污水罐腐蚀原因分析及防腐建议

CORROSION ANALYSIS AND ANTICORROSION SUGGESTIONS OF SEWAGE TANK

某公司污水罐罐体出现大面积穿孔,附着大量垢物。罐体为碳钢材质,其防腐形式为环氧底漆+环氧云铁中间漆+环氧煤沥青。分析其原因,介质形成典型的H2S-NH3-HCN-H2O腐蚀环境,而罐体采用的防腐涂料在污水中耐蚀性差,导致腐蚀穿孔。文章建议采取环氧富锌底漆2道,环氧云铁中间漆1道,内衬层采用聚硫橡胶改性环氧树脂玻璃钢4层,聚硫橡胶改性环氧树脂漆4道,并严格控制施工质量,便可较好的控制罐体的腐蚀。

Large corrosion perforation appeared in the sewage tank of certain company and a lot of dirt adhered on it.The tank is made of carbon steel and the anticorrosion solution is epoxy primer+epoxy with micaceous iron oxide pigmen+epoxy coal tar.After analyzing the corrosion reasons,it is found out that the medium is typical H2S-NH3-HCNH2O corrosive environment and the anticorrosion performance of the anticorrosion coating is bad in sewage,resulting in the corrosion perforation.This paper suggests that two layers of epoxy zinc rich primer and one layer of epoxy with micaceous iron oxide pigmen shall be chosen as the coating.The lining layer shall be four layers of thiokol-modified epoxy FRP and four thiokol-modified epoxy resin paint.Meanwhile,the construction quality shall be under strict control.In so doing,the tank corrosion can be controlled effectively.