| 摘要 |
PURPOSE:To supply the liquid nitrogen accurately without using any other drives in a small space with minimizing the size with dispensing with thermocouple, etc., by opening/closing a rotating liquid nitrogen supply adjustment valve through the pressure detected by a liquid surface sensor. CONSTITUTION:Liquid nitrogen 21 in a liquid nitrogen container 18 is depressed in its surface by gas such as nitrogen which is supplied from a nitrogen cylinder, etc. though an inlet 17, and is pressing down rotating blades 12 of rotating liquid nitrogen supply adjustment valve 8 through pipes 19, 14. On the other hand, in a liquid nitrogen cooling reservoir 2, the liquid surface is lowered down due to the evaporation of nitrogen 21, and when the surface becomes lower than a liquid surface sensor 3, the temperature inside the sensor 3 increases and the volume of filled gas 4 is enlarged. Then a bellows 9 extends, and a lock of stopper 11 preventing the rotation of cam 13 is removed. Therefore, the blades 12 begin to rotate, and the valve 8 opens, and the nitrogen is automatically supplied to the reservoir 2. And when the liquid surface becomes higher, the bellows 9 drives the stopper 11 and locks and stops the rotation of blade 12. Thus, a constant level of liquid surface can be maintained. |
