US3885939A - Cryostat control - Google Patents

Cryostat control Download PDF

Info

Publication number
US3885939A
US3885939A US46407874A US3885939A US 3885939 A US3885939 A US 3885939A US 46407874 A US46407874 A US 46407874A US 3885939 A US3885939 A US 3885939A
Authority
US
United States
Prior art keywords
refrigerant
cryostat
contaminant
flow
heat exchanger
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
Arvel Dean Markum
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hughes Missile Systems Co
Original Assignee
General Dynamics Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Dynamics Corp filed Critical General Dynamics Corp
Priority to US05464078 priority Critical patent/US3885939A/en
Priority to US05/538,651 priority patent/US3933003A/en
Application granted granted Critical
Publication of US3885939A publication Critical patent/US3885939A/en
Anticipated expiration legal-status Critical
Assigned to HUGHES MISSILE SYSTEMS COMPANY reassignment HUGHES MISSILE SYSTEMS COMPANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: GENERAL DYNAMICS CORPORATION
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J1/00—Processes or apparatus for liquefying or solidifying gases or gaseous mixtures
    • F25J1/02—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
    • F25J1/0243—Start-up or control of the process; Details of the apparatus used; Details of the refrigerant compression system used
    • F25J1/0257—Construction and layout of liquefaction equipments, e.g. valves, machines
    • F25J1/0275—Construction and layout of liquefaction equipments, e.g. valves, machines adapted for special use of the liquefaction unit, e.g. portable or transportable devices
    • F25J1/0276—Laboratory or other miniature devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/02—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point using Joule-Thompson effect; using vortex effect
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/12—Inflammable refrigerants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/20—Processes or apparatus using other separation and/or other processing means using solidification of components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2280/00—Control of the process or apparatus
    • F25J2280/40—Control of freezing of components
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/0318—Processes
    • Y10T137/0391—Affecting flow by the addition of material or energy

