GB1048987A - Electrochemical cell - Google Patents

Abstract

An electrolytic cell, suitable for producing tetraalkyl lead compounds using lead particles as anode and a solvent solution of an organic magnesium compound as electrolyte, comprises a hollow main shell 1 having end plates 5, 6 with aligned apertures, tubular electrode assemblies 8 supported in the apertures within the main shell, each electrode assembly comprising a cathode and consumable particulate metal serving as anode, hollow end closure members 3, 4 at opposite ends of the main shell, means connecting the cathodes to a source of negative potential through the main shell as at 44, 45 and means connecting the anode material to a source of positive potential through one of the end closure members as at 46 on member 4. Preferably a second shell 2 is desposed between the main shell 1 and the upper closure member 3 and has steel tubes 19 aligned with the electrode assemblies 8 supported between apertured plates 16, 17, and supporting tubular diaphragm structures 48 which extend throughout each assembly 8 to insulate the steel cathode surface 47 from the particulate anode material, the main shell, second shell and end closure members being electrically isolated from each other by gaskets 32, 33, 40, 41. Electrolyte is supplied through inlet 28 and particulate anode material is supplied through inlet 27 in the upper closure member 3, electrolyte containing product being removed at 36a and anode material being removed via outlet 36f, the anode particles filling the spaces within the lower closure member 4 and the tubular diaphragms within the assemblies 8 and part of the upper closure member 3. Heat exchange fluid is fed into the main shell at 11 and circulates around the electrode assemblies 8 prior to removal at 12, 13. Inlet and outlet pipes 20, 21 allow similar passage of heat exchange fluid through shell 2 or removal of condensation. The diaphragm structures are made of woven filaments of glass, nylon, polythene, polypropylene or PTFE or of regular arrays of overlying filaments of the thermoplastic insulating polymers welded together at their intersections. With woven materials as the waffle weave material 50, a reinforcing wire cage may be provided comprising vertical rods 58 and interwoven transverse wires 59 and a spiral coil 52 of metal plastic or other rigid material inert to the electrolyte. Preferably the diaphragm is formed by two tubular insulating materials an inner tube 66 of plain orthogonally woven filaments as of glass, nylon or polypropylene, which may be a double turn with an overlap and an outer tube having little vertical flexibility formed by obliquely overlapping filaments of polypropylene welded together at their intersections as in Specification 1,048,988. The fabrics of both diaphragms may be coated with an epoxy resin. <PICT:1048987/C6-C7/1> <PICT:1048987/C6-C7/2> <PICT:1048987/C6-C7/3>