旋风分离器在费托反应器的分离应用模拟分析

Simulation and Analysis of Cyclone Separator in Fischer-Tropsch Reactor

本工作针对费托反应器顶部气固分离情况,开展反应器顶部旋风分离器的流场模拟研究,研究气相和颗粒相流动特征。结果表明:固相颗粒在离心力作用下在壁面富集,气相则在压差力作用下流向分离器中心,并由升气管排出分离器,实现气-固两相分离。固相颗粒与旋风分离器壁面碰撞后多为折线运动,与气体的跟随性较差。在旋风分离器顶板外沿、直筒段和锥体段交界处存在气相轴向速度大于0的区域,造成顶板下方和旋风分离器外筒变径处颗粒停留时间长,存在颗粒聚集。此外,旋风分离器的分离效率与颗粒粒径有关。模拟结果表明,粒径为10μm以上的颗粒分离效率均可达到99.9%以上,能够满足工艺要求的分离效果。

In view of the gas-soild separation at the top of Fischer-Tropsch reactors,the flow field simulation of cyclone separator was discussed and the gas-solid flow characteristics was checked.The results showed that the solid phase particles were enriched on the wall of the cyclone separator under centrifugal force.Under the pressure,the gas was moved towards the center of the separator and discharged from the ascending pipe.The solid particles were collided with the wall of cyclone separator and moved in a broken line which had poor following property with gas.The axial velocity of the gas was greater than zero at the outer edge of cyclone separator roof,straight cylinder section and cone section junction,which resulted a long residence time and enriched.In addition,the separation efficiency of cyclone separator was related to the size of particles.The simulation results showed that the separation efficiency could reach 99.9%when particle size was above 10μm,which could meet the separation requirements.