| 摘要 |
PCT No. PCT/JP85/00385 Sec. 371 Date Mar. 12, 1986 Sec. 102(e) Date Mar. 12, 1986 PCT Filed Jul. 8, 1985 PCT Pub. No. WO86/00693 PCT Pub. Date Jan. 30, 1986.There is disclosed high-purity nitrogen gas production equipment for production of ultra-high-purity nitrogen gas for use in the electronics and other industries, for example in connection with the production of silicon semiconductors. The conventional nitrogen gas production equipment of cryogenic air separation type tends to develop troubles and yields product nitrogen gas only at high cost and in comparatively low purity. The equipment according to the invention is such that a liquid nitrogen storage means (23) is connected via a first feeding pipeline (24a) to a distillation column (15) into which air is introduced from the outside via an air compression means (9) and heat exchange means (13), (14) while the above storage means (23) is also connected via a second feeding line (24b) to the above heat exchange means (13), (14). In this way, the raw material air is chilled to a cryogenic temperature as a result of absorption of the latent heat of evaporation by liquid nitrogen in the heat exchangers and the cryogenic compressed air is further chilled in the distillation column (15 ) by the heat of evaporation of liquid nitrogen. By taking advantage of the difference in boiling point, the nitrogen is withdrawn in gaseous state while oxygen is retained in liquid state. The resulting nitrogen gas is combined with the vaporized liquid nitrogen originating from the liquid nitrogen storage tank (23) to give product nitrogen gas. By these features, low-cost, high-purity nitrogen gas can be produced without machine troubles. |
