| US 7,478,540 B2 | ||
| Methods of freezeout prevention and temperature control for very low temperature mixed refrigerant systems | ||
| Kevin P. Flynn, Novato, Calif. (US); Mikhail Boiarski, Macungie, Pa. (US); and Oleg Podtcherniaev, Odintsovo (Russian Federation) | ||
| Assigned to Brooks Automation, Inc., Chelmsford, Mass. (US) | ||
| Filed on Feb. 07, 2006, as Appl. No. 11/349,060. | ||
| Application 11/349060 is a continuation in part of application No. 11/332495, filed on Jan. 13, 2006, abandoned. | ||
| Application 11/332495 is a continuation of application No. 12/281881, filed on Oct. 28, 2002, granted, now 7,059,144. | ||
| Claims priority of provisional application 60/335460, filed on Oct. 26, 2001. | ||
| Prior Publication US 2006/0168976 A1, Aug. 03, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. F25B 41/00 (2006.01); F25B 49/00 (2006.01); F25J 1/00 (2006.01) | ||
| U.S. Cl. 62—196.4 [62/197; 62/612; 62/114] | 21 Claims |
| 1. A very low temperature refrigeration system utilizing mixed refrigerants, the system comprising:
a compressor in fluid communication with a refrigeration process, the refrigeration process including a high pressure line
on a high pressure side of the refrigeration system between the compressor and an evaporator, a low pressure line on a low
pressure side of the refrigeration system in a refrigerant return path between the evaporator and the compressor, and at least
one heat exchanger cooling refrigerant in the high pressure line from refrigerant in the low pressure line; and
a bypass circuit connected either:
a) from a point in the refrigeration process where high pressure refrigerant flows, prior to where the high pressure line
exits a cold end of the refrigeration process, and to a point in the refrigeration process where the coldest low pressure
refrigerant in the system flows, the bypass circuit including a valve controlling bypass flow of bypassed refrigerant, the
result of the bypass flow being to achieve warming of the coldest low pressure refrigerant; or
b) from a compressor high-pressure refrigerant line between the compressor and an entrance to the high pressure line of the
refrigeration process, and to a suction line of the compressor; or
c) from a point in the refrigeration process where high pressure refrigerant is at its coldest temperature, and to a point
in the refrigeration process where low pressure refrigerant exits the coldest of the at least one heat exchangers in the refrigeration
process, bypassed refrigerant not passing through a heat exchanger between the point where high pressure refrigerant is at
its coldest temperature and the point where low pressure refrigerant exits the coldest of the at least one heat exchanger.
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