TBS干扰床分选机分选过程数值模拟

Numerical simulation on separation process of TBS

采用计算流体力学(CFD)和离散元素法(DEM)耦合技术对干扰床分选机(TBS)的分选过程进行数值模拟,研究TBS内部流场和颗粒运动特性及分选效果。研究结果表明:沿轴向运动的水流是TBS内流场的主要运动形式,随着高度的增加,在数值上水流的轴向速度和径向速度的差值逐渐增大,水流最终发展为趋于稳定的均匀流;分选桶中会产生涡环和短路流,随着上升水流速度的增加,产生涡环的位置逐渐升高,短路流流量也会随之增大。不同尺度的颗粒在TBS分选时的运动特性不同。颗粒密度相同时,从溢流口排出的颗粒,粒度越大,运动轨迹越长,停留时间越长;排矿口排出的颗粒,粒度越小,停留时间越长。结构参数影响TBS的分选效果,排矿口直径为150mm和200mm时,Ep值分别为0.110和0.107,分选效果较好。TBS分布板的开孔率为14%~16%时,分配率曲线接近重合,Ep值为0.107和0.109,分选效果最好。

The separation process of interference bed separator(TBS) was numerically simulated by the coupling technology of computational fluid dynamics(CFD) and discrete element method(DEM),and the flow field, particle movement characteristics and separation effect of TBS were studied.The results show that the axial flow is the main form of flow field in TBS. With the increase of the height, the difference between the axial velocity and the radial velocity of the flow increases gradually, and the flow finally develops into a stable uniform flow;vortex ring and short-circuit flow is produced in the separation drum. With the increase of the rising water velocity, the position of vortex ring gradually increases, and the flow of short-circuit flow also increases. The movement characteristics of particles with different sizes are different in TBS separation. When the particle density is the same, the larger the particle size is, the longer the trajectory and the longer the residence time is;the smaller the particle size is, the longer the residence time is. When the diameter of the discharge port is 150 mm and 200 mm, the Ep values are 0.110 and 0.107,respectively, and the separation effect is better. When the opening rate of TBS distributor is in the range of 14% to 16%,the distribution rate curve is close to coincidence, and the Ep values are 0.107 and 0.109,so the separation effect is the best.