EP0188976B1 - Mischkryostat - Google Patents

Mischkryostat Download PDF

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Publication number
EP0188976B1
EP0188976B1 EP19850420228 EP85420228A EP0188976B1 EP 0188976 B1 EP0188976 B1 EP 0188976B1 EP 19850420228 EP19850420228 EP 19850420228 EP 85420228 A EP85420228 A EP 85420228A EP 0188976 B1 EP0188976 B1 EP 0188976B1
Authority
EP
European Patent Office
Prior art keywords
dilution
circuit
evaporator
enclosure
pumping
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
Application number
EP19850420228
Other languages
English (en)
French (fr)
Other versions
EP0188976A1 (de
Inventor
Alain Daniel Benoit
Serge Pujol
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.)
Centre National de la Recherche Scientifique CNRS
Original Assignee
Centre National de la Recherche Scientifique CNRS
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 Centre National de la Recherche Scientifique CNRS filed Critical Centre National de la Recherche Scientifique CNRS
Publication of EP0188976A1 publication Critical patent/EP0188976A1/de
Application granted granted Critical
Publication of EP0188976B1 publication Critical patent/EP0188976B1/de
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C3/00—Vessels not under pressure
    • F17C3/02—Vessels not under pressure with provision for thermal insulation
    • F17C3/08—Vessels not under pressure with provision for thermal insulation by vacuum spaces, e.g. Dewar flask
    • F17C3/085—Cryostats
    • 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
    • F25B9/12—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point using 3He-4He dilution
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2270/00—Applications
    • F17C2270/05—Applications for industrial use
    • F17C2270/0518—Semiconductors
    • 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
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D2400/00—General features of, or devices for refrigerators, cold rooms, ice-boxes, or for cooling or freezing apparatus not covered by any other subclass
    • F25D2400/28—Quick cooling

