芳烃抽提装置环丁砜溶剂管线弯头穿孔原因分析

Failure analysis on corrosive perforations of the elbow in solvent sulfolane pipelines of aromatic extraction unit

对芳烃抽提装置中环丁砜溶剂管线弯头穿孔处进行了多项理化分析,确认环丁砜循环系统管线弯头处的穿孔失效性质为流动加速腐蚀(FAC)。环丁砜溶剂分解产生的酸和溶解的氧是主要的腐蚀介质;环丁砜溶剂在管线弯头、焊缝凸起等处的流向变化、湍流,加速了腐蚀进程。

Several physical and chemical analyses were performed for the corrosive perforation site of the elbow in solvent sulfolane pipelines of aromatic extraction unit. It was confirmed that the perforation failure was caused by flow accelerated corrosion(FAC). The main corrosion media are the acid from decomposition of the solvent sulfolane and the dissolved oxygen. The flow direction change and turbulence of the solvent sulfolane in the elbow site and weld flush accelerated the corrosion process.