Abstract: Disc filter assembly in which a plurality of filter discs are mounted on common shaft for rotation to selectively dispose disc surfaces under vacuum in a confined body of slurry through a portion of said rotation and to discharge formed cake from said surfaces by "blow" action through another portion of rotation. Each disc has plurality of sectors in sequential arrangement circumferentially of shaft mounted on a hollow center shaft and communicating with passage-defining means controlled by a valve at the end of the shaft. A connector having a curved passage establishes communication between a disc sector and the passage-defining means which it connects by externally applied welding.

Abstract: An automatic control is disclosed to keep rotary vacuum filter slurry feed below an upper overflow level and above a lower prime level in a continuous operation in closed circuit with at least one rotary separation stage comprising the slurry feed supply and into which excess filtrate is returned to maintain a predetermined slurry level at filtration. An operator regulates speed of separator rotation in accordance with measurement of level to provide selected speed of rotation for longest dry time for lowest cake moisture.