JPH03116908A - Superconducting electromagnet - Google Patents
Superconducting electromagnetInfo
- Publication number
- JPH03116908A JPH03116908A JP25588389A JP25588389A JPH03116908A JP H03116908 A JPH03116908 A JP H03116908A JP 25588389 A JP25588389 A JP 25588389A JP 25588389 A JP25588389 A JP 25588389A JP H03116908 A JPH03116908 A JP H03116908A
- Authority
- JP
- Japan
- Prior art keywords
- container
- superconducting coil
- cryogenic temperature
- pressure
- temperature refrigerant
- 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.)
- Pending
Links
- 239000003507 refrigerant Substances 0.000 claims abstract description 36
- 238000001704 evaporation Methods 0.000 abstract description 6
- 230000008020 evaporation Effects 0.000 abstract description 6
- 229910052734 helium Inorganic materials 0.000 abstract description 5
- 239000001307 helium Substances 0.000 abstract description 5
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 abstract description 5
- 239000007788 liquid Substances 0.000 abstract description 5
- 230000002159 abnormal effect Effects 0.000 abstract description 3
- 238000000034 method Methods 0.000 abstract 1
- 239000002826 coolant Substances 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 238000010791 quenching Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- -1 but in either case Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000002595 magnetic resonance imaging Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Landscapes
- Containers, Films, And Cooling For Superconductive Devices (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は、医療用磁気共鳴イメージング装置（ＭＲ１装
置）等において使用される超電導磁石に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a superconducting magnet used in a medical magnetic resonance imaging apparatus (MR1 apparatus) and the like.
（従来の技術）
ＭＨＩ装置では、強く、かつ均一な磁界を必要とすると
ころから超電導磁石が使用されることが多い。(Prior Art) Superconducting magnets are often used in MHI devices because they require a strong and uniform magnetic field.
この超電導磁石は、第２図に示すように、内筒１ａと外
筒１ｂの両開孔部を上下一対の環状の端板（図示せず）
で閉塞した極低温冷媒容器１内に液体ヘリウム等の極低
温冷′ｖＸ、２と超電導コイル３とを収容して構成され
ている。極低温冷媒容器の外筒１ｂに開けた孔には大口
径の放圧管４が取付けられている。As shown in FIG. 2, this superconducting magnet has a pair of upper and lower annular end plates (not shown) extending through the openings of both the inner cylinder 1a and the outer cylinder 1b.
The superconducting coil 3 is constructed by housing a cryogenic coolant such as liquid helium and a superconducting coil 3 in a cryogenic refrigerant container 1 closed with liquid helium. A large-diameter pressure relief pipe 4 is attached to a hole drilled in the outer cylinder 1b of the cryogenic refrigerant container.
極低温冷媒容器１は、通常、それと類似の形状でもう−
回り大きな寸法の真空断熱容器（図示せず）内に同軸的
に納められ、真空断熱される。The cryogenic refrigerant container 1 usually has a similar shape to that of the cryogenic refrigerant container 1.
It is housed coaxially in a vacuum insulated container (not shown) with a large circumference and is vacuum insulated.
このような構成の超電導磁石においては、超電導コイル
が極低温冷媒に直接接しているため、何らかの原因によ
って超電導コイルがクエンチすると、超電導コイルから
の熱によって極低温冷媒が急激に蒸発してしまう。In a superconducting magnet with such a configuration, the superconducting coil is in direct contact with the cryogenic refrigerant, so if the superconducting coil quenches for some reason, the cryogenic refrigerant will rapidly evaporate due to the heat from the superconducting coil.
そこで、極低温冷媒容器には、クエンチ発生時の異常な
圧力上昇を避けるため、大口径の放圧管を設けておく必
要があった。Therefore, it was necessary to provide a large-diameter pressure relief pipe in the cryogenic refrigerant container in order to avoid an abnormal pressure rise when quenching occurs.
（発明が解決しようとする課′８）
しかしながら、大口径放圧管を備えた超電導磁石におい
ては、そこを通して流入する大気からの熱侵入が大きく
なり、定常時における極低温冷媒の蒸発量が大きく、熱
効率が低いという課題かあった。(Problem to be solved by the invention '8) However, in a superconducting magnet equipped with a large-diameter pressure relief tube, heat intrusion from the atmosphere flowing through the tube becomes large, and the amount of evaporation of the cryogenic refrigerant during steady state is large. There was also the issue of low thermal efficiency.
