FUEL SYSTEM USING DUAL PRESSURE HI-SPEED CENTRIFUGAL PUMP ARRANGEMENT

摘要

An improved system for providing fuel uses a centrifugal pump arrangement that provides dual pressure. The dual pressure pump assembly includes a centrifugal pump for supplying pressurized fluid to an associated downstream use, and an auxiliary pump stage for selectively boosting pressure of delivered flow. The auxiliary pump stage in one preferred arrangement includes a start and turbo-pump stage where inlet fuel from an associated airframe is fed to a centrifugal pump portion of the turbo-pump that outlets to an inlet of the centrifugal pump. The auxiliary pump stage in another arrangement includes a recirculation passage communicating with the outlet of the high-speed centrifugal pump and the turbine, and the outlets from the start and turbo-pump stage feed an inlet of the high speed centrifugal pump, and a flow valve is disposed in the recirculation passage. In still another arrangement, the auxiliary pump stage includes an electric motor for start-up.