液-固流化床中液速分布与颗粒循环流动  

Radial Profile of Liquid Velocity and Particles Circulation in Liquid-Soild Fluidized Beds

作　　者：郝晓刚[1] 张忠林[1] 郭金霞[1] 孙彦平[1] 

机构地区：[1]太原理工大学化工学院,山西太原030024

出　　处：《高校化学工程学报》2004年第3期297-302,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(20006011);山西省自然科学基金(20021017)

摘　　要：通过理论分析和实验研究考察了液-固平板流化床中颗粒流和液流的运动规律,提出了将分散的颗粒流连续介质化的假设和基于容积通量的流体力学表达方式,建立了液体流动和颗粒循环流动的数学模型并定义了颗粒流与液流的有效粘度。理论计算表明,液体通量的径向分布为抛物线,液流有效粘度和液含率与表观液速有关;颗粒通量的径向分布也为抛物线且颗粒上流区与回流区的分界点在0.577D,循环流动强度取决于液含率和液体密度,但颗粒循环分界点的位置与颗粒类型和操作液速无关。实验观察支持模型预测结果。The liquid and particle flow in two-dimensional liquid-solid fluidized beds was studied by taking the dispersed particles and liquid as co-existing continua. The mathematical models of liquid flow and the particle circulation were developed by the method of hydrodynamic and under the assumption that the liquid phase and the particle phase are Newtonian. A definition of particle flow and liquid flow effective viscosity based on volume flux was proposed. The radial distribution of liquid flux is parabola, the liquid effective viscosity and the porosity of liquid are affected by the superficial liquid velocity according to the theoretical calculation. The radial distribution of the particle flux is also parabola and the dividing point between the particle upflow and the particle backward flow is verified near 0.577D. The circulation flow intensity of particle depends on the porosity and density of liquid, but the dividing point of particle circulation has no relationship with the particle type and the operated liquid velocity. Good agreements between the model and the reported data are achieved.

关 键 词：液-固流化床 模型 液速分布 颗粒循环流动 

分 类 号：TQ051.13[化学工程]