Three kinds of anti-coking technologies for the settler of catalytic cracking unit and their application were introduced. The primary cyclone separator (primary cyclone) - secondary cyclone direct connection structure can prevent the reaction oil and gas from entering the settler through the outlet of the primary cyclone riser. The oil and gas carried by the primary cyclone dipleg and the oil and gas after stripping in the stripping section enter the primary cyclone riser through the gas rapid export channel to avoid entering the upper part of the settler, which can significantly reduce the residence time of the reaction oil and gas in the settler and significantly alleviate the coking of the settler. A catalyst sealing hopper is set at the outlet of the primary cyclone dipleg, which can further reduce the amount of oil and gas carried by the primary cyclone dipleg, and then relieve the coking of the settler. The comprehensive separation efficiency of two-stage cyclone separator in series operation can reach more than 99.99%, and the average solid content of oil slurry of multiple units can be reduced to less than 2.1 g/L. Compared with the primary cyclone - secondary cyclone direct connection structure, the anti-coking settler with double reactor gas collection chambers expands the form of primary cyclone - secondary cyclone direct connection, increases the oil-gas buffer space between the primary cyclone outlet and the secondary cyclone inlet, and has a good anti-interference effect on the fluctuation of reaction pressure and other operating conditions, which can meet the requirements of long-term production of the unit.

介绍了3种催化裂化装置沉降器防结焦技术及其应用。粗旋风分离器（粗旋）－单级旋风分离器（旋分）直联结构可以避免反应油气由粗旋升气管出口串入沉降器，粗旋料腿携带的油气和汽提段汽提后的油气由导气管进入粗旋升气管，避免进入沉降器上部空间，可以显著降低反应油气在沉降器中的停留时间，沉降器结焦问题得到显著改善。粗旋料腿出口设置料封斗，可以进一步减少粗旋料腿携带的油气量，进而减缓沉降器结焦速率。两级旋分串联操作，综合分离效率达到99.99%以上，多套装置油浆平均固含量降至2.1g/L以下。与粗旋－单级旋分直联结构相比，双集气室防结焦沉降器增加了粗旋出口－单级旋分入口之间的油气缓冲空间，对反应压力等操作条件波动有较好的抗干扰作用，可以满足装置长周期生产要求。