Abstract: Fluidized bed systems for segregating cleaning or classifying particulate matter of differing physical properties such as particle density or size. Multiple stage beds preferably operate in a partially fluidized state and the classification structure provides for full peripheral discharge of both floats from the upper portion of each bed and sinks from the lower portion of each bed to alleviate the tendency of fluidized medium to both short circuit the particles of the upper stage and restrict the flow of particles from the upper stage to the lower stage.

Abstract: Method and apparatus for detecting deterioration of a replaceable liner in a pump transporting an electrically conductive fluid medium. A conductive component is isolated, during normal operation, from the conductive fluid medium by the electrically insulative liner. The conductive component is positioned at a predetermined location relative to the liner such that upon a selected degree of wear of the liner, an electrical circuit is completed upon contact of the fluid medium and the conductive member.