Abstract:

The mesoscale structure in the gas-solid fluidization bed seriously affects the macroscopic properties of fluidization, such as mass transfer, heat transfer, reaction efficiency, and so forth. Thus, the study of mesoscale structure is important. We briefly review the definition and classification of mesoscale structures in the fluidization system. Then, the causes of mesoscale structure formation are analyzed from the fluid-particle, particle-particle interactions (inelastic collision and forced perspective), based on summarizing the latest research progress. Primarily, we focus on the agglomerate, which system's relevant driving force or source of granular energy nanoparticles. The van der Waals force calculation is reviewed between fine particles and agglomerates' theoretical force balance model. It is very significant to study a dynamic of the mesoscale structure with inter-particle forces. It can provide precise control of the mesoscale structure technique and has broad application prospects in chemical engineering.

Key words: fluidization, mesoscale structure, dynamic evolution, multi-phase flow, interparticle interaction

摘要：

气固流化床中的团聚等介尺度结构严重影响气固的整体流化特性、传热、传质和反应效率，因此介尺度结构的研究至关重要。简要回顾颗粒介尺度结构的定义与分类，然后从流体-颗粒、颗粒-颗粒之间的力和非弹性碰撞相互作用出发，总结分析了颗粒介尺度结构形成原因和动力学演化过程的研究现状和发展动态。重点关注细颗粒与超细纳米颗粒形成的介尺度结构，即结块，并针对结块形成原因，讨论了颗粒间范德华力计算以及结块的力平衡理论模型，提出了细颗粒介尺度结构进一步的研究方向，即研究带有颗粒-颗粒作用力的介尺度结构的动态演化规律，为精准调控介尺度结构提供理论依据。

关键词: 流态化, 介尺度结构, 动力学演化, 多相流, 颗粒间相互作用力