二甲苯装置吸附塔底封头焊缝缺陷现场修复技术

On-site repair technology for weld defects of bottom cover of adsorption tower in xylene plant

焊接技术广泛应用于承压特种关键部件的连接与制作,掌握无损检测与修复技术对保障核电、水电、化工及机械等关键设备运行安全具有重要意义。对二甲苯装置吸附塔底封头焊接材料WSTE36进行特性归类、焊接环境和修复难点分析,采用TOFD技术对二甲苯装置吸附塔底封头焊缝缺陷进行检测,确定缺陷大小和位置,根据缺陷类别制定合理修复方案,通过碳弧气刨等手段进行缺陷消除与设备修复。为避免增加返修次数,可多次进行缺陷检测,精准定位缺陷位置。在采用碳弧气刨消除缺陷时,应控制角度与进程,前期采用大进程刨削,后期改用角磨机小进程打磨。在热处理过程中,实施多点布温,实时监测温度,避免温度过高对吸附剂产生不良影响,从而影响设备后续使用。修复完成后,采用TOFD技术对设备再次进行缺陷检测,直到设备修复完好。二甲苯装置吸附塔底封头焊缝缺陷现场修复工艺的应用与总结,为相似设备的焊接缺陷检测与修复提供了经验与参考,为保障核电化工、重要机械等领域关键承压设备运行安全奠定了基础。

Welding technology is widely used in the connection and production of special key components under pressure.Mastering non-destructive testing and repair technology is of great significance for ensuring the safe operation of key equipment such as nuclear power,hydropower,chemical industry,and machinery.Classify the characteristics,welding environment,and repair difficulties of WSTE36 welding material for the bottom head of the adsorption tower in the xylene unit.Use TOFD technology to detect defects in the weld seam of the bottom head of the adsorption tower in the xylene unit,determine the size and location of the defects,develop a reasonable repair plan based on the defect category,and eliminate defects and repair equipment through methods such as air gouging.To avoid increasing the number of repairs,multiple defect inspections can be conducted to accurately locate the defect location.When carrying out air gouging to eliminate defects,control the angle and process.In the early stage,use large process gouging,and in the later stage,use an angle grinder for small process polishing.During the heat treatment process,implement multi-point temperature control and real-time temperature monitoring to avoid adverse effects on the adsorbent caused by high temperature and affecting the quality of repair.After the repair is completed,TOFD technology is used to perform defect detection on the equipment again until it is fully repaired.The application and summary of on-site repair technology for weld defects in the bottom head of the adsorption tower of the xylene unit provide experience and reference for welding defect detection and repair of similar equipment,and lay a foundation for ensuring the safe operation of key pressure equipment in nuclear power,chemical industry,important machinery and other fields.