【摘要】 为深入理解粉煤灰颗粒在旋转摩擦起电器内的运动特性,提高粉煤灰的荷电效果.采用标准k-ε湍流模型,结合颗粒轨道模型,分别以粒径为20,40和60μm的球形炭、灰颗粒为研究对象,对不同进气速率和摩擦轮转速下的颗粒运动进行数值仿真.模拟结果表明:颗粒在起电器内的运动行为和入口速率、摩擦轮转速、颗粒的粒径及种类均有关.在研究粒径范围内,颗粒粒径越大,平均速率越大,摩擦起电效果越好.粉煤灰颗粒的碰撞摩擦主要是与起电器外壳内壁面的碰撞摩擦以及颗粒和颗粒间的碰撞.入口速率和摩擦轮转速对颗粒的运动特性影响很大,最佳摩擦充电的条件为入口速率3 m/s,摩擦轮转速5 kr/min.颗粒在摩擦起电器右下方有堆积现象.该结论与文献中的实验结果基本一致,从而证明了本模拟结果的可靠性.更多还原

【Abstract】 In order to understand motion characteristics of fly ash particles in the charging chamber of rotary triboelectrostatic separator and improve the charging effect of fly ash, the standard k-ε turbulence model and particle trajectory model were adopted to simulate the motion of spherical carbon and ash particles with particle sizes of 20, 40 and 60 μm at different air feed rates and friction wheel velocities. The simulation results show that the movement behavior of particles in the charger is related to the inlet flow rate, the speed of friction wheel, the particle size and type. In the particle size range studied, the larger the average particle size is, the better the effect of friction electrification is.It has also been shown that the collision friction of fly ash particles is mainly the collision friction with the inner wall of charger shell and the collision between particles.The inlet flow rate and the speed of friction wheel have great influence on the motion characteristics of fly ash. The optimum separation conditions are 3 m/s inlet flow rate and 5 kr/min friction wheel speed. It is found that many particles accumulated in the lower right part of the friction charger. These results are in good agreement with the experimental results in literature, which proves the reliability of the simulation results.更多还原