| 摘要 |
PROBLEM TO BE SOLVED: To manage a gas phase region of a gas phase type freezing storage container while keeping it at an adequate temperature. SOLUTION: In the gas phase type freezing storage container 1 for freezing and storing frozen storage objects 15 in the gas phase region 14 held at an extremely low temperature by stored liquid nitrogen 12a, a temperature sensor 8 and a liquid level sensor 9 are provided for detecting the temperature of the gas phase region 14 and for detecting the liquid level of a liquid phase region 13, respectively. In a liquid supply pipeline 4 guided from a liquid nitrogen supply pipeline 3 to the liquid phase region 13, a liquid supply valve 6 is provided which is controlled to be open/closed in accordance with the gas phase temperature detected by the temperature sensor 8 and the liquid level detected by the liquid level sensor 9. When the detected gas phase temperature exceeds a set gas phase temperature and the detected liquid level does not reach a set upper limit liquid level H, the liquid supply valve 9 is controlled to be open for bubbling the liquid phase region 13 with the supply of the liquid nitrogen 12, whereby the temperature of the gas phase region 14 is lowered. Then, when the detected liquid level reaches the set upper limit liquid level H, the liquid supply valve 9 is controlled to be closed. COPYRIGHT: (C)2005,JPO&NCIPI
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