| 摘要 |
1,182,615. Gas mixture separation process. R. STOKLOSINSKI. 1 June, 1967, No. 25441/67. Heading F4P. A binary gas mixture e.g., air rectification column 24 has at least two superposed reboilers 26, 27 heated respectively by a portion of the air feed and by at least a portion of nitrogen effluent fraction, and the column also has at least two superposed condensers 28, 29 located above the highest reboiler 27 and at least one of which condensers is cooled by at least a portion of the liquid oxygen bottoms fraction. In operation feed air at just above atmospheric pressure having been freed of water vapour and carbon dioxide at 20 and cooled to dew point in an exchanger 22 is fed to about the mid-point of the column 24. Nitrogen effluent having been warmed in exchanger 22 is in part directed through purifiers 20 and in part to a compressor 30 by which it is forced through exchanger 22 and the reboiler 27 where it is liquefied after which it is expanded at a valve 34 and returned to the column as reflux. Air for heating reboiler 26 is withdrawn from the feed stream at the warm end of exchanger 22, compressed at 32, cooled in exchanger 22 and after being liquefied in said reboiler 26 is expanded at 36 and fed to the column as reflux. As shown both condensers 28, 29 are cooled by liquid oxygen bottoms expanded at valves 42, 40 and the resulting oxygen vapour having been warmed in exchanger 22 is compressed at 31 and discharged as product. Build-up of impurities in the boiling oxygen in condensers .'28, 29 is avoided by withdrawing a portion thereof : by a pump 44, purifying at 46 and returning -to the condensers. |
