摘要:为了研究 CXM 超细分级磨粉碎室内的粉碎机理,利用 Fluent 软件对粉碎室内的流场进行计算机数值模拟分析,并结合实验对粉碎室 的粉碎效果进行验证。结果表明,在齿形磨壁粉碎室内,磨盘与磨壁的最小间隙处,气流速度明显增大,且喷射气流冲向齿槽,有利于冲击粉 碎;齿形槽内涡流的存在,能增大颗粒之间碰撞的几率,提高粉碎室内的粉碎效率;在磨盘与磨壁间隙处,速度与动压力分布呈周期性变化趋势,有利于破坏物料环流层,避免过粉碎现象产生,同时在一定程度上起到分散作用,减少粉体团聚;配备齿形磨壁后,设备的台时产量提高,齿形磨壁粉碎颗粒的粒径主要集中在 10~45 μm,粒径分布较窄而且粒度满足粉末涂料的要求,节约巨大的涂装成本。
关键词:粉碎机理;粉碎室;数值模拟;齿形磨壁
Abstract:To study the comminution mechanism of grinding chamber in CXM ultrafine classifier mill,Fluent software was used to research the flow field of grinding chamber by computer numerical simulation analysis and verified the grinding effect of the grinding chamber by testing. The results show that in the tooth grinding chamber wall, the airflow velocity increases obviously at minimum clearance place of millstone and the wall. The jet-stream wind rushes to the tooth shape groove which is helpful for impact grinding. The existence of vortex can increase the collision probability of particles in the tooth shape groove and improve the grinding efficiency in grinding chamber. At clearance place of millstone and the wall, the cyclical change trend of speed and dynamic pressure distribution is helpful for destroying the material circulation layer. That can avoid the phenomena of over crushing,to a certain extent,has dispersion effect at the same time and reduces the powders agglomeration. The equipment unit capacity upgrades after equipping tooth grinding wall. Grinding particle sizes of tooth grinding wall are mainly concentrated at 10-45 μm.The particle size distribution is narrow and meets the requirements of powder coatings,which can save huge cost of painting.
Keywords:comminution mechanism;grinding chamber;numerical simulation;tooth grinding wall