| 摘要 |
Recovery of pure nitrogen (I) by low temperature rectification of air, by feeding air into pressure column (A), feeding liquid fraction containing oxygen into low pressure column (B), discharging nitrogen gas above substance exchange section (B1), with (partial) condensation, and taking (I) below (B1). (Part of) cold fluid is passed from a flowing supply system into (B) above (B1) or into upper zone of (A). Recovery of highly pure nitrogen (I) by low temperature separation of air in a rectifier system involves feeding air (1, 3) into a pressure column (4); taking a liquid fraction (11) containing oxygen and feeding this into a low pressure column (5); discharging gaseous nitrogen (18) above a substance exchange section (25) with at least one theoretical or practical plate; (partly) condensing this in a head condenser (17) by indirect heat exchange with a refrigerant (13); and taking (I) (26, 27, 30) from the low pressure column (5) below the substance exchange section (25). The novelty is that the process uses a refrigerant supply system with flowing cold fluid (II) (31, 32, 34; 38) and at least part of (II) is passed from the supply system into the low pressure column (5) above the substance exchange system (25) or into the upper zone of the pressure column (4). An Independent claim is also included for the apparatus used.
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