| 摘要 |
PURPOSE:To transfer liquid nitrogen of a proper quantity of an ultra-low temperature device by liquefying nitrogen gas supplied from a nitrogen gas feeding device by a liquefying device, and storing it in a liquid nitrogen container, when liquid nitrogen is automatically supplied in an ultra-low temperature device such as an ultra-electromagnet in which liquid nitrogen is used. CONSTITUTION:Nitrogen gas supplied from a nitrogen gas feeding device 1 is cooled to an ultra-low temperature and liquefied by a nitrogen gas liquefying device consisting of an ultra-low temperature refrigerator 3, a cooling water feeding device 4, and a liquefying device 6, and liquefied liquid nitrogen is stored in a liquid nitrogen container 7. A leak valve 9 for leaking liquid nitrogen by a prescribed flow amount in the atmosphere is provided in the liquid nitrogen container 7 for storing liquid nitrogen stably. A shut out valve 13 is interposed in a liquid nitrogen transfer pipe 12 for connecting the liquid nitrogen container 7 and the ultra-low temperature device 11 to each other. When the rest amount of liquid nitrogen in the ultra-low temperature device 11 is reduced beyond a prescribed amount, the leak valve is closed, and also the shut-out valve 13 is opened, so that liquid nitrogen may be transferred to the ultra-low temperature device 11 automatically. |
