重油催化裂化装置新型四旋系统的工业应用

INDUSTRIAL APPLICATION OF A NEW FOURTHSTAGE SEPARATOR IN RFCC UNIT

中海油中捷石化50万t/a催化裂化装置由于原四旋系统设计不合理,引起废剂回收罐设备本体温度超出设计温度,四旋旋分料腿频繁堵塞,致使大量催化剂粉尘无法回收至废剂罐内,导致临界喷嘴磨损严重,排入大气中的烟气的粉尘含量增大,烟气进入临界喷嘴后的泄气量忽高忽低,致使三旋运行工况不稳定,已严重影响三旋分离性能。根据装置实际情况,经过多方研究论证,采用了中国石油大学(华东)的新型泄气旋风分离技术,装置改造后,四旋操作运行平稳,有效提高了催化剂粉尘回收效率,解决了料腿频繁堵塞、临界喷嘴磨损、设备超温等问题,保证了装置长周期安全运行。

Due to the improper design of the previous fourth-stage cyclone separator of the 500kt/a RFCC unit in Zhongjie Petrochemical Company of CNOOC,a lot of abnormal accidents arose,such as over-temperature of the recycling bin for waste catalyst,frequent blockage of the dipleg of the fourthstage cyclone separator.As a consequence,the critical nozzle was frequently worn down due to the increased solids concentration in the gas from the outlet of the fourth-stage cyclone separator.Another induced consequence is the highly fluctuating leakage flow rate from the hopper of the third-stage cyclone separator,which has seriously affected the separation efficiency of the third-stage cyclone separator.After much research and feasibility studies,a new fourthstage separator developed by China University of Petroleum(East China),which employed a combination of inertial and centrifugal separation,was employed to replace the previous separator.After the revamp,the dust recovery efficiency of the fourthstage separator was greatly increased and the frequent blockage of the dipleg was also eliminated.The over-temperature of the recycling bin of the waste catalyst and the erosion problem of the critical nozzle were also resolved,which ensures long and safe operation of the RFCC unit.