| 摘要 |
<p>Air is compressed in a compressor 2, pre-purified in an unit 4, and cooled in a heat exchanger 6. The resulting flow of air is subjected to a first rectification in a double rectification column 12 so as to separate the air into an oxygen-rich fraction and a nitrogen-rich fraction. A further oxygen fraction, enriched in argon, is withdrawn from the double rectification column 12 and is introduced into the bottom of a second rectification column 34 in which relatively pure argon is separated from the oxygen. A stream of relatively impure argon is supplied from an independent source to an intermediate region of the second rectification column 34 through an inlet 40. <IMAGE></p> |
