JPH0336084B

PURPOSE:To effectively suck water containing oil in a wave surface, by a method wherein an inner cylinder, having a float located to the lower part of a suction funnel and around a waterway, is slidably engaged with an outer cylinder having an open port at its upper part and a discharge port at its lower part. CONSTITUTION:When suction liquid in a liquid storage chamber 10 is decreased to decrease buoyancy of a float 6 and an inner cylinder 3 is lowered to below a liquid level W.L., after surface liquid is sucked through the upper edge of a suction funnel 4, it is fed through a waterway 5 and the liquid storage chamber 10 to a float separating tank for oil water by means of a drain port. Thereafter, when an amount of liquid stored in the liquid storage chamber 10 is gradually increased, the upper end of the inner cylinder 3 is forced to emerge from the liquid level W.L. by virtue of the buoyancy of the float 6 and suction of surface liquid through the funnel 4 is suspended. When drainage through a drain port 2 is continued and the amount of the liquid in the liquid storage chamber 10 is decreased, the inner cylinder 3 is lowered to below the liquid level in conformity with the float 6, and a surface liquid is started to be sucked again through the funnel 4.