搅拌罐内流场及脱硫剂分散数值模拟

Numerical Simulation for Flow Field and Desulfurizer Dispersion Behavior in the Stirred Vessel

基于多重坐标系的静、动网格法和气-液-固三相流等技术建模,采用VOF(volume of fluid)和DPM(discrete phase model)模型捕捉瞬态流场下的自由液面和脱硫剂分散的空间分布规律.数值模拟与水模试验得到的漩涡深度及高度具有一致性.结果表明,搅拌器转速和搅拌器浸入深度显著影响流场轴向速度和径向速度的分布,最大速度主要分布在搅拌器叶端;自由液面的漩涡深度随搅拌器转速的增加而增加,当漩涡底部延伸至搅拌器上端,受漩涡卷吸的脱硫剂颗粒开始进入流场内部,通过4股循环流动在罐内充分扩散.

In order to capture the free surface and get the spatial distribution of desulfurizer dispersion in transient flow field,the VOF（ Volume of Fluid） model and DPM（ Discrete Phase Model） model,as well as static and dynamic grids based on the multiple reference frame and gas-liquid-solid three phases flow modeling technology were used. The vortex depth and height obtained by numerical simulations were in good agreement with the water model experiments. Results showed that the rotational speed and stirrer immersed depth significantly affect the axial velocity distribution and radial velocity distribution,and the maximum speed mainly distributed in the blender blade tips. The vortex depth of free surface increased with the increase of stirring speed significantly,and when the vortex bottom extended to the mixer upper,the desulfurizer particles entrained by the vortex began to disperse into the internal flow field and diffuse completely through four circulation flow in the stirred vessel.