Definitions

  • the invention relates to dilution cryostats according to the first part of claim 1, that is to say to devices or installations for achieving very low temperatures, of the order of 1 Kelvin.
  • the invention relates to apparatuses of the above type which can be used for laboratory research purposes, or even for industrial purposes, for example for the analysis of the physical properties of various materials or, more particularly, of materials. superconductors.
  • the invention relates, more specifically, to devices or installations making it possible to reach very low temperatures, less than 1 Kelvin.
  • Dilution cryostats can be classified into two categories.
  • this cold point is formed either by a wall of the dilution chamber, or by the latter which is arranged in a sealed enclosure.
  • the operating principle of these cryostats consists of introducing helium in the gaseous phase into the sealed enclosure, in order to perform precooling prior to the subsequent operating mode in dilution.
  • An embodiment of this type is provided by the publication EP-A-0 015 728.
  • the second category relates to dilution apparatus comprising, in order to remedy the above drawbacks, a sample changer placed in relation to the cold point, as may be considered on the basis of the publication DE-A-2 744 346.
  • a sample changer placed in relation to the cold point, as may be considered on the basis of the publication DE-A-2 744 346.
  • the object of the invention is to remedy the above drawbacks by proposing a new dilution cryostat designed to allow rapid commissioning, from the sole components of said device or installation, as well as access quick to change the sample.
  • the single figure is a schematic view illustrating the structure of the dilution cryostat according to the invention.
  • the dilution cryostat according to the invention comprises a suspension framework 1 to which is suspended a first precooling stage 2 under which is fixed a second precooling stage 3 associated with a suspended dilution unit 4.
  • the frame 1 mainly comprises a plate 5 under which a sealed enclosure 6 is fitted, by means of a removable seal 7.
  • the assembly makes it possible to isolate the internal volume which can be evacuated using the pump 8 and the valve 9.
  • the first precooling stage 2 comprises an exchange plate 10 made of a metal having very good thermal conductivity characteristics and, for example, of copper.
  • the plate 10 is suspended from the plate 5 by the pumping tubes described below and having a low thermal conductivity.
  • the plate 10 is extended downwards by a removable enclosure 11 with a closed bottom.
  • This enclosure constructed of a conductive material, such as copper or aluminum, is not waterproof and only serves as a barrier to thermal radiation.
  • the first precooling stage 2 comprises an evaporator 16 carried by the exchange plate 10.
  • the evaporator 16 is connected to an evacuation pipe 17 controlled by a valve 18.
  • the evaporator 16 is also connected to its inlet , via a line 19, to a reservoir 20 of a cryogenic liquid, such as liquid nitrogen.
  • the reservoir 20 is enclosed in a sealed compartment 21.
  • the reservoir 20 is placed in charge with respect to the evaporator 16.
  • the pipe 17 is responsible for discharging, in the open air, the vaporized nitrogen.
  • the precooling plate 10 also supports an exchanger-condenser 22 with two independent circuits, the function of which appears in the following.
  • the second precooling stage 3 comprises an exchange plate 23 which is suspended from the plate 10 by the pumping and circulation tubes described below and having a low thermal conductivity.
  • the plate 23 is made of a metal which is a very good conductor of heat and, for example, of copper.
  • the plate 23 is extended downwards by a removable enclosure 24, with a closed bottom. This enclosure, constructed of a conductive material, such as copper or aluminum, is not waterproof and only serves as a barrier to thermal radiation.
  • the plate 23 supports an evaporator 29 comprising a discharge line 30 passing through the plate 10 and the plate 5 and comprising, outside the latter, a valve 31 placed upstream of an extraction pump 32.
  • the evaporator 29 is connected, by a pipe 33 including a valve 34, to a tank 35 containing a cryogenic product, such as liquid helium.
  • the tank 35 is enclosed in the sealed compartment 21.
  • a screen 36 connected to the liquid nitrogen tank 20, protects it from thermal radiation.
  • the pipes 17, 19 and 33 pass through the plate 5 by a thermal insulation sheath formed by the compartment 21.
  • the plate 23 also supports an exchanger-condenser 37 with two independent internal circuits, the function of which appears in the following.
  • the dilution unit 4 comprises, according to the invention, a main evaporator-distiller 40, suspended from the plate 23 by a main pumping circuit 41 rising vertically and passing through the plates 10 and 5 successively.
  • the main evaporator-distiller 40 is connected at its base by a pipe 43 to a dilution chamber 44 constituting the cold point of the dilution unit 4.
  • the dilution chamber 44 is shaped so that its bottom represents a fixing support of a sample 45 to be analyzed.
  • the main pumping circuit 41 comprises a pump 46, the outlet of which is connected, by a valve 47, to a main discharge circuit 48 constituted by a small section pipe passing through the exchanger-condenser 22 and 37.
