Apparatus for removing suspended oil droplets from water

Claim 1

Apparatus for separating oil droplets suspended in a waste water stream produced on an offshore rig comprising: a pipe, having an upper, middle, and lower portion, vertically positioned adjacent said offshore rig in a body of water, said pipe extending from a location above the surface of said body of water to a submerged location substantially below the surface; a line positioned vertically adjacent said pipe and extending from a location above the surface of said body of water to the lower portion of said pipe; means for injecting said waste water stream into the middle portion of said pipe; means for injecting gas from said line directly into the lower portion of said pipe wherein said injecting means includes a diffuser to disperse said gas into gas bubbles such that said gas bubbles countercurrently contact said waste water stream as said gas bubbles rise toward the upper portion of said pipe attaching to said oil droplets and reducing the overall density of said oil droplets sufficiently so that the upward velocity of said oil droplets is greater than the downward velocity of said waste water stream, thereby promoting the separation of said oil droplets from said waste water stream; and means for withdrawing said oil droplets from the upper portion of said pipe.