摘要 |
In a process in which gas is "humidified", such as by passing it at S, Fig. 2, into a tower F, undergoes a chemical treatment at G, such as a steam/hydrogen process for enrichment of hydrogen in deuterium and is subsequently dehumidified, such as in a tower H before leaving at T, both the humidification and dehumidification processes are each carried out in at least two successive stages so that the operating lines b, c, d and B, C, D, respectively, Fig. 4, on a diagram representing the relationship between the total heat content of the humidified gas and the heat content of the liquid, such as water, which humidifies the gas or is condensed therefrom, more nearly approximate the saturation curve without intersecting it than would a single operating line. The term "humidify" refers <PICT:0881941/III/1> <PICT:0881941/III/2> <PICT:0881941/III/3> to partial or complete saturation of a gas with a vapour of any liquid. The liquid in tower F is circulated by pump K through heater D, or steam may be injected instead of using heater D, and pump L circulates the liquid in tower H through cooler E, pumps M, N, and heat exchangers A, B, C, ensuring heat exchange between the liquid in the bottom of tower F and top of tower H and so on. Alternatively heat exchangers A, B, C, may be omitted and liquid circulated directly between corresponding sections of the towers. In a modification the tower H is omitted and the gas passes from the chemical treatment G to a series of cooler condensers such as A, B, C. In a further embodiment, Fig. 3, ammonia synthesis gas is fed into heat exchangers D, C, B, so that liquid nitrogen, the "humidifying" liquid, is condensed under a pressure of 5-10 atmospheres. After the hydrogen has been enriched in deuterium in process G, and also expanded, it is passed up tower F where the nitrogen is re-evaporated. Reference has been directed by the Comptroller to Specification 815,098. |