GB243666A - Improved method of and apparatus for purifying oil - Google Patents

Abstract

243,666. Sharples Specialty Co., (Assignees of Clark, L. H.). Nov. 29, 1924, [Convention date]. Recovering waste lubricants.- Oils, containing decomposition products, free fatty acids and colloidally suspended substances either naturally or by reason of being used for immersing electric switches, circuit breakers, or transformer coils, or for lubricating internal combustion engines or steam turbines, are treated with an aqueous reagent that has the property of being dispersed more easily than water through the oil and also the property of causing impurities to be removed from the oil. As examples of such a reagent solutions of sodium silicate, particularly a solution in which silica predominates by weight, caustic soda, soda ash, trisodium phosphate, or other alkaline substances are mentioned. The oil to be purified is fed into a tank 1 through a pump 2 and pipe 3 and is then agitated by members 7 with the desired quantity of aqueous reagent supplied through the pipe 5. The mixture may be heated by a steam coil or electric device 6. A pipe 9 leads the heated mixture to a centrifugal separator 10, the aqueous part of the mixture being discharged with the impurities through a spout 11, and the oil passing through a spout 12 into a receiving tank 13. If insufficiently purified the oil is treated by the addition of a small quantity of Fullers earth or similar adsorptive material introduced through a pipe 13', and is then passed into a centrifugal clarifier 15. The oil may be kept in the tank until a desired quantity has accumulated, a ball valve 17 controlling its passage to the clarifier.