GB1224760A - Process and apparatus for protecting the anodes of an electrolytic cell against short-circuiting - Google Patents

Abstract

1,224,760. Mercury cathode cells. SOLVAY ET CIE. Oct.11, 1968 [Oct. 31, 1967; Nov.22, 1967], No. 48327/68. Heading C7B. The anode (or group of anodes) of a flowing mercury cathode cell for electrolyzing alkali metal halide solutions is automatically protected against a short-circuit with the mercury cathode by quickly removing it away from the cathode to increase the anode-cathode gap under the impulse of a shortcircuit detector when threatened with short-circuit. The anode(s) 6 may be supported by rods 5 from a Cu bar 7 which moves away from the cathode under tension of springs 15 over the cell cover 2 when released by latches 14 connected via pivoted linkages 12 to a pneumatic cylinder 11 cn the bar, as shown. Alternatively the pneumatic cylinder may directly raise the bar Fig.2. Current may be fed to the bar by a flexible connection 8 which connects to the base-plate (1) of the preceding cell in the series. At least one electrically conducting probe (not shown) may protrude from the anode base, electrically insulated therefrom, e.g. a Ti wire covered with PTFE except at the protruding end which is platinized. The short-circuit detector may comprise a contact voltmeter or ammeter connected between the probe and conducting base-plate. The protection is particularly applicable to Ti, Ta, Zr, Nb metal or alloy anodes coated with a Pt group metal or alloy or its oxide.