Patent ID: 7381329
Filing Date: 2008-06-03
Classification: B01D

Abstract:
1. An apparatus for thickening and dewatering a mixture of solids and liquids with a belt filter press having an upper and lower belt, with a gravity screening zone and a wedge zone to create pressure between the belts, said apparatus being comprised of: (a) a lower permeable belt consisting of a woven, plain weave synthetic material with openings ranging in size from 300 microns-by-300 microns square (U.S. Standard Sieve Size 50) to 1,000 microns-by-1,000 microns square (U.S. Standard Sieve Size 18) and open area ranging in size from 20% at 300 micron square openings to 45% at 1,000 micron square opening to allow solids to be retained and liquid to pass through the lower permeable belt; (b) a rectangular upper belt assembly consisting of a rectangular frame, connected to the lower belt assembly by four screw and bolt assemblies at each corner of the rectangular frame; (c) an upper non-permeable belt consisting of a synthetic material; (d) a gravity screening zone of the belt filter press wherein a mixture of solids and liquids is allowed to drain through the lower permeable belt without pressure being applied by the upper belt; and (e) a wedge zone following the gravity screening zone where the spacing between the two belts becomes increasingly narrow as the mixture of solids and liquid is conveyed along the belt press, wherein the pressure applied by the upper non-permeable belt increases as the spacing between the belts decreases, and (f) a means for adjusting the spacing between the upper non-permeable belt and the lower permeable belt by mechanical means at each corner of the rectangular upper assembly to increase or decrease the compression in the wedge zone, and (g) a means for adjusting the compression pressure at the four corners of the rectangular upper belt assembly, so that an increase in the flow of the mixture of solids and liquids will increase the compression in the wedge zone.