GB1363757A - Process and apparatus for concentrating isotopes by the simultaneous exchange of heat and mass - Google Patents

Abstract

1363757 Enriching with deuterium V R THAYER 30 Oct 1971 50540/71 Heading C1A In concentrating an isotope, e.g. deuterium, of an element by exchange between physically separable feed fluid and circulating fluid, an exchange vessel having a hot zone and a cold zone is used and the vessel contains at least one conduit which traverses the hot zone and feed fluid is passed through the vessel over the exterior of the conduit, circulating fluid is passed countercurrent to the feed fluid through the vessel over the exterior of the conduit and after passing through the vessel at least one of said fluids is passed through the conduit and at least one of said fluids is withdrawn from a selected point in the vessel, at which point the fluid contains the maximum concentration of isotope. In the embodiment shown in Fig. 1, the fluids are the physically separable liquids water and ethyl mercaptan. Water is introduced into the top of the tower 10 via inlet 16 and flows countercurrently to ethyl mercaptan introduced at the bottom of the tower via inlet 22. The mercaptan leaves the tower via line 12 and is returned down the tower via coil 12a thereby exchanging heat with materials flowing over it. The mercaptan recycles via line 12b. The water leaves the tower by line 13 and passes to steam stripper 11 which removes the mercaptan content of the water which is returned to the tower via line 57. The stripped water leaves via line 14 and after yielding its heat content to the contents of the tower by passing through coil 14b passes to waste. Product of increased deuterium content is withdrawn via line 28 from the centre of the tower and the heat requirements of the exchange process are balanced by means of the cooling coil 17b and the steam coil 26 of the steam stripper. In Fig. 2 an embodiment using liquid water and gaseous H2S is shown. The waterfeed enters tower 100 by line 106, and passes down it countercurrent to a stream of H2S cycling via line 109 from the top to the base of the tower. Water leaving the tower by line 101 is recycled to coil 101b where it acts in heat exchange in section 140 of the tower with the material moving past it. The water leaves the coil by spray 150 falling on to perforated plate 110. Part of the water is withdrawn from the plate via line 102 to steam stripper 120, when the H2S stripped therefrom is returned to section 140 via line 109, and the water heated by steam coil 26 is fed through coil 103b in section 142 of tower 100 and then to waste. The H2S entering via 105 is humidified and heated in section 142 before passing through plate 110. The available heat in section 142 is fed to section 140 by recycling water via line 130 to coil 101b. The heat balance of the process is maintained by steam coil 26 and cooling coil 121b and product of enriched deuterium content is withdrawn via line 160.