Solids-liquid slurry separating centrifuge

Claim 1

In a solids-liquid separating centrifuge having a rotary bowl, a rotary conveyor mounted coaxially therein, means for rotating said bowl and conveyor about their common axis in the same direction at a differential speed, means for feeding a solids liquid slurry into said bowl, an outlet for solids at an end portion of said bowl, and a separate outlet for liquid from said bowl constructed and arranged to permit the formation in said bowl of a pool of said slurry having its surface at least approximately as close to the bowl axis as said solids outlet; solids discharge mechanism for discharging solids through said bowl end portion to said solids outlet comprising a frusto-conical interior in said bowl end portion having its smaller diameter end at said solids outlet, a frusto-conical, helically bladed hub on said conveyor located coaxially within, and extending substantially the full length of, said frusto-conical interior and having a larger cone angle such as to define with said interior a frusto-conical passage which, at its smaller diameter end, is wider than at its larger diameter end and is approximately equal in cross-sectional area to its larger diameter end, said hub being helically bladed by at least one helically extending blade mounted on said hub to define a helix which has a diminishing spacing between successive turns thereof about said common axis from the larger diameter end toward the smaller diameter end of said passage.