PTA加氢反应器腐蚀与风险分析

介绍了某石化公司PTA加氢反应器衬里的腐蚀和修复情况并探讨了腐蚀机理和腐蚀原因。认为介质中超标的Br-和碱洗夹带的Cl-是造成腐蚀的主要原因,装置扩能和进料管堵塞对腐蚀有一定的促进作用。对腐蚀风险进行定性分析后认为,PTA加氢反应器的腐蚀风险属低风险等级,通过合理修复处理能够满足正常生产。对于较浅的腐蚀点坑,可进行打磨并圆滑过渡;对较深或已穿透复层的腐蚀坑,可打磨后补焊处理;对大面积的腐蚀点坑甚至是穿透性的点蚀坑带采用贴板处理。工艺上应加强管理和监控,避免Br-和Cl-含量超标,检修时应注意检查清理进料管的积料,防止因进料管堵塞引起介质偏流造成腐蚀加剧。

Corrosion and Risk Analysis of PTA Hydrogenation Reactor

The corrosion and maintenance of the PTA hydrogenation reactor are described in detail, and corrosion mechanisms and corrosion causes are studied. The over - specifications of Br - in media and Cl- carried over in alkaline washing are the culprits of corrosion. In addition, the capacity - expansion and feed pipe blocking have aggravated corrosion. The corrosion risk analysis concluded that the corrosion risk level of PTA hydrogenation reactor is in the ＂low class＂. The corrosion damages can be properly repaired for normal operation. As for the shallow corrosion pits, they can be polished for smooth transition. The deep or penetrated corrosion pits can be welded after polishing. The widespread corrosion pits or penetrated corrosion pits can be welded with stainless steel sheet. In addition, the corrosion management and monitoring must be strengthened to prevent Br - and Cl- contents from being out of limits ; The feed pipe should be inspected and cleared to prevent corrosion caused by deflected flow resulted from pipe blocking during overhaul.