| 摘要 |
Oxygen and nitrogen are produced by the fractionated cryogenic distillation of air in a three-column process having a first pressurized column, a secondary column and a low-pressure column. Oxygen and nitrogen are produced by the fractionated cryogenic distillation of air in a three-column process having a first pressurized column (7), a secondary column (8) and a low-pressure column (9). Pressurized nitrogen (55, 56, 57, 266, 267) is drawn from the upper part of the pressurized column (7) and/or from the upper part of the secondary column (8). The nitrogen pressure is used to increase the fluid pressure in subsequent fractions (53, 253, 258, 450). The first is a nitrogen-enriched liquid fraction (50, 266) down-stream from the first condenser-evaporator (11). The second is a nitrogen-enriched liquid fraction (51, 52) down-stream from the second condenser-evaporator (22). The third is an oxygen-enriched liquid fraction (30) down-stream from the first condenser-evaporator (11). The second part (37) of the first oxygen-enriched fraction upstream from the second condenser-evaporator (22).
|
