Centrifugal scroll screen apparatus

A centrifugal scroll screen apparatus including:

• a housing;
• a screen assembly mounted for rotation in said housing and comprising a base-of-spoke piece and a substantially frustoconical screen member having an inner screening surface and removably secured by its base to the base-of-spoke piece, the base of spoke piece cooperating with the housing to substantially divide the housing into housing portions receiving filtrate passing through the screen member and product passing through the base-of-spoke piece respectively;
• a scroll assembly having a plurality of substantially helical scroll vanes and mounted for rotation within said screen member with an edge of each said vane lying in selected proximity to said screening surface;
• drive means selected to differentially drive the rotation of said screen assembly and said scroll assembly and including respective concentric drive shaft portions extending axially substantially through said screen assembly, the scroll assembly drive shaft being connected to the scroll assembly by an axial adjuster comprising a shaft portion and a scroll portion each having a respective camming surface whereby relative rotation of said scroll portion and said shaft portion axially adjusts said selected proximity, and locking means selectively operable to rotationally secure said scroll portion and said shaft portion;
• and
• an inlet assembly supported on said housing and cooperating with an open apical end of said screen member to deliver material to be screened to said screening surface.