摘要 |
900,438. Cold separation of gas mixtures. LINDE'S EISMASCHINEN A.G. GES. FUR. June 10, 1959 [June, 11, 1958], No. 19872/59. Class 8(2). In a gas mixture e.g. air rectification process wherein incoming compressed air is cooled in pairs of nitrogen regenerators 1, 2, Fig. 1, and oxygen regenerators 4, 5 and wherein a portion of the cooled air is reheated by passing it through an additional regenerator e.g. a nitrogen regenerator 3 at least part of said reheated air is cooled in a counter current heat exchanger 15 traversed by cold nitrogen product which is discharged through a line 18 at substantially ambient temperature; the so-cooled portion of the re-heated air being added to the main flow of air entering the column 8 at a point 7 whilst the remainder of the re-heated air is fed to the. low pressure section of the column preferably after expansion in a turbine 12. Regenerators 1, 2 are supplied with slightly impure nitrogen from a point 13 and regenerators 4, 5 are supplied with gaseous oxygen from a point 9; product liquid oxygen being with-drawn through a duct 19. In a modification an additional regenerator 2<SP>1</SP>, Fig. 2, is connected in parallel to regenerator 2, cold air to be re-heated in regenerator 3 is withdrawn from a point 20 at the cold end of regenerator 1, 2 the re-heated air leaving the top of regenerator 3 through a line 22 is cooled in exchanger 15 before combining with that in a line 11 and traversing a gel absorber 24 and a further exchanger 15<SP>1</SP> the exchangers 15, 15<SP>1</SP> being traversed by nitrogen from an auxiliary column 25 interposed between the low and high pressure sections of the column 8. |