Definitions

  • Joule-Thomson effect cooling devices commonly referred to as cryostats, as well known in the art to produce cryogenic temperature levels.
  • the cryostats may be employed to maintain radiation sensing devices at the extremely low temperatures required. Examples of conventional Joule-Thomson effect cryostats maybe found in U.S. Pat. Nos. 2,991,633, 3,095,711, 3,353,371, 3,415,078 and 3,431,750. I
  • cryostats In order to achieve a rapid initial cool-down, large coolant or refrigerant flows are required in conventional cryostats. Only a fraction of this cool-down flow is, however, needed for steady stateoperation of the cryostat. Thus, a cryostat designed to meet the initial cool-down flow requirements would be inherently inefficient during steady state operation, while a more efficient steady state flow design would have an excessively long cool-down period.
  • cryostats Since in many cryostat applications the coolant or refrigerant flow is limited by the available supply, techniques have been developed to provide sufficient cooldown flow without providing excessive steady state flow. While certain self-regulating flow control mechanisms have been developed for cryostats, these mechanisms, which have been either thermal-mechanical, electro-mechanical, or chemical in nature, have been rather complicated, overly complex and often prone to operational difficulties. All rely upon external forces, thus consuming energy such as electrical power and all include at least some moving parts. In some cases the basic cooling characteristics of the cryostat have been altered by the flow regulating mechanism.
  • the invention is directed to a cryostat flow control in which the refrigerant flow rate is controlled by the addition of a contaminant or foreign fluid to the refrigerant.
  • the contaminant having a higher solidification point than the refrigerant, will solidify in the cryostat and cause a partial or complete refrigerant flow stoppage.
  • refrigeration slows or ceases with a resultant rise in cryostat temperature which in turn then melts the solidified contaminant.
  • the refrigerant flow will then resume until the temperature is again reduced to freeze up or solidify the refrigerant contaminant.
  • the alternate freeze-up and melting cycle achieves a greatly reduced average steady state refrigerant flow rate.
  • FIG. 1 is a schematic illustration of a cryostat utilizing the control of the present invention.
  • FIG. 2 is an enlarged section view of a portion of the heat exchanger tube of the cryostat of FIG. 1.
  • FIG. 3 is a graphical representation of the operational cycle of a cryostat having the flow control of the present invention.
  • the cryostat control of the present invention is applicable to any type of cryostat (counterflow, regenerative, Joule-Thomson expansion, etc.).
  • a Joule-Thomson expansion cryostat 10 having a coiled tubing heat exchanger 12 and liquid refrigerant reservoirv 14 is illustrated in FIG. 1.
  • a high pressure refrigerant gas supply 16 provides refrigerant to the heat exchanger 12 through a control valve 18.
  • the refrigerant cooled in the inlet side of the heat exchanger 12 is expanded through an expansion valve 20,
  • liquid refrigerant is then discharged from the cryostat 10 through a refrigerant exhaust 22 after passing through the other side (outlet side) or heat exchanger 12.
  • the refrigerant gas is at the same temperature as its surroundings.
  • the cryostat 10 When admitted to the cryostat 10 it passes throughthe inlet side of the heat exchanger 12 and out from the heat exchanger 12 through the expansion valve or nozzle 20.
  • This lower temperature refrigerant is then forced through the outlet side of the heat exchanger 12 and thereby decreases the temperature of the incoming refrigerant.
  • This incoming refrigerant then expands through the expansion valve 20 and drops to an even, lower temperature than the preceding increment of refrigerant. This process continues until such time that the refrigerant becomes liquefied at the expansion nozzle 20. The system then remains stabilized at the boiling temperature of the refrigerant.
  • a gaseous contaminant or foreign fluid is'introduced into the refrigerant from a contaminant supply 24.
  • a mixing chamber 26 may be provided to uniformly distribute or disperse the contaminant vapor throughout the refrigerant supplied to the cryostat 10. Alternately other methods of agitation, stirring, or heating may be utilized for this purpose.
  • the contaminant 30, having a solidification temperature higher than that of the refrigerant will precipitate out of solution from the refrigerant and freeze-up. This will reduce and eventually block the flow of refrigerant through the heat exchanger tube 28. As the refrigerant flow is reduced, refrigeration slows or ceases until the cryostat temperature rises and melts the solidified contaminant. Refrigerant flow then resumes and decreases the cryostat temperature until the contaminant blockage occurs again. The cycle of alternate freeze-up and melting occurs indefinitely until the refrigerant supply is stopped. The operation of the cryostat is graphically illustrated in FIG. 3.
  • the type of contaminant, ratio of contaminant weight to refrigerant weight and the type of refrigerant can be varied to accommodate any desired cooling cycle and cryostat configuration.
  • the maximum temperature reached during cycling, and the frequency of the cycling is dependent upon the percentage by weight of contaminant in the refrigerant gas supply.
  • Any desired coolant cycle can be tailored by proper selection of the refrigerant and contaminant in the proper proportions.
  • a list of possible cooling cycles is provided below.
  • a cryostat including a coiled tube heat exchanger
  • a high pressure refrigerant gas supply to provide a refrigerant to said cryostat, said refrigerant comprising a mixture of 16% Freon-l4 and 84% Freon-23;
  • a contaminant into the refrigerant for said cryostat, said contaminant comprising 10 parts per million by weight water vapor, said contaminant having a solidification point above that of the refrigerant to alternately freeze and melt in the coiled tube heat exchanger of said cryostat to reduce the flow of refrigerant through said cryostat.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Clinical Laboratory Science (AREA)

Abstract

Flow control for a cryostat in which the refrigerant flow rate is controlled by adding a contaminant to the refrigerant.

