METHOD OF CLEANING OF USED LUBRICATING OIL Russian patent published in 1996 - IPC

FIELD: production of lubricating oils. SUBSTANCE: cleaning process is conducted by treatment of oil preliminarily heated up to 90 to 100 C, heated to the melting point by carbamide making up 2 to 15% of the mass of oil to be cleaned, with subsequent separation of cleaned oil. These conditions enhance the degree of cleaning of used oil due to the fact that short-time action of fine-dispersed globules of melted carbamide on the hydrocarbon basis of oil and active portion of additive is ensured, and sediment of impurities is formed on granules as adsorbent without formation of stable suspension (sediment is separated by natural deposition, at deposition slime there is no crushing of carbamide granules in centrifuges). EFFECT: enhanced degree of oil cleaning and yield. 1 dwg, 2 tbl