| 摘要 |
A, filtered, compressed and purified air stream is divided into first and second air streams 18 and 20 respectively. The first air stream is separated by a low temperature rectification process operating in accordance with a Claude cycle to produce liquid oxygen in a lower pressure column 28 of a double column air separation unit. A Claude expander 24 expands at least a major portion of the first air stream into the high pressure column 28. The second air stream 20 is further compressed in a booster-compressor 60, is cooled in a main heat exchanger 20 and is expanded in a turboexpander 64 with the performance of work which is in turn applied to the work of compression of the second air stream. Liquid oxygen is pumped by pump 72 from a lower pressure column 36 to substantially a desired delivery pressure and is vaporized within a mixing column 68 by countercurrent contact the second air stream 20 which is also introduced into the mixing column. A liquid stream composed of the liquid produced in the mixing column is introduced into an intermediate location of a lower pressure column 36 to add the refrigeration of the second air stream to the process. <MATH> |
