| 摘要 |
<p>A first stream of air is compressed in a main air compressor 2 and a booster compressor 6, is cooled at a first pressure by passage through a main heat exchanger 8. The cooled stream is introduced without further compression into the higher pressure column 18 of a double rectification column 16 including in addition to the column 16 a lower pressure column 20 and a condenser-reboiler 22. A second stream of compressed air is expanded from a second pressure in an expansion turbine 40 with the performance of external work. The expanded second stream of air is introduced into the lower pressure column 20. An oxygen product, typically impure, is taken from the bottom region of the lower pressure column. The second pressure is less than the first pressure column. The second pressure is less than the first pressure, the second air stream being taken from intermediate the compressors 2 and 6. <IMAGE></p> |
