快速流态化过程颗粒团理想模型建立

Establishment of Ideal Cluster Model in the Process of Fast Fluidization

颗粒团聚是快速流态化过程中一个重要现象。根据鼓泡床气泡模型,类比推导出快速流态化颗粒团理想模型。以颗粒团理想模型为基础,研究颗粒团周边气固流动结构,成功预测了晕的存在以及“反向穿透”的现象。结果表明:颗粒团内的稀相颗粒在颗粒团晕范围内保持一个动态平衡;对于催化裂化(FCC)颗粒,其他条件相同时,颗粒团的晕厚度随着颗粒粒径的增大而增大,随着操作风速的增大而减小;反向穿透颗粒流体积流量随着粒径的增大而增大。

The cluster is an important phenomenon in the process of fast fluidization. Based on the bubble model of bubbling bed, an ideal model of cluster in the process of fast fluidization is derived by analogy. Based on the ideal cluster model, the gas-solid flow structure around the cluster is studied, which successfully predicts the existence of cloud and the phenomenon of “reverse penetration”. The results show that the dilute phase particles in the cluster maintain a dynamic equilibrium in the range of cloud;for FCC particles, when other conditions are the same, the cloud thickness of cluster increases with the particle size, but decreases with operating wind velocity;the volume flow rate of reverse penetrating particle flow increases with the particle size.