Super critical helium refrigeration process and apparatus

A closed loop, supercritical gas refrigeration apparatus comprising:

• a. Compressor means to compress a supply of gaseous material to superatmospheric pressure and to force the compressed gaseous material through a refrigerative load,
• b. high pressure fluid flow path means to convey substantially all of the compressed gaseous material from the compressor to the refrigerative load, said path means including;
• (1) means to divide the gaseous material into two streams,
• (2) means to expand the gaseous material in each stream,
• (3) means to recombine the two streams, and
• (4) means to pass the gaseous material through a cooling bath and the refrigerative load,
• c. means to expand and liquify a portion of the gaseous material after it has passed through the refrigerative load,
• d. means to introduce the liquid portion of the material into the cooling bath,
• e. low pressure fluid flow path means to return the expanded gaseous material from the liquid portion of the material in the cooling bath to the compressor, and
• f. heat exchange means arranged to provide heat transfer from the gaseous material flowing in the high pressure fluid flow path means to the gaseous material flowing in the low pressure fluid flow path means, such that the combination of the cooling of the gaseous material in the high pressure fluid flow by expansion, by heat exchange and by the cooling bath forms a stream of cold, supercritical gas which is passed through the refrigerative load.