Thickening device and method
AssigneeEnvirotech Corporation
InventorRobert C. Emmett, Jr.
Life of this patent
Estimating the term…
Abstract
A machine is disclosed for separating solids from feed liquor by gravity settling to form thickened subnatant. The machine includes a liquid-holding tank having an upstanding tubular column mounted therein for receiving the feed liquor. An inlet is formed in the upper portion of the column to admit clarified supernatant into the column for mixing with, and dilution of, the feed liquor. A plurality of subadjacent compartments include reagent introduction and mixing means to receive the feed liquor and to mix a chemical flocculating reagent thereinto. At the bottom of the column is an outlet to discharge the flocculated liquor directly into a pulp blanket stratum established within the tank.
Claims21
A machine for continuously separating suspended solids from a feed stream liquor by gravity settling comprising:
- a. a liquid-holding tank for containing a body of liquid in generally quiescent condition;
- b. an upstanding tubular column mounted within said liquid-holding tank;
- c. means mounted at the upper end of said tubular column to convey a stream of feed liquor into the interior of said tubular column;
- d. flocculating-mixing compartments formed within said tubular column, one below another, to sequentially receive the feed liquor;
- e. mixing means mounted within each of said flocculating-mixing compartments to blend the liquid therein;
- f. reagent introduction means mounted within each of said flocculating-mixing compartments to disperse a chemical flocculating reagent into the compartment for enhancing the flocculation of suspended solids within the feed liquor;
- g. discharge means in liquid-flow communication with the lowermost one of said flocculating-mixing compartments and with the interior of said liquid-holding tank for discharging the flocculated feed liquor into a pulp blanket stratum at the bottom of said liquid-holding tank;
- h. raking means including rake arms mounted within said liquid-holding tank to urge solids settled in the pulp blanket stratum to underflow discharge;
- and
- i. overflow means mounted on said liquid-holding tank to remove clarified supernatant therefrom.
An improved process for continuously separating suspended solids from a feed stream liquor by gravity settling comprising the following steps:
- a. introducing feed stream liquor into a first zone in liquid flow communication with a liquid-holding tank which holds a body of liquid in generally quiescent condition;
- b. then diluting the feed stream liquor with clarified liquid from a stratum of supernatant liquid held within the liquid-holding tank;
- c. then passing the diluted feed liquor through a plurality of subadjacent stages and, in each of said stages, dispersing chemical flocculating reagent into the diluted feed liquor and mechanically mixing the liquor and reagent to promote the aggregation of suspended particles into flocs;
- d. then discharging the flocculted and diluted feed stream directly into a pulp blanket stratum formed at bottom of the liquid-holding tank proper;
- e. removing settled pulp from the liquid-holding tank;
- and
- f. removing a clarified supernatant from the liquid-holding tank.
Dependencies are inferred from the claim text.