| 摘要 |
<p>PURPOSE:To save waste owing to discharge of liquid nitrogen and reduce cost and installation areas by sending vaporized gas into adsorption barrels to lower the pressure therein and make the impurities having been adsorbed releasable and installing a plurality of adsorption barrels within one heat-insulating layer. CONSTITUTION:The heat exchanger 2 formed by the 1st-3rd heat exchangers 2a thru 2c is provided in a hermetic type heat-insulating vessel 1. Next, liquid nitrogen (LN2) is put up to about half the level in the vessel 1 and the helium gas containing unrefined air is cooled with the heat exchangers 2a-2c through feed pipe 3 and is then to a mist separator 4. The pipe 11 of the auxiliary heat exchanger 10 provided at its bottom end with the orifice 9 with filter opening near the bottom of the vessel 1 is passed through the heat exchanger 2 and is connected to a vacuum pump 12. Further, the separator 4 communicates to the adsorption barrels 7, 7'. Thus, the waste through releasing of liquid nitrogen is saved and the cost and installation areas are reduced.</p> |
