基于DEM弛张筛面与颗粒群双向耦合的动态特性
|
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。
Two-way coupling between screen surfaces and particles can provide more actual reference to the system dynamic 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 compared with catenary to find relative tolerance,identifying the feasibility of equivalent method.The influence of eccentric mass,dip angles and size composition on screening efficiency,production ratio and vibrating velocity have been studied.The results indicate that screening efficiency will increase as each of three parameters decreased nonlinearly.Production ratio will decrease disproportionally with the increment of eccentric mass,which will reach minimum under 25% of hardscreening,but the relationships with dip angles and size composition is opposite.Additionally,the eccentric 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.
Two-way coupling between screen surfaces and particles can provide more actual reference to the system dynamic 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 compared with catenary to find relative tolerance,identifying the feasibility of equivalent method.The influence of eccentric mass,dip angles and size composition on screening efficiency,production ratio and vibrating velocity have been studied.The results indicate that screening efficiency will increase as each of three parameters decreased nonlinearly.Production ratio will decrease disproportionally with the increment of eccentric mass,which will reach minimum under 25% of hardscreening,but the relationships with dip angles and size composition is opposite.Additionally,the eccentric 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.
引文
[1]彭利平,刘初升,董海林,等.弛张筛面大挠度非线性变形分析与实验[J].煤炭学报,2014,39(5):976-980.PENG Liping,LIU Chusheng,DONG Hailin,et al.Nonlinear deformation analysis and experiment of large deflection of flip-flow screen surface[J].Journal of China Coal Society,2014,39(5):976-980.
[2] ZHAO Yuemin,LIU Chusheng,FAN Maoming,et al.Research on acceleration of elastic flip-flow screen surface[J].International Journal of Mineral Processing,2000,59(4):267-274.
[3] SONG Baocheng,LIU Chusheng,PENG Liping,et al.Dynamic analysis of new type elastic screen surface with multi degree of freedom and experimental validation[J].Journal of Central South University,2015,22(4):1334-1341.
[4]董海林,夏云飞,刘初升,等.张紧量对弛张筛筛面动力学参数的影响[J].选煤技术,2012(3):27-31.DONG Hailin,XIA Yunfei,LIU Chusheng,et al.Influence of tensional amount on dynamic parameters of surface of flip-flop screen[J].Coal Preparation Technology,2012(3):27-31.
[5]邹梦麒,刘初升,武继达,等.张紧量对单边驱动式弛张筛筛面动力学参数的影响[J].煤炭学报,2018,43(2):571-577.ZOU Mengqi,LIU Chusheng,WU Jida,et al.Influence of tensional amount on dynamic parameters of unilateral driven flip-flop screen surface[J].Journal of China Coal Society,2018,43(2):571-577.
[6]王新文,桑冬一,赵军生,等.弛张筛筛面安装方式对其寿命影响的分析研究[J].煤矿机械,2015,36(7):237-239.WANG Xinwen,SANG Dongyi,ZHAO Junsheng,et al. Analysis and research on effect of flip-flow screen surface installation to life[J].Coal Mine Machinery,2015,36(7):237-239.
[7] MUKHERJEE D.Discrete particle simulation techniques for the analysis of colliding and flowing particulate media[D]. Berkeley:University of California,Berkeley,2013.
[8]赵跃民,刘初升.弹性筛面上潮湿细粒煤炭筛分机理的研究[J].煤炭学报,2000,25(S1):206-208.ZHAO Yuemin,LIU Chusheng. Study on screening mechanism of moist fine coal on elastic screen surface[J]. Journal of China Coal Society,2000,25(S1):206-208.
[9] LIU Chusheng,JIN Xin L U.Study on nonlinear characteristic of particle motion during the process of coal screening[J].Journal of China Coal Society,2009,34(4):556-559.
[10] LI J,WEBB C,PANDIELLA S S,et al.Discrete particle motion on sieves-a numerical study using the DEM simulation[J]. Powder Technology,2003,133(1):190-202.
[11] CLEARY P W,SAWLEY M L.DEM modelling of industrial granular flows:3D case studies and the effect of particle shape on hopper discharge[J]. Applied Mathematical Modelling,2002,26(2):89-111.
[12] LI J,WEBB C,PANDIELLA S S,et al.A Numerical simulation of separation of crop seeds by screening-effect of particle bed depth[J].Food&Bioproducts Processing,2002,80(2):109-117.
[13] LIU Chusheng,WANG Hong,ZHAO Yuemin,et al.DEM simulation of particle flow on a single deck banana screen[J]. International Journal of Mining Science and Technology,2013,23(2):273-277.
[14] ZHAO Lala,ZHAO Yuemin,BAO Chunyong,et al.Optimisation of a circularly vibrating screen based on DEM simulation and Taguchi orthogonal experimental design[J].Powder Technology,2017,310:307-317.
[15] ZHAO Lala,ZHAO Yuemin,BAO Chunyong,et al.Laboratory-scale validation of a DEM model of screening processes with circular vibration[J].Powder Technology,2016,303:269-277.
[16] CURRAN M,ZHENG K,GUPTA H,et al. Handling rack vibra-tions in FSO-based data center architectures[A].In 2018 International Conference on Optical Network Design and Modeling(ONDM)[C].2018:47-52.
[17] CLEARY P W.Prediction of coupled particle and fluid flows using DEM and SPH[J].Minerals Engineering,2015,73:85-99.
[18] FERNANDEZ J W,CLEARY P W,SINNOTT M D,et al. Using SPH one-way coupled to DEM to model wet industrial banana screens[J].Minerals Engineering,2011,24(8):741-753.
