GB242272A - Improvements in and relating to methods of and apparatus for purifying oil - Google Patents

Abstract

242,272. British Thomson-Houston Co., Ltd., (Assignees of Brunt, C. G. van). Oct. 29, 1924, [Convention date]. Recovering waste lubricants. - In the re-conditioning of oils containing finely divided. solids in suspension by treatment with an alkali silicate or other weakly basic agglomerating substance soluble in water, the mixed oil and silicate are floated on heated water in a settling tank to separate the sludge, and the cleansed oil is then freed from diluents in an evaporator, and is finally used to preheat used oil passing to the mixer. Using the apparatus shown, used crankcase oil of an internal combustion engine, is drawn through a pipe 9 by a pump 10 and forced through a pipe 11, a heat exchanger 12, and a pipe 13 to a mixer 39 into which water-glass solution is drawn from a pipe 28 by the rotation of the paddle shaft 29 formed with a helical groove G and having only a small clearance in the housing 30. The mixture passes down a pipe 15, and in a zig-zag path for about an hour over the surface of water in a tank 16 provided with baffles 35. The sludge settles out and is discharged through a pipe 45. The oil passes over a baffle 51, under a baffle 50, and through an outlet 17 and a pipe 18 to a trough 19, from which it is distributed over the surface of an evaporator 20 for the removal of diluents. The oil is then cooled by passage through the exchanger 12 and is discharged through a pipe 22. One litre of waterglass solution of 48-50‹ Be. to 50 litres of oil is suitable. 0.1 per cent of resin preferably in solution as in benzol, or of manganese or other heavymetal resinate, preferably in solution in benzol and with 0.1 per cent of stearic or other fatty acid, may be added as described in Specification 235,861. The process is preferably conducted at about 70-80‹ C., an electric heater 38 being provided in the tank 16 to maintain this temperature. Water is fed continuously to the tank 16 through a pipe 40, a pipe 44 surrounding the discharge pipe 45, and a pipe 54 opening opposite the heater 38. The discharge of sludge through the pipe 45 is regulated by moving a valve, comprising a capillary groove in the end of a shaft 47, more or less into its bearing 46. The shaft 47 is flattened beneath the tank 16 to disintegrate the sludge. The evaporator 20, as described in Specification 235,861, comprises an electric heater in a narrow flat casing having capillary ridges and grooves on the outside. The temperature varies from about 125‹ C. at the top to about 150‹ C. at the bottom. The arrangements for continuously feeding and discharging the tank 16 may be dispensed with.