Investigation of the Cathodic Protection Potential Distribution on the Exterior of Steel Tank Bottoms

In this study, a 3-D mathematical model considering the medium nonuniformity was established to determine the cathodic protection potential distribution on the exterior of steel tank bottom. Totally six anode placement methods practically used in industry were investigated, including vertical anodes around tank bottom, horizontal anodes under tank bottom, deep-well anodes, inclined well anodes, tape anodes and net anodes. For each method, various influential factors, such as soil resistivity, bitumen sand base, setting parameters of anodes, tank bottom diameter, surface condition of tank bottom metal, properties of medium contacting with tank bottom, oxygen concentration distribution, were also studied and compared. The present results are of practical value in determining the reasonable cathodic protection system parameters and buried position of the anodes.