GB539910A - Improvements relating to degreasing plants - Google Patents

Abstract

539,910. Degreasing apparatus. FRASER & FRASER, Ltd., and HELLER, M. July 17, 1940, No. 11814. [Classes 32 and 91] [Also in Group I] A de-greasing plant is provided with a closed vessel 1 adapted to receive the degreasing liquid which may be contaminated with water or other liquid of lighter density, said vessel having a domed top 1a with a valve-controlled outlet 29 in its middle, whereby the lighter liquid, which floats on the denser de-greasing liquid, can be removed by adding further de-greasing liquid in amount sufficient to displace the lighter liquid through the outlet. The vessel 1 contains a solvent, e.g. tri- or per-chlorethylene, which is heated by a heating coil 40 and passed by means of a centrifugal pump 11 and pipe 15 to a steam-jacketed degreasing tank 3. The articles to be de-greased are placed in a basket 4 in the tank 3, which is then closed by a lid 3a ; the basket can then be rotated by a handwheel 3b Surplus solvent flows back to the tank 1 through a pipe 16, and after an interval the contents of the tank 3 are returned to the tank 1 by the pump 11. Soluble oil or the like removed from the articles in the tank 3 floats on the surface of the solvent and, under rotation of the basket 4, collects at the centre of the concave surface of the liquid, and on the return flow of liquid to the tank 1 flows down a tube 41 and is thereby removed with the liquid from the tank 3. The latter tank now contains the hot articles moistened with solvent, and solvent vapours mixed with air ; the latter are circulated by a pump 12 in a closed system including the tank 3, pipe 23, condenser 6, separator 7, pipe 25 and heater 2 to recover the solvent, which passes from the separator 7 to a storage tank 8 from which it can be led to the tank 1. When, after repeated use, it is necessary to purify the solvent in the tank 1, the soluble oil or the like floating on the surface is first removed through the outlet 29 ; the solvent is then pumped into the distilling retort 9, evaporated therein, condensed in the condenser 10 and returned to the storage tank 8.