颗粒凝聚力对筒仓装卸过程影响的研究
发布时间：2018-11-23 19:58
【摘要】：考虑到散体颗粒的凝聚力特性对筒仓装卸过程的影响,运用离散元分析方法对散体颗粒在筒仓中的堆积与流动过程进行计算分析,以期揭示筒仓卸料的内在机理。研究采用线性粘附接触模型和Herz-Mindlin无滑动接触模型进行数值模拟,得到了不同黏聚能量密度下颗粒在筒仓堆积过程中的力链分布、接触力变化,以及卸料过程中不同颗粒层的流动状态、速度分布和质量流率等相关评价指标。结果表明:在堆积过程中颗粒的接触矢量呈网状分布类似于桁架的结构,凝聚力使得接触力密度变得不均匀,但在颗粒堆积稳定后呈现出与干燥颗粒堆积力链分布相似的情况,颗粒黏聚能量密度由0变化至40 000J/m~3时法向接触力和切向接触力的变化量差异明显;在卸料时,凝聚力会造成颗粒流动的滞缓性;颗粒卸料的质量流率与颗粒间的凝聚力成反比。这对准确预测颗粒凝聚力对筒仓装卸过程所带来的影响,以及提高筒仓卸料效率具有重要意义。
[Abstract]:Considering the influence of cohesive characteristics of granular particles on the loading and unloading process of silo the discrete element analysis method is used to calculate and analyze the accumulation and flow process of granular particles in silo in order to reveal the internal mechanism of silo unloading. The linear adhesion contact model and Herz-Mindlin non-sliding contact model were used to simulate the distribution of force chain and the change of contact force during silo stacking with different cohesive energy density. The flow state, velocity distribution and mass flow rate of different granular layers in discharging process are also evaluated. The results show that the contact vector distribution of particles is similar to that of truss structure in the process of stacking. The cohesive force makes the contact force density become uneven, but the distribution of the contact force chain is similar to that of dry particles after the particle stacking is stabilized, and the distribution of contact vector is similar to that of truss structure. The change of particle cohesion energy density from 0 to 40,000 J / m ~ 3 in normal contact force and tangential contact force is obviously different. When discharging, the cohesive force will result in the tardiness of particle flow, and the mass flow rate is inversely proportional to the cohesion between particles. It is of great significance to accurately predict the effect of particle cohesion on silo loading and unloading process and improve silo unloading efficiency.
【作者单位】： 武汉理工大学物流工程学院;武汉理工大学港口物流技术与装备教育部工程研究中心;湖北工业大学机械工程学院;
【基金】：湖北省自然科学基金重点项目(2012FFA059)
【分类号】：O347.7
本文编号：2352548
[Abstract]:Considering the influence of cohesive characteristics of granular particles on the loading and unloading process of silo the discrete element analysis method is used to calculate and analyze the accumulation and flow process of granular particles in silo in order to reveal the internal mechanism of silo unloading. The linear adhesion contact model and Herz-Mindlin non-sliding contact model were used to simulate the distribution of force chain and the change of contact force during silo stacking with different cohesive energy density. The flow state, velocity distribution and mass flow rate of different granular layers in discharging process are also evaluated. The results show that the contact vector distribution of particles is similar to that of truss structure in the process of stacking. The cohesive force makes the contact force density become uneven, but the distribution of the contact force chain is similar to that of dry particles after the particle stacking is stabilized, and the distribution of contact vector is similar to that of truss structure. The change of particle cohesion energy density from 0 to 40,000 J / m ~ 3 in normal contact force and tangential contact force is obviously different. When discharging, the cohesive force will result in the tardiness of particle flow, and the mass flow rate is inversely proportional to the cohesion between particles. It is of great significance to accurately predict the effect of particle cohesion on silo loading and unloading process and improve silo unloading efficiency.
【作者单位】： 武汉理工大学物流工程学院;武汉理工大学港口物流技术与装备教育部工程研究中心;湖北工业大学机械工程学院;
【基金】：湖北省自然科学基金重点项目(2012FFA059)
【分类号】：O347.7
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