GB470558A - Drying process - Google Patents

Abstract

470,558. Drying systems. WACKER GES. FUR ELEKTROCHEMISCHE INDUSTRIE GES., DR. A. Jan. 6, 1937, No. 387. Convention date, Jan. 20, 1936. [Class 34 (ii)] Metals, moulded articles, fibrous materials, powders and the like are dried by treatment with a volatile .organic solvent insoluble in water and containing a small proportion of an emulsifying agent. Solvents such as benzine, benzene, trichlorethylene, perchlorethylene, carbon tetrachloride may be used and the emulsifying agent may be an alkali salt of a resin or fatty acid or a metal insoluble soap such as calcium oleate. The article to be dried may be immersed in the boiling liquid. Vigorous motion is preferably given to liquid or article or both. The article may be subject to pretreatment or after - treatment with a liquid solvent or the vapour of a solvent and a greasing agent may be added to prevent corrosion. When the water content of the liquid becomes too high it may be allowed to stand for the water be decanted or water may be distilled from the separated portion and the residue chiefly emulsifier, be again added to the treatment liquid. The process may be conducted in open or closed vessels. In the case of carbontetrachloride an open vessel may be used where the upper part is cooled and the lower part filled with boiling treatment liquid. The article may be lowered into the liquid and taken out again. In apparatus of this.kind a part of the condensate formed in the cooling zone may be collected, freed from water and returned to the treatment liquid. For continuous operation articles to be dyed may be mounted. on conveyers. Six examples are given including pinewood, filter paper, aluminium sheet, artificial resin, a glass lens and cotton threads. In each case the advantage of the emulsifying agent is stressed.