Patent ID: 6258262
Filing Date: 2001-07-10
Classification: B01D,B30B

Abstract:
A screw press type filter comprising:a filter cylinder including an arrangement of alternatively spaced, parallely disposed annular fixed and movable plates each having an inner diameter, the inner diameter of said movable plates being slightly greater than the inner diameter of said fixed plates, and said fixed and movable plates having small filtration clearances defined therebetween, and wherein said filter cylinder has a substantially constant cylindrical space defined by openings in said fixed plates;an inlet port at an inlet end of said filter cylinder and an outlet port at an outlet end thereof;a screw installed in, and extending through, the cylindrical space in said filter cylinder;means for rotating said screw identified by a rotary drive mechanism and cam means for moving said movable plates eccentrically with respect to said fixed plates; whereby raw water fed through the inlet port of said filter cylinder is pushed toward the outlet port thereof while said filtration clearances between the plates are always reproduced by the shaking movement of the movable plates;a valve disk opposed to a rear end of said screw installed in a rear end of said filter cylinder, which contains the outlet port thereof, for closing said outlet port until raw water to be processed is fed under pressure to said outlet port; andmeans for progressively reducing the pitch of the screw over a region ranging from the inlet end to the outlet end of said filter cylinder.