| 摘要 |
An apparatus for dewatering a pulp is described, comprising a vessel having a pulp chamber for pulp to be dewatered; a pulp inlet to the vessle; pulp outlet from the vessel; a filtrate chamber with an outlet for filtrate expelled from the pulp; a stationary cylindrical screen mounted within the vessel and defining said plup chamber and filtrate chamber on opposite sides thereof; and mechanical cleaning means supported by a shaft and disposed in the pulp chamber close to the screen face of the screen for removing a mat of pulp therefrom. The apparatus further comprises a backflushing means mounted outside the vessel and including a cylinder with first and second end portions and a piston mounted within the cylinder for reciprocal movement therein. The first end portion communicates with the interior of the apparatus, and the second end portion communicates with the filtrate chamber. Furthermore, the backflushing means comprises a power transmitting means for actuating the piston in the cylinder to move reciprocally in cycles each cycle comprising a slow stroke for drawing filtrate slowly into the cylinder and removing pulp slowly therefrom, and a fast stroke for expelling said drawn-in filtrate quickly out from the cylinder and drawing pulp quickly into the cylinder, said quickly expelled filtrate causing a backlfush through the screen. |
