PUMP DESIGN FOR CIRCULATING SUPERCRITICAL CARBON DIOXIDE

WIPO Patent Application WO2005052365

A3

In accordance with an embodiment of the present invention, a pump assembly for circulating a supercritical fluid is disclosed. The pump assembly comprises an impeller for pumping fluid between a pump inlet and a pump outlet; a rotating pump shaft coupled to the impeller, wherein the pump shaft is supported by corrosion resistant bearings; a rotor of a DC motor potted in epoxy and encased in a non-magnetic material sleeve; and a stator sealed from the fluid via a polymer sleeve. The pump can be of centrifugal type. The bearings can be made of silicon nitride balls combined with bearing races made of Cronidur® and can operate without oil or grease lubrication. The polymer sleeve can be a PEEK