METHOD OF RECOVERING WORKED OUT OIL FROM FOAMY OIL-CONTAINING INDUSTRIAL WASTES Russian patent published in 1997 - IPC

FIELD: chemical engineering. SUBSTANCE: wastes are heated in reactor with bubbling compressed air followed by settling down upon cooling and taking off oil phase containing 0.5-1.5 vol % water. Isolated oil phase is one again heated in two steps: first at 95-105 C with bubbling compressed air supplied through nozzles arranged tangentially along periphery of reactor, and then at 110-140 C with additionally entered compressed air from below of the reactor with velocity exceeding that of air supplied through tangentially arranged nozzles. The second heating lasts until acid number of product 10-20 mg KOH/g and particle admixture 0.4-0.7% are achieved. EFFECT: enlarged oil resource and improved environmental condition. 2 tbl