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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%.
Euler-Euler two-fluid model was used to simulate the solid-liquid suspension characteristics of suspended solid stirred tank with solid content 9.2% (?). The simulation results of two modified drag coefficient models were compared. The axial and radial distribution and the uniformity of suspension were investigated.The results showed that the obvious bottoming sedimentation was formed when the stirring speed was less than 600 r / min, the rotation speed increased from 400 r / min to 1100 r / min, the stacking height decreased from 0.16 to 0, and the sedimentary zone shrank to disappear until the center of the groove bottom.With the centrifugal force, the solid particles in the circulating flow moved to the direction of long vortex, the solid content of the circulating flow was low, The uniformity of suspension is reduced.Under the dimensionless z / H = 1/3 boundary, the two-phase flow in the tank can be divided into the upper and lower circulation zones. The particle distribution is affected by the confluence of the circulating flows, With the increase of non-dimensional axial height, the stability of solid-liquid suspension is stable at 0.5-0.7, the rotation speed increases from 400 r / min to 1100 r / min, the average value of the upper circulation decreases by 37.2% .