Patent ID: 6287474
Filing Date: 2001-09-11
Classification: B01D

Abstract:
A deep bed filter comprising:a tank defining an internal space for containing a liquid to be filtered, and an inlet for directing liquid to be filtered into said tank;a bed of granular filter media disposed in said tank occupying a portion of the internal space in said tank;an outlet receiving a flow of filtered liquid after passing through said media bed;at least one agitator element mounted within said tank space;periodically operated drive means for causing said agitator element to be moved so as to cause dispersal of said filter media and liquid within said tank space to form a slurry mixture of said liquid and said granular media;an annular separator having an inner cylindrical screen having flow openings formed therein smaller than the size of said granular filter media to prevent said granular media flow from passing therethrough while allowing flow therethrough of filtered solids dispersed into said liquid by agitation set up by said movement of said agitator element within said tank, said annular separator mounted to be stationary within said tank;outlet means drawing liquid out through said separator flow openings and into an annular space within said separator, and out of said tank; andmeans for creating localized liquid flow at the surface of said inner cylindrical screen of said annular separator directing dispersed media at said screen surface so as to dislodge granular media drawn onto said flow openings during outflow of liquid through said openings, said means for creating localized flow comprising a rotor mounted to be rotated within said separator inner wall to create turbulence at said separator inner cylindrical screen, said means for rotating said agitator element also rotating said rotor.