| 摘要 |
<p>PURPOSE:To decrease a consumption quantity of pressurizing gas required when a refrigerant is supplied to a shroud, by providing a tank in a position higher than the shroud and connecting the both tank and shroud while providing a liquid level detector in the tank so as to intermittently supply the low temperature liquefied refrigerant to be controlled. CONSTITUTION:A tank 20, being arranged in the upper part of a shroud 2, provides inside a liquid level sensor 7. If an output of the liquid level sensor 7 changes, a selector valve 11 operates to stop the supply of LN2. And then the LN2 in the shroud 2 is continually maintained to a full level because the quantity of the LN2, even if it is consumed, is supplied into the shroud 2 from an inner tank 26. As a result, the LN2 results to be only required to be intermittently fed to the shroud by pressurizing gas, causing a consumption quantity of the pressurizing gas to be decreased.</p> |
