催化裂化装置反应系统磨损及裂纹问题分析与对策

Analysis and countermeasure of crack and wear in reaction system of FCC Unit

某炼化公司催化裂化装置长周期运行过程中出现过翼阀阀板磨穿、二段提升管裂纹和VQS三臂旋流头磨损等问题。翼阀阀板磨穿是因为MIP循环斜管停用导致经旋风分离器催化剂总量下降了约25%~35%,翼阀排料过程中存在“半截流”现象,措施为将料腿由φ451 mm优化为φ377 mm;二段提升管裂纹主要是局部母材缺陷导致,通过更换该段筒节有效解决,2019年大检修时将二段提升管材质由16MnR升级为15CrMoR;提升管出口带预汽提密闭旋流式快速分离系统(VQS)三臂旋流头顶板、底板、外侧板及顶封头磨损磨穿问题,通过贴板和将封头改为平盖,并将侧拉环型锚固钉改为龟甲网,解决了磨穿问题。

There were several problems during long cycle operation in FCC unit,such as wear perforation of wing valve plate,cracking of the second riser and abrasion of VQS swirling head.The wear perforation of wing valve plate was caused by the suspension of MIP circulating inclined pipe,which led to a decrease of about 25%~35% in the total amount of catalyst through cyclone separator.There was a phenomenon of“semi-outflow”in the discharging process of wing valve.The countermeasure was to optimize the feed leg from φ451 mm to φ377 mm.The cracks of the second stage riser were mainly caused by local base metal defects.It could be effectively solved by replacing the barrel section.It utilized the 15CrMoR instead of 16MnR for the second riser material during maintenance in 2019.The abrasion and wear problems of the top plate,bottom plate,outer plate and top head of VQS swirling head were solved by sticking the plate and changing the head to flat cover,and changing the side pull ring anchor nail to tortoiseshell net.