  • the circuit 48 comprises, at beyond the exchanger-condenser 37, an expansion restrictor 49 beyond which it passes through an exchanger 50 placed in relation to the main evaporator-distiller 40.
  • the circuit 48 includes a second expansion restrictor 51 beyond which it passes through an exchanger 52 concentrically surrounding the tube 43 The circuit 48 then opens into the upper part of the dilution chamber 44.
  • the dilution cryostat further comprises a bypass pumping circuit 53 comprising an evaporator-distiller 54 suspended from the plate 23 by a column 55 also passing through the plates 10 and 5.
  • the column 55 is controlled by a valve 57 at the -from which it is connected to the main circuit 41.
  • the evaporator 54 is connected, by a pipe 56, to the dilution chamber 44.
  • the dilution cryostat further comprises a branched discharge circuit 58 also connected to the outlet of the pump 46 by a valve 59.
  • the circuit 58 passes through the exchanger-condenser 22, then the exchanger-condenser 37 beyond which it is connected to column 55 in the part of the latter located above the plate 23 of the second precooling stage 3.
  • a reserve 42 containing the quantities of 3 He and 4 He necessary for operation and mixed in gaseous form.
  • a valve 100 allows the reserve to be emptied using the pump 46, a valve 101 allowing the 3 He, 4 He mixture to return to the reserve at the end of use.
  • the structure described above has the advantage of allowing easy installation and removal of the sample 45. In fact, for all these operations, it suffices to establish the normal pressure in the enclosure 6 by the valve 9, then successively dismantle the speakers 6, 11 and 24.
  • the structure of the cryostat is also chosen so that the effective commissioning of the device can take place quickly.
  • the structure of the device is chosen so that the pre-cooling phase is carried out more simply and more quickly than according to the prior art.
  • a pumping and vacuuming phase can occur simultaneously with a precooling which is ensured in the following manner.
  • the valve 18 is open, so that the liquid nitrogen passes by gravity through the evaporator 16, in order to ensure the cooling of the plate 10. Simultaneously, the valves 31 and 34 are open and the pump 32 is turned on. running, so as to create a circulation of helium in the evaporator 29 responsible for cooling the exchange plate 23.
  • the valve 57 is then closed, as is the valve 47, while the valve 59 is, on the contrary, open.
  • the pump 46 is started, so as to discharge the cryogenic mixture extracted from the reserve 42 into the branched discharge circuit 58.
  • the cryogenic mixture in the gas phase is cooled by passing through the exchanger-condenser 22, then from the exchanger-condenser 27, before being introduced into column 55 where it arrives at low temperature.
  • the cold mixture then borrows the pipe 56, crosses the dilution chamber 44 and rises through the main pumping circuit 41, before being recycled by the pump 46.
  • This circulation has the effect of cooling the dilution unit by internal circulation, while the dilution cryostats, of the known type, provide a pre-cooling phase by external circulation of a cryogenic product in the vapor phase, such as helium.
  • valves 47 and 57 are open, while the valve 59 is closed.
  • the pump 46 then delivers cryogenic mixture into the main circuit 48. After being cooled in the exchanger 22, the mixture condenses in the exchanger-condenser 37, before expanding through the restrictors 49 and 51. The liquid thus obtained accumulates in the lower parts of the apparatus until completely filling the mixing chamber 44, then the tube 56, as well as the exchanger 52, finally, partially, the evaporators 40 and 54 where the levels balance .
  • the reserve 42 begins the distillation of the mixture in the two evaporators.
  • the 4 He fraction remains at the bottom of the cryostat and the 3 He fraction is pumped by the pump 46.
  • the pure 3 He fraction thus obtained is then discharged by the valve 47, cooled in the exchanger 22, condensed in the exchanger 37, expanded in 49, further cooled in 50, expanded in 51 and, finally, cooled by the exchanger 52, before diluting in the fraction 4 He contained in the dilution chamber 44 thereby cooling the sample.
  • the 3 He fraction rises to the two evaporators by diffusing into the 4 He fraction, cooling the exchanger 52 in passing and preventing any heat from descending along the tubes 56 and 43.
  • the structure of the dilution cryostat according to the invention makes it possible, using the same cryogenic mixture, to ensure precooling by circulation of the mixture in the gas phase inside the constituent elements of the dilution unit 4, then d '' maintain operation in dilution mode by circulating the same mixture in the liquid phase, switching from one operating mode to another being effected by the control of valves 47, 59 and 57. It thus becomes possible to put into service quickly such an apparatus and thus fully benefit from the advantages of rapid change of samples due to the structure of the removable concentric envelopes 6, 11 and 24. It also becomes possible to apply to the sample 45 all the desired temperature ranges, since this depends only on the circulation mode and not on the temperature of the cryogenic liquid reserves 20 and 35.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Sampling And Sample Adjustment (AREA)

