| 摘要 |
PURPOSE:To obtain N2 having high purity economically by introducing N2 having low purity contg. O2 or Ar into an adsorber at a specified low temp. and removing O2 and Ar by adsorption and liberating the adsorbed O2 and Ar together with desorbed gas. CONSTITUTION:Low purity N2 contg. 99.999-99.9999% N2 contg. a trace amt. of O2 and Ar, separated from a top of a fractionating column 1 is introduced into an adsorber 4 or 5 packed with A-type zeolite at -100--200 deg.C. And, for example, high purity N2 having >=99.9999% purity which has been freed of O2 and Ar by passing through an adsorbent in the adsorber 4 is discharged through a pipe 203, changeover valve 11, and a pipe 204. On the other hand, low purity N2 is introduced into the adsorber 5 before the adsorbent in the adsorber 4 is saturated with O2 and Ar to proceed removal by adsorption of O2 and Ar similarly as described above. Further, O2 and Ar adsorbed in the adsorber 4 is desorbed by the external dry N2, etc. at room temp. to regenerate the adsorbent. In the above-described low temp. region, the amt. of O2 and Ar to be adsorbed is much, and the amt. of N2 to be adsorbed is extremely little.
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