Ultra-high speed vacuum pump system with first stage turbofan and second stage turbomolecular pump

Abstract

An ultra-high speed vacuum pump evacuation system includes a first stage ultra-high speed turbofan and a second stage conventional turbomolecular pump. The turbofan is either connected in series to achamber to be evacuated, or is optionally disposed entirely within the chamber. The turbofan employs large diameter rotor blades operating at high linear blade velocity to impart an ultra-high pumpingspeed to a fluid. The second stage turbomolecular pump is fluidly connected downstream from the first stage turbofan. In operation, the first stage turbofan operates in a pre-existing vacuum, with the fluid asserting only small axial forces upon the rotor blades. The turbofan imparts a velocity to fluid particles towards an outlet at a high volume rate, but moderate compression ratio. The secondstage conventional turbomolecular pump then compresses the fluid to pressures for evacuation by a roughing pump.

Description

[0001] This invention was made with Government support under Contract No. DE-AC02-76CH03000 awarded by the United States Department of Energy. The government has certain rights in this invention. technical field [0002] The present invention relates to a vacuum pump for generating an ultra-high vacuum in an evacuated chamber. More specifically, the present invention relates to a vacuum pumping system including a first stage high speed turbofan and a second stage turbomolecular pump and a method of using the vacuum pumping system. Background technique [0003] Turbomolecular pumps (TMP; also sometimes referred to as turbopumps) are widely used to generate ultra-high vacuum in evacuated chambers. Vacuum pumps generally include turbomolecular pumps, drag pumps, centrifugal pumps, diffusion pumps, cryopumps, titanium sputter pumps, getter pumps, and the like. In general, turbomolecular pumps are used to pump gases, such as at 10 -8 Pa(10 -10 Torr) range, compressed to a pre...

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