超细分级磨盘结构对粉碎腔流场的影响及优化

Influence and optimization of ultra-fine classification grinding disc structure on flow field in crushing chamber

非金属矿物材料加工中,超细分级磨是集超细粉碎与分级于一体的超细粉体制取设备,其原理是利用粉碎腔内磨盘的高速旋转,使粉碎腔内的物料与磨盘上的叶片发生激烈的冲击、碰撞等作用,在机械和气流的双重作用下被粉碎。研究粉碎腔内的机械结构、流场分布及影响因素对保证超细粉碎粒度、提高粉碎效率等方面具有重要的工程意义,实验采用计算流体力学软件Fluent对超细分级磨流场进行数值模拟仿真,通过单因素实验法,观察粉碎腔流场分布情况。实验结果表明:磨盘上的叶片数量和宽度变化对粉碎腔内气流速度影响较小,对粉碎腔内的气流压力和气流轴向速度影响较大;进入粉碎腔的物料运动至粉碎区域得不到充分分散,易造成团聚现象;利用模拟仿真结果对粉碎腔内的磨盘进行了结构优化,对优化结果进行了验证。

In the processing of non-metallic materials,the ultra-fine classification mill is an ultra-fine powder preparation equipment which integrates ultra-fine grinding and classification,whose principle is to make use of the high-speed rotation of the grinding chamber.The material in the grinding chamber has a fierce impact and collision with the blade on the grinding disc,and it is crushed under the dual action of machinery and air flow.The study of the mechanical structure,flow field distribution and its influencing factors in the crushing chamber has important engineering significance to ensure the ultra-fine grinding particle size and improve the grinding efficiency.In this paper,the flow field of ultra-fine classification mil is numerically simulated by computational fluid dynamics soft-ware Fluent,and the flow field distribution is observed by single factor experiment.The experimental results show that the change of the number and width of the blade on the grinding disc has little influence on the air flow velocity in the grinding chamber,but has a great influence on the air pressure and axial velocity in the grinding chamber.The movement of the material entering the grinding chamber is not fully dispersed to the grinding area,which is easy to cause agglomeration.The structure of the grinding disc in the grinding chamber is optimized by using the simulation results,and the optimization results are verified.