| 摘要 |
<p>A process and apparatus for producing a high purity nitrogen vapour product from the rectification of air within high and low pressure columns 24 and 26 respectively, operatively associated with one another by a condenser-reboiler 28. The high pressure column incorporates a sufficient number of theoretical stages to produce a high purity nitrogen vapour which downstream of being condensed in the condenser-reboiler 28, serves partially to condense in a heat exchanger 42 a lower purity nitrogen fraction produced at the top the low pressure column 26. In such service, the condensed, high purity nitrogen vapour is at least partially vaporized and utilized as a product stream. Since there is intermixing with the high purity nitrogen produced within the high pressure column 24 and the lower purity nitrogen vapour produced in the low pressure column 26, the low pressure column 26 can incorporate fewer theoretical stages and therefore can be built at less expense than similar air separation plants of the prior art. <IMAGE></p> |
