高校化学工程学报Issue(5)：729-736,8.DOI:10.3969/j.issn.1003-9015.2013.05.001
石英砂二元混合颗粒初始流化过程的研究
Initial Fluidization Processes of Binary Quartz Sand Particles with Equal Density
摘要
Abstract
The initial fluidization processes of binary mixture particles of quartz sands are studied in an experimental fluidization cold model made of perspex with the dimensions of300 mm×3000 mm. Four quartz sand particle groups with equal particle density and different mean diameters, corresponding to Groups A, B, C, D according to the Geldart classification method, respectively, were used. Different two groups of particles with different mass fractions mixing together forms the different binary particle systems in this study. The initial fluidization curves (Δp-ug) and minimum fluidization velocities umf were measured by a FXC-Ⅱ/32 pressure measurement system. Experimental results show that, for each binary particle mixture, the particle sizes, size difference and mass fractions of the two particle components have important impacts on its initial fluidization properties. It was observed that Group A component can improve the fluidization quality of other components, i.e. the Group B, C, D component. With too much Group C component, binary particle mixtures show serious channeling in the initial fluidization process. There exists a critical mass fraction for the flotsam component (i.e. particle component with smaller mean diameter) xf=0.4, under which the complete segregation of the two particle components is readily to happen during initial fluidization processes. For binary mixtures with large particle size differences, the minimum fluidize velocity umf decreases with increasing smaller particle fraction. However, for binary mixtures with one component having strong inter-particle forces, umf increases with The initial fluidization processes of binary mixture particles of quartz sands are studied in an experimental fluidization cold model made of perspex with the dimensions of300 mm×3000 mm. Four quartz sand particle groups with equal particle density and different mean diameters, corresponding to Groups A, B, C, D according to the Geldart classification method, respectively, were used. Different two groups of particles with different mass fractions mixing together forms the different binary particle systems in this study. The initial fluidization curves (Δp-ug) and minimum fluidization velocities umf were measured by a FXC-Ⅱ/32 pressure measurement system. Experimental results show that, for each binary particle mixture, the particle sizes, size difference and mass fractions of the two particle components have important impacts on its initial fluidization properties. It was observed that Group A component can improve the fluidization quality of other components, i.e. the Group B, C, D component. With too much Group C component, binary particle mixtures show serious channeling in the initial fluidization process. There exists a critical mass fraction for the flotsam component (i.e. particle component with smaller mean diameter) xf=0.4, under which the complete segregation of the two particle components is readily to happen during initial fluidization processes. For binary mixtures with large particle size differences, the minimum fluidize velocity umf decreases with increasing smaller particle fraction. However, for binary mixtures with one component having strong inter-particle forces, umf increases with increasing smaller particle fraction. Finally, in this study a modification was made for the existing umf correlation of the BD binary mixture, which has better agreements among the measured and predicted results.关键词
二元混合颗粒/起始流化特性/分级/沟流/质量分数Key words
binary particles/initial fluidization process/segregation/channeling/mass fraction分类
化学化工引用本文复制引用
陈晓娜,张永民,唐军,黄金库,卢春喜,王祝安..石英砂二元混合颗粒初始流化过程的研究[J].高校化学工程学报,2013,(5):729-736,8.基金项目
国家自然科学基金(20906101)；国家973项目(2012CB215004)。 （20906101）
