METHOD AND APPARATUS FOR RECOVERING WASTE OIL

PROBLEM TO BE SOLVED: To treat waste oil in a layer of a given thickness of about several millimeters to several tens of centimeters in short time by rotating an impeller at a high speed.SOLUTION: A storage tank 24 storing the waste oil by making a waste oil layer that floats on the surface of water as the waste oil layer is equipped with the impeller 20 in the vicinity of an opening edge 25 of the storage tank 24. An oil recovery tank 44 is disposed outside of the storage tank 24. The storage tank 24 is further provided with an overflowing device 29. The impeller 20 has rigid vanes 10 radially projecting from around a horizontal rotation shaft 1, the rotation shaft 1 is fixed above the opening edge 25 of the storage tank 24 so as to position the tip of the vane 10 pointing downward in the waste oil layer. A guide plate 33 is mounted on the opening edge 25 and the lower end 35 of the guide plate 33 is submerged in the waste oil layer 29a. The impeller 20 is thus rotated at 30 to 60 rpm to scoop the waste oil from the agitated surface thereof with the impeller 20 to transfer the scooped waste oil to the oil recovery tank 44.