO. OF PAGES 

# 9 Unclassified 

### 203 20. SECURITY CLASS(Thispope) 22. PRICE Unl

### imited Unclassified EPA Form2220.1 (9-73)ENVIRONMENTAL PROTECTION AGENCY POSTAGEANDFEESPAID Technical Publications Branch ENVIRONMENTAL PROTECTIONAGENCY

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## 0 or if changeofaddressisneeded

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