Underwater tanker ballast water/oil separation

Claim 1

Apparatus adapted to rest on the floor of a body of water for underwater offshore treatment of tanker ballast water containing entrained or emulsified oil therein, said apparatus comprising: a vertical standpipe communicating from a point near the floor of said body of water to a point above the water surface; an upwardly convex shell encircling said standpipe and attached thereto at a point above its lower end, said shell and standpipe defining an annular volume which is sealed against upward flow of liquid, said shell being open at the bottom; an annular vertical baffle spaced from and encircling said standpipe below said convex shell, said baffle being joined at its upper end to said shell, dividing said annular volume into two zones, each of which is sealed against upward flow of liquid but which is open at its lower end for liquid flow; means for introducing ballast water to the interior of said standpipe; means near the top of said standpipe for recovering oil separated from said ballast water; and means for recovering oil collected in each of said separate annular zones.