Abstract: This invention relates to a new and unique method for the extraction and reclamation of perchlorethylene dry cleaning solvent from spent dry cleaner filter cartridges which utilize a layer of activated charcoal and paper filter media to perform the filtering function. The spent filter cartridges are separated into component parts. The charcoal and paper filter media are separated, collected and immersed in a boiling liquid solution contained in a boiling sump. The resulting perchlorethylene-laden vapors are collected and condensed to form a condensate. The condensate is allowed to settle by gravity into two homogeneous layers the upper layer of which contains water and the lower layer of which contains perchlorethylene in order to separate and collect the perchlorethylene for reuse or sale. The water in the upper layer is recycled into the boiling sump for reuse. The charcoal and filter media components are removed from the boiling sump, dried, and collected for recycling or sale.

Abstract: A contaminated article is subjected to vapor degreasing operations wherein the vapor degreasing solvent is a blend consisting essentially of methylene chloride and either 1,1,1-trichloroethane or trichloroethylene. Addition of methylene chloride to the solvent blend is found to stabilize the other component of the blend in the presence of contaminants encountered in the conventional vapor degreasing process; thus extending the normal life of the degreasing solvents.

Abstract: A contaminated article is subjected to vapor degreasing operations wherein the vapor degreasing solvent comprises a blend consisting essentially of perchlorethylene and trichlorethylene, wherein in the preferred embodiment, the perchlorethylene comprises about 81 volume percent of the degreasing solvent, while the trichlorethylene comprises the remaining 19 volume percent of the solvent blend.The solvent blend extends the normal life of perchlorethylene degreasing solvents alone, or in combination with stabilizers and the like, or, alternatively, allows the utilization of trichlorethylene at temperatures higher than those that would normally cause pyrolysis. The degreasing solvent blend not only extends the operational life of perchlorethylene-based vapor degreasing solvents, but also reduces the cost of conducting vapor degreasing operations.