催化裂化装置再生器跑剂分析与对策

Analyses and of catalyst loss in FCC regenerator and countermeasures

中国石化青岛炼油化工有限责任公司催化裂化装置2014年6月起发生再生器跑剂事件,对再生器旋风分离器差压、主风分布板压力降和大小分布环压力降等重要参数加强跟踪分析。在工艺上排除了反再系统未知蒸汽进入再生器、外取热器换热管束泄漏和催化剂理化性质差异等可疑因素后,在设备检查过程中发现再生器跑剂根本原因是7号和8号旋风分离器二级旋分两段料腿之间的锥体连接件的焊缝断裂,造成周围烟气夹带着催化剂颗粒向低压区的料腿内部高速流动,旋风分离器正常工作状态被破坏,旋风分离器收集的催化剂在经过筒体和锥体进入灰斗时被反窜上行的气流大量带出,造成再生器大量跑剂。通过对旋风分离器焊缝断裂部位重新焊接以及对11组旋风分离器的相同位置全部贴板采取加强的有效措施,彻底解决了再生器旋风分离器焊缝断裂这一影响装置长周期运行的难题。

The catalyst loss occurred in the FCC regenerator of SINOPEC Qingdao Refining and Chemical Company in June 2014. The monitoring of some important parameters was strengthened, such as differential pressure of the regenerator cyclone, pressure drop of the main air distribution plate and size distribution ring. Some causes were excluded, like steam entering the regenerator, leakage of tube bundle of external catalyst cooler and differences in physical and chemical properties of catalysts. It was found in the inspection that the welds on the cone connector between the dip legs of No. 7 and No. 8 two-stage cyclones were fractured, which caused catalyst entrainment in the surrounding flue gas and flow to the low-pressure area within the legs at a high flow rate. The normal operating condition of cyclone was destroyed. The collected catalyst in the dust hopper was entrained up by the upstream flow, which resulted in the catalyst loss. Broken welds region of cyclones were re-welded, and reinforcing plates were installed on the same position of eleven groups of cyclones. The problems that the welds were easily broken in the regenerator cyclone which would affect the long-term operation of the unit were basically solved.