| 摘要 |
<p>Method of cryogenic rectification uses a plant with a first column (59) with a top condenser operating at a higher pressure than a second column (60) with a bottom reboiler. Feed air (2) at 39-100 psia is supplied to the reboiler and then on to both columns. A second air feed (5) at lower pressure is supplied directly to the first column. Lower purity oxygen is withdrawn from the second column(47) and warmed by heat exchange with both feed air streams. Nitrogen enriched vapour (62) and oxygen enriched liq. (28) are both produced in the first column. The vapour is condensed by indirect heat exchange with the liq. in the top condenser and used as reflux in one or both columns. The now vaporised liq. is passed directly to the second column.</p> |
