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CHLORINATED SOLVENTS FOR METAL PARTS CLEANING: RED SHORT AND LONG RANGE IMPLEMENTATION TO REPLACE

RIVER ARMY DEPOT

Ed Hanna

Introduction

Good morning. My name is Ed Hanna. I am an engineer employed in the Production Engineering Division at Red River Army Depot (RRAD). Among other duties, I serve with Mr. Terry Funderburg, Chief of Environmental Management Division, as co-chairman of the RRAD Center of Technical Excellence (CTX) and HAZMIN working group.

Purpose

This briefing will explain the RRAD CTX effort to eliminate DESCOMs dependence on chlorinated solvents for degreasing and cleaning of metal parts. While this started out as a DESCOM effort, it has grown to the point where we have provided, and received, information from the Air Force, Marine Corps, and Navy as well as Army installations. A version of this briefing has been presented to both Commanding General (CG), DESCOM and CG, AMC. )

Alternate Technologies

I assume that most of you here, even if you have not been directly involved with the HAZMIN or CIX Plans, understand what they are about. If not, these efforts can be summarized by two points:

The main thrust of the HAZMIN Plan is the elimination of the use of hazardous materials, and resulting generation of hazardous waste, through source reduction.

To accomplish the AMCDESCOM HAZMIN Plan, DESCOM designated various depots as CTX to implement and research command-wide elimination, or at least reduction, in the use of specific hazardous materials.

RRAD was designated as CTX for waste streams and emissions resulting from the use of

chlorinated solvents. ~~

Before proceeding with specific equipment requirements, I need to give a short review of what has been accomplished to date to provide background and continuity. '3

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Approximately 75% of the chlorinated solvents purchased by DESCOM activities are used for vapor degreasing. About 15% is used as the base material for nonferrous paint strippers and the remainder for manual parts cleaning in small vats.

First, I want to briefly review work done on the replacement of chlorinated solvent base paint strippers. Methylene chloride and dichlorobenzene base paint strippers for nonferrous metals are used at several depots. Methylene chloride is classified as a hazardous material by the EPA, is a suspected human carcinogen, and, as with all chlorinated solvents, is now considered an atmospheric pollutant. Working with U.S. Construction Engineering Research Laboratory and the US. Army Toxic and Hazardous Materials Agency (CERL and USATHAMA), RRAD and Sacramento Army Depot (SAAD) have researched the availability of commercial paint strippers that do not contain chlorinated solvents, phenols, cresols, or other chemicals described on the EPA list of total toxic organics. In addition to testing samples submitted by manufacturers, RRAD and SAAD conducted extensive, and expensive, tests in production lines for over a year using USATHAMA recommended, nonchlorinated solvent, commercial paint strippers. None of the strippers tested were totally acceptable. Some worked reasonably well at removing alkyd enamel and polyurethane coatings, but all performed poorly on epoxy coatings. The strippers experienced excessive evaporation even when an oil seal was used. The oil seals proved to be a problem as they were not as free rinsing as advertised and caused contamination problems in other solutions located downstream of the strippers. RRAD and SAAD are again using chlorinated solvent base strippers to meet production requirements. CERL plans to do additional work in this area and both RRAD and SAAD have agreed to support thcm with field tests of any new products developed. However, we have not as yet found a suitable replacement for chlorinated solvent paint strippers on nonferrous items.

Now we can discuss degreasing. Some form of degreasing process is necessary before any subsequent metal finishing operation such as cleaning, paint stripping, repainting, plating, etc. Grease and oils cannot be allowed to contaminate these processes or block the adhesion of applied coatings.

In the March 1990 Phase I Chlorinated Solvent Briefing to CG, DESCOM, we presented alternatives to vapor degreasing for cleaning metal parts. They included the alternatives below:

Process changes

Substitute products

Solvent waste reduction

New equipment technologies.

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We discussed in detail new equipment technologies investigated and these included the 3 following:

Vacuum degreasers

Fluidized bed degreasing

Ultrasonic cleaning

High-pressure water blast equipment

Bakeovens.

