PRODUCTION OF OXYGEN ENRICHED AIR

摘要

A pressure swing adsorption process is provided for the direct production from ambient air of a moderately enriched oxygen product gas. The production of a product gas having an oxygen concentration of 23 to 30% is effected by a three step cycle wherein (1) the feed air is charged to a bed of nitrogen selective adsorbent until the bed is brought from atmospheric pressure to a pressure in the range of up to 4 atmospheres, (2) reducing the bed pressure to an intermediate level by withdrawal of oxygen enriched product gas therefrom and (3) finally venting the bed to restore atmospheric pressure. By an alternative mode including a fourth step of purging the bed following the venting step, a product of 23 to 45% oxygen concentration is obtained.