【摘要】 在综合考虑流动、反应、传质的基础上 ,建立了适用于模拟提升管和下行床反应器中催化裂化过程的二维返混模型 ,并利用正交配置法进行数值求解 ,得到了各产物在两种反应器内的不同浓度分布规律。这种结果源于两者流动结构和混合状况的差异。和提升管相比 ,由于下行床内的气固两相流动更接近平推流 ,气固速度和颗粒浓度径向分布均匀 ,气固轴向返混小 ,因而可得到更高的汽油收率。更多还原

【Abstract】 Based on the hydrodynamics, FCC kinetics and mass transfer models, a two-dimensional dispersion model was developed to simulate the FCC process in the riser and downer reactors. The orthogonal method was used to solve the mathematic model equations, for indicating the concentration distribution of the products in the reactor. The results indicated that due to different flow patterns and different mixing performances, there exists apparent disparity of the concentration distribution between riser and downer reactors. Compared to the riser reactor, the gas-solid flow in downer is more close to the plug-flow, the gas and solid velocities and concentrations are more uniform and the axial backmixing is obviously smaller, thus more gasoline yield can be gained.更多还原