Technology Evaluation

The chart, in the following presentation slides, graphically compares the advantages and disadvantages of vapor degreasing with the possible replacement technologies. Performance factors are not all of equal importance when attempting to rate the various methods of degreasing. The primary criteria used to evaluate all of these methods was in order of importance:

Environmental impact -1 Proven technology

Commercially available now

Cost.

Technology Selected

RRAD recommended the use of substitute chemicals and water blast equipment as the most promising technology for short range implementation based on environmental acceptability, commercial availability, and implementation cost.

RRAD recommended vacuum degreasers, ultrasonic cleaners, and fluidized beds as promising long range technology based on environmental acceptability, commercial availability, and the potential for replacing chemical paint strippers as well as chlorinated degreasing solvents with ultrasonics and fluidized beds.

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General Karegeannes concurred in the use of high-pressure water cleaning equipment and, if necessary, nontoxic substitute chemicals. He tasked RRAD with quantifying the amount of

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equipment, material, and estimated cost for command wide implementation of the recommended short range technologies. This information was presented to him in the Phase I1 CIX briefing, March 27. 1991.

Because some items cannot be cleaned using high-pressure water equipment, RRAD has continued to pursue the use of alternate degreasing chemicals and technologies.

Several depots have, or are considering, the acquisition of fluidized beds. We will briefly discuss special applications that can utilize these beds.

New Developments

After the briefing in March 1990, new legislation was passed that directly affects the use of chlorinated solvents.

The Toxic Substances Control Act (TSCA) has been around for a number of years, but in May 1990, Congress strengthened it. This act gives EPA the power to control the production, use, and disposal of hazardous materials.

The Clean Air Act Amendments (CAAA) were passed in the fall of 1990. The goal of CAAA is to reduce the 2.7 billion Ib of toxic chemicals emitted to the atmosphere annually by 75 to 90% by the year 2000. The government plans to accomplish this by not only reducing emission levels, but also hy taking many of these substances out of production. The phase-out schedule for two common degreasing chemicals, 1-1-1-trichloroethane and CFC-113, is shown in the following presentation slides. CFC-113 is a freon material used for cleaning in ammunition and electronic applications. Even though only two solvents are shown, all solvents currently used for vapor degreasing will be affected by the CAAA.

The EPA has published 40 CFR 82, "Stratospheric Ozone Protection Regulation," to implement the Montreal Protocol on substances that deplete the ozone layer. This law will eventually eliminate the use of ozone depleting substances for parts cleaning, degreasing, air conditioning, and fire fighting. Methyl chloroform (l,l,l-trichloroethane) was added to this list of substances in June 1990. Halon compounds, including 1301 used as a fire extinguishing material in all Army combat vehicles, also are scheduled for elimination.

DoD completed tasking of DoD Directive 4210.15. This directive is to be used by DoD to implement Section 1003(b) of the Resource, Conservation and Recovely Act (RCRA). DoD policy now places the higliest~priority on reduction of volume~and toxicity of wastes~generafed through pollution prevention, rather than waste treatment. If a less hazardous material can be used to accomplish a task, it must be used.

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As I stated, all of these laws and regulations have been passed or implemented within the

3 last year. Two additional laws are under consideration that will also impact AMC operations. These are the Clean Water Act (CWA) and the Indoor Air Quality (UO) Act. The CWA is supposed to do for water what the CAAA does for the atmosphere and will have similar penalties for violations. In the past, we have been primarily concerned with satisfying the EPA The IAQ Act may also involve Occupational Safety and Health Administration (OSHA) and health professionals.

From our contacts with the other depots, it is obvious most do not want to eliminate the use of chlorinated solvent cleaning. Most are afraid replacements will not be as effective or efficient at removing grease and oil from metal surfaces. However, these new laws make it imperative that substitute methods and products be implemented. The degreasing requirement cannot be eliminated, but the method used to accomplish it m u ~ t be changed.

That concludes the review portion of this briefing.

Fluidized Bed Degreasing/Paint Stripping

Fluidized beds have received a lot of command attention so I need to briefly discuss this technology. RRAD and Letterkenny Army Depot (LEAD) both have operating beds. RRAD has two HAZMIN projects that utilize this type of technology. 3

RRAD was chosen by DESCOM and USATHAMA as the site for testing a fluidized bed parts cleaning system to determine if it can replace both chlorinated solvent vapor degreasing and chemical paint stripping operations. Tests at RRAD have shown that for some items, particularly steel parts with a hardness below 45 on the Rockwell C Scale, and cast steels and cast irons with no special heat treatment, a fluidized bed system can replace chlorinated solvent vapor degreasing and chemical paint stripping operations.

