GB434542A - Improved electrolytic apparatus - Google Patents

Abstract

434,542. Electrolytic cells. FRANKLIN, H. B., 72, Ladbroke Grove, Notting Hill, London. March 22, 1934, No. 8998. [Class 41] Upward circulation of electrolyte through a series of superimposed cells is provided by means of narrow tubes 6 extending from the liquid level of one cell into the gas space of the cell above. Liquid is supplied to the lowest cell from a reservoir 7 and is drawn upwards through the tubes 6 by the generated gases in a succession of drops, being restored to the reservoir 7 by a tube 8 from which the gas escapes to the atmosphere. The cells may be formed in a single casing 1 separated by partitions 2 through which pass the tubes 6 and bipolar electrodes 5 of carbon or platinum. The tubes 6 are in staggered arrangement. By using electrodes of platinum and tantalum respectively in one or more of the cells, an alternating current supply may be used without external rectification. In the modification shown in Fig. 2, each connecting passage 6 is formed in an L-shaped extension 2<a> of the partition which is housed in a gasspace formed by a channel 2<b> on the underside of the partition above. The apparatus is suitable for the production of hypochlorites, chlorates and bromates. In a modified apparatus suitable for the production of iodine, bromine and per-salts, the communication between cells is provided by a cylindrical vessel 11, Fig. 3, mounted on a partition 2 below which it is tapered into a narrow neck 11<b>. From the vessel 11 there also depends a cylinder 12 enclosing the vessel 11 of the next lower cell. One electrode pole 5a is located within the vessel 11 and the other pole 5<b> in the space between the cylinder 12 and the casing 1, the connection passing through an aperture 13 in the cylinder 12. The electrolytic product in the inner compartment is circulated upwardly by the gases, while that in the outer compartment remains therein. In the apparatus shown in Fig. 4, the cells are formed by recesses 16 in insulating blocks 15 which are placed together with a diaphragm between. The partitions between the cells are dished to form a gas-space 16<b> into which liquid and gas are discharged from the cell below by a duct 17, the lower end of the duct dipping slightly from the liquid level to promote formation of gas locks. The diaphragm may consist of an asbestos or filter cloth sheet or of such material mounted at appropriate points in a sheet of rubber. It preferably, however, consists of a solid plate 18 having cavities 19 in which sand, glass-wool, asbestos or the like is mounted between perforated walls. Each electrode is connected to the electrode of opposite polarity in the cell above or below by a wire passing through the side walls of the diaphragm support. The electrodes may consist of platinum wire or of graphite members with platinum wire connections.