Patent ID: 6990818

Claim:
A device for the re-condensation by means of a cryogenerator of low boiling gases evaporating from a liquid gas container ( 2 ) having a tubular neck ( 8 ) with an end flange and extending from said end flange into said liquid gas container and having at its end in said gas container a cold area ( 26 ), a cooling device, a so-called cold head, comprising a regenerator ( 21 ) and a pulse tube ( 23 ) with a heat exchanger ( 25 ) disposed therebetween supported on said tubular neck ( 8 ), said heat exchanger ( 25 ) being contained in said cold area ( 26 ), said regenerator ( 21 ) and said pulse tube ( 23 ) of said cooling device being each surrounded by a thermally insulating heat shield ( 29 , 30 , 31 , 32 ) forming a vacuum chamber extending around said liquid gas container ( 2 ) and having an outer wall consisting of a thin-walled tube, which is provided with stiffening means so as to be able to withstand the ambient pressure, a heat transfer ring ( 10 ) arranged in said tubular neck ( 8 ) and having an annular recess, said cold area ( 26 ) having annular projections extending into said annular recess in said heat transfer ring ( 10 ) in spaced, relationship with the walls of said recess, whereby a gas passage from the vapor space above the liquid gas both in said container to the cooling device is provided, and said cold head and said tubular neck ( 8 ) are axially movable relative to each other to permit different thermal expansions.