基于离散元法的粉碎机冲击力测试

Test of impact force of crusher based on discrete element method

为分析前后立式粉碎机粉碎内腔所受冲击力的情况及其影响因素,对改进前后立式粉碎机、中黄39大豆进行实体测量,测定其物理特性与力学特性,建立其EDEM模型并进行模拟仿真,得知:改进前后粉碎机粉碎下盖内腔所受冲击力均大于各自上盖内腔,改进后粉碎机下盖内腔所受冲击力大于改进前,改进前后粉碎机上盖内腔所受冲击力大小无明显区别。以1.01~1.20 s改进前后粉碎机粉碎下盖内腔所受冲击力为评价指标,研究不同大豆数目以及不同粉碎刀具的转速对下盖内腔所受冲击力的影响。结果表明:随着大豆颗粒从100粒增至800粒,改进前后粉碎机下盖内腔所受冲击力增大值出现在大豆数目为600左右。随着粉碎刀具转速从6200增至7000 rpm改进前后粉碎机下盖内腔所受冲击力逐渐增大。且在相同转速以及相同大豆颗数的情况下,改进后粉碎机下盖内腔所受冲击力均大于改进前。改进前后粉碎机下盖内腔所受冲击力最大值出现大豆数目为600,刀具转速为7000 rpm,其值分别为64.97与69.56 N,改进前后粉碎机下盖内腔所受冲击力最小值出现大豆数目为400,刀具转速为6200 rpm,其值分别为39.35与41.27 N.试验与软件仿真结果所得结论一致,该结果为研究立式粉碎机的粉碎内腔冲击力提供理论参考与依据。

In order to analyze the impact force on the inner chamber of the vertical mill before and after improvement and its influencing factors,the physical and mechanical properties of the improved vertical crusher and Zhonghuang 39 soybean were measured with the EDEM model established and simulated.It was found that the impact force on the lower cover of the crusher before and after improvement was greater than that on the respective upper cover.The impact force on the lower cover of the improved crusher was greater than that before improvement,and the impact on the upper was greater than that before improvement,without any obvious difference in strength.Taking the impact force on the inner of the lower cover of the crusher before and after 1.01~1.20 s improvement as the evaluation index,a study was made of the impact force on the inner cavity of the lower cover of the crusher with different number of soybeans and the rotational speed of different crushing tools.The results showed that with the increase of soybean particles from 100 to 800,the impact force on the inner chamber of the lower cover of the crusher before and after the improvement appeared in the number of soybeans about 600.The impact force on the inner of the lower cover of the crusher increases gradually with the increase of the rotational speed of the crushing tool from 6200 to 7000 rpm.Under the same rotational speed and the same number of soybean seeds,the impact force on the inner of the lower cover of the improved crusher is greater than that before the improvement.The maximum impact force on the lower cover of the mill before and after improvement is 600 soybeans,and the tool speed 7000 rpm,which are 64.97 and 69.56 N,respectively.The minimum impact force on the lower cover of the mill before and after improvement is 400 soybeans,and the tool speed is 6200 rpm,which are 39.35 and 41.27 N,respectively.The results of the experiment are in agreement with those of the software simulation,which provides theoretical reference and basis for the future study of the impact force in the crushing chamber of the vertical mill.