Corrosion Potential Evaluation and Materials Selection for Wet Electrostatic Precipitator Applied for SO3 Mist Removal

For Wet Electrostatic Precipitators (WESP) applied for SO₃ mist removal, suitable corrosion resistant alloys were selected in coal fired power plant fueled with high sulfur content coal. As the preliminary study, the corrosion potential of the WESP was examined, because the collecting electrode might be polarized anodically by the electrical discharge; these experiments failed to show accelerated corrosion on the collecting electrode. Alloy selection was based on comparative studies of corrosion resistance against general corrosion, localized corrosion, and SCC. Alloy S32053 was useful when the pH is 0.5 or more; alloys N06022 or N10276 should be used when the pH is less than 0.5.