| 摘要 |
<p>866,577. Preventing corrosion. STURTEVANT ENGINEERING CO. Ltd. Jan. 20, 1960 [Jan. 20, 1959], No. 2082/59. Class 123(1) An impressed current anode assembly for the cathodic protection of liquid-containing metal vessels, especially the tanks of oil tanker ships carrying sea water ballast, consists of a rod 1 of titanium, tantalum or other metal on which an anodic film is formed covered at its mid-portion with a layer 5 of platinum or other metal not affected by the electrolyte and forming the anode proper. The rod 1 passes through an insulating bushing 2 in the tank roof and is connected to a source of direct current. The lower end of the rod terminates a short distance from the tank bottom and is held in an insulating block 3. In operation, the anodic film on the rod prevents flow of current therefrom into the sea water electrolyte. When oil is fed into the tank any electro-static charge carried by the oil in the vicinity of the rod 1 discharges through the film which is conductive with respect to electrostatic potentials. Consequently, when the level of the incoming oil reaches the anode 5 no discharge spark occurs.</p> |
