Apparatus for cleaning liquids containing in suspension solid particles and particularly cellulosic pulps

Claim 2

IN A SCREENING APPARATUS FOR SCREENING FIBRES IN LIQUID SUSPENSION, IN COMBINATION, A TANK HAVING A PERIPHERAL WALL; A SUBSTANTIALLY CYLINDRICAL SCREEN WITHIN SAID TANK SPACED FROM SAID PERIPHERAL WALL AND FORMING A SCREENING CHAMBER IN SAID TANK; INLET MEANS COMMUNICATING WITH SAID TANK FOR INTRODUCING FIBRES IN LIQUID SUSPENSION TO THE OUTSIDE OF SAID SCREENING CHAMBER SO THAT THE LIQUID AND PART OF THE FIBRES SUSPENDED THEREIN WILL PASS THROUGH SAID SCREEN INTO SAID SCREENING CHAMBER WHILE REFECTED FIBRES AND OTHER HEAVY SOLID PARTICLES WILL BE HELD BACK BY THE SCREEN; OUTLET MEANS COMMUNICATING WITH THE INTERIOR OF SAID SCREENING CHAMBER FOR DISCHARGING THEREFROM STOCK PASSED THROUGH SAID SCREEN; AND ROTOR MEANS IN THE INTERIOR OF SAID CYLINDRICAL SCREEN SUBSTANTIALLY COAXIALLY THEREWITH AND INCLUDING AT LEAST A PAIR OF BLADES ANGULARLY DISPLACED FROM EACH OTHER, ONE OF SAID BLADES HAVING A CONCAVELY CURVED SURFACE FACING THE INNER SURFACE OF THE SCREEN AND HAVING A TRAILING EDGE LOCATED CLOSER TO SAID INNER SCREEN SURFACE THAN THE LEADING EDGE THEREOF SO AS TO PROVIDE, DURING ROTATION OF SAID ROTOR MEANS, AN INCREASED PRESSURE ON THE INNER SURFACE OF SAID SCREEN FACING AT ANY INSTANT SAID ONE BLADE MEANS AND THE OTHER OF SAID BLADES HAVING A CONVEXLY CURVED SURFACE FACING THE INNER SURFACE OF SAID SCREEN AND HAVING A LEADING EDGE LOCATED CLOSER TO SAID INNER SCREEN SURFACE THAN THE TRAILING EDGE THEREOF SO AS TO PROVIDE A SUCTION ON THE INNER SURFACE OF SAID SCREEN FACING AT ANY INSTANT SAID OTHER BLADE.

Claim 3

IN A SCREENING APPARATUS FOR SCREENING FIBRES IN LIQUID SUSPENSION, IN COMBINATION, A TANK HAVING A PERIPHERAL WALL OF SUBSTANTIALLY CIRCULAR CROSS-SECTION; A SUBSTANTIALLY CYLINDRICAL SCREEN ARRANGED WITHIN SAID TANK SUBSTANTIALLY COAXIALLY WITH SAID PERIPHERAL WALL AND FORMING A SCREENING CHAMBER WITHIN SAID TANK AND BETWEEN SAID SCREEN AND SAID PERIPHERAL WALL AN ANNULAR SPACE; INLET MEANS ARRANGED TANGENTIALLY TO THE PERIPHERAL WALL FOR FEEDING FIBRES IN LIQUID SUSPENSION INTO SAID ANNULAR SPACE TO PRODUCE A CYCLONE EFFECT CAUSING THE STOCK TO ROTATE IN ONE DIRECTION IN SAID ANNULAR SPACE TO SEPARATE THEREBY HEAVY IMPURITIES BY CENTRIFUGAL ACTION FROM THE STOCK AND CAUSING THE STOCK TO SWEEP OVER THE OUTER SURFACE OF THE SCREEN SO THAT THE LIQUID AND PART OF THE FIBRES SUSPENDED THEREIN WILL PASS THROUGH SAID SCREEN INTO SAID SCREENING CHAMBER WHILE REJECTED FIBRES WILL BE HELD BACK BY THE SCREEN; OUTLET MEANS COMMUNICATING WITH THE INTERIOR OF SAID SCREENING CHAMBER FOR DISCHARGING THEREFROM STOCK PASSED THROUGH SAID SCREEN; ROTOR MEANS IN THE INTERIOR OF SAID CYCLINDRICAL SCREEN; ROTOR MEANS IN THE INTERIOR OF SAID CYLINDRICAL SCREEN SUBSTANTIALLY COAXIAL THEREWITH AND INCLUDING AT LEAST A PAIR OF BLADE MEANS ANGULARLY DISPLACED FROM EACH OTHER, ONE OF SAID BLADE MEANS CONSTRUCTED SO AS TO PROVIDE, DURING ROTATION OF SAID ROTOR MEANS, AN INCREASED PRESSURE ON AN INNER SURFACE PORTION OF SAID SCREEN FACING AT ANY INSTANT SAID ONE BLADE MEANS AND THE OTHER OF SAID BLADE MEANS CONSTRUCTED SO AS TO PROVIDE A SUCTION ON AN INNER SURFACE PORTION OF SAID SCREEN FACING AT AN INSTANT SAID OTHER BLADE MEANS; A REJECT CHAMBER ADJACENT SAID TANK FOR RECEIVING FIBRES REJECTED BY SAID SCREEN; AND A CONDUIT COMMUNICATING WITH AN END PORTION THEREOF ARRANGED TANGENTIALLY WITH RESPECT TO SAID PERIPHERAL WALL OF SAID TANK WITH THE INTERIOR OF THE LATTER AND WITH THE OTHER END THEREOF COMMUNICATING WITH THE INTERIOR OF SAID REJECT CHAMBER.

