| 摘要 |
870,277. Preventing corrosion. METAL & PIPELINE ENDURANCE Ltd. Feb. 25, 1959 [Feb. 25, 1958; May 16, 1958], Nos. 6101/58 and 15852/58. Class 123(1) [Also in Group XXXVI] An impressed current cathodic protection anode consists of a hemispherical body 10 of lead or of lead alloyed with from 1 to 10% of silver and/or 16% of antimony in which is embedded a number of rods of graphite or wires 12 of a platinum group metal such as platinum, iridium or rhodium or such metals alloyed with one another or with silver, gold, palladium or a base metal such as copper. The rods or wires 12 protrude into depressions 11 formed on the body 10 so that, in use, they are in contact with the electrolyte, for example, sea-water. The effect of the platinum or graphite electrodes is to render the lead passive and free from disintegration by causing the formation thereon of an adherent, conductive coating of lead peroxide. In modifications, a platinum alloy wire is welded to the bottom of each depression 11 or the platinum alloy may be in the form of sheets or strips which are either welded or pinned to the lead body. In a further modification the rods of graphite may be replaced by powdered graphite which is distributed uniformly throughout the mass of the lead body. The base of the anode is encircled by an insulating sleeve 13. |
