潮湿原煤颗粒在三自由度混联振动筛中筛分效率研究

Study on screening efficiency of moist raw coal particles on 3-DOF hybrid vibrating screen

为研究潮湿难筛分原煤颗粒在两平移一转动三自由度混联振动筛中的筛分效率变化规律,基于三维离散元法,运用EDEM软件模拟潮湿原煤颗粒的筛分过程.自主设计了两平移一转动三自由度混联振动筛,以研究各振动参数对原煤颗粒筛分效率的影响;综合采用动态筛分效率和阻碍粒排出率作为模拟筛分效率的评定指标,得出各自由度振动组合中的最佳激振模式及振动方向对潮湿原煤颗粒在筛面运动的作用;以动态筛分效率为参考值,采用正交实验方法,分析各因素对筛分效率的影响,得出影响因素分别为:外在水分、振动自由度、频率、振幅;用优选的筛分方案进行离散元模拟实验,验证了多维振动有利于潮湿难筛分原煤颗粒的分散、透筛及防堵.

To study the variation law of screening efficiency of difficult screened moist raw coal particles on the 3-DOF hybrid vibrating screen with two translational and one rotational degree of freedom which was designed independently to research the influence of various vibration parameters,EDEM software was used to simulate the screening process of particles based on DEM.Dynamic screening efficiency and hindering particles excretion rate were used as evaluation indices in simulation screening effect.Then the optimal excitation mode in each combination with all freedom was obtained as well as the effect of vibration direction on moist raw coal particle motion on screen surface.Orthogonal experiment was used in analyzing the effect of various factors on screening efficiency with dynamic screening efficiency as reference value.It was found that the Influence factors were external moisture,vibrational freedom,frequency and amplitude.The optimal screening scheme was used for the simulation experiment and the results verified that multidimensional vibration was beneficial to the screening process of difficult screened particles and could prevent jamming the screen holes.