| 摘要 |
<p>Nitrogen is purified by rectifying cooled compressed purified feed air (10) in a column (12) to give O-rich bottoms liquid (28) and a high-purity N-rich overhead (14) which is condensed with part (22) used as column reflux and part as a product stream (23). A recycle stream is compressed, cooled and returned to the column, and a refrigerant stream (44) is expanded (42) with performance of work and indirectly heat-exchanged with the feed air and recycle streams, the work being used in recycle stream compression. A secondary refrigerant stream (48) is vaporised in condensing the overhead, and indirectly heat-exchanged with the feed air and recycle streams before reliquefying. A nitrogen generator is also claimed.</p> |
