GB955662A - Improvements in or relating to apparatus for electrolysis - Google Patents

Abstract

<PICT:0955662/C3/1> <PICT:0955662/C3/2> A cooling member for cooling an electrolyte during electrolysis, e.g in the manufacture of persulphate solutions from which hydrogen peroxide can be produced, comprises a hollow body through which cooling liquid can be passed, at least the major part of the external surface of which is of titanium or tantalum and which can be anodically polarized to produce a corrosion resistant and electrically non-conductive surface film. An electrolysis anode may be provided on the cooling member by securing an electrically conducting metal element in metal to metal contact with the Ti or Ta. Fig. 1 shows a cooling tube 1 of titanium with a lead 2 spot welded to it passing through an electrolyte cell 5. The tube may be in the form of a U or spiral. Another tube, Fig. 2 (not shown), has a platinum wire anode helically wound around and spot welded on it or secured by strips of titanium or plastic. The tube may be helically grooved to receive the wire, Fig. 3 (not shown). Anodes in the form of rings and longitudinal strips on the tube are also described, Fig. 4 (not shown). In a further embodiment the tube may be of copper and have a titanium sheath, Fig. 5 (not shown). Fig. 6 shows a cooling member comprising annular tubes 12, 28, 27 forming passages therebetween for cooling liquid, the tubes 27, 28 being secured to a flanged ring 16. The tube 12 is of copper and has a titanium sheath 13 and the tubes 27, 28 and the ring 16 are of polyethylene. Cooling liquid enters the member by a tube 33, flows through a chamber 25 and through an opening 129 into a chamber 26. As it flows upwardly through the chamber 26 to an outlet 32, a polyethylene helix 130 causes it to take a spiral path. Electrolyte to be cooled can be fed axially through the cooling member over its inner surface and then directed over its outer surface by means of a surrounding ceramic diaphragm, shown in chain lines, having openings at its top. The cooling member is provided with a brass nut and bolt 35 and 36 which are electrically connected with the titanium sheath through a titanium flange 15. In this way the cooling member can be anodically polarized. A platinum anode comprising a platinum wire can be spirally wound around and spot welded to the titanium sheath. Specification 627,648 is referred to.