Enclosed flotation device
OwnerGerald G. Greeninventor
Life of this patent
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Abstract
A process for clarifying by flocculation a turbid liquid which forms a foam with injected gas and which contains material that, with gas, will form a floatable floc. A gas compatible with the liquid is injected into the liquid in order to form foam atop the body of liquid, and components of a floc within the body of liquid. The liquid after said treatment with gas is permitted to reside quietly so that the floc components form a floatable floc and rise to the surface of the body of liquid. Clarified liquid collects below the floc. Gas for injection into the body of liquid can be withdrawn from a region containing the foam, whereby to recover liquid from the foam, thereby substantially eliminating loss of liquid as foam.
Claims16
A process for clarifying by flocculation a turbid liquid which forms a foam with injected gas, and which contains material which, with gas, will form a floatable floc, said process comprising:
- in an injection vessel, on a continuous basis injecting into a body of said liquid a gas compatible with said liquid, whereby to form a foam atop the body of liquid and to form components of floc within said body of liquid;
- retaining said foam in said injection vessel in such manner as to prevent its escape;
- continuously and for a substantial period of time reinjecting into said body of liquid such of said gas which escapes said body of liquid and at least some of said foam, whereby substantially to eliminate loss of liquid in the form of foam;
- thereafter on a continuous basis transferring liquid from said body of liquid to a closed flocculation vessel wherein said liquid is quietly contained, whereby to form a three phase system comprising liquid at the bottom, high solid floc atop the liquid and froth-gas atop the floc, and on a continuous basis withdrawing liquid and floc from levels where their respective phase exists.
Apparatus for clarifying a liquid capable of forming a foam with a gas, and having a substance to be removed which forms a floatable flock with said gas, said apparatus comprising:
- an injection vessel having a bottom, sidewall, and closed top to form a lower injection region and an overlaying foam-retention region for receiving and preventing the escape of foam thereform;
- injector means for injecting gas and foam from said foam-retention region into a body of liquid contained in said injection region;
- means for supplying liquid to be clarified to said injection vessel a flocculation vessel having a bottom, closed top, and sidewall;
- said liquid in said flocculation vessel after residing quietly therein forming three phases at three levels:
- liquid, high solid floc, and froth-gas;
- a transfer conduit connecting said flocculation vessel to a level in said injection vessel below the surface of said body of liquid for transferring liquid from the injection vessel to the flocculation vessel;
- counterbalance passage means interconnecting the froth-gas level to said overlaying region;
- means at the floc level for removing floc from the flocculation vessel;
- and means at the liquid level for removing liquid from the flocculation vessel.
Dependencies are inferred from the claim text.