基于DEM的进料速率对颗粒筛分影响的研究

 振动筛是工程上常用的筛分设备，如何提高振动筛的处理量和筛分效率是振动筛设计和应用的主要问题。应用离散单元法(discrete element method, DEM)模拟和分析筛分过程，研究了进料速率对颗粒筛分效率的影响，结合工厂振动筛实验结果，分析了最佳筛分效率下的进料速率值。提出了分层和透筛细粒比的概念，拟合不同进料速率下分层和透筛区中细粒比与时间的变化曲线图，得到了细粒比随时间变化的函数关系式。运用分层和透筛中细粒含量随时间的变化率来表示分层速率和透筛速率，量化了筛分中分层和透筛过程。进一步分析了分层速率和透筛速率与进料速率的关系，得到最佳分层和透筛速率下进料速率的值。

Study on Feeding Rate Affected to Particle Screening Base on DEM

Vibrating screen is the most commonly used screening machinery in the industry. How to enhance screening capacity and efficiency is the major issue during the design and application. Discrete element method (DEM) was employed to simulate and analyze the sieving process. The influence of feeding rate on the screen efficiency was studied and the value of feeding rate under the optimal screen efficiency was obtained. In the study, the fine particle ratio in the stratification region or in the penetration region was defined. The curve of fine particle ratio changed with time was fitted and the functions represent the change of fine particle ratio were established. The change rate of the content of fine particle was used to study the rate of stratification and penetration and the process of stratification and penetration were quantified. Furthermore, the relationship between stratification and penetration rate and feeding rate was analyzed and the value of feeding rate under optimal stratification and penetration was also obtained.