| 摘要 |
A gaseous feed of oxygen containing both light and heavy impurities is introduced through inlet 50 into a first liquid-vapour contact column 10 thereby producing a first fraction having an enhanced concentration of heavy impurities and a second fraction having a reduced concentration of heavy impurities. A gaseous first stream of the second fraction is condensed in a condenser 54 and returned to the column 10 as reflux through inlet 56. A second stream of the second fraction is fed into a second liquid-vapour contact column 12 having a reboiler 64 in which light impurities are stripped from the feed by ascending vapour. The second stream is introduced into the column 12 at a level above which there are liquid-vapour contact surfaces whereby there is produced at the top of the column 12 a fraction having a substantially greater concentration of light impurities than the feed to that column. A portion of this fraction is condensed in condenser 66 and used to provide reflux for the column 12, while another such portion is subjected to further fractionation in columns 2 and 8 to produce an argon product. |