本発明は上記課題を解決するためになされたもので、小
口径の放圧管を用いても超電導コイルのクエンチ時にお
ける異常上昇を押えることができる超電導磁石を提供す
ることを目的とするものである。The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a superconducting magnet that can suppress abnormal rise during quenching of a superconducting coil even if a small-diameter pressure relief tube is used. .
［発明の構成コ
（課題を解決するための手段）
本発明の超電導磁石は、極低温冷媒容器と、この冷媒容
器内に収納された極低温冷媒および超電導コイルとを備
えた超電導磁石において、前記超電導コイルの外層にポ
ーラス絶縁層を配置したことを特徴とするものである。[Configuration of the Invention (Means for Solving the Problems) A superconducting magnet of the present invention includes a cryogenic refrigerant container, a cryogenic refrigerant housed in the refrigerant container, and a superconducting coil. It is characterized in that a porous insulating layer is disposed on the outer layer of the superconducting coil.
（作用）
上述のような構成の本発明装置においては、超電導コイ
ルにクエンチが発生しても、超電導コイルの外側に設け
たポーラス絶縁層の断熱効果によって、極低温冷媒の急
激な蒸発が抑制され、従って、放圧管の口径を小口径と
しておいても極低温冷媒容器内の圧力が異常に上昇する
ことを防止できる。(Function) In the device of the present invention configured as described above, even if quench occurs in the superconducting coil, rapid evaporation of the cryogenic refrigerant is suppressed by the heat insulating effect of the porous insulating layer provided on the outside of the superconducting coil. Therefore, even if the diameter of the pressure relief pipe is made small, it is possible to prevent the pressure inside the cryogenic refrigerant container from increasing abnormally.
（実施例） 次に、図面を参照しながら本発明の詳細な説明する。(Example) Next, the present invention will be described in detail with reference to the drawings.
第１図は本発明にかかる超電導磁石の実施例を示すもの
で、第２図におけると同一部分には同一の符号を付しで
ある。FIG. 1 shows an embodiment of a superconducting magnet according to the present invention, and the same parts as in FIG. 2 are given the same reference numerals.
第１図において、超電導磁石は内筒１ａと外筒１ｂの両
開孔部を上下一対の環状の端板（図示せず）で閉塞した
極低温冷媒容器１内に液体ヘリウム等の極低温冷媒２と
超電導コイル３とを収容して構成されている。極低温冷
媒容器の外筒１ｂに開けた孔には小口径の放圧管５が取
付けられている。In FIG. 1, a superconducting magnet is installed in a cryogenic refrigerant container 1 in which both openings in an inner cylinder 1a and an outer cylinder 1b are closed with a pair of upper and lower annular end plates (not shown), and a cryogenic refrigerant such as liquid helium is stored in the cryogenic refrigerant container 1. 2 and a superconducting coil 3. A small-diameter pressure relief pipe 5 is attached to a hole drilled in the outer cylinder 1b of the cryogenic refrigerant container.
また、超電導コイル３の外周にはポーラス絶縁層６が設
けられている。このポーラス絶縁層は例えばガラス布の
巻回層でもよく、あるいは超電導コイル表面に直接、発
泡剤を吹付けたり、非金属材料を低温溶射させたもので
もよいが、いずれの場合も常時は液体ヘリウム等の極低
温冷媒かしみこみ、かつ適度の熱絶縁性と、冷媒の通過
を抑制する性質を備えたものを使用する。Further, a porous insulating layer 6 is provided on the outer periphery of the superconducting coil 3. This porous insulating layer may be, for example, a wound layer of glass cloth, or may be made by spraying a foaming agent directly onto the superconducting coil surface or by low-temperature spraying a nonmetallic material, but in either case, liquid helium is used at all times. Use a material that can penetrate cryogenic refrigerant, such as, has appropriate thermal insulation properties, and has properties that suppress the passage of refrigerant.
上記のようにして極低温冷媒２、超電導コイル３および
ポーラス絶縁層６を収納した極低温冷媒容器１は、第２
図の場合と同様に、それと類似の形状でもう−回り大き
な寸法の真空断熱容器（図示せず）内に同軸的に納めら
れ、真空断熱されて使用される。The cryogenic refrigerant container 1 containing the cryogenic refrigerant 2, the superconducting coil 3, and the porous insulating layer 6 as described above has a second
As in the case shown in the figure, it is housed coaxially in a vacuum insulated container (not shown) of a similar shape but larger in size, and is used while being vacuum insulated.
