高固含率搅拌槽内颗粒分布及悬浮特性的数值模拟

发布时间：2018-05-27 13:10

本文选题：固液悬浮 + 搅拌槽　；参考：《过程工程学报》2017年01期

【摘要】：采用Euler-Euler双流体模型对固含率9.2%(?)的高固含率悬浮搅拌槽内固液悬浮特性进行了模拟,对比了两种修正的曳力系数模型的模拟效果,考察了固含率轴向和径向分布及悬浮均匀度的变化规律.结果表明,搅拌速度低于600 r/min时,槽底会形成明显的中心密集沉积,转速从400 r/min增至1100 r/min,堆积高度由0.16减小至0,沉积区向槽底中心收缩直至消失.在离心力的作用下,循环流内的固相颗粒向远涡方向运动,循环流涡心处固含率低,悬浮均匀性降低.以无因次高度z/H=1/3为界,可将槽内两相流分为上、下循环区;颗粒分布受循环流交汇影响,固相在径向方向上随流场分散.固液悬浮均匀度?随无因次轴向高度的增加,稳定在0.5~0.7,转速从400 r/min增至1100 r/min,上循环区的?值平均降低37.2%.
[Abstract]:Using Euler-Euler two-fluid model for solid holdup 9.2C) The simulation results of two modified drag coefficient models were compared, and the axial and radial distribution of solid holdup and the variation of suspension uniformity were investigated. The results show that when the stirring speed is less than 600 r/min, there will be obvious central dense deposition at the bottom of the trough, the rotational speed will increase from 400 r/min to 1100 r / min, the height of deposition will decrease from 0.16 to 0, and the deposition area will shrink to the center of the trough and disappear. Under the action of centrifugal force, the solid particles in the circulation flow move to the direction of the far vortex, the solid holdup at the vortex center of the circulation flow is low, and the suspension uniformity is decreased. With dimensionless height z/H=1/3 as the boundary, the two-phase flow in the channel can be divided into upper and lower circulation regions, the particle distribution is affected by the circulation flow intersection, and the solid phase is dispersed with the flow field in the radial direction. Solid liquid suspension uniformity? With the increase of dimensionless axial height, the rotation speed increases from 400 r/min to 1100 r / min. The average value decreased by 37.2%.
【作者单位】：北京科技大学钢铁冶金新技术国家重点实验室;北京科技大学冶金与生态工程学院;
【基金】：国家高技术研究发展计划(863)基金资助项目(编号:2013AA065703)
【分类号】：TQ051.72

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