| 摘要 |
1,044,889. Cold separation of gas mixtures. LINDE A.G. Aug. 17, 1964 [Aug. 17, 1963], No. 33483/64. Heading F4P. Revaporization of condensible impurities, e.g. water and carbon dioxide, deposited within the crude gas paths 10, 15 of switchable heat exchangers 9, 13 of the tube or plate type having counterflowing product cold gas chambers 12a, 12b is effected under partial vacuum'of 0.05 to 0.5 atmosphere produced by a pump 16 connected to whichever crude gas path 10, 15 is being de-frosted; the flow in chambers 12a, 12b being combined to produce gas which is thereby discharged through a line 14 free of re-vaporized condensible impurities, and the heat capacity of the exchangers is such that the heat of condensation and the cold of vaporization can be stored. Re-vaporization under vacuum is assisted by a reverse flow of a rinsing gas, e.g. cold nitrogen, in quantity between one and three times the quantity given by the product of the pressure of the rinsing gas and the quantity of crude gas divided by the pressure of the crude gas. As shown, the crude gas comprises compressed air which after traversing switchable absorbers 20, 21 is fed to the on stream exchanger in countercurrent flow with cold oxygen gas, and the so-cooled air free of carbon dioxide and water is paired by cold purified air leaving switchable nitrogen regenerators 3, 7 and the whole of the compressed air is fed through a line 4 to a rectification column (not shown). The process may serve to produce crude ethylene from coke oven gas.
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