GB1062297A - Improvements in or relating to ion exchange apparatus - Google Patents

Abstract

1,062,297. Countercurrent flow ion exchange process. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Feb. 17, 1966 [Feb. 18, 1965], No. 7088/65. Heading B1J. An ion exchange stage comprises a resincontaining vessel 1, main liquid inlet means 6, product liquid outlet means 9 provided with resin retention means, bypass outlet 10, bypass inlet 11 and liquid overflow outlet 12 having resin retention means 13. In operation, the upward flow of liquid from inlet 6 forms an inverted packed bed 20. Lower region 19 then contains a settling mass of resin in liquid. A flow of liquid and resin is introduced through bypass inlet 11 and the resin settles on to the packed bed. Periodically the flow through inlet 6 is reduced, for example by means of a time switch controlling variable speed pump 7, and the resin falls towards the bottom of vessel 1. A multiple stage apparatus providing a closed cycle for resin flow (Fig. 2, not shown) comprises 3 water-softening stages (100), (200), (300) and 3 resin regeneration stages (400), (500), (600). Flow control means may be provided, for example in stages (300), (600) to ensure a net upward flow of liquid. In the apparatus of Fig. 1, flow control valve 14 is responsive to variations in the pressure differential measured by pitot head 15. In the apparatus of Fig. 3 (not shown), the product liquid outlet pipe (8) passes vertically through the top of the vessel and has a right-angle bend which is above the right angle bend in the liquid overflow pipe (12). The difference in height of the overflow points determines the extent of the net upward flow of liquid.