CRYOGENIC RECONDENSER WITH REMOTE COLD BOX

摘要

CRYOGENIC RECONDENSER WITH REMOTE COLD BOX A recondenser cycles a working volume of cryogen gas through a remote cold box and a coaxial recondensing, heat exchanger transfer line which is inserted into a cryostat. The working volume of gas is compressed to a high pressure and cooled through cooling means which include a mechanical refrigerator of the regenerator-displacer type. The cooled gas is expanded through a first JT valve to a medium pressure and further cooled. The further cooled medium pressure gas is transferred in a closed coaxial transfer line to a cryostat in which boiloff is recondensed. A second JT valve in the cryostat end of an inner tube coaxially positioned in an outer tube forming the transfer line expands the gas to a lower pressure and forms a liquid-gas mixture. The liquid-gas mixture is passed in heat exchange relation with the boil-off from an inner tube to an outer tube of a coaxial recondensing heat exchanger. The outer surface of the outer tube at the cryostat end of the transfer line has burrs which provide the necessary surface area on which to recondense the boil-off. The gas is transferred back to the cooling means through intermediate channels formed between the outer tube and the coaxially positioned inner tube.