このような構成の本発明の超電導磁石においては、定常
時には、極低温冷媒２がポーラス絶縁層６にしみこみ、
超電導コイルを冷却して超電導状態に保つ。In the superconducting magnet of the present invention having such a configuration, during normal operation, the cryogenic coolant 2 penetrates into the porous insulating layer 6,
Cools the superconducting coil and maintains it in a superconducting state.
一方、超電導コイル３がクエンチした場合にはポーラス
絶縁層６は熱絶縁機能と極低温冷媒２の流動抵抗とによ
る断熱効果をもたらすので、超電導コイル３と極低温冷
媒２間の過渡的な熱伝達は悪くなる。そのため、クエン
チ時における極低温冷媒の急激な蒸発は抑制される。On the other hand, when the superconducting coil 3 is quenched, the porous insulating layer 6 provides a thermal insulation effect due to the thermal insulation function and the flow resistance of the cryogenic coolant 2, so that transient heat transfer between the superconducting coil 3 and the cryogenic coolant 2 is prevented. becomes worse. Therefore, rapid evaporation of the cryogenic refrigerant during quenching is suppressed.
以上の理由から、放圧管の口径を小さくしても極低温冷
媒容器内の圧力が異常に上昇することはない。For the above reasons, even if the diameter of the pressure relief pipe is made small, the pressure inside the cryogenic refrigerant container will not rise abnormally.
このように、本発明によれば、小口径放圧管の使用が可
能となり、放圧管を通しての熱流入を大幅に低減するこ
とができ、定常時における極低温冷媒の蒸発量を低く抑
えることができる。As described above, according to the present invention, it is possible to use a small-diameter pressure relief pipe, the heat inflow through the pressure relief pipe can be significantly reduced, and the amount of evaporation of cryogenic refrigerant during steady state can be kept low. .
［発明の効果］
上述のごとく、本発明に係る超電導磁石においては、放
圧管を通しての熱流入を大幅に低減することができ、定
常時における極低温冷媒の蒸発量を低く抑えることがで
きる。[Effects of the Invention] As described above, in the superconducting magnet according to the present invention, the heat inflow through the pressure relief tube can be significantly reduced, and the amount of evaporation of the cryogenic refrigerant during steady state can be suppressed to a low level.
第１図は本発明の超電導磁石の実施例を示す横断概略図
、第２図は従来の超電導磁石の横断概略図である。
１・・・・・・・・・極低温冷媒容器
１ａ・・・・・・内筒
１ｂ・・・・・・外筒
２・・・・・・・・・極低温冷媒
３・・・・・・・・・超電導コイル
４・・・・・・・・・大口径放圧管
５・・・・・・・・・小口径放圧管
６・・・・・・・・・ポーラス絶縁層FIG. 1 is a cross-sectional schematic diagram showing an embodiment of the superconducting magnet of the present invention, and FIG. 2 is a cross-sectional schematic diagram of a conventional superconducting magnet. 1...Cryogenic refrigerant container 1a...Inner tube 1b...Outer tube 2...Cryogenic refrigerant 3... ......Superconducting coil 4......Large diameter pressure relief tube 5......Small diameter pressure relief tube 6...Porous insulation layer
Claims (1)
温冷媒および超電導コイルとを備えた超電導磁石におい
て、前記超電導コイルの外層にポーラス絶縁層を配置し
たことを特徴とする超電導磁石。A superconducting magnet comprising a cryogenic refrigerant container, a cryogenic refrigerant housed in the refrigerant container, and a superconducting coil, characterized in that a porous insulating layer is disposed on the outer layer of the superconducting coil.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25588389A JPH03116908A (en) | 1989-09-29 | 1989-09-29 | Superconducting electromagnet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25588389A JPH03116908A (en) | 1989-09-29 | 1989-09-29 | Superconducting electromagnet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03116908A true JPH03116908A (en) | 1991-05-17 |
Family
ID=17284890
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25588389A Pending JPH03116908A (en) | 1989-09-29 | 1989-09-29 | Superconducting electromagnet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03116908A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007080940A (en) * | 2005-09-12 | 2007-03-29 | Toshiba Corp | Superconducting coil apparatus |
| WO2019239650A1 (en) * | 2018-06-15 | 2019-12-19 | 株式会社日立製作所 | Superconducting electromagnet device |
-
1989
- 1989-09-29 JP JP25588389A patent/JPH03116908A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007080940A (en) * | 2005-09-12 | 2007-03-29 | Toshiba Corp | Superconducting coil apparatus |
| WO2019239650A1 (en) * | 2018-06-15 | 2019-12-19 | 株式会社日立製作所 | Superconducting electromagnet device |
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