| 摘要 |
<p>PURPOSE:To reduce evaporation loss of expensive low temperature liquid at initial filling, by providing heat transmission members in inner and outer storage tanks while encapsulating gas having lower boiling point than the temperature of storage liquid in inner tank in a bellows between said tanks. CONSTITUTION:A radiation shielding board 12 to be arranged adjacent to a low temperature storage tank 13 is formed with a vacuum insulating section 14 against the inner tank 11 while a gas encapsulating section 15 is filled with gas having lower boiling point than the temperature of low temperature liquid in the inner tank 11 and relatively high heat conductivity. In order to block leakage of gas in said section 15 to vacuum insulating section 14 and to absorb thermal shrinkage between inner tank and radiation shielding board, heat transmission members 16, 16' and bellows 24 are provided. Heat transmission members 16, 16' are made of metal having high heat conductivity, and fixed with interval to contact thermally with inner tank 11 and radiation shielding board 12. Then adsorbent having high adsorption under low temperature is filled in a space 19 provided in the heat transmission member 16 contacting with the inner tank 11. Prior to filling low temperature liquid in the inner tank 11, liquid nitrogen is filled in low temperature storage tank 13 to pre-cool the inner tank 11.</p> |
