Abstract
Impressed current cathodic protection using uniformly distributed ribbon anodes has proved to be effective in controlling the corrosion of soil-side aboveground storage tank bottoms. Parallel and concentric ribbon anodes are two of the most common patterns of laying anode beds some distance underneath tank bottoms. At the design stage, rule-of-thumb approach and historical data are employed to determine the spacing between ribbon nodes. Computer-aided finite element analysis is potentially also available to assist in determining anode distributions. However, because of its complexity, this approach is not frequently used in practice. In this work, we address the design issue by taking a simplified approach based only on the geometries and the cathodic protection current requirement. The derived enable the determination (using a pocket calculator) of the number of concentric or parallel anodes, the spacing between them, and the anode bed resistances. Support of the derived resistance is established by comparing them with the well-known expressions for symmetrical geometries.
