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 a chamber 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 pumping speed 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 second stage conventional turbomolecular
pump then compresses the fluid to pressures for evacuation by a roughing pump.