Claims (6)

1. Verdünnungskryostat vom zwei Vorkühlungsetagentyp (2, 3), die mit wenigstens einem unabhängigen Vorrat von Tiefsttemperaturflüssigkeit einem Kühlungstiefsttemperaturmischungsreservoir (42), einer Verdünnungskammer (44) der Mischung und einem Kreis des Anstauens bzw. Rückführens (48) und Pumpens (41) verbunden sind, mit zwischen dem Vorrat und dem Reservoir einer Pumpe (46), einem Verdampfer (40), der auf dem Pumpkreis angeordnet ist und Kondensatorkühlern (22, 37), die auf dem Rückführkreis angeordnet sind,
dadurch gekennzeichnet, daß er aufweist:
- einen Kreis des umleitenden Pumpkreis (53) mit einem Verdampfer (54), der zwischen der Verdünnungskammer (44) und der zweiten Vorkühlungsetage (3) angeordnet ist, und mit einem Ventil (57), das zwischen der Verdünnungskammer (44) und der zirkulationspumpe (46) angeordnet ist,
- und einen Umleitungsrückführkreis (58), der oberhalb der Pumpe durch ein Einlaßventil (59) gesteuert wird, das durch die erste und zweite Etage (2, 3) hindurchtritt, und in den Umleitungspumpkreis (53) unterhalb des Verdampfers bezüglich der verdünnungskammer mündet.
2. Verdünnungskryostat nach Anspruch 1, dadurch gekennzeichnet, daß der Verdampfer (54) des Umleitungspumpkreises (53) im wesentlichen in derselben Ebene wie der Verdampfer (40) des Hauptpumpkreises (41) angeordnet ist und mit diesem letzteren und der Verdünnungskammer (44) eine Verdünnungseinheit (4) bildet, die von einer dichten Umhüllung (6) umgeben ist.
3. Verrdünnungskryostat nach Anspruch 2, dadurch gekennzeichnet, daß die Verdünnungseinheit (4) in einer Umhüllung (24) eingeschlossen ist, die an der zweiten Vorkühlungsetage (3) aufgehängt ist, die unterhalb einer ersten Etage (2) angeordnet ist, an der eine Zwischenumhüllung (11) aufgehängt ist, die die umhüllung (24) der Verdünnungseinheit umgibt, und die selbst von einer äußeren umhüllung (6) umgeben ist, die an einem Stütztragwerk (1) angehängt ist, wobei die Umhüllungen in Verbindung mit einer Pumpen-und Vakuumeinheit (8, 9) stehen.
4. Verdünnungskryostat nach Anspruch 3, dadurch gekennzeichnet, daß die Haupt- und Umleitungspump und Rückführkreise die erste und zweite Vorkühlungsetage durchqueren.
5. Verdünnungskryostat nach Anspruch 3, dadurch gekennzeichnet. daß die Umhüllungen (6, 11, 24) konzentrisch und den Etagen (2, 3) und dem Tragwerk (1) angepasst sind.
6. Verdünnungskryostat nach Anspruch 3, dadurch gekennzeichnet. daß die Kühlmittel (20, 21 und 35, 36) der ersten und zweiten Etage von dem Stütztrag werk getragen werden.
EP19850420228 1984-12-17 1985-12-16 Mischkryostat Expired EP0188976B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8419488A FR2574914B1 (fr) 1984-12-17 1984-12-17 Cryostat a dilution
FR8419488 1984-12-17

Publications (2)

Publication Number Publication Date
EP0188976A1 EP0188976A1 (de) 1986-07-30
EP0188976B1 true EP0188976B1 (de) 1989-03-08

Family

ID=9310794

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19850420228 Expired EP0188976B1 (de) 1984-12-17 1985-12-16 Mischkryostat

Country Status (5)

