POSM装置洗涤塔塔盘腐蚀失效分析及维护建议

Corrosion Failure Analysis and Maintenance Suggestions for the Tray of Scrubber of POSM Device

某石化POSM装置洗涤塔塔盘在服役过程中发生腐蚀失效,以腐蚀塔盘为对象进行失效分析,分别进行了宏观检查、化学成分分析、金相分析、扫描电镜及能谱分析、物相分析。结果表明:洗涤塔塔顶气相夹带的对甲苯磺酸含有游离的硫酸,遇水溶解后在一定温度下浓缩成高浓度的硫酸溶液,进而对塔盘产生了腐蚀。另外,结合塔盘的服役情况,推断了在目前的操作工况下硫酸对塔盘材料S22053的腐蚀速率。最后,根据分析结果给出了洗涤塔的运行维护建议。

The corrosion failure of the scrubber tray of a petrochemical POSM device occurred during its service.The failure analysis was carried out with the corrosion tray as the object.The macroscopic inspection,chemical composition analysis,metallographic analysis,scanning electron microscopy and energy spectrum analysis,phase analysis were carried out respectively.The results show that the p-toluene sulfonic acid entrained in the gas phase at the top of the scrubber contains free sulfuric acid,which were dissolved in water and concentrated into a high concentration of sulfuric acid solution at a certain temperature,thus caused corrosion to the tray.In addition,based on the service condition of the tray,the corrosion rate of sulfuric acid to the tray material S22053 under the current operating conditions was deduced.Finally,according to the analysis results,the operation and maintenance suggestions of the scrubber were given.