| 摘要 |
The extraction of argon and air by fractionated distillation comprises moving compressed and purified air (13) in contra-flow (36, 46) past a flow of product gas, and chilling (9). Part of the flow of compressed and purified air (13) is then released (14) into a pressurised column (18). An oxygen-enriched fraction (26) is released from the pressurised column into a low pressure column (19) and is then further fractionated. A liquid (38) containing oxygen and argon is drawn from the lower section of the low pressure column (19) and is released into an argon column (39), where is fractionated into an argon-rich head gas and an oxygen-rich sump gas. One portion (47) of the vapour ascending the argon column (39) is returned to the lower section of the low pressure column (19). The argon product (42) is drawn off from the argon column (39) from an intermediate point which represents a theoretical or real base point beneath the head of the argon column (39). The argon product (42) is substantially drawn off in liquid form and dispensed to a tank (44). A residual gas (41) containing nitrogen is drawn off from the head of the argon column (39). |
