Patent ID: 7632416

Claim:
A hydrocyclone fluid treatment system comprising: a tank having an internal chamber, a chamber wall that includes a tapered section, a fluid inlet, a filtered fluid outlet and an effluent outlet, wherein a diameter of the internal chamber is larger near the fluid inlet than at the effluent outlet; a filter positioned within the internal chamber of the tank, the filter having a multiplicity pores formed therein and defining a filtered fluid region within the filter, wherein the fluid inlet is arranged such that fluid entering the chamber through the fluid inlet flows into a hydrocyclone region defined between the chamber wall and the filter; the filtered fluid outlet is arranged to discharge filtered fluid from the filtered fluid chamber that has passed through the filter, the effluent outlet is arranged to discharge a concentrated effluent that has generally not passed through the filter, and wherein the fluid treatment system is suitable for operation in a manner in which a vortex of flowing fluid is formed in the hydrocyclone region of the internal chamber between the chamber wall and the filter with the filter located in a central region of the vortex and such that the filter acts as a cross-flow filter; and a circulating cleaning assembly positioned in a hydrocyclone region defined between the chamber wall and the filter, wherein the circulating cleaning assembly is arranged to help clean the filter and is driven by the vortex of flowing fluid formed in the hydrocyclone region of the internal chamber.