Conical piston solids discharge centrifugal separator

Abstract

A centrifugal separator includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected during a feed mode of operation. The feed liquid is separated into centrate and solids, which accumulate along the inner surface of the bowl. A piston assembly includes a conical piston coupled to a piston actuator by a two-part piston shaft. During the feed mode of operation, the piston shaft is disconnected, the piston is held in an uppermost position by hydraulic pressure from the feed liquid, and a centrate valve on the piston is urged open to permit the centrate to flow out to a centrate discharge port. In a solids discharge mode of operation, the piston shaft is connected and the piston actuator urges the piston axially downward, closing the centrate valve and forcing the accumulated solids from the bowl via the opening in the conical lower end of the bowl.

Description

technical field [0001] The present invention relates generally to centrifuges, and more particularly to centrifuges capable of automatically draining solids that accumulate during separation. Background technique [0002] Various types of centrifuges are known for separating heterogeneous mixtures into components on the basis of specific gravity. The heterogeneous mixture, which may also be referred to as feed material or feed liquid, is injected into the bowl of the centrifuge. The drum rotates at high speed, forcing the mixture particles with higher specific gravity to be separated from the liquid by sedimentation. As a result, a dense mass of solids is pressed against the surface of the bowl and clarified liquid, or "centrate", forms radially inward from the mass of solids. The drum can be rotated at a speed sufficient to generate a force 20,000 times the force of gravity to separate the solids from the filtrate. [0003] Solids collect along the walls of the bowl, whi...

AI Technical Summary

Problems solved by technology

For example, many separators are not suitable for complete drainage of residual sticky solids, resulting in poor yields

This can be especially problematic for high-value materials such as those used in pharmaceutical processes

In addition, many separators, when accelerating the feed liquid to the rotational speed of the bowl, generate high shear forces on the feed material, which can damage sensitive materials such as biological material including intact cells

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