Device for liquefying gases

Apparatus for selectively liquifying one component contained in a gaseous body comprising no more than two components which comprises means for compressing a portion of said gaseous body, means for feeding said pressurized portion to a refrigeration stage for cooling to a temperature below the inversion temperature of said one component at the pressure to which said portion is so compressed, a collecting container having liquid and vapor spaces, a first duct connecting said refrigeration stage to said collecting container, a first Joule-Thompson valve in said first duct for selectively reducing the pressure of said cooled pressurized portion when said gaseous body comprises only one component, a separation container having liquid and vapor spaces, a second duct connecting a point of said first duct, between said refrigeration stage and said first Joule-Thompson valve, to said separation container, a third duct connecting the liquid space of said separation container to said first duct at a point between said first Joule-Thompson valve and said collecting container, a second Joule-Thompson valve in said third duct functioning to selectively reduce the pressure of the liquid part of said cooled pressurized portion when said gaseous body comprises two components, means to exchange heat in counterflow relationship between said second duct and a section of said third duct between said second Joule-Thompson valve and said first duct, and a fourth duct connecting the vapor space of the collecting container to said compressing means, for feeding vapor from said vapor space to said compressing means.