GB551559A - Improvements relating to the degreasing of metal and other non-porous articles - Google Patents

Abstract

551,559. Degreasing non-porous articles. FRASER & FRASER, Ltd., and PARTISCH, K. J. A. Aug. 25, 1941; Nos. 10823/41 and 5904/42. [Class 91] In the degreasing of non-porous articles contaminated with an oil emulsion, the spotting of the articles by the drying out of the emulsifier thereon is avoided by maintaining the emulsifier in a moist and loosely adherent state by means of steam or water, applied just before or at the beginning of the degreasing operation, so that the emulsifier is removed together with the oil by the degreasing agent. The method may be applied to continuous or non-continuous degreasing plant. When steam is used the subsequent removal of the oil emulsion may be effected by condensing vapours of the solvent on the articles, or by exposing them to condensed solvent vapours dripping down upon them from a condenser, or by subjecting them to a spray of the solvent, or by dipping them into the liquid solvent. In a convenient method of treating the articles in a degreasing tank simultaneously with steam and solvent vapour, the mixture is supplied to the tank by means of a combined steam injector and solvent vaporizer comprising a pair of concentric tubes 1, 2, terminating in discharge nozzles 3, 4, with a helix 5 in the space therebetween. Solvent is supplied at an inlet 7 and is vaporized by the steam passing through the inner tube from a supply connected thereto at 8. When water is used the articles are bathed therewith immediately prior to the solvent treatment and this can be conveniently effected in a degreasing tank 9, Fig. 2, by supplying water thereto prior to admitting a solvent heavier than water so that a layer of water floats on the latter and contacts with the articles in a removable perforated container 10 before they are immersed in the solvent. Valve-controlled inlets 13, 11 for the water and solvent respectively and a single valve-controlled outlet 15 are provided..The latter apparatus may be adapted for use in a continuous degreasing plant, the articles to be cleaned being conveyed through the tank in a downward direction.