FACILITY AND METHOD FOR PRODUCING LIQUID HELIUM

摘要

The invention relates to a facility for producing liquid helium from a source gas mixture (5) substantially comprising nitrogen and helium. The facility includes a cryogenic purifier (2) including a system (9) for separating the nitrogen from the source gas mixture with a view to producing helium at a temperature lower than the temperature of the source gas. The facility (1) also includes a helium liquefier (3) that subjects the helium to a work cycle including, in series: compressing the helium, cooling and decompressing the compressed helium, and reheating the cooled, decompressed helium. The facility includes a helium transfer pipe (4) connecting an outlet of the purifier (2) to an inlet of the liquefier in order to transfer helium produced by the purifier (2) into the work cycle of the liquefier (3). The facility is characterized in that the cryogenic purifier (2) includes a decompression system (8) that includes an inlet to be connected to a source (6) of pressurized nitrogen gas. Said system (8) for decompressing (7) the nitrogen gas exchanges heat with the separation system (9) in order to transfer cold from the decompressed nitrogen gas to said separation system (9).