| 摘要 |
<p>A fractionated distillation process to extract nitrogen from air uses a pressure column and a low-pressure column. Liquid nitrogen is drawn from the low-pressure column or the head condenser and released into the pressure column, and residual gas from the evaporating fluid is released from the head condenser and allowed to expand, yielding energy. A fractionated distillation process to extract nitrogen from air uses a pressure column (4) and a low-pressure column (5). A supply of air (1, 3) is introduced to the pressure column (4). An oxygen-rich liquid fraction (8, 10) is drawn from the pressure column (4) and released into the low-pressure column (5). Gaseous nitrogen (23) is released from the low-pressure column (5) to a head condenser (7) where it is in indirect contact with an evaporating fluid (20), and is at least partially condensed. Liquid nitrogen (24, 26, 28, 29, 19) is drawn from the low-pressure column (5) or the head condenser and released into the pressure column (4). Especially, residual gas (22, 31, 32, 33) from the evaporating fluid (20) is released from the head condenser and allowed to expand (34), yielding energy.</p> |
