GB1403096A - Solid-jacket centrifuge with a slurry accelerator body - Google Patents

Abstract

1403096 Screw centrifuges KLOCKNER-HUMBOLDT-DEUTZ AG 23 Oct 1972 [23 Oct 1971] 48820/72 Heading B2P A solid-jacket centrifuge for separating the liquid and solids constituents of a slurry comprises an outer rotatable centrifuge drum 2, an inner screw-conveyor drum 9 having solidsdischarge-screw flights 10 thereon and rotatable at a speed different from that of the drum 2, a slurry feed pipe 18 at one end of the drum 2 and a solids discharge outlet 3 at its other end, an independently driven slurry-accelerating rotatable body 16 mounted coaxailly within, and radially spaced from, the screw-conveyor drum 9, the body 16 having a feed chamber 21 formed therein in communication with the feed pipe 18 and, through apertures 22 in the body, with the interior of the drum, he feed chamber being traversed by one or more through-flow channels 25 through which clarified liquid can travel axially. In operation, the accelerating body 16 and at least part of the axial extent of the screw-conveyor drum is immersed in the liquid in the drum 2. The slurry to be treated is fed to the chamber 21 through the feed pipe 18 and passes through the openings 22 in the accelerating body 16 and openings 11 in the screw-conveyor drum 9. In addition to being centrifugally accelerated by the screw-conveyor drum 9 and the centrifuge drum 2, the slurry is imparted a higher centrifugal acceleration, starting from the region of the liquid level in the drum, by the accelerating body 16 which is driven at a higher speed than the drums 2 and 9. The clarified liquid moves along the outer wall of the body 16 towards its front edge 30 and then back through the interior of the body and via the channels 25 into a collecting chamber 24 formed in the body where it is scooped off by one or more drain pipes 29 rotating with the drum 2 to be discharged into a chamber 28 in the drum 2 and via openings 31 into a discharge space 32 with centrifuge housing 1. In another embodiment. Fig 2 (not shown), the centrifuge drum and the screw-conveyor drum are frusto-conical and the accelerating body is cylindrical. In a modification of the latter embodiment, Fig 3 (not shown), the accelerating body is frusto-conical and is provided along its inner wall, in the feed chamber, with one or more further flow channels (34) through which part of the liquid which may contain same solids may pass into the collecting chamber (24") and be removed through openings (35) in the end wall thereof for recirculation into the drums (9" and 2").