A system for separating a heavy fraction from a liquid includes an upper section in fluid connection with-an inlet, an impeller within the upper section and a flow restrictor positioned below the impeller having a diameter less than the diameter of a a lower section housing to form a gap between the flow restrictor and the lower section housing. An inlet of a conduit is positioned radially inward from an interior wall of the lower section housing and below the flow restrictor. The conduit includes an outlet outside of the lower section. The lower section is generally cylindrical from the top of the gap to a baffle positioned below the flow restrictor, which defines a settling section. The lower section further includes a slurry outlet in operative communication with the settling section.