LAUSR

Abstract Flue gas desulfurization (FGD) technology is now basically compulsory in the fossil power industry under the pressing environmental challenges globally, and the wet type of it particularly prevails thanks to the higher desulfurization efficiency than the dry type. However, the service conditions of wet FGD units are usually so harsh due to corrosivity and erosivity of the flue gases and the limestone slurries, which therefore drives special attention to the reliability of relevant equipment in the units. In this paper, to comprehensively command the degradation extent of one wet FGD unit in service, and especially to identify the causes of the failed components in the absorber, corrosion evaluation and failure analysis was performed on the four process systems of it during the overhaul. Then, by means of field investigation and multiple materials characterization methods, the vulnerable locations and components in the unit were revealed, and the causes of severe degradation and failure of them were clarified. Finally, related mechanisms were discussed in detail and pertinent recommendations were proposed point by point.