Evertable drum centrifuge filter

Abstract

An evertable drum centrifuge has a housing extending along an axis, a hollow filter drum rotatable in the housing about the axis and having a front end wall formed with a fill opening centered on the axis, and a nonrotatable fill tube extending along the axis and having a back end. A fill head complementarily engageable in the fill opening is fitted in a closed position in the fill opening and a suspension to be filtered is introduced through the fill tube and fill opening into the drum. A bearing rotatably supports the fill head on the fill-tube back end and a static seal is engaged between the fill head and the fill opening. A pair of dynamic seals flank the bearing, define with the head and fill tube an annular compartment surrounding the fill tube, and each have a head ring fixed rotationally on the head and having a face, a fill-tube ring fixed rotationally on the fill tube and having a face axially engaging the face of the respective head ring, and a spring urging the faces of the respective fill-tube ring and head ring axially together. The compartment is pressurized with a fluid that is forced from the compartment between the faces of the dynamic seals.