Centrifugal separator

A centrifugal separator for separating solids from a liquid stream, comprising:

• a rotatable drum comprising a perforated outer wall, the rotatable drum having a first end and a second end, the perforated outer wall having perforations that are about 30 microns or less;
• an auger positioned within the rotatable drum, the auger having a helical flight that has an outer edge that is immediately adjacent to an inner surface of the outer wall;
• an inlet in communication with the first end of the rotatable drum, the inlet receiving the liquid stream to be separated;
• a solids outlet at the second end of the rotatable drum;
• a driver that engages the rotatable drum and the auger, the driver being controlled by a processor that is programmed with instructions to cause the driver to:
• rotate the rotatable drum about an axis of rotation at a first rotational speed of 800 rpm or more to apply a centrifugal force to fluids within the rotatable drum, the perforated outer wall permitting liquid to exit the rotatable drum;
• and
• rotate the auger about the axis of rotation at a second rotational speed that is different than the first rotational speed such that the outer edge of the auger removes solids from the inner surface of the perforated outer wall and the auger conveys the solids toward the solids outlet;
• a source of high pressure fluid adjacent to an outer surface of the perforated outer wall and extending parallel to the axis of rotation, the processor further comprising instructions to cause the source of high pressure fluid to continuously apply a pressure differential across the perforated outer wall when the rotatable drum is rotating at the first rotational speed and while the inlet receives the liquid stream to be separated to clear the perforations of obstructions and such that a portion of the high pressure fluid enters the rotatable drum.