| abstract |
The method and the device are used to obtain highly pure oxygen from less pure oxygen in a distillation system which has a high-pressure column (2) and a low-pressure column (3). A feed fraction (1) made from less pure oxygen is introduced into the high pressure column (2). A pre-cleaned oxygen fraction (8, 9, 11) from the high pressure column (2) is introduced into the low pressure column (3). A highly pure oxygen product (16, 214, 242, 599, 600, 601) is drawn off from the low pressure column (3). Furthermore, a first stream (106, 460) of a heat transfer fluid in a high-pressure column sump evaporator (4) is at least partially condensed by indirect heat exchange with an evaporating liquid from the high-pressure column (2), then at least partially expanded (109) and in one Low-pressure column head condenser (6) is at least partially evaporated by indirect heat exchange with a condensing gas from the low-pressure column (3). The heat transfer fluid (107) is cooled downstream of the high-pressure column bottom evaporator (4) and upstream of the expansion (109) in a supercooling heat exchanger (105) by indirect heat exchange. |