Tests at RRAD indicate tempered aluminum parts cannot be cleaned in fluidized beds unless heat treating capability exists to replace the temper removed by the high temperatures of the bed. Magnesium parts cannot be cleaned in a fluidized bed.

The tests at RRAD utilizing a fluidized bed for degreasing and paint stripping were completed in July but have not as yet been published. Results from tests performed at LEAD have confirmed RRAD findings. Because of the high cost of fluidized beds, and limitations on degreasing aluminum unless heat treating capability is provided, RRAD does not recommend their

cheaper methods of degreasing. W m i m e a n s g - w i t h chlorinated solvents. There are better and

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RRAD Rubber Products Fluidized Bed

There is an application for which we do recommend fluidized beds. The second RRAD fluidized bed project is part of the rubber products modernization project. The use of vapor degreasers and chlorinated solvents to remove large volumes of rubber from metal parts is a problem unique to RRAD and ORADA. The present method of denuding, or removing rubber, from roadwheels at RRAD is to cut the bulk of the rubber off using vertical turret lathes. Wheels are then placed into vapor degreasers until the remaining rubber dissolves or falls off. These methods are slow, messy, labor intensive, and generate hazardous waste and emissions. Several years ago, the Production Base Modernization Agency contracted Chamberlain Guard Corporation to identify and evaluate all of the methods of rubber removal from metal. Chamberlain Guard recommended use of fluidized beds as the most efficient and environmentally acceptable method. RRAD has awarded a $3.3 million contract to SeghersDinamec Inc. to manufacture and install a fluidized bed system to denude track and roadwheels. The fluidized bed system will replace the existing systems eliminating the use of 18,000 gallyear of trichloroethane and 26,000 Ibjyear of waste rubber contaminated with trichloroethane. The system will have the capability of providing T-4 temper for aluminum roadwheels. The equipment installation should be completed by April 1992.

The large rectangular shaped fluidized bed, 1 of 2 of the type to be used in RRAD’s Rubber Products Division, is completely enclosed, remotely operated, and includes quench tanks and equipment to remove any charred rubber residues on metal parts.

The fluidized bed installed by USATHAMA for degreasing and paint removal at RRAD is only 48 inches in diameter and has limited capacity. The large, automated system to be installed in the rubber shop has high capacity and can perform degreasindpaint stripping faster than rubber denuding. This is the type system that would be required for high-volume depot degreasing and paint stripping operations if a fluidized bed were to be used for production purposes. As previously stated, we believe there are more economical methods to accomplish this.

High-pressure Water Implementation

Now let’s move on to high-pressure water cleaning equipment (high-pressure being defined as the 150 to 400 psig range). To determine the amount of equipment required, a questionnaire was prepared and sent to all depots and depot activities. The information shown in the slide presentation (following text) was gencrated from the responses received. The projected cost for each type of equipment as well as the total cost per depot is shown.

One of AAD’s CTX efforts is directed at finding alternatives for the use of open cleaning vats containing petroleum base solvents with their discharge of volatile organic compounds (VOCs) to the atmosphere. AAD has also selected high-pressure water cleaning equipment as one means of accomplishing their CTX goal. AAD and RRAD have shared information obtained

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about this equipment and are working together during the implementation phase of these CTX projects. The chart, however, reflects only requirements for replacement of equipment used to perform cleaning utilizing chlorinated solvents. AAD petroleum CTX requirements are not duplicated.

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As would be expected, depots with maintenance missions have the highest equipment requirements for alternatives to vapor degreasing.

High-pressure Water-Glove Box

As we review the depot equipment requirements, I will show pictures of the individual types of equipment (in the slide presentation following this text) and explain their uses. You will note that many of the water blast machines are similar to corresponding types of abrasive blast cleaning machines. Some companies manufacture both types. While I will mention brand names of the various machines shown, none of these machines are sole sources. There is more than one manufacturer for each type.

