为了研究仓壁材料性质、粒径对煤粉运动壁摩擦角的影响,用Jenike剪切测试仪,测试不同粒径煤试样在不锈钢板、碳钢板、环氧板3种常用仓壁材料上的运动壁摩擦力.结合Jenike松散物料流动理论,探讨了不同粒径煤试样运动壁摩擦系数的变化.结果表明:仓壁材料表面的粗糙度越大,煤粉的运动壁摩擦系数越大;材料刚度越大,煤粉的运动壁摩擦系数也越大;水分一定时,煤试样中小粒径煤粉含量越多,壁摩擦系数越大.同时,用离散单元法(DEM)对这一壁摩擦过程进行模拟研究.分析比较模拟结果和实验结果表明:数值模型能够有效模拟实验过程,仓壁材料粗糙度、刚度以及煤粉粒径对壁摩擦系数的影响规律与实验结果相同。
Effects of particle size and wall material on wall friction characteristics of pulverized coal were investigated by means of Jenike shear test. The wall materials include stainless steel, carbon steel and epoxy. Combining Jenike's theory of flow of particulate solids, the variation of friction co- efficient of pulverized coal with different particle size was studied. Results show that the wall friction force increases with the increasing in roughness and stiffness of wall materials, and also increases with the increasing in fine particle content of coal under same moisture capacity. On the other hand, the friction characteristics of pulverized coal were numerically simulated using the discrete element method (DEM). Comparing the results of the simulation and the experiment, reasonable agreements are obtained.