Patent ID: 6662595
Filing Date: 2003-12-16
Classification: F25J

Abstract:
A process for obtaining a compressed product (22; 336) by low temperature separation of air in a rectification system which has a pressure column (3) and a low pressure column (4), wherein:a. a first flow (50) of compressed and purified feedstock air (1) is cooled in a main heat exchanger system (2; 102a, 102b) and is fed (51, 677) into the pressure column (3), b. at least one fraction (5) from the pressure column (3) is expanded (7) and fed into the low pressure column (4), c. an oxygen-rich fraction (24; 218a) from the low pressure column (4) is liquid-pressurized (25; 220) and delivered (28; 224, 226) to a the mixing column (27), d. a heat exchange medium (66) is fed into the lower area of the mixing column (27) and is brought into countercurrent contact with the oxygen-rich fraction (26; 226), e. a gaseous top product (28) is removed from the upper area of the mixing column (27) and f. a product fraction (19; 218a; 335) is removed from the rectification system, liquid-pressurized (20; 220; 337), vaporized in indirect heat exchange (2, 102b) with the gaseous top product (28) of the mixing column (27) and is withdrawn as the compressed product (22; 336), and g. indirect heat exchange is carried out for vaporization of the liquid-pressurized product fraction (21) in the main heat exchanger system (2; 102a, 102b).