Anode Arrangement on the Outer Wall of Large Tank Bottom and Potential Distribution

Author of the article:Ma Hanyue, Huang Chunrong, Mu Hua, Shi Daiyan

Author's Workplace：China Petroleum Engineering & Construction Corp. Southwest Company

Key Words：Storage tank; Cathodic protection; Meshed anode; Linear anode; Potential distribution

Abstract：As an important technology to ensure the safe operation of large storage tank, the cathodic protection technology on the outer wall of the large storage tank bottom is attached great importance to engineering application and research.The relationship between auxiliary anode arrangement and potential distribution in the cathodic protection system of large storage tank bottom wall has been summarized so as to guide the formulation of technical scheme, construction, operation, detection and maintenance of the cathodic protection system.By studying the existing scientific research literature at home and abroad and combining the operating conditions of a petrochemical oil storage tank, and through field testing, data processing and result analysis,three layout modes containing meshed anode, linear spiral anode and linear clip anode can meet the cathodic protection criteria.Under the conditions of this study, the potential distribution of meshed anode is more uniform.When the linear anode spiral layout is selected, the potential at the edge should be made more negative, so as to ensure that the central potential meets the requirements of the cathodic protection criteria;When the linear anode paper clip layout is selected, the potential at the starting position of the anode should be adjusted to more negative to ensure that the potential of the anode end and even entire tank bottom meets the requirements of the cathodic protection criteria.