Sludge dewatering apparatus and process

Claim 2

The process of claim 1 including directing a high pressure water spray against the said top surface of the screen belt and against the bottom surface of the capillary belt after removal of solids from the screen belt for further removing any solids adhering to said belts; and squeezing any remaining sprayed water from said belts.

Claim 3

Apparatus for removing water from a flowable material comprising: a base supporting spaced upstanding members; first rotatable means mounted on each of said members; an endless porous screen belt extending between the members and removably mounted on said spaced rotatable means and arranged such that the rotatable means moves the belt between said members in an upper run forwardly in a horizontal plane, and in a lower run in a reverse direction; floWable material feed means adjacent one of said members for feeding flowable material onto said screen belt which allows free water in the flowable material to drain through the belt pores; second rotatable means mounted on each of said members between said first rotatable means; an endless capillary belt made of relatively inert synthetic fibers having pores therein of a size sufficient to develop a capillary force capable of absorbing water from the flowable material while still having the ability to later release such water by the application of an external force; said capillary belt being mounted on said second rotatable means which moves the capillary belt in an upper run and horizontally underneath the screen belt with its upper surface in contact with the lower surface of the screen belt thereby effecting by capillary force, the transfer of additional water from the flowable materal on the porous screen belt to the capillary belt; and capillary belt dewatering means mounted on said base beneath the capillary and screen belts for periodically removing the absorbed water from the capillary belt during the time the belts move horizontally in the upper run between said members.

Claim 4

Apparatus according to claim 4 wherein said flowable material feed means comprising a container having an inlet and an outlet through which flowable material is discharged onto said screen belt; side walls on said container extending parallel to said belt for containing the flowable material on said belt; and flowable material levelling means on said container for maintaining the flowable material at a predetermined level, thereby causing water in said flowable material to freely fall through the screen belt before the screen belt contacts the capillary belt.

Claim 5

Apparatus according to claim 4 wherein the capillary belt dewatering means includes at least one combined belt support and dewatering device, the belt support portion being mounted to contact the inner surface of the capillary belt, a belt diverting portion in said dewatering device which directs the capillary belt downwardly from the horizontal plane for passage through the dewatering device which squeezes water from the belt.

Claim 6

Apparatus according to claim 4 wherein said capillary belt dewatering means comprises multiple combined belt support and dewatering devices, each of said device including a pair of spaced rollers positioned to support the screen and capillary belts as they move in said horizontal planes; a pair of vertically disposed belt squeezing rollers between the support rollers, said squeezing rollers being spaced from each other a distance less than the thickness of the capillary belt, the support and squeezing roller arrangement being such that the capillary belt moves over the top of one support roller then downwardly for movement between the squeezing rollers which squeezes water from the belt, and then over the top of the other support roller to resume movement in said horizontal plane.

Claim 7

Apparatus according to claim 7 wherein the feed means is mounted on one of said members and above the first rotatable means thereon and in a position to discharge flowable material onto the screen belt, so that free water in the flowable material is permitted to flow through the screen from the time the material is discharged onto the screen belt until the latter contacts the capillary belts.

Claim 8

Apparatus according to claim 8 wherein the first rotatable means on said base opposite the feed means is spaced a horizontal distance from the second rotatable means thereon to permit the screen belt to separate from the capillary belt; said first rotatable means comprising a compression set of rollers through which the screen belt moves for further dewatering the flowable material and simultaneously transferring the flowable material to one of the compression rollers; and scraper means adjacent said compression rollers for removing solid dewatered material from said screen belt.