US 12,125,635 B2
Superconducting electromagnet
Naoki Iwamoto, Tokyo (JP); Tomonori Tanaka, Tokyo (JP); and Tatsuya Inoue, Tokyo (JP)
Assigned to CANON MEDICAL SYSTEMS CORPORATION, Tochigi (JP)
Appl. No. 17/608,151
Filed by Canon Medical Systems Corporation, Tochigi (JP)
PCT Filed Jul. 10, 2019, PCT No. PCT/JP2019/027271
§ 371(c)(1), (2) Date Nov. 2, 2021,
PCT Pub. No. WO2021/005732, PCT Pub. Date Jan. 14, 2021.
Prior Publication US 2022/0293317 A1, Sep. 15, 2022
Int. Cl. H01F 6/04 (2006.01); G05D 7/01 (2006.01); H01F 6/06 (2006.01)
CPC H01F 6/04 (2013.01) [G05D 7/0133 (2013.01); H01F 6/06 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A superconducting electromagnet comprising:
an inner vessel containing a superconducting coil and liquid coolant to cool the superconducting coil;
an outer vessel thermally insulated from the inner vessel and holding the inner vessel in the outer vessel;
a discharge pipe to discharge, to an outside of the outer vessel, coolant gas generated by evaporation of the liquid coolant in the inner vessel; and
a first spring check valve, a second spring check valve, and a third spring check valve that are disposed in the discharge pipe, wherein
the discharge pipe includes a first split-flow pipe and a second split-flow pipe that are connected in parallel to each other, wherein the second split-flow pipe is larger in diameter than the first split-flow pipe,
a part of the second split-flow pipe is branched into at least a first branch pipe and a second branch pipe,
the first spring check valve is disposed in the first split-flow pipe to open when a pressure difference between an upstream side and a downstream side of the first spring check valve in the first split-flow pipe becomes more than or equal to a first set pressure higher than atmospheric pressure,
the second spring check valve is disposed in the first branch pipe to open when a pressure difference between an upstream side and a downstream side of the second spring check valve in the first branch pipe becomes more than or equal to a second set pressure higher than the first set pressure,
the third spring check valve is disposed in the second branch pipe to open when a pressure difference between an upstream side and a downstream side of the third spring check valve in the second branch pipe becomes more than or equal to a third set pressure higher than the first set pressure, and
the second branch pipe is different from the first branch pipe in terms of at least one of diameter, length, and inner volume.