US 5,458,738 AGranted

Clarifying suspended solids from liquid process streams

AssigneeKamyr, Inc.

InventorsJ. Wayne Chamblee, Brian F. Greenwood, Louis O. Torregrossa, Gunther Plattner

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Abstract

Liquid process streams--such as white water, pressate, or washer filtrate from a pulp and paper mill--are clarified in an efficient manner using a gas sparged hydrocyclone, which takes up a minimum of floor space. A liquid stream having a consistency of less than about 0.5% solids is introduced into a first end of a vortex. Gas is sparged into the liquid in the vortex to cause particles to attach to gas bubbles and move through a rejects outlet at the first end of the vortex, while clarified liquid is removed from a second end of the vortex. A pedestal is typically provided at the accepts outlet, having a radial clearance with the inside of a porous tube through which the gas is sparged that is about 8-12% the radius of the porous tube.

Claims20

Dependent claims

A method of clarifying a liquid stream containing suspended solid particles, the liquid stream comprising a pulp and paper mill process stream, and the liquid stream having a solids consistency of less than about 0.5%, and more than 90% of the particles having a maximum dimension of less than 500 microns, comprising the steps of substantially sequentially and continuously:

(a) introducing the liquid stream having a consistency of less than about 0.5% into a first end of a vortex;
(b) sparging gas into the liquid stream in the vortex to cause particles to attach to gas bubbles and move back toward the first end of the vortex, while the majority of the liquid stream moves toward a second end of the vortex, opposite the first end, to produce a clarified stream;
(c) removing the clarified stream from the second end of the vortex in an accepts stream, the accepts stream having a greatly reduced particles content compared to the liquid stream at the first end of the vortex;
(d) removing the particles attached to the gas bubbles from the first end of the vortex in a rejects stream;
and
(e) using the accepts stream from step (c) in a pulp and paper mill process.

3 more elements

Dependencies are inferred from the claim text.