GB216103A - A process for the protection of metal parts of plant in conducting communication with the earth through streams of water against the harmful influences of stray currents, and apparatus for carrying out the process - Google Patents

Abstract

216,103. Wurstemberger, F. von. May 14, 1923, [Convention date]. Incrustation and corrosion, preventing. - In order to avoid corrosive effects of stray earth currents, from an earthed electric distribution network, .on the pipes and machine parts in electric power stations, the metal part to be protected is made cathodic by diverting the stray currents so that the potential of the protected part is somewhat below that of the adjacent metal parts and the earth or water, without attaining the potential of the return pole of the source. In this way the, corrosive action is diverted from the protected part to other parts of the mass of the plant. In an arrangement for a traction system, the condenser 10, Fig. 2, to be protected is insulated from the metallic masses M by a coat of oil colour, or by insulating washers 30, between the connected parts, and is electrically connected through a regulating resistance 31 with the return pole of the generator. In consequence, the condenser 10 instead of being anodic is rendered cathodic relative to the water 33, and corrosive action is avoided. The dotted lines indicate the directions of the stray earth currents which, by the arrangement described, become reversed through the condenser. In a modification, the anode current from the mass M is diverted to a seperate anode arranged in the stream of water and the corrosive action is confined to this anode.