GB600492A - Improvements in or relating to sewage filter beds - Google Patents

Abstract

600,492. Filtering liquids. AMES CROSTA MILLS & CO., Ltd., and BOLTON, J. F. Sept. 10, 1945, No. 23221. [Class 46] In a filtering means for fluids, such as sewage comprising a single filter bed and moving sprinkler means for distributing fluid over it, the sprinkler means is constructed so that one part distributes to one area of the filter bed and another part distributes to another. Means are also provided for supplying fluid selectively to either part of the distributor and for collecting fluid from the floor of the bed and delivering it as secondary fluid to the other part of the distributor to enable the system of alternating series filtration to be employed with a single filter bed. The filter bed shown in Fig. 1, is circular and is divided by a ridge c into two equal concentric areas c<SP>1</SP> and c<SP>2</SP> from the sloping floors of which the fluid drains to collecting channels a<SP>2</SP>, b<SP>2</SP> and passes along pipes q<SP>1</SP>, p<SP>1</SP> to humus tanks q, p, Fig. 6. The sprinkler has two pairs of rotating arms e, d supported on a hollow pillar f. The fluid is passed up the pillar into one or other of two annular troughs each of which feeds a pair of arms e or d and one of the areas c<SP>2</SP> or c<SP>1</SP>. Adjustable valves r and u, Fig. 6, are set so that the incoming fluid is passed to the longer pair of sprinkling arms d and collected from the outer filter arms c<SP>1</SP>. The fluid then passes through the tank q to the valve u whence it is returned by a pump t to the shorter pair of sprinkler arms e, collected from the inner filter area c<SP>2</SP> and discharged through the tank p and the valve u. By reversing the valves the fluid passes first through the inner and then through the outer filtering area.