[19] KRUGGEL-Emden H,ELSKAMP F.Modeling of screening processes with the discrete element method involving non-spherical particles[J]. Chemical Engineering&Technology,2014,37(5):847-856.
[20] ELSKAMP F,KRUGGEL-Emden H,HENNIG M,et al.Benchmarking of process models for continuous screening based on discrete element simulations[J].Minerals Engineering,2015,83(3):78-96.
[21] DONG K,ESFANDIARY A H,YU A.Discrete particle simulation of particle flow and separation on a vibrating screen:Effect of aperture shape[J].Powder Technology,2017,314:195-202.
[22] XIONG Xiaoyan,NIU Linkai,GU Chengxiang,et al.Vibration characteristics of an inclined flip-flow screen panel in banana flip-flow screens[J].Journal of Sound&Vibration,2017,411:108-128.
[2] ZHAO Yuemin,LIU Chusheng,FAN Maoming,et al.Research on acceleration of elastic flip-flow screen surface[J].International Journal of Mineral Processing,2000,59(4):267-274.
[3] SONG Baocheng,LIU Chusheng,PENG Liping,et al.Dynamic analysis of new type elastic screen surface with multi degree of freedom and experimental validation[J].Journal of Central South University,2015,22(4):1334-1341.
[4]董海林,夏云飞,刘初升,等.张紧量对弛张筛筛面动力学参数的影响[J].选煤技术,2012(3):27-31.DONG Hailin,XIA Yunfei,LIU Chusheng,et al.Influence of tensional amount on dynamic parameters of surface of flip-flop screen[J].Coal Preparation Technology,2012(3):27-31.
[5]邹梦麒,刘初升,武继达,等.张紧量对单边驱动式弛张筛筛面动力学参数的影响[J].煤炭学报,2018,43(2):571-577.ZOU Mengqi,LIU Chusheng,WU Jida,et al.Influence of tensional amount on dynamic parameters of unilateral driven flip-flop screen surface[J].Journal of China Coal Society,2018,43(2):571-577.
[6]王新文,桑冬一,赵军生,等.弛张筛筛面安装方式对其寿命影响的分析研究[J].煤矿机械,2015,36(7):237-239.WANG Xinwen,SANG Dongyi,ZHAO Junsheng,et al. Analysis and research on effect of flip-flow screen surface installation to life[J].Coal Mine Machinery,2015,36(7):237-239.
[7] MUKHERJEE D.Discrete particle simulation techniques for the analysis of colliding and flowing particulate media[D]. Berkeley:University of California,Berkeley,2013.
[8]赵跃民,刘初升.弹性筛面上潮湿细粒煤炭筛分机理的研究[J].煤炭学报,2000,25(S1):206-208.ZHAO Yuemin,LIU Chusheng. Study on screening mechanism of moist fine coal on elastic screen surface[J]. Journal of China Coal Society,2000,25(S1):206-208.
[9] LIU Chusheng,JIN Xin L U.Study on nonlinear characteristic of particle motion during the process of coal screening[J].Journal of China Coal Society,2009,34(4):556-559.
[10] LI J,WEBB C,PANDIELLA S S,et al.Discrete particle motion on sieves-a numerical study using the DEM simulation[J]. Powder Technology,2003,133(1):190-202.
[11] CLEARY P W,SAWLEY M L.DEM modelling of industrial granular flows:3D case studies and the effect of particle shape on hopper discharge[J]. Applied Mathematical Modelling,2002,26(2):89-111.
[12] LI J,WEBB C,PANDIELLA S S,et al.A Numerical simulation of separation of crop seeds by screening-effect of particle bed depth[J].Food&Bioproducts Processing,2002,80(2):109-117.
[13] LIU Chusheng,WANG Hong,ZHAO Yuemin,et al.DEM simulation of particle flow on a single deck banana screen[J]. International Journal of Mining Science and Technology,2013,23(2):273-277.
[14] ZHAO Lala,ZHAO Yuemin,BAO Chunyong,et al.Optimisation of a circularly vibrating screen based on DEM simulation and Taguchi orthogonal experimental design[J].Powder Technology,2017,310:307-317.
[15] ZHAO Lala,ZHAO Yuemin,BAO Chunyong,et al.Laboratory-scale validation of a DEM model of screening processes with circular vibration[J].Powder Technology,2016,303:269-277.
[16] CURRAN M,ZHENG K,GUPTA H,et al. Handling rack vibra-tions in FSO-based data center architectures[A].In 2018 International Conference on Optical Network Design and Modeling(ONDM)[C].2018:47-52.
[17] CLEARY P W.Prediction of coupled particle and fluid flows using DEM and SPH[J].Minerals Engineering,2015,73:85-99.
[18] FERNANDEZ J W,CLEARY P W,SINNOTT M D,et al. Using SPH one-way coupled to DEM to model wet industrial banana screens[J].Minerals Engineering,2011,24(8):741-753.
[19] KRUGGEL-Emden H,ELSKAMP F.Modeling of screening processes with the discrete element method involving non-spherical particles[J]. Chemical Engineering&Technology,2014,37(5):847-856.
[20] ELSKAMP F,KRUGGEL-Emden H,HENNIG M,et al.Benchmarking of process models for continuous screening based on discrete element simulations[J].Minerals Engineering,2015,83(3):78-96.
[21] DONG K,ESFANDIARY A H,YU A.Discrete particle simulation of particle flow and separation on a vibrating screen:Effect of aperture shape[J].Powder Technology,2017,314:195-202.
[22] XIONG Xiaoyan,NIU Linkai,GU Chengxiang,et al.Vibration characteristics of an inclined flip-flow screen panel in banana flip-flow screens[J].Journal of Sound&Vibration,2017,411:108-128.