大型搅拌槽流场的数值模拟和不同转速下矿浆体积分数分布研究

Numerical simulation on fl ow fi eld of large mixing tank and study on distribution of volume fraction of slurry at various stirring velocity

基于多相流欧拉理论对某企业大型矿浆搅拌槽内流场进行了三维模拟,深入研究了不同转速下矿浆体积分数沿径向和轴向的分布情况。数值模拟结果表明,搅拌槽内形成2个垂直环流及周向环流,对矿浆体积分数分布起到主要影响的是垂直环流。搅拌槽内矿浆流速在桨叶区出现最大值,槽体中上部流速较小;同一转速下,搅拌槽内矿浆体积分数随着垂直高度的增加而降低,搅拌槽中部矿浆体积分数基本相等,搅拌槽上部体积分数随高度的增加呈线性降低;随着转速增加,各垂直高度上的矿浆体积分数减小。

Based on multi-phase flow Euler theory, 3D simulation on the flow field of the large slurry mixing tank in an enterprise was conducted, and the axial and radial distribution of the volume fraction of the slurry at various stirring velocity was analyzed. The numerical simulation results showed： there were two main vertical cycles and a circumferential cycle in the mixing tank, and the vertical cycles dominated the distribution of the volume fraction; the highest fl ow velocity of the slurry appeared at the impeller region, and the fl ow velocity was considerably low at the upper and middle region of the tank; at the same stirring velocity, the volume fraction of the slurry in the mixing tank declined with the increase of the vertical height, the volume fraction of the slurry in the middle region of the tank kept basically same, the volume fraction of the slurry in the upper region of the tank linearly decreased with the increase of the height; with the increase of the stirring velocity, the volume fraction at each vertical height declined.