Apparatus for the separation of a gas component from a gas mixture by freezeout

Claim 1

A cooling trap for the removal of a gas component from a gas mixture, comprising: a housing having an inlet for said gas mixture, an outlet for said gas mixture, and means defining a gas flow path between said inlet and said outlet in a general flow direction; a multiplicity of staggered cooled and uncooled plates in said housing lying along said path and extending generally perpendicular to said flow direction, said plates being arranged such that said gas mixture flows in a meandering pattern across and around said plates from said inlet to said outlet over cooling surfaces formed by said cooled plates; at least one cooling coil in said housing adapted to be traversed by a cryogenic coolant for cooling said cooled plates, said cooling coil comprising: cooling sections with turns of coolant tubes of highly thermally conductive material in heat conducting relationship with respective groups of said cooled plates, and intermediate sections between said cooling sections formed by tubes of low thermal conductivity in turns bridging the turns of the tubes of highly thermally conductive material bridged by said intermediate section; a respective heating coil on each of said cooling sections for heating the plates thereof; and means for controlling coolant flow to said cooling coil and the heating effect of said heating coils to maintain an inlet temperature of said plates at which said plates are initially contacted by said gas mixture and proximal to said inlet equal to a saturation temperature of said component at a starting concentration thereof in said gas mixture, a temperature of said plates at said outlet substantially equal to the saturation temperature of a selected residual concentration of said component in said gas mixture, and a substantially linear temperature distribution along said plates between said inlet and said outlet.