Description

United States Patent Markum 1 May 27, 1975 CRYOSTAT CONTROL 3,413,821 12/1968 Villaume ct a1. 62/514 3,415,078 1 l L' [75] Inventor: Arvel Dean Markum, San Juan 2/ 968 62/5l4 Capistrano, Calif. Assignee? General y f Corporatiml, Primary Examiner-William F. O'Dea Pomona Cahf' Assistant Examiner Rona1d C. Capossela [22 Filed: p 25 1974 Attorney, Agent, or FirmAlbert J. Miller; Edward B.
Johnson [21] Appl. No.1 464,078
[52] US. Cl. 62/474; 62/502; 62/514;
' 137/13; 165/40 57 AB [51] Int. Cl. F25b 43/00 [58] Field of Search 1. 137/13; 165/40; 62/85,
62/114, 195, 474, 475, 502, 511, 514 Flow control for a cryostat 1n wh1ch the refngerant flow rate is controlled by adding a contaminant to the [56] References Cited refngeram- UNITED STATES PATENTS 3,270,756 9/1966 Dryden 137/13 1 Claim, 3 Drawing Figures 1 6 REFRIGERANT Z6 -1 MlXlNG CHAMBER SUPPLY AVE. STEADY STATE TEMP.
PATENTEDi-im' 27 5 SUPPLY REFRIGERANT CHAMBER 1 CRYOSTAT CONTROL BACKGROUND OF THE INVENTION Joule-Thomson effect cooling devices, commonly referred to as cryostats, as well known in the art to produce cryogenic temperature levels. The cryostats may be employed to maintain radiation sensing devices at the extremely low temperatures required. Examples of conventional Joule-Thomson effect cryostats maybe found in U.S. Pat. Nos. 2,991,633, 3,095,711, 3,353,371, 3,415,078 and 3,431,750. I
In order to achieve a rapid initial cool-down, large coolant or refrigerant flows are required in conventional cryostats. Only a fraction of this cool-down flow is, however, needed for steady stateoperation of the cryostat. Thus, a cryostat designed to meet the initial cool-down flow requirements would be inherently inefficient during steady state operation, while a more efficient steady state flow design would have an excessively long cool-down period.
' Since in many cryostat applications the coolant or refrigerant flow is limited by the available supply, techniques have been developed to provide sufficient cooldown flow without providing excessive steady state flow. While certain self-regulating flow control mechanisms have been developed for cryostats, these mechanisms, which have been either thermal-mechanical, electro-mechanical, or chemical in nature, have been rather complicated, overly complex and often prone to operational difficulties. All rely upon external forces, thus consuming energy such as electrical power and all include at least some moving parts. In some cases the basic cooling characteristics of the cryostat have been altered by the flow regulating mechanism.
SUMMARY OF THE INVENTION The invention is directed to a cryostat flow control in which the refrigerant flow rate is controlled by the addition of a contaminant or foreign fluid to the refrigerant. After initial cool-down, the contaminant, having a higher solidification point than the refrigerant, will solidify in the cryostat and cause a partial or complete refrigerant flow stoppage. When the refrigerant flow is thus reduced or stopped, refrigeration slows or ceases with a resultant rise in cryostat temperature which in turn then melts the solidified contaminant. The refrigerant flow will then resume until the temperature is again reduced to freeze up or solidify the refrigerant contaminant.
The alternate freeze-up and melting cycle achieves a greatly reduced average steady state refrigerant flow rate.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a cryostat utilizing the control of the present invention.
FIG. 2 is an enlarged section view of a portion of the heat exchanger tube of the cryostat of FIG. 1.
FIG. 3 is a graphical representation of the operational cycle of a cryostat having the flow control of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The cryostat control of the present invention is applicable to any type of cryostat (counterflow, regenerative, Joule-Thomson expansion, etc.). For purposes of illustration, a Joule-Thomson expansion cryostat 10 having a coiled tubing heat exchanger 12 and liquid refrigerant reservoirv 14 is illustrated in FIG. 1. A high pressure refrigerant gas supply 16 provides refrigerant to the heat exchanger 12 through a control valve 18. The refrigerant cooled in the inlet side of the heat exchanger 12 is expanded through an expansion valve 20,
I or alternately through a nozzle or orifice, and collected in the liquid refrigerant reservoir 14. The liquid refrigerant is then discharged from the cryostat 10 through a refrigerant exhaust 22 after passing through the other side (outlet side) or heat exchanger 12.
Initially, the refrigerant gas is at the same temperature as its surroundings. When admitted to the cryostat 10 it passes throughthe inlet side of the heat exchanger 12 and out from the heat exchanger 12 through the expansion valve or nozzle 20. As the refrigerant expands through the expansion valve 20, it drops in temperature because of the Joule-Thomson effect. This lower temperature refrigerant is then forced through the outlet side of the heat exchanger 12 and thereby decreases the temperature of the incoming refrigerant. This incoming refrigerant then expands through the expansion valve 20 and drops to an even, lower temperature than the preceding increment of refrigerant. This process continues until such time that the refrigerant becomes liquefied at the expansion nozzle 20. The system then remains stabilized at the boiling temperature of the refrigerant.
In order to effect control of the cryostat 10 in accordance with the present invention, a gaseous contaminant or foreign fluid is'introduced into the refrigerant from a contaminant supply 24. A mixing chamber 26 may be provided to uniformly distribute or disperse the contaminant vapor throughout the refrigerant supplied to the cryostat 10. Alternately other methods of agitation, stirring, or heating may be utilized for this purpose.
As illustrated most clearly in FIG. 2, once cool-down has been achieved, the contaminant 30, having a solidification temperature higher than that of the refrigerant, will precipitate out of solution from the refrigerant and freeze-up. This will reduce and eventually block the flow of refrigerant through the heat exchanger tube 28. As the refrigerant flow is reduced, refrigeration slows or ceases until the cryostat temperature rises and melts the solidified contaminant. Refrigerant flow then resumes and decreases the cryostat temperature until the contaminant blockage occurs again. The cycle of alternate freeze-up and melting occurs indefinitely until the refrigerant supply is stopped. The operation of the cryostat is graphically illustrated in FIG. 3.
The type of contaminant, ratio of contaminant weight to refrigerant weight and the type of refrigerant can be varied to accommodate any desired cooling cycle and cryostat configuration. The maximum temperature reached during cycling, and the frequency of the cycling is dependent upon the percentage by weight of contaminant in the refrigerant gas supply.
In a 0.118 inch diameter, 1 inch long, finned tube cryostat, having a gas-flow rate of 1.1 standard liters per minute of 16% Freon-l4 and 84% Freon-23 at a supply pressure of 500 pounds per square inch, 10 parts per million by weight of water vapor as a contaminant in the refrigerant will cycle the refrigerated tip of the cryostat from 250 Kelvin to Kelvin at about 10 second intervals. While the exact location of the refrigerant flow blockage was not determined, it is believed to occur near or at the expansion nozzle.
Any desired coolant cycle can be tailored by proper selection of the refrigerant and contaminant in the proper proportions. A list of possible cooling cycles is provided below.
Temperature Range Refrigerant Contaminant l95- 275K Freon 23 Water Vapor 145 275K Freon 14 Water Vapor 145 l65K Freon 14 Xenon l 12 165K Methane Xenon 88 120K Argon Krypton 78 120K Nitrogen Krypton 78 95K Nitrogen Methane ever, the cryostat operating temperature is achieved, the cyclical freeze-up will significantly reduce the flow of refrigerant flow through the cryostat.
While specific embodiments of the invention have been illustrated and described, it is to be understood that these embodiments are provided by way of example only and that the invention is not to be construed as being limited thereto, but only by the proper scope of the following claims.
What I claim is:
l. In combination:
a cryostat including a coiled tube heat exchanger;
a high pressure refrigerant gas supply to provide a refrigerant to said cryostat, said refrigerant comprising a mixture of 16% Freon-l4 and 84% Freon-23; and
means to introduce a contaminant into the refrigerant for said cryostat, said contaminant comprising 10 parts per million by weight water vapor, said contaminant having a solidification point above that of the refrigerant to alternately freeze and melt in the coiled tube heat exchanger of said cryostat to reduce the flow of refrigerant through said cryostat.

