| 摘要 |
<p>Air is separated in a double rectification column including a lower pressure rectification column 14. A first oxygen product containing less than 3.5% by volume of argon impurity is withdrawn through an outlet 38 the column 14 which has a packed section 40 below the level of the outlet 38. Argon impurity is striped from liquid descending through the packed section 40 and a second relatively pure oxygen product containing less than 100 volumes per million is withdrawn from below the section 40 through an outlet 44. Impurities less volatile than oxygen are preferably separated from the second oxygen product in a side rectification column 48. <IMAGE></p> |
