Cenrifuge filter with closable bypass

Abstract

A drum centrifuge has a housing, a drum in the housing, an axially extending outer foraminous side wall in the interior of the drum forming an outer chamber, and a transversely extending foraminous end wall in the drum forming a bypass chamber radially inward of the outer chamber. A suspension is fed to the interior of the drum while same is rotating so that the suspension is thrown centrifugally against the outer wall and separates into a radially outer body of filter cake having an inner surface and a radially inner body of liquid sitting on the inner surface. A drainage chamber is formed at the end wall and a drain passage extends between the drainage chamber and the outer chamber while a bypass passage extends between the drain chamber and the bypass chamber. A float valve in the passage is radially displaceable when a liquid level in the passage rises radially inward above a predetermined level between a radially outer position blocking flow through the passage and a radially inner position permitting flow through the passage. A dip tube is radially displaceable in the drain chamber between a radially outer position maintaining the liquid level in the drainage chamber and in the passage radially outward of and below the predetermined level and a radially inner position allowing the liquid level in the drainage chamber and passage to rise radially inward above the predetermined level and thereby open the float valve.