CASE STUDY # 116
1. Headline: Spinning rings hardened on a fluidized bed dry
process eliminates waste production.
2. Background: See below.
3. Cleaner Production Principle: new technology
4. Description of Cleaner Production Application: This audit
of manufacturer of spinning rings used in the textile
industry suggests that by replacing the conventional
cyanurated salts bath followed by rapid oil cooling
hardening process with a dry process on a fluidized bed
there is almost no waste generated. Baskets containing
parts to be hardened are dipped into a fluidized bath of
nitrogen and corundum particles at temperature between 840
and 860 deg C. Baskets are then dipped into another
fluidized bath at 50 deg.C. Corundum left on processed
parts is recovered and recycled.
Material/Energy Balance and Substitution
FEEDSTOCKS: 0.4 Kg of corundum, 25 m3 of
nitrogen and 0.63 GJ of electricity per
1000 spinning rings.
WASTES: Negligible amount of dust
MEDIUM: Fluidized bath of nitrogen
and corundum particles
5. Economics
COST: (Annual production of
300,000 spinning rings)
CAPITAL COST: FF 185,000 (1979 figures)
OPERATION/MAINTENANCE: 60% of the O&M costs for the
standard technology (excluding treatment plant operating
costs).
DISPOSAL & FEEDSTOCK: FF 125,000 (1979 figures, including
the capital cost for the treatment plant).
6. Advantages
FEEDSTOCK REDUCTION: Corundum left on processed parts is
recovered and recycled.
WASTE PRODUCTION: The polluting wastes generated by the
standard technology: used cyanurated salts, oil fumes, and
rinse water at a pH of 12.5 (3.5 m3 per 1,000 rings,
containing 75 Equitox) are completely eliminated.
IMPACT/PROBLEMS: This technology is more flexible in its
application than the standard technology.
7. Constraints: No information provided.
8. Contact and Citation:
Compendium on Low and Non-waste Technology, United Nations
Economic and Social Counsel, "Hardening of Spinning Rings
by a Dry Process on a Fluidized Bed", Monograph
ENV/WP.2/5/Add.71
9. Keywords: France, textile, spinning ring, new technology,
fluidized bed, salt, cyanurated salt, corundum, ISIC 3800.
10. Reviewers Comments: This case study was originally
abstracted for the US EPA Pollution Prevention Information
Clearinghouse. It underwent a UNEP IE funded technical
review in 1994 for quality and completeness. It was edited
for the ICPIC diskette in July 1995.
(DOCNO: 400-071-A-308)