FIELD: cryogenic production of inert gases; methods of obtaining xenon in air separation units equipped with krypton columns plants for liberation of component from gas mixture, xenon in particular. SUBSTANCE: method consists in freezing-out xenon from gas mixture fed continuously and containing oxygen and methods, removing gas admixtures followed by discontinuation of delivery of mixture and extraction of cleaned xenon. Product containing methane in the amount from 0.0001 to 0.0003 of volume fractions and xenon above 0.00025 of volume fraction is used as gas mixture. Freezing pressure of Pfr. = (20000/X)Pa is maintained at temperature Tfr. = 77,4K, where X is content of oxygen in mixture by volume. According to second method, product containing methane in the amount from 0.0001 to 0.003 of volume fractions and xenon below 0.00025 of volume fraction is used as gas mixture; freezing-out pressure Pfr. is set below (20000/X) Pa and freezing-out temperature Tfr., below 77.4 K. Both versions may be realized in plant intended for liberation of component from gas mixture provided with freezer whose housing is connected with starting gas mixture source and with vacuum system and provided with at least one tube for delivery of refrigerant. Freezer is located in bath filled with refrigerant and connected with both ends of tubes having common fins located normally relative to tubes; they have two types of profiles. Three-flow heat exchanger fitted in line connecting the gas mixture source with freezer manifold has second passage built in line connecting the freezer with vacuum system; third passage is built in line connecting the both with additional vacuum system. EFFECT: extended range of oxygen concentrations in starting mixture; increased productivity at protracted continuous production of xenon in industries; reduced consumption of refrigerant. 20 cl, 6 dwg
Authors
Dates
1999-08-10—Published
1997-10-23—Filed