Design of cryogenic distillation system of pilot plant for tritium removal process demonstration

The structure, specification and material of column, cold box and heat exchangers of the cryogenic distillation system were designed. At least four heat exchangers which are a liquid nitrogen adsorber procooler, a liquid nitrogen precooler, a cold helium precooler and a condenser for hydrogen liquefaction, are required for the various purposes and operating conditions in cryogenic distillaton. Stainless steel was selected as a material of the cryogenic distillation apparatus and especially copper was selected to increase the heat transfer efficiency as material of the heat exchanger surface where the hydrogen fluid and the refrigerant contacted. The dimensionless variable relationships was used to find the overall heat transfer coefficients and to determine the specifications of heat exchangers. In the calculation, 20% margin of the contact area for heat exchange and the compensation of heat transfer coefficient as temperature variation were considered. The pressure drop through the heat exchangers was calculated