The glove box cabinet shown is similar to glove box abrasive cleaning equipment. The machine shown is built by Graymills Corp. It is used for low volume cleaning of individual parts. It will primarily be used to replace manual cleaning of parts in open, small vats utilizing either chlorinated or petroleum type solvents. '3

High-pressure Water-Tumble Blast Type

This type of equipment will be utilized for high-volume cleaning of small parts, a common use for vapor degreasers. Maintenance depots generate large volumes of small parts (fasteners, brackets, etc.) that must be degreased before electroplating or phosphatizing. It is not practical to clean these parts individually. This machine is built by Goff Corp.

High-pressure Water-Spin Blast Type

This type of equipment is used to clean larger items in an automatic mode. Examples are engine blocks, transmission housings, etc. This machine is also built by Goff Corp.

High-pressure Water-Turn Tables ~

These are the workhorsesnf _this type o f equipment. They are primarily used to automatically clean high volumes of large items but can be adapted to clean small parts as well. A large Mart Corp. machine is shown, but most of the units requested are smaller4own to 36 inches table diameter. Mart Corp. has a General Services Administration contract covering a number of turntable sizes with National Stock Numbers.

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.l High Pressure Water-Agitated Tanks

These tanks are similar to solvent immersion type tanks currently used at some depots. The tanks proposed are closed and use hcated, aqueous cleaning solutions circulated over and through the work by high-pressure pumps. Tanks vary in size and can degrease basket loads of small parts up to engine blocks and heads. These machines are not true water blast equipment, hut they have been requested by several depots to replace vapor degreasers. A Graymills unit is shown.

High-pressure Water-Circuit Board Type

A variation of the agitated type tanks are manufactured specifically to clean circuit hoards and other electronic parts including the "super clean" status required hy MIL-P-28809. This machine is built by Electronic Control Designs Inc. ECD also manufactures a similar washer to clean silk screen racks. Racks are now manually cleaned by wiping with methylethyl ketone solvent.

High-pressure Water-Conveyor Type

These are automated cleaning machines for high volume production. Machines combine both immersion and high-pressure spray cleaning. Machines can have multiple stages. Machines

Equipment shown is being built for Tooele Army Depot (TEAD) Maintenance Modernization Project by Ransohoff Corp.

can be used to clean basket loads of small parts or individual large parts such as engine blocks. 1

High-pressure Water-Vehicles

The Canadian Army has adopted a variation of high-pressure water cleaning equipment to replace manual steam cleaning of vehicle hulls. The slide presentation shows a Leopard tank hull-about the size of our M-1 Tank. This machine has automatic sludge separation and oil skimmers and recycles the cleaning solution. The pollution from wash racks used to steam clean vehicles is not toxic and does not attack the ozone layer. However, the sheer volume of water generated, the amount of soap used, and the oil, grease, and dirt that are routed through the IWTP warrants further investigation of this type of equipment. In addition, this machine reduces labor and improves safety. You eliminate personnel crawling on top of, and inside of, slippery vehicle hulls. This machine was built by Proceco at an installed cost of $300,000.

I would like to pause in the briefing to show a short video depicting the operation of a tumblc type cleaning machine. The video is only about 5 minutes long. I chose this video ,) because it is short, but still adequately describes the operation of these machincs. Note the

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solution recirculation, oil skimming, and sludge removal features that are common to all of the high-pressure water blast machines proposed. When the solvent in a degreaser becomes contaminated with oil to the point it raises the boiling temperature by 1O"F, it must be removed and disposed of. A man, wearing life support equipment must enter the degreaser and clean out the sludge disposals. Use of equipment with nontoxic solutions, oil skimmers and automatic sludge removal will not only reduce both pollution and labor-it will also eliminate a dangerous work requirement. In the past, RRAD and other depots, have had personnel overcome by fumes while working inside of degreasers.

Advantages-High-pressure Water Equipment

No toxic chemicals-hot water is the principal cleaning agent.

Operating temperature-machines operate at approximately 200°F. It is hot enough for parts to flash dry, but low enough that plastic and rubber parts are not damaged and metal tempers are not affected. Machines can degrease some parts that cannot be cleaned in a vapor degreaser, hot caustic solution, or a fluidized bed.

