METHOD FOR LIQUEFACTION OF HELIUM Russian patent published in 2023 - IPC F25J1/02 

FIELD: cryogenic technology.

SUBSTANCE: invention can be used in cryogenic helium installations, especially medium and high productivity. The helium liquefaction method includes helium flow cooling in the first, second and third stages. The liquefaction is carried out in an autonomous circuit, into which helium is reduced from the storage of gaseous helium to a pressure of 1.2-2.0 MPa, after which it is cooled in the first stage. Water vapor is adsorbed at a level of 273-278 K, and at a level of 80 K, adsorption of nitrogen and partially hydrogen impurities is carried out. Next, the flow is cooled to 6-7 K in the second stage with adsorption with neon and hydrogen at a level of 25-30 K due to recovery of cold obtained in the helium refrigeration cycle. Next, the flow is liquefied in the third stage due to expansion in the expander to a pressure of 0.125-0.135 MPa and discharged to the storage. In the helium refrigeration cycle, the helium return flow is compressed from a pressure of 0.105 MPa to a direct flow pressure of 2.5 MPa, then it is cooled from 300 K to 80 K by recuperative heat exchange between the return and direct flows and liquid nitrogen, and then the direct flow is successively expanded in two expanders to the pressure of the return flow with a decrease in temperature to 5.8-6.8 K and the transfer of cold to the helium flow in the second stage.

EFFECT: simplification of the technological process while increasing efficiency.

1 cl, 1 dwg