Country Link
US (1) US4672823A (de)
EP (1) EP0188976B1 (de)
JP (1) JPH0621755B2 (de)
DE (1) DE3568628D1 (de)
FR (1) FR2574914B1 (de)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4770006A (en) * 1987-05-01 1988-09-13 Arch Development Corp. Helium dilution refrigeration system
FR2626658B1 (fr) * 1988-02-03 1990-07-20 Centre Nat Etd Spatiales Procede et appareillage pour l'obtention de tres basses temperatures
KR950007694B1 (ko) * 1988-03-28 1995-07-14 부라더 고교 가부시기가이샤 단축복합운동장치
US5060482A (en) * 1990-01-25 1991-10-29 Jackson Henry W Continuously operating 3 He-4 He dilution refrigerator for space flight
US5070702A (en) * 1990-05-07 1991-12-10 Jackson Henry W Continuously operating 3 HE evaporation refrigerator for space flight
GB9609311D0 (en) * 1996-05-03 1996-07-10 Oxford Instr Uk Ltd Improvements in cryogenics
DE10130171B4 (de) * 2001-06-22 2008-01-31 Raccanelli, Andrea, Dr. Verfahren und Vorrichtung zur Tieftemperaturkühlung
GB2493553B (en) 2011-08-11 2017-09-13 Oxford Instr Nanotechnology Tools Ltd Cryogenic cooling apparatus and method
GB2584135A (en) * 2019-05-23 2020-11-25 Oxford Instruments Nanotechnology Tools Ltd Cryogenic cooling system
FR3107586B1 (fr) * 2020-02-21 2022-11-18 Air Liquide Dispositif et procédé de réfrigération à dilution
CN112325498B (zh) * 2020-11-06 2022-03-29 格物致寒(苏州)科学仪器有限公司 一种稀释制冷系统及方法
US11946680B2 (en) * 2021-07-08 2024-04-02 Maybell Quantum Industries, Inc. Integrated dilution refrigerators
CA3235548A1 (en) * 2021-11-02 2023-05-11 Anyon Systems Inc. Dilution refrigerator with continuous flow helium liquefier
FR3129201B1 (fr) * 2021-11-16 2024-01-19 Air Liquide Système de pompage cryogénique et intégration innovante pour la cryogénie Sub Kelvin inférieure à 1,5K
FR3129198B1 (fr) * 2021-11-17 2023-10-27 Air Liquide Dispositif de réfrigération cryogénique

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2744346A1 (de) * 1977-10-01 1979-04-05 Gerd Binnig Direkt ladbarer mischkryostat mit proben-schnellwechsel
US4223540A (en) * 1979-03-02 1980-09-23 Air Products And Chemicals, Inc. Dewar and removable refrigerator for maintaining liquefied gas inventory
NL7902014A (nl) * 1979-03-14 1980-09-16 Philips Nv 3he-4he verdunningskoelmachine.
NL7902438A (nl) * 1979-03-29 1980-10-01 Philips Nv 3he-4he koelmachine.
US4277949A (en) * 1979-06-22 1981-07-14 Air Products And Chemicals, Inc. Cryostat with serviceable refrigerator
IL63517A (en) * 1981-08-06 1984-05-31 Rosenbaum Ralph Multiple-chamber cooling device particularly useful in a dilution refrigerator
JPS5880474A (ja) * 1981-11-06 1983-05-14 株式会社日立製作所 極低温冷却装置
EP0089391B1 (de) * 1982-03-23 1986-06-04 International Business Machines Corporation Verfahren und Verdünnungskältemaschine zum Kühlen bei Temperaturen unter 1 K
US4548053A (en) * 1984-06-05 1985-10-22 The United States Of America As Represented By The United States Department Of Energy Combined cold compressor/ejector helium refrigerator

Also Published As

Publication number Publication date
JPS61191845A (ja) 1986-08-26
DE3568628D1 (en) 1989-04-13
US4672823A (en) 1987-06-16
EP0188976A1 (de) 1986-07-30
FR2574914B1 (fr) 1987-03-06
JPH0621755B2 (ja) 1994-03-23
FR2574914A1 (fr) 1986-06-20

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