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团聚体的物性参数对于超细颗粒聚团流化过程 (包括 C类颗粒的聚团鼓泡流化和 E类颗粒的聚团散式流化 )具有重要作用 ,直接影响流化过程中气固两相的流动行为。该文根据实验数据 ,对一种纳米级 Si O2 颗粒 (16 nm)在聚团散式流化状态下的聚团特征参数及曳力系数进行了计算分析。结果表明 :在 14～ 35 mm/ s气速范围内 ,团聚体 (二次颗粒 )的等阻力球平均粒径为 30 1μm ,二次颗粒群曳力系数高于单颗粒曳力系数 ,二者之比随床层空隙率增加而减小。通过分析获得了聚团散式流化状态下二次颗粒群与单个二次颗粒曳力系数之比的表达式
Aggregate physical parameters play an important role in the ultrafine particle agglomeration fluidization process (including the agglomeration bubbling of C-type particles and the conglomeration-type fluidization of E-type particles), which directly affects the gas-solid Two-phase flow behavior. According to the experimental data, the characteristic parameters and drag coefficient of agglomeration of a nanoscale Si O2 particle (16 nm) in the state of agglomeration and fluidization are calculated and analyzed. The results show that the mean particle size of the iso-drag sphere of the agglomerates (secondary particles) is 30 1 μm at 14-35 mm / s, and the drag coefficient of the secondary particles is higher than the drag coefficient of the single particles The ratio decreases as the bed porosity increases. Through the analysis, the expression of the ratio of the drag coefficient of the secondary particles to the single secondary particles in the dispersed fluidized state is obtained