| 摘要 |
<p>PCT No. PCT/JP84/00151 Sec. 371 Date May 21, 1985 Sec. 102(e) Date May 21, 1985 PCT Filed Mar. 29, 1984 PCT Pub. No. WO85/04466 PCT Pub. Date Oct. 10, 1985.A producing apparatus of highly pure nitrogen gas which is used in electronic industry for manufacturing silicon semiconductors. Conventional nitrogen gas producing apparatus of low temperature separation method and of PSA method are subjected to troubles frequently, the cost of the obtained product nitrogen gas is high, yet the purity is not very high. By the apparatus of this invention, the liquefied nitrogen storage means (15) is connected to the heat exchangers (13, 14) through the inlet channel (16), the compressed air reaching the heat exchangers (13, 14) through the air compressor (9) and the impurity removing means (12) is cooled down to ultra low temperature by using the evaporation heat of the liquefied nitrogen then is sent into the rectifying column (15), and the nitrogen is taken out in gas form by utilizing the difference in the boiling point and oxygen is left in liquid form. The obtained nitrogen gas is combined with the gassified liquid nitrogen from the liquefied nitrogen storage means (15) and made into product nitrogen gas. Highly pure nitrogen, therefore, can be produced at a low cost and with almost no trouble of the apparatus.</p> |
