Filter apparatus

Claim 1

A filter apparatus for extracting particulate matter from a fluid comprising means defining a fluid passageway formed with a fluid inlet and a fluid outlet, a filter element disposed in said passageway between said inlet and said outlet and in intercepting relationship relative to the fluid passing therethrough, said filter element comprising a pair of spaced apart substantially circular cylindrical concentric foraminous walls defining therebetween an annular filter chamber, a particulated granular filter medium in said filter chamber, a supply conduit disposed in communication with said filter chamber for introducing said filter medium thereto and a discharge conduit disposed in communication with said filter chamber at a position remote from said supply conduit for withdrawing said filter medium therefrom, separator means in communication with said discharge conduit for separating said filter medium from any entrained particulate filtered material, conveying means for recirculating the separated said filter medium to said supply conduit, collector means formed with an inlet port overlying a portion of and disposed contiguous to the upstream face of said filter element and the filtered particulate material formed thereover, said collector means including discharge means for discharging the collected particulate material to a position exteriorly of said passageway, conduit means connected to the interior of said collector means for effecting a reduction in the fluid pressure therein below the fluid pressure in said passageway of a magnitude sufficient to cause the particulate material adjacent to said inlet port to be dislodged from said upstream face, and drive means for effecting relative movement between said collector means and said filter element in a manner to progressively traverse substantially the entire area of said upstream face for collecting the particulate material thereon.