Size and type range-a size and type of machine is available for most applications.

Automatic sludge collection and oil separation-simplifies waste collection and reduces :3 maintenance.

High-pressure Water Equipment Requirements and Pay Back

Equipment requirements for those depots that have requested high-pressure water cleaning equipment to replace operations using chlorinated solvents are shown in the slide presentation. The pay back time was determined by dividing the investment cost by the savings each depot has stated they will realize in the first full year of operation of this equipment. The pay back times will probably be shortened as these solvent materials become more expensive, harder to obtain, and their use for metal cleaning is banned. More accurate pay back times will be obtained when the formal economic analysis is completed. The 7.0 year figure at the bottom of the chart on high-pressure water equipment requirements is not an average of the figures above, but rather the result of dividing total DESCOM investment by total DESCOM savings for calendar year (CY) 1993.

_ _ _ _ _ ~ Chlorinated Solvent Reduction

We have discussed the types of equipment recommended and the costs to be incurred. Now let's see what we get for the money expended. This chart compares the volumes of material used, hazardous waste generated, and costs for the CYs 1988 and those projected for 1993. I '3

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1 used 1988 figures because I have not been able to obtain complete 1990 figures and for continuity since I used 1988 figures in the briefing last year. I used CY-93 as the first full year of operation assuming that the equipment will be purchased and installed in CY-92.

As I stated prcviously, most depots are reluctant to give up cleaning with chlorinated solvents even though they know they will be forced to do so. For that reason, most of the depot point-of-contacts were very conservative about predicting reductions in solvent use and waste generation. All said they intended to continue to operate vapor degreasers for as long as possible. Therefore, we should see better numbers in CY-93 than predicted and will certainly see almost total elimination of chlorinated solvents in the out years as they become harder to obtain and more expensive to use. The reductions in volumes of solvent used, hazardous waste generated, and cost savings for each depot as well as DESCOM wide totals are depicted in the slide presentation. The first year benefits are also summarized in the slide presentation.

__

Summation

Degreasing of metals in some form must continue.

We have presented the amount of equipment, material, and estimated cost required for implementation of the high-pressure water cleaning.

We have listed the predicted reductions in solvent usage, hazardous waste reduction, and cost savings.

We are continuing to investigate all technologies currently available to DESCOM to eliminate, or reduce, the use of chlorinated solvents.

Next Steps

Final estimates will have to be made to include both acquisition and installation costs:

Decisions of contractor furnish only versus contractor furnish and install will have to be made for each type of equipment and depot involved and included as part of the specification requirements. For example, small glove box units can be purchased and then easily installed by the depots with in-house personnel. It may be best to make the contractor responsible for furnishing and installing large turntable units requiring

specialized installatian and some~assembly on site,^ The contractor will~be required~ to provide start-up assistance and provide training to both operating and maintenance personnel.

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Questions regarding site preparation, foundation requirements, additional utilities, etc. ) will have to be resolved.

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Economic analyses must be prepared for implementation of this project. Some people have

,3 asked, Why do you need an environmental assessment (EA) to justify obeying the law? This EA will justify the use of high-pressure water over other methods-not compare its use to continued use of chlorinated solvent degreasing. New laws have severe civil and criminal penalties for violations. Avoidance of fines, possible depot closures, and inability to produce needed items for the Army may be considered in these economic analyses. A basic EA format will be prepared by the CIX and furnished to individual depots for their use.

Funding has to be obtained by DESCOM and furnished to individual depots. Most of the equipment will be procured using WIMCA and Defense Environmental Restoration Account funding.

Specifications will have to be prepared. A basic specification will be prepared by RR4D CDC for each distinct type of equipment. The specification will contain a section that will allow individual depots to specify features required for their application and location.

The acquisition process must be accomplished. Procurement of the glove box units for all depots requiring them under both the AAD and RRAD CTX programs is now in progress. AAD Contracting Office is performing this effort as a consolidated buy for all of the depots. The majority of the remainder of the equipment will be procured and installed in FY-92. Funds, economic analysis, and specifications will be furnished to the depots to allow local acquisition 3 actions:

Equipment installation

Evaluation of the performance of equipment.

