加氢型酸性水汽提装置腐蚀分析与防护

Corrosion Analysis and Protection of Hydrogenation Type Acidic Water Stripping Unit

采用现场宏观腐蚀检查、管线超声波测厚、腐蚀介质分析、在线腐蚀探针监测及能谱分析等方法对加氢型酸性水汽提装置的酸性水储罐、汽提塔顶酸性气线弯头进行了腐蚀分析。分析结果表明,酸性水中的少量氯化物及酚类物质极易穿透涂层,使得腐蚀介质与金属基体发生腐蚀反应,导致涂层鼓泡、脱落。汽提塔顶酸性气线弯头背弯处减薄最为严重,主要原因为湿硫化氢腐蚀,而流体的冲刷磨损起到了促进作用,两者循环反复进行导致弯头背弯处快速减薄并穿孔。针对装置的腐蚀情况,提出了应用效果较好的防护措施。

The acidic water storage tank and acid gas line of stripping tower top were analyzed by means of in-site macroscopic corrosion inspection,line ultrasonic thickness,corrosion medium,on-line corrosion monitoring probe and energy spectrum analysis method for hydrogenation type acidic water stripping device.Analysis results indicated that a small amount of chloride and phenol of acidic water penetrated the surface coating easily,and corrosion reaction happened between corrosive medium and metallic matrix,which resulted in bubbling,and falling off.The main reason of corrosion reduction on acid gas line of stripping tower top was wet hydrogen sulfide corrosion,and fluidic erosive wear promoted corrosion reduction,leading to perforation under the action of corrosion and fluidic erosive wear.Finally,in view of the corrosion situation of devices,the better protective measures were put forward.