液硫储罐检修难点及应对措施

DIFFICULTIES IN THE OVERHAUL OF LIQUID SULFUR TANK AND THE COUNTERMEASURES

某天然气净化厂在一次例行巡检途中发现,液硫罐顶出现白色蒸汽,拆开顶部保温层后发现罐顶出现腐蚀穿孔。由于液硫罐属净化厂关键要害装置,承担液硫存储和成型等生产调节任务,一旦腐蚀扩大,混入空气,引发硫化亚铁自燃,后果不堪设想。经调查确定是呼吸孔接管伴热蒸汽泄漏,与硫化氢作用形成腐蚀。依据制度将液硫储罐作为重大安全隐患整改项目进行紧急停工检修。对液硫罐在检修过程中的工艺条件确认、质量管控、安全监管等难点进行了介绍,同时提出相应的解决措施,并总结了检维修过程中的典型做法。

A corrosion perforation was found on the top of the liquid sulfur tank after dismantling the top insulation layer in certain Natural Gas Purification Plant during routine inspection.Since the liquid sulfur tank is a key device in purification plant which plays the role of production and regulation in liquid sulfur storage and molding,disastrous consequences will occur once spontaneous combustion of ferrous sulfide is triggered by the expanding of the corrosion if air enters the tank.After investigation and research,it was confirmed that the corrosion was caused by leakage from ventilation breather acting with hydrogen sulfide.Emergency shutdown overhaul was carried out with liquid sulfur tank taken as the rectification item of major safety risks according to corresponding regulations.This paper introduces the difficulties during the shutdown overhaul such as the confirmation of processconditions,qualitycontrolandsafety supervision.Meanwhile,it puts forward relevant solutions to the difficulties and summarizes the typical practice during the overhaul process.