Patent ID: 6634508
Filing Date: 2003-10-21
Classification: B01D,B30B

Abstract:
A screw press in which an outer tube, over which a screen is tensioned, is divided into a first portion in a freely rotatable condensing zone at a front half thereof, and a second portion in a filtering and dewatering zone at a rear half thereof, wherein the first portion of the outer tube is separate from, and rotatable relative to, the second portion of the outer tube, a freely rotatable screw shaft being provided within the divided outer tube, filtered fluid being separated from sludge supplied to a starting end of the condensing zone by the screen of the outer tube, and a cake being removed at a discharge port at a rear end of the filtering and dewatering zone, wherein a sludge supply path is provided in the screw shaft, a supply hole of the supply path being formed at the starting end of the condensing zone, and a scraper extending on an outer periphery of a screw vane from the starting end to the rear end, the scraper being caused to make pressured sliding contact with an inner peripheral surface of the outer tube, so that filtering and dewatering are performed as the first portion of the outer tube in the condensing zone and the screw shaft are rotated.