催化裂化提升管反应器出口快分构件优化

Optimization of Fast Separator Structure of FCC Riser Reactor

针对京博石化一套FCC装置内粗旋结构,提出了一种内置导流板的粗旋结构,并采用Fluent软件对优化模型内气相流场、颗粒运行轨迹及分离效率进行数值研究,并与现场粗旋进行了对比。模拟结果表明:优化模型内切向速度呈驼峰分布;轴向速度呈马鞍形分布;压力分布呈轴对称分布,其沿轴向基本不变,而是随着半径的减小而降低。与现场模型相比,优化模型的切向速度、轴向速度都有所提高,有利于气-固的分离;压降有所降低,提高了旋风分离器的性能;分离效率主要是对粒径范围5～20μm的颗粒提高较大。此外,随着入口速度的增大,其分离效率增大的同时压降也增大,因此需综合考虑。

A new fast separator with internal flow guide was proposed compared with traditional riser structure in an FCC unit for Jingbo Petrochemical.The gas flow profile, particle movement and separation efficiency were simulated using Fluent for both optimized and traditional riser structure.For the optimized structure, simulation results suggest that the tangential velocity exhibits hump type distribution, and axial velocity is saddle-shape distribution.The pressure distribution is axial symmetry.The pressure does not change along the axial direction, but decreases with radius.Compared with traditional structure, both of tangential velocity and axial velocity in the optimized structure are higher, which is in favor of gas and solid separation.In addition, for the optimized structural design, pressure drop is much lower, which indicates higher cyclone separation efficiency.It can be observed that the separation efficiency for 5-20 μm particles can be greatly improved.As inlet velocity increases, separation efficiency will improve, but this will lead to a higher pressure drop.Therefore, the determination of inlet gas velocity in operation should consider the above two factors.