重整碱洗系统腐蚀原因分析及防护措施

西北某炼厂连续重整装置反再干燥系统DN800分离器(￠800×1510×6 mm,材质:316L)投用4年后多次出现腐蚀泄漏,且泄漏部位主要集中在底部封头,经判定为氯离子及保温层下腐蚀。其次,碱洗系统水洗侧排水弯头、管线焊缝等部位经常发生腐蚀渗漏。常规处置方案为铺焊消漏、管线预制更换,工作频繁,复发性高。本文针对该腐蚀类型及防护措施进行详细介绍。

Corrosion analysis and protection measures of reforming alkali washing system

The DN800 separator(￠800×1510×6,material:316L)of reverse re drying system in a refinery in Northwest China suffered corrosion and leakage for many times after 4 years of operation,and the leakage was mainly concentrated in the bottom head,which was determined to be corrosion under chloride ion and insulation layer.Secondly,corrosion and leakage often occur in the drainage elbow and pipeline weld on the water washing side of the alkali washing system.The conventional treatment plan is laying welding to eliminate leakage,pipeline prefabrication and replacement,which is frequent and has high recurrence.The following is a detailed summary of the corrosion type and protection measures.