CRYOPUMP-DESIGN AND APPLICATION

CRYOPUMP-DESIGN AND APPLICATION

ABSRACT

Cryopumping is associated with vacuum technology involving cryogenic engineering. The term is derived from the Greek word Kryo's, which means cold or frost. Cryogenics is frequently applied to very low temperature refrigeration applications such as the liquefaction of gases and in the study of physical phenomenon at temperatures approaching Absolute Zero. In the field of cryogenic engineering, one is concerned with the developing and improving low-temperature techniques, processes and equipment. Various areas involving cryogenic application are Space Simulation & high vacuum technology, Rocket propulsion systems, studies in high energy physics, Electronics, mechanical design, Biological and Medical applications, food processing, Manufacturing processes, Recycling materials.

In space simulation and high vacuum technology, to produce a vacuum that approaches that of outer space (from 10-12 torr to 10-14 torr) (1 pa =10-2 torr), cryopumping is used. Cryopumping, or freezing out the residual gases is used to provide the ultra high vacuum required in space simulation chambers and in test chambers. For space propulsion system the cold or free space is simulated by cooling a shroud within the environmental chamber by means of liquid nitrogen. Dense gases helium at less than 20K or liquid helium is used to cool the cryopanels that freeze out the residual gases.

Thus the cryopump serves an important means to maintain high vacuum, which is useful in space simulation programs.

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