| 摘要 |
939,690. Electrodialysis. P. KOLLSMAN. March 17, 1960, No. 9428/60. Class 41. [Also in Groups XIII and XXIX] A method of controlling the electrical resistivity of bodies of ion exchange material, e.g. membranes 17, 18 or fillers, during operation of a multi-membrane electrodialysis cell 11 through which liquids to be treated are passed, comprising extracting heat from the effluent (ducts 79, 80) and adding heat to the influent (ducts 77, 78), including the heat extracted, the total amount of heat added being less than the difference between that contained by the effluent and that contained by the unheated influent. A pump 53 delivers liquid to be desalted via a unit 13 (see Group XXIX) which controls the pressure of the liquid, a heat exchanger 12 and temperature-actuated mechanisms 14, 15 (see Group XIII), to the ducts 77, 78 which lead respectively to the dilution and concentration chambers D, C of the cell 11. The effluent from each set of chambers leaves via the ducts 79, 80 and traverses the heat exchanger 12, the duct 79 incorporating further mechanisms 14, 15. The mechanisms 15 are bimetallically-operated valves which by-pass liquid through ducts 56, 57 upon a predetermined high temperature being attained. The mechanisms 14 are bimetallically operated heat exchangers which regulate the supply of a heating or cooling fluid through lines 65, 66. Electrolyte is passed successively through end chambers 21, 22 from a supply line 81 to an outlet 83, also traversing the heat exchanger 12. The electrodes 19, 20 are platinum, and the membranes 17, 18 comprise a mixture of 72% by weight ion-exchange resin and 28% polythene which has been pressed, heated and irradiated. In a modification, Fig. 5 (not shown), two cells are connected in series, the diluent from the first cell passing straight through the second before dividing, both portions traversing the heat exchanger but one portion first becoming the concentrate for the second cell. The concentrate from the first cell traverses the heat exchanger as in Fig. 1. Details of cell operation are given, including flow rates, temperatures (e.g. 70‹ C. to 110‹ C.), voltages and amperages (e.g. 1.0 to 2.5). In one test, the apparatus was operated under a pressure of 30 1b. per square inch. Specification 796,149 is referred to. |
