CASE STUDY # 196
1. Headline: Cleaning In Stages
2. Background: See below.
3. Cleaner Production Principle: Process modification
4. Description of Cleaner production Application: Washing
grease off parts was efficiently achieved in three drums
of solvent placed in series. The parts are initially
placed in the first cleaning drum labeled "prewash". The
parts are then removed and placed into the second drum or
the "dirty" drum. The last drum or the "clean" drum will
clean the parts to meet quality standards. As the solvent
solution in the "clean" drum becomes contaminated, it is
transferred to the "dirty" drum. The more spent solution
in the "dirty" drum is transferred to the prewash drum.
Thus, the solution is not disposed of as waste until it
becomes completely spent. This operation produces on the
average a drum of spent solvent every 6.5 days.
Case Study Summary
Incentives: economic incentives
Original Manufacturing Process and Previous Waste/Emission
Management Methods: This facility used to clean parts in
a single 55-gallon drum of solvent. The single drum of
spent solvent had to be changed on the average every 4
days, because it could not clean the parts well enough to
meet quality standards.
Stage of Development: fully implemented
Results of Application: 39% reduction in the amount of
spent solvent generated, 8,700 lb/yr waste prevented.
Effects on Products: the parts are cleaned better
5. Economics
Investment cost: $1,100 (1988)
Payback time: 0.08 years (30
days)
6. Advantages
Wastes generated
55 gal every 4 days (before)
55 gal
every 6.5 days (after)
Economic benefits: 13,400 $/yr net annual savings
Liability reduction: reduced liability resulting from
reduced quantity of waste generated
Regulatory compliance: source reduction
7. Constraints
8. Contacts and Citation
Type of Source Material: Guide
Industry/Program Contact and Address: not provided
Citation:
Author: Waste Advantage, Inc.
Title: Industrial Waste Prevention. A Guide To
Developing An Effective Waste Minimization Program.
Date of Publication: April 1987
9. Keywords United States, USA, cleaning, process
modification, grease, solvent.
10. Reviewer's Comments: This case study was originally
abstracted from the publication cited above for the US
EPA's Pollution Prevention Information Clearinghouse. It
underwent a UNEP IE funded review in 1994 for quality and
completeness. It was edited for the ICPIC diskette in
July 1995.
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