Abstract: During normal operation of a 1.0 MTPY catalytic cracking unit, a sudden catalyst loss (cat loss) fault occurred, and there was no decreasing trend. During the process, there were no abnormalities in the process operation parameters, and the concentration of particulate matter in the discharged flue gas and the solid content of the oil slurry exceeded the standard. By analyzing the particle size distribution, APS (average particle size), and morphology of the catalyst inside the system, it was determined that the catalyst had severely broken, producing a large number of fine powders. It was found that the main wind distributor nozzle and feed nozzle gas velocity of the unit did not change, but the pressure drop of the steam stripping steam pipe changed significantly, and the steam outlet line speed far exceeded the design value, reaching more than 75 m/s. Therefore, it is speculated that the cause of the catalyst loss is the impact and thermal collapse caused by the rupture of the steam stripping steam pipe. Measures such as reducing the unit's processing load, reducing the steam input into the two reactors, and increasing the amount of catalyst replacement have been taken to effectively reduce the catalyst loss without stopping the unit.

Key words: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">FCCU, catalyst, loss, impact crushing, thermal collapse, particle diameter, particle size distribution

摘要： 某１.０Ｍｔ／ａ催化裂化装置正常运行中突然出现催化剂跑损（跑剂）故障，且无减小趋势，过程中工艺操作参数无异常，外排烟气颗粒物浓度和油浆固含量超标。通过分析系统内催化剂的粒度分布、APS（平均粒径）、形貌等变化，发现催化剂发生了严重破碎，产生了大量细粉。核算发现，该装置主风分布器喷嘴和进料喷嘴气速均未发生变化，汽提蒸汽管的压力降发生了较大的变化，蒸汽喷出线速度远超过设计值，达到７５ｍ／ｓ以上，故推测催化剂跑损原因为汽提蒸汽管断裂导致的催化剂冲击破碎和热崩破碎。采取降低装置加工负荷、减少两器通入蒸汽量、加大平衡剂置换量等措施，在满足装置不停车的前提下有效地降低了催化剂跑损量。

关键词: font-family:-apple-system, blinkmacsystemfont, ", font-size:14px, background-color:#FFFFFF, ">催化裂化装置, 催化剂, 跑损, 冲击破碎, 热崩, 颗粒直径, 粒度分布