Patent ID: 7959012

Claim:
An apparatus for treating oil-based sludge comprising: a boiler; a heat exchanger having a circulatory steam path in fluid communication with the boiler and a sludge path receiving sludge; a plurality of serially-aligned mixers in fluid communication with the sludge path of the heat exchanger, wherein each mixer receives the sludge; a separation tank in fluid communication with the plurality of mixers; and wherein the separation tank comprises: a tank having a plurality of walls; a hydrocyclone mounted entirely within the tank receiving sludge from the plurality of mixers; wherein the hydrocyclone includes a solids outlet directing a solids component towards a bottom portion of the tank and a fluid outlet directing a liquid component into the tank; a means for conveying separated solids along the bottom portion of the tank to a solids outlet; and a plurality of fluid outlets vertically located along a tank wall, wherein each outlet includes a valve providing selective fluid communication from the tank.