摘要:
介绍了国内某石化公司的煤制氢离子液吸收系统洗涤塔顶部电除雾器连接腔及绝缘子腐蚀并损坏的情况，通过宏观、低倍分析、材质分析、金相检验、电镜分析、XRD分析等理化分析，确定电除雾器腐蚀物为铁及亚铁的硫酸盐化合物，判断腐蚀的起因是由于洗涤塔内酸性气体反窜至电除雾器连接腔及绝缘室，酸性气体在连接腔内40℃环境下形成稀硫酸溶液，黏附烟气中灰尘形成糊状垢物，对连接腔体造成严重腐蚀及污染电除雾器的绝缘子，导致碳钢材质的连接腔在酸性介质条件下发生均匀腐蚀、局部点蚀及绝缘子受污染放电碎裂损坏。根据所得结论，采取有效的改进措施，确保离子液吸收系统设备平稳、安全运行。
关键词: 反窜；碳钢；连接腔；绝缘子；均匀腐蚀；局部点蚀
Abstract: The paper introduces the corrosion and damage of the Electric Demister connecting cavity and insulator at the top of the scrubber in the Coal-to-Hydrogen Ion Liquid Absorption System of a Chinese petrochemical plant. Through analysis in general, low-magnification, material, metallographic examination, electron microscope , XRD and other physicochemical analyses, it is determined that ferric and ferrous sulfates are the corrosive matters of the electric demister and the corrosion is caused by acidic gases from the scrubber backflowing to the electric demister cavity and insulator, which forms a dilute sulfuric acid solution in the chamber at 40 ℃, and turns into a pasty fouling after adsorbing dust in the flue gas. The acidic medium causes uniform corrosion and localized pitting on the carbon steel connection cavity and the insulators are damaged by electric discharge after contamination. Based on such conclusions, effective counter measures are taken to ensure the smooth and safe operation of the ionic liquid absorption system.
Keywords: backflow; carbon steel; connecting cavity; insulator; uniform corrosion; localized pitting
关键词: 反窜；碳钢；连接腔；绝缘子；均匀腐蚀；局部点蚀
Abstract: The paper introduces the corrosion and damage of the Electric Demister connecting cavity and insulator at the top of the scrubber in the Coal-to-Hydrogen Ion Liquid Absorption System of a Chinese petrochemical plant. Through analysis in general, low-magnification, material, metallographic examination, electron microscope , XRD and other physicochemical analyses, it is determined that ferric and ferrous sulfates are the corrosive matters of the electric demister and the corrosion is caused by acidic gases from the scrubber backflowing to the electric demister cavity and insulator, which forms a dilute sulfuric acid solution in the chamber at 40 ℃, and turns into a pasty fouling after adsorbing dust in the flue gas. The acidic medium causes uniform corrosion and localized pitting on the carbon steel connection cavity and the insulators are damaged by electric discharge after contamination. Based on such conclusions, effective counter measures are taken to ensure the smooth and safe operation of the ionic liquid absorption system.
Keywords: backflow; carbon steel; connecting cavity; insulator; uniform corrosion; localized pitting