Abstract: An apparatus for classifying a mixture of fine and coarse particles in a fluid stream by size or density comprises a housing, a boundary layer momentum transfer device, and an inlet flow control mechanism. The housing comprises an inlet, an interior chamber, and a fine particle outlet. The boundary layer momentum transfer device comprises a plurality of disks stacked in spaced, parallel relation in the interior chamber. The disks are rotatable about a disk axis. The disks have respective central openings cooperatively defining a plenum having a closed axial end and an opposing open axial end. The plenum communicates with spaces defined between each adjacent disk to cooperatively define a fine particle flow path from the interior chamber, through the spaces, through the plenum and the open axial end thereof, and to the fine particle outlet. The inlet flow control mechanism communicates with the interior chamber and provides an adjustable inlet flow path into the interior chamber.

Abstract: A radial inflow centrifugal filter device for separating fine particulates from a fluid flow, including a rotatable plurality of hollow parallel disks mounted in spaced apart relationship and attached via spacers to a tube. The hollow drive tube is in flow communication with the interior hollow plenum of the disks which is at a lower pressure relative to the open space between the disks. Rotating the tube causes the disks to rotate. Particulate-laden fluid is allowed to enter the filter device at the perimeter of the rotating disks and experiences a change in momentum due to the interaction of boundary layers of fluid established on each side of every disk. The centrifugal force imparted to both the fluid and particulates causes them to be separated in opposite directions.