GB869414A - Improvements in or relating to apparatus for the production of heavy water - Google Patents

Abstract

<PICT:0869414/III/1> Apparatus for thee production of heavy water comprises a dual-temperature H2-H2O D-exchange plant for producing a D-enriched product, which comprises a combination of a single exchange tower 12 consisting of alternate water-water vapour countercurrent contacting sections 13 and low temperature, e.g. 90 DEG C. vapour phase H2-H2O D-exchange catalyst beds 14, and a plurality of high temperature, e.g. 600 DEG C. H2-steam D-exchange catalyst beds 16 and H2O-steam countercurrent contacting columns 15 so arranged that water passes through the contacting columns, while H2 and water vapour pass alternately through the contacting columns and the catalyst beds. Water enters the "Trail" column 12 at 11 and flows down countercurrent to H2 and steam The D-enriched water flows through contacting columns 15, 15a, 15b and is withdrawn at 18b and transfers D to the H2 and steam which passes in countercurrent up columns 15 and catalyst beds 16 with associated heat exchangers 17. The D-poor H2 from the top of the "Trail" tower is recycled through 19. D-enriched H2 may be withdrawn through 20 and condenser 21, from which water is returned through 22, to distillation apparatus 23 as in Specification 869,413, whence the D-rich fraction at 27 is converted to heavy water. The D-poor fraction passes through rehumidifier 24, through which water is circulated by pump 26, catalyst beds 16a, 16b with associated heat exchangers 17a, 17b, and contacting columns 15a, 15b. Alternatively, the water may pass to waste at 18, and fresh water be supplied to columns 15a, 15b at 11a, 11b. In a simpler apparatus (Fig. 1, not shown) the distillation is eliminated, and D-enriched H2 or H2O may be withdrawn below the "Trail" column.