Claims (1)

1. IN COMBINATION: A CRYOSTAT INCLUDING A COILED TUBE HEAT EXCHANGER, A HIGH PRESSURE REFRIGERANT GAS SUPPLY TO PROVIDE A REFRIGERANT TO SAID CRYOSTAT, SAID REFRIGERANT COMPRISING A MIXTURE OF 16% FREON-14 AND 84% FREON-23, AND MEANS TO INTRODUCE A CONTAMINANT INTO THE REFRIGERANT FOR SAID CRYOSTAT, SAID CONTAMINANT COMPRISING 10 PARTS PER MILLION BY WEIGHT WATER VAPOR, SAID CONTAMIANT HAVING A SOLIDIFICATION POINT ABOVE THAT OF THE REFREGERANT TO ALTERNATELY FREEZE AND MELT IN THE COILED TUBE HEAT EXCHANGER OF SAID CRYOSTAT TO REDUCE THE FLOW OF REFRIGERANT THROUGH SAID CRYOSTAT.
US05464078 1974-04-25 1974-04-25 Cryostat control Expired - Lifetime US3885939A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US05464078 US3885939A (en) 1974-04-25 1974-04-25 Cryostat control
US05/538,651 US3933003A (en) 1974-04-25 1975-01-06 Cryostat control

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05464078 US3885939A (en) 1974-04-25 1974-04-25 Cryostat control

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/538,651 Division US3933003A (en) 1974-04-25 1975-01-06 Cryostat control

Publications (1)

Publication Number Publication Date
US3885939A true US3885939A (en) 1975-05-27

Family

ID=23842466

Family Applications (1)

Application Number Title Priority Date Filing Date
US05464078 Expired - Lifetime US3885939A (en) 1974-04-25 1974-04-25 Cryostat control

Country Status (1)

Country Link
US (1) US3885939A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2638206A1 (en) * 1975-08-26 1977-03-10 Air Liquide Isenthalpic refrigeration expansion feed - has feed circuit carrying alternate fluids with varying cooling capacities
US4166365A (en) * 1976-10-09 1979-09-04 Sanji Taneichi Apparatus for liquefying refrigerant and generating low temperature
FR2520131A1 (en) * 1982-01-19 1983-07-22 Telecommunications Sa REGULATION DEVICE FOR A JOULE-THOMSON EFFECT REFRIGERATOR
EP0488001A1 (en) * 1990-11-28 1992-06-03 Licentia Patent-Verwaltungs-GmbH Regenerative gas refrigerator
US5956958A (en) * 1995-10-12 1999-09-28 Cryogen, Inc. Gas mixture for cryogenic applications
US20070209371A1 (en) * 2006-03-13 2007-09-13 Raytheon Company MIXED GAS REFRIGERANT SYSTEM FOR SENSOR COOLING BELOW 80ºK

