Fast cycle water vapor cryopump

Abstract

The disclosure relates to a closed circuit refrigerator having both rapid heating/defrost and cooling rates for the cryosurface and which operates on a continuous basis. The system is based upon a refrigeration process of the type which employs compression of a mixture of vapor refrigerant components with partial condensation and partial evaporation with steps of intermediate cooling and at least partial phase separation. The evaporator of the refrigeration system is placed in a vacuum system as a "Meissner" coil. The cryosurface has, thermally coupled thereto, both a defrost tube and an evaporator tube, the defrost tube carrying refrigerant fluid therein at raised temperature when made operational during a defrost cycle and the evaporator tube carrying low temperature refrigerant fluid therein when made operational during a cool down operation. Appropriate valves determine the refrigerant fluid both, i.e., through cooling heat exchangers or through a heating heat exchanger.

Dependencies are inferred from the claim text.