Patent ID: 7520997

Claim:
A system for separating a heavy fraction from a liquid, comprising: a housing, a mechanism in operative connection with the housing to induce rotational flow within an upper section of the housing, a flow restrictor positioned below the upper section of the housing, the flow restrictor having a diameter less than the inner diameter of the housing so that a gap is formed between the flow restrictor and the housing, the flow restrictor causing liquid including the heavy fraction passing from the upper section to below the flow restrictor to pass through the gap, the housing further comprising an inlet positioned above the flow restrictor through which liquid including the heavy fraction enters the housing into the upper section and a first outlet positioned below the flow restrictor through which liquid having a reduced heavy fraction exits the housing, the first outlet being positioned radially inward from an interior wall of the housing, the housing being generally cylindrical from the top of the gap to a baffle positioned below the flow restrictor, the baffle defining a settling section for the heavier fraction, the housing further comprising a second outlet in operative communication with the settling section, wherein there is no mechanism to induce rotational flow in the housing below the flow restrictor.