Enclosed flotation apparatus and process

Claim 2

Flotation apparatus of claim 2 which includes means for maintaining the gas in said freeboard space at a super atmospheric pressure.

Claim 3

Flotation apparatus of claim 3 wherein said draft means for drawing and dispersing gas into the liquid comprises a rotor mounted in the tank for rotation about a generally vertical axis with the bottom of said rotor adjacent to and spaced from the bottom of the tank, said rotor comprising a central axial portion, a plurality of generally axially extending vanes supported by and extending generally radially of said axial portion, and generally axially extending portions projecting generally transversely of said vanes at location on said vanes spaced from the axis of said rotor; and stator means supported in saiD tank with its lower end substantially above the bottoms of said rotor vanes, said stator means being generally vertical and spaced concentrically about said rotor vanes, said stator including a plurality of elongated members spaced apart to enable liquid flow therebetween from the interior of said stator toward the surrounding portion of said enclosed tank.

Claim 4

A process for simultaneously separating insoluble materials and oxygen from a contaminated oxygen-bearing liquid comprising the steps of establishing and maintaining in an enclosed tank an ever changing body of contaminated oxygen-bearing liquid with an overlying freeboard space closed to the atmosphere, continuously introducing a substantially oxygen-free gas into said freeboard space drawing said gas from said freeboard space by a draft means extending downwardly into said tank and into said liquid body and dispersing same within said liquid body as bubbles thereby to float contaminants to the surface of the liquid body while concomitantly displacing oxygen from said liquid, discharging floated contaminants and at least some of the displaced oxygen from the freeboard space in said tank and separately discharging the residual liquid from which said contaminants and oxygen have been separated.

Claim 5

The process of claim 5 wherein gas in said freeboard is maintained at a pressure above atmospheric.

Claim 6

The process of claim 6 wherein gas is continuously bled from said freeboard space to the atmosphere.

Claim 7

The process of claim 7 wherein the contaminants comprise a mixture of a water insoluble liquid and particulate matter and said oxygen-free gas is a petroleum gas.