Filtering apparatus and method

Claim 1

APPARATUS FOR SEPARATING A CARRIER FLUID FROM PARTICLES THAT LIE IN SUSPESION IN THE FLUID COMPRISING: A FRAME; MEANS FOR ROTATABLY SUPPORTING SAID FRAME; MOTOR MEANS COUPLED TO SAID FRAME TO ROTATE IT; A SCREEN MOUNTED ON SAID FRAME, SAID SCREEN HAVING FIRST AND SECOND FACES EXTENDING WITH A PRIMARILY RADIAL DIRECTIONAL COMPONENT FROM THE AXIS OF ROTATION OF THE FRAME AND HAVING A MULTIPLICITY OF HOLES; FIRST CONDUIT MEANS FOR APPLYING FEED FLUID CONTAINING THE CARRIER FLUID AND SUSPENDED PARTICLES, TO A RADIALLY INNER LOCATION ALONG SAID SCREEN AT A FIRST FACE THEREOF; SECOND CONDUIT MEANS FOR CARRYING AWAY FILTRATE THAT INCLUDES PRIMARILY THE CARRIER FLUID THAT HAS PASSED THROUGH SAID SCREEN; AND THIRD CONDUIT MEANS FOR CARRYING AWAY CONCENTRATE THAT INCLUDES CARRIER FLUID WITH SUSPENDED PARTICLES THEREIN THAT HAS PASSED TO THE RADIALLY OUTERMOST PORTION WITHOUT HAVING PASSED THROUGH THE SCREEN; SAID FRAME HAVING A SURROUNDING WALL WHICH ROTATES WITH THE REST OF THE FRAME TO FORM A SUBSTANTIALLY CLOSED CONTAINER THAT CAN BE FILLED WITH THE CARRIER FLUID AND SUSPENDED PARTICLES.

Claim 14

A method applicable to a feed containing a carrier fluid and particles heavier than the fluid, for separating the carrier fluid from the particles, comprising: flowing said feed containing carrier fluid with the particles therein along a first face of a screen from a first end thereof to a second end thereof; exhausting fluid from a second face of the screen opposite the first face, to create a pressure differential across the screen that urges the passage of the carrier fluid from the first face of the screen to the second face of the screen; rapidly rotating the screen and the carrier fluid and particles about an axis that is oriented so that the screen extends primarily radially from said axis, and at a speed that causes a greater proportion of particles that are smaller than the openings in the screen to reach said second end of the screen at said first face thereof than the proportion of carrier fluid, while flowing said feed along said screen and exhausting said fluid from the second screen face, and supporting fluid on said first face of said screen against unrestricted radially outward movement, whereby centrifugal forces resulting from rapid rotation can act for an appreciable time on particles so their precipatation helps in preventing movement to the screen.

Claim 15

A method applicable to a feed containing a carrier fluid and particles heavier than the fluid, for separating the carrier fluid from the particles, comprising: flowing said feed containing carrier fluid with the particles therein along a first face of a screen from a first end thereof to a second end thereof; exhausting fluid from a second face of the screen opposite the first face, to create a pressure differential across the screen that urges the passage of the carrier fluid from the first face of the screen to the second face of the screen; rapidly rotating the screen and the carrier fluid and particles about an axis that is oriented so that the screen extends primarily radially from said axis, and at a speed that causes a greater proportion of particles that are smaller than the openings in the screen to reach said second end of the screen at said first face thereof than the proportion of carrier fluid, while flowing said feed along said screen and exhausting said fluid from the second screen face, and supporting fluid on said first face of said screen against unrestricted radially outward movement, whereby centrifugal forces resulting from rapid rotation can act for an appreciable time on particles so their precipatation helps in preventing movement to the screen.