F25J 1/0218

Processes or apparatus for liquefying or solidifying gases or gaseous mixtures requiring the use of refrigeration, e.g. of helium or hydrogen {Details and kind of the refrigeration system used; Integration with other units or processes; Controlling aspects of the process using a multi-component refrigerant [MCR] fluid in a closed vapor compression cycle as at least a three level refrigeration cascade with at least one MCR cycle with one or more SCR cycles, e.g. with a C3 pre-cooling cycle}