GB1267993A - Improvements in or relating to electrodes - Google Patents

Abstract

1,267,993. Direct connections. MARSTON EXCELSIOR Ltd. 8 April, 1970 [28 April, 1969], No. 21583/69. Heading H2E. [Also in Division C7] An electrode assembly, for the chloro-alkali electrolysis of brine in a mercury cathode cell, comprises a conductive metal boss 27 friction welded to a film-forming metal electrode body 26, a conductive metal current feeder 33 in removable electrical contact with the boss, and means clamping the feeder in such contact and isolating the boss and feeder from any corrosive attack. Such means may comprise a ring 28 with screw-threaded periphery 29 affixed to the body 26 around the boss, a tube 37 and tubular body 35 surrounding the feeder, and an annular clamping nut 38 in threaded engagement with the ring, all of film-forming metal. A pair of sealing O-rings 32 may be mounted in annular channels 31 on the internal surface 30 of the ring. The surfaces 47, 48 of the feeder 33 and boss 27 may be frusto-conical to reduce electrical resistance of the joint formed. The clamping nut 38 may be omitted, and a screwthreaded connection provided between the ring affixed to the electrode body and the tubular body of the tube surrounding the feeder (Fig. 1), with the sealing ring replaced by a tape of unsintered P.T.F.E. Alternatively (Fig. 4), the current feeder (61) may be screwed on to a threaded stud (53) friction welded to the body (50) within the boss (52) to clamp it in electrical contact with the boss, with a ceramic or plastic tube (56) seated on a rubber washer (54) surrounding the boss and secured at its upper end by a clamping ring (57) screwed on to the feeder. The conductive metal is selected from Cu, Al, Ag or Al coated with Ag or Sn. The film-forming metal is selected from Ti, Nb, Ta, or alloys thereof, e.g. Ti-0À15% Pd; the electrode body may be provided with a coating of Pt group metal or alloy or oxide thereof.