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3270756A (en) * 1963-04-09 1966-09-06 Hugh L Dryden Fluid flow control valve
US3413821A (en) * 1967-02-23 1968-12-03 Air Prod & Chem Cryogenic refrigeration for crystal x-ray diffraction studies
US3415078A (en) * 1967-07-31 1968-12-10 Gen Dynamics Corp Infrared detector cooler

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3270756A (en) * 1963-04-09 1966-09-06 Hugh L Dryden Fluid flow control valve
US3413821A (en) * 1967-02-23 1968-12-03 Air Prod & Chem Cryogenic refrigeration for crystal x-ray diffraction studies
US3415078A (en) * 1967-07-31 1968-12-10 Gen Dynamics Corp Infrared detector cooler

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2638206A1 (en) * 1975-08-26 1977-03-10 Air Liquide Isenthalpic refrigeration expansion feed - has feed circuit carrying alternate fluids with varying cooling capacities
US4166365A (en) * 1976-10-09 1979-09-04 Sanji Taneichi Apparatus for liquefying refrigerant and generating low temperature
FR2520131A1 (en) * 1982-01-19 1983-07-22 Telecommunications Sa REGULATION DEVICE FOR A JOULE-THOMSON EFFECT REFRIGERATOR
EP0084308A2 (en) * 1982-01-19 1983-07-27 Societe Anonyme De Telecommunications (S.A.T.) Regulating device for a Joule-Thomson effect cooling apparatus
EP0084308A3 (en) * 1982-01-19 1983-08-03 Societe Anonyme De Telecommunications Regulating device for a joule-thomson effect cooling apparatus
US4468935A (en) * 1982-01-19 1984-09-04 Societe Anonyme De Telecommunications Device for regulating a Joule-Thomson effect refrigerator
EP0488001A1 (en) * 1990-11-28 1992-06-03 Licentia Patent-Verwaltungs-GmbH Regenerative gas refrigerator
US5956958A (en) * 1995-10-12 1999-09-28 Cryogen, Inc. Gas mixture for cryogenic applications
US20070209371A1 (en) * 2006-03-13 2007-09-13 Raytheon Company MIXED GAS REFRIGERANT SYSTEM FOR SENSOR COOLING BELOW 80ºK

Similar Documents

Publication Publication Date Title
US2494120A (en) Expansion refrigeration system and method
US6477847B1 (en) Thermo-siphon method for providing refrigeration to a refrigeration load
KR20010105225A (en) Apparatus and method for providing refrigeration at a very cold temperature
US3933003A (en) Cryostat control
US3125863A (en) Dense gas helium refrigerator
US4048814A (en) Refrigerating plant using helium as a refrigerant
US3885939A (en) Cryostat control
US3415078A (en) Infrared detector cooler
US3827247A (en) Process of complete cryogenic vaporization of liquefied natural gas
CA2451766A1 (en) External loop nonfreezing heat exchanger
Benoit et al. Dilution refrigerator for space applications with a cryocooler
JP3304978B2 (en) Cryogenic method
US3782129A (en) Proportionate flow cryostat
US3990265A (en) Joule-Thomson liquifier utilizing the Leidenfrost principle
Best et al. Developments in geothermal energy in Mexico—Part five: The commissioning of an ammonia/water absorption cooler operating on low enthalpy geothermal energy
US3470065A (en) Production of cold neutrons
Sigurdson A general computer model for predicting the performance of gas sorption refrigerators
Lashmet et al. A closed-cycle cascade helium refrigerator
Valkov Test Results on a 5 Kilowatts-Scale Chemical Heat Pump Prototype
JPS6099968A (en) Method of cooling brine
Arend et al. Cooling of a system of superconducting magnets by means of pumped subcooled liquid helium
KR20230002438A (en) Apparatus and method for generating cryogenic temperatures and uses thereof
Landa et al. The self-regulating effect used in Joule-Thomson microcryogenic systems
JPH03247963A (en) Cryogenic refrigerator
Nicol et al. Continuous Refrigeration between 4.2 and 1° K

Legal Events

Date Code Title Description
AS Assignment

Owner name: HUGHES MISSILE SYSTEMS COMPANY, CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GENERAL DYNAMICS CORPORATION;REEL/FRAME:006279/0578

Effective date: 19920820