射流与搅拌协同式浮选机槽体内颗粒运动与分布规律探究

Movement and distribution of particles in the tank of jet and agitation combined flotation machine

  • 摘要: 为了探究射流与搅拌协同式浮选机槽内颗粒运动与分布规律,建立了射流与搅拌协同式浮选机槽体几何模型,利用COMSOL软件模拟了槽体内部受叶轮搅拌作用下的流场分布以及颗粒运动,搭建了射流与搅拌协同式浮选装置试验系统并对其进行颗粒分散效果试验。结果表明:部分颗粒穿过叶轮叶片之间的间隙,在流场的作用下向下做螺旋运动;另一部分颗粒被叶片甩出,在叶片与流场的耦合作用下向四周与上方做螺旋运动;绘制了所有粒子的运动轨迹曲线用以探究浮选机工作过程中的颗粒运动与分布规律,颗粒在浮选槽底部、四周壁面以及槽体拐角处的粒子运动轨迹曲线重合度高,粒子运动至此处的概率大,大量粒子运动至此处,浮选槽体上部以及槽体壁面与叶轮之间区域粒子运动轨迹重合度较小,粒子运动至该处的概率低,少量颗粒在该处分布;粒子分布均匀程度并不随着叶轮搅拌速度的提高而增大,而是存在最佳叶轮工作参数,经模拟与试验得出射流与搅拌协同式浮选机在叶轮转速为6.25 r/s的条件下具有较好的颗粒分散性能;颗粒的分散效果受到槽体的形状及内部结构的影响,在槽体内增加挡板或者将方形槽体柱式化均能有效的促进颗粒均匀分布。探究射流与搅拌协同式浮选机槽体内颗粒的运动与分布规律,有利于优化装置结构以及提高浮选效率。

     

    Abstract: In order to explore the movement and distribution of particles in the tank of jet and agitation co-flotation machine, a geometric model of the tank of jet and agitation co-flotation machine was established. The COMSOL software was used to simulate the flow field distribution and particle movement in the flotation tank under impeller agitation, and a test system of jet and agitation co-flotation device was set up to test the particle dispersion effect. The results showed that some particles pass through the gap between the impeller blades and spiral downward under the action of flow field, the other part of the particles are thrown out by the blade and move helically around and up under the coupling effect of the blade and the flow field. The trajectory curves of all particles were drawn to explore the particle movement and distribution law during the operation of the flotation machine. It was found that the trajectory curves of particles at the bottom of the flotation cell, around the wall and at the corner of the tank have a high coincidence degree, which indicates that the probability of particles moving there is large. The coincidence degree of particle motion trajectories in the upper part of the flotation tank and the area between the wall and the impeller is small, and the probability of particle movement there is low, and only a few particles are distributed there. The uniformity of particle distribution does not increase with the increase of impeller stirring speed, but there is an optimal impeller working parameter. The results of simulation and test showed that the jet and agitation co-flotation machine has better particle dispersion performance under the condition of impeller speed of 6.25 r/s. The particle dispersion is affected by the shape and internal structure of the tank. Adding baffle or using column flotation cell can effectively promote the uniform distribution of particles. The study of the movement and distribution of particles in the tank is beneficial to optimize the structure of the jet and agitation co-flotation machine and improve its flotation efficiency.

     

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