US 12,372,274 B1
Helium phase separation refrigerator
John Davis, Edmonton (CA); Paul Kim, Edmonton (CA); Marvin Hirschel, Opal (CA); and James Suranyi, Sturgeon County (CC)
Assigned to Zero Point Cryogenics Incorporated, Edmonton (CA)
Filed by Zero Point Cryogenics Incorporated, Edmonton (CA)
Filed on Dec. 13, 2024, as Appl. No. 18/980,522.
Claims priority of application No. CA 3259443 (CA), filed on Dec. 12, 2024.
Int. Cl. F25B 9/12 (2006.01); F25B 9/14 (2006.01)
CPC F25B 9/12 (2013.01) [F25B 9/14 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A cryogenic refrigerator comprising:
one or more cooling elements arranged to at least partially liquefy helium from a gas containing a mixture of helium-3 and helium-4 to produce liquid helium having a sufficient concentration of helium-3 to enable the separation of the helium-3 and helium-4 when further cooled into separate helium-3 rich and dilute phases;
a reservoir arranged to receive an incoming flow of helium including the liquid helium produced by the one or more cooling elements to form a volume of the liquid helium in the reservoir, and to expose a surface of the volume of the liquid helium to evaporation to cool the reservoir under evaporation of the liquid helium; and
one or more pumps connected to the reservoir to remove evaporated gaseous helium from a space above the surface to form an outgoing flow of helium from the reservoir to the one or more pumps, and the one or more cooling elements being connected to an outlet of the one or more pumps to receive the helium of the outgoing flow of helium for continuous operation of the cryogenic refrigerator, the one or more pumps being arranged to sufficiently lower a pressure in the space above the surface of the liquid helium to cool the liquid helium to cause the liquid helium in the reservoir to separate into the separate helium-3 rich and dilute phases, where the helium-3 rich phase is adjacent to the surface for further evaporation into the space above the surface and further cooling as the one or more pumps in operation continue to remove evaporated helium-3 above the surface after phase separation.