Method and apparatus for the production of a printed product by low-temperature fractionation of air

The method and device are used for the production of a printed product (22; 336) by low-temperature fractionation of air in a Retifiziersystem which has a pressure column (3) and a low pressure column (4). A first stream (50) compressed and greinigter feed air (1) in a main heat exchanger system (2; 102a, 102b), and dropped into the pressure column (3) is introduced (51, 677). At least one fraction (5) from the pressure column (3) is released (7) and in the low pressure column (4) is fed. An oxygen-rich fraction (24; 218a) from the low pressure column (4) is brought to pressure liquid (25; 220) and a mixing column (27) given (26; 224, 226). A heat carrier (66) is introduced into the lower region of the mixing column (27) and in countercurrent contact with the oxygen-rich fraction (26; 226) accommodated. From the upper region of the mixing column (27) a gaseous overhead product (28) is removed. A product fraction (19; 218a; 335) is removed from the rectification system, fluid brought to pressure (20; 220; 337) in indirect heat exchange (2, 102b) with the gaseous head product (28) of the mixing column (27) evaporates and, as printed product (22; 336) drawn off. The indirect heat exchange to evaporate the liquid pressure put on product fraction (21) in the main heat exchanger system (2; 102a, 102b) is performed.