GB578382A - Improvements in or relating to water treating apparatus and methods - Google Patents

Abstract

578,382. Treating water. INFILCO, Inc. Jan. 7, 1944, No. 338. Convention date, Jan. 7, 1943. [Class 46] In a water softening or clarification process the water is treated in contact with a large body of slurry accumulated from previous treatment and the water is circulated between the lower body of slurry and an upper body of clarified water, the separation of the clear water at the interface being promoted by subdividing the flow into a number of narrow streams by sloping surfaces which act as receiving surfaces for the solids separating, these solids passing thence to the main body of slurry. Raw water and reagent respectively enter a conical tank by pipes 77, 78 and under the influence of an impeller 25 pass to and rise upwardly in a reaction cylinder 50 mixed with slurry drawn from the lower portion of the tank. The precipitate and flocs arising from the reactions with the reagent are agglomerated on the slurry particles; agitator arms 29 facilitate this action. From the top of the reaction chamber 50, which is closed at the top, the liquid passes by radial conduits 69 which are slotted at the sides to provide openings 73 for the liquid to pass laterally into the narrow spaces formed by a nest of sloping baffle rings 74 on the surfaces of which the solids settle to pass thence into the main body of slurry in the tank, while the clear water rises up into the clarified-water space 51 and eventually passes over a weir 14 to a launder 15 and service line 16. Sludge concentrated in a pocket or chamber 60 is drawn off by a pipe 62. The circulation flow is greater than the rate of raw water admittance. A modification is described in which the narrow streams are formed by radially-arranged sloping plates, Figs. 1 and 2 (not shown), additional sloping plates being inserted towards the outer periphery of the tank. Specification 578,383 is referred to.