We would see a more rapid reduction in the use of chlorinated solvents, if a policy statement is issued to the effect that, once alternative means of degreasing are provided, chlorinated solvents will not be used. Both CG, DESCOM and CG, AMC have stated their intentions to do this, with General Tuttle making it clear it will apply to all AMC installations, not just depots.

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PURPOSE

Provide a

current status of RRAD

Chlorinated Solvents CTX effort,

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1

3

BRIEFING OUTLINE 0 PURPOSE

BACKGROUND

NEW DEVELOPMENTS

0 HIGH PRESSURE WATER CLEANING

MACHINE VIDEO 0 FLUIDIZED BED

CHLORINATED SOLVENT REDUCTION

0 SUMMARY 0 NEXT STEPS

VAPOR DEGREASING

ALTERNATIVES

0 Solvent Waste Reduction

0 Substitute Products

0 Industry Studies

New Equipment Technologies ~

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New Equipment I Tech no 1 o g i es

B) VACUUM DEGREASING

QD FIAJIDIZEI) BED DEGREASING (PAINT STRIPPING)

WATER BLAST

@ ULTRASONIC CLEANING

@ BAKE OVENS

RECOMMENDATIONS SHORT RANGE

Substitute Chemicals

Water B l a s t Equipment

LONG RANGE

U 1 Lrasonic Cleaners

63 Vacuum Degreasers

63 Fluidized Bed

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TECHNOLOGIES SELECTED

@ WATER BLAST EQUIPMENT

SUBSTITUTE CHEMICALS

FLUIDIZED BED

ALTERNATE TECHNOLOGY C 0 MP A l l I S 0 N 0 - BEST @3 - A ITRAGE Q - I'ORST Y - YES N - IVO U - UNfiVOFN VAPOR DEGREASERS VACUUM DEGREASERS FLUIDIZED BED IYATER BLAST

BAKE OVENS

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ALTERNATIVES EVALUATION

CRITERIA 0 Environmental Impact

6, Proven Technology

0 Commercial Availability

e cos t

NEW LAWS/DIRECTIVES 8 TOXIC SUBSTANCES CONTROL ACT

( TSCA 1

0 CLEAN AIR ACT AMENDMENTS ( CAAA )

40 CFR 82 EPA - STRATOSPHERIC OZONE PROTECTION

DoD DIRECTIVE 4210-15 - HAZARDOUS MATERIALS POLLUTION PREVENTION ( RCRA 1

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3

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P R 0 D U C T I 0 N P I-IAS I< - 0 UT S C I-IED ULE

100 90 80

70 60

50

4.0

30

20

10 0

1991 1992 1993 1994 1995 199G 1997 1990 1999 2000 2001

YEAR

OZONE DEPLETANTS

TRICIILOROETIIANE CLASS 1 SUBSTANCES

DEPOT FLUIDIZED BEDS

0 LETTERKENNY

RED RIVER

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3

3

I

Largest Users

Are

Maintenance Depots

3

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J

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w s I I - 5 0

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* * * *

WATER BLAST

ADVANTAGES

No Toxic Chemicals

Operating Temperature

Size & Type Range

Automatic Sludge Collection and Oil Separation

I-I I CXI PRESSURE WATER EQUIPMENT REQUIREMENTS

SUMMAT I O N

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FIRST YEAR BENEFITS

0 109,000 GAL, SOLVENT USE REDUCTION

0 51,000 GAL. HAZARDOUS WASTE REDUCTION

0 8656,000 OPERATING COST SAVINGS

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.

IN SUMMARY,.. ODEGREASING MUST BE PERFORMED

0 QUANTIFIED REQUIREMENTS ( EQUIPMENT/COST 1

0 IDENTIFIED REDUCTIONS ( SOLVENT/HAZ. WASTE 1

0 NEW TECHNOLOGIES/BETTER METHODS

NEXT STEPS

0 PREPARE FINAL ESTIMATES

0 PREPARE ECONOMIC ANALYSES

OBTAIN FUNDING

0 PREPARE SPECIFICATIONS

0 ACQUISITION

0 EQUIPMENT INSTALLATION PERFORMANCE EVALUATION

0 POLICY STATEMENT

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