张新, 武兵, 牛蔺楷, 熊晓燕, 董致新. 基于DEM弛张筛面与颗粒群双向耦合的动态特性[J]. 煤炭学报, 2019, (6). DOI: 10.13225/j.cnki.jccs.2018.1175
引用本文: 张新, 武兵, 牛蔺楷, 熊晓燕, 董致新. 基于DEM弛张筛面与颗粒群双向耦合的动态特性[J]. 煤炭学报, 2019, (6). DOI: 10.13225/j.cnki.jccs.2018.1175
ZHANG Xin, WU Bing, NIU Linkai, XIONG Xiaoyan, DONG Zhixin. Dynamic characteristics of two-way coupling between flip-flow screen and particles based on DEM[J]. Journal of China Coal Society, 2019, (6). DOI: 10.13225/j.cnki.jccs.2018.1175
Citation: ZHANG Xin, WU Bing, NIU Linkai, XIONG Xiaoyan, DONG Zhixin. Dynamic characteristics of two-way coupling between flip-flow screen and particles based on DEM[J]. Journal of China Coal Society, 2019, (6). DOI: 10.13225/j.cnki.jccs.2018.1175

基于DEM弛张筛面与颗粒群双向耦合的动态特性

Dynamic characteristics of two-way coupling between flip-flow screen and particles based on DEM

  • 摘要: 颗粒和弛张筛筛面的双向耦合可以为筛机的系统动力学分析提供更加可靠的参考依据,但利用离散元软件EDEM和动力学仿真软件RecurDyn在进行联合仿真时,EDEM不支持柔性体的计算。为了模拟弛张筛面和物料的动态特性,提出了线性分段插值的方法对筛板进行近似柔性化处理。首先计算了近似柔性筛面中点在静止状态和内死点时的挠度和筛孔收缩率,并和悬链线柔性筛面的相对误差进行比较,证明了近似柔性化方法的可行性。然后基于所建立的近似刚柔耦合模型,研究了偏心块质量,筛面倾角和入料粒度组成对筛分效率、生产率和颗粒速度等筛分性能指标的影响。结果表明:筛分效率,生产率和颗粒速度等筛分性能指标与偏心块质量,筛面倾角和入料粒度组成等参量之间均为非线性关系。筛分效率随着偏心块质量、筛面倾角和入料粒度含量的减小而增加;生产率随着偏心块质量的增加而减小,而生产率与筛面倾角、入料粒度含量之间的关系却相反,但难筛颗粒含量为25%时生产率最低,此外,为了考虑筛分效率和生产率同时达到最优,偏心块质量应取为0.5m0;颗粒运动速度随着偏心块质量和筛面倾角的增加呈递增趋势,但受入料粒度组成的影响较小。研究为进一步揭示潮湿细粒煤的运动规律和弛张筛筛面的动力学分析提供了思路。

     

    Abstract: Two-way coupling between screen surfaces and particles can provide more actual reference to the system dy- namic analysis of screening machine. However,the algorithm of flexibility is so complex that the part of contact of both cannot be calculated due to the disability of interface does not support the import of flexible models when performing co-simulation among EDEM and RecurDyn. Aiming at the problems proposed currently,the method of piecewise linear interpolation will be adopted to verify the equivalence of similar panels and flexible panels. Bending and shrunk ratio of pores have been calculated,under static and inner dead point position in the mid-point of similar panels,and com- pared with catenary to find relative tolerance,identifying the feasibility of equivalent method. The influence of eccentricmass,dip angles and size composition on screening efficiency,production ratio and vibrating velocity have been stud- ied. The results indicate that screening efficiency will increase as each of three parameters decreased nonlinearly. Pro- duction ratio will decrease disproportionally with the increment of eccentric mass,which will reach minimum under 25% of hard-screening,but the relationships with dip angles and size composition is opposite. Additionally,the eccen- tric mass is set as for optimum between screening efficiency and production ratio. The content of size composition has a less effect on particles velocities,while the increases of eccentric mass and dip angles lead to the increment of particles velocities gradually. This paper provides a research thought for further revelation of motion rules of moist fine coals and for dynamic analysis of flip-flow screen surfaces.

     

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