Claim 4

IN A SCREENING APPARATUS FOR SCREENING FIBRES IN LIQUID SUSPENSION, IN COMBINATION, A TANK HAVING A PERIPHERAL WALL OF SUBSTANTIALLY CIRCULAR CROSS-SECTION; A SUBSTANTIALLY CYLINDRICAL SCREEN ARRANGED WITHIN SAID TANK SUBSTANTIALLY COAXIALLY WITH SAID PERIPHERAL WALL AND FORMING A SCREENING CHAMBER WITHIN SAID TANK AND BETWEEN SAID SCREEN AND SAID PERIPHERAL WALL AN ANNULAR SPACE; INLET MEANS ARRANGED TANGENTIALLY TO THE PERIPHERAL WALL FOR FEEDING FIBRES IN LIQUID SUSPENSION INTO SAID ANNULAR SPACE TO PRODUCE A CYCLONE EFFECT CAUSING THE STOCK TO ROTATE IN ONE DIRECTION IN SAID ANNULAR SPACE TO SEPARATE THEREBY HEAVY IMPURITIES BY CENTRIFUGAL ACTION FROM THE STOCK AND CAUSING THE STOCK TO SWEEP OVER THE OUTER SURFACE OF THE SCREEN SO THAT THE LIQUID AND PART OF THE FIBRES SUSPENDED THEREIN WILL PASS THROUGH SAID SCREEN INTO SAID SCREENING CHAMBER WHILE REJECTED FIBRES WILL BE HELD BACK BY THE SCREEN; OUTLET MEANS COMMUNICATING WITH THE INTERIOR OF SAID SCREENING CHAMBER FOR DISCHARGING THEREFROM STOCK PASSED THROUGH SAID SCREEN; ROTOR MEANS IN THE INTERIOR OF SAID CYCLINDRICAL SCREEN; ROTOR MEANS IN THE INTERIOR OF SAID CYLINDRICAL SCREEN SUBSTANTIALLY COAXIAL THEREWITH AND INCLUDING AT LEAST A PAIR OF BLADE MEANS ANGULARLY DISPLACED FROM EACH OTHER, ONE OF SAID BLADE MEANS CONSTRUCTED SO AS TO PROVIDE, DURING ROTATION OF SAID ROTOR MEANS, AN INCREASED PRESSURE ON AN INNER SURFACE PORTION OF SAID SCREEN FACING AT ANY INSTANT SAID ONE BLADE MEANS AND THE OTHER OF SAID BLADE MEANS CONSTRUCTED SO AS TO PROVIDE A SUCTION ON AN INNER SURFACE PORTION OF SAID SCREEN FACING AT AN INSTANT SAID OTHER BLADE MEANS; A REJECT CHAMBER ADJACENT SAID TANK FOR RECEIVING FIBRES REJECTED BY SAID SCREEN; AND A CONDUIT COMMUNICATING WITH AN END PORTION THEREOF ARRANGED TANGENTIALLY WITH RESPECT TO SAID PERIPHERAL WALL OF SAID TANK WITH THE INTERIOR OF THE LATTER AND WITH THE OTHER END THEREOF COMMUNICATING WITH THE INTERIOR OF SAID REJECT CHAMBER.