基于光滑粒子流体动力学(SPH)方法的环模制粒成型数值模拟方法研究

Numerical Simulation Method of Ring Die Pelletizing Based on SPH

环模制粒是饲料工业、生物质能源等领域广泛采用的工艺,其核心是单个模孔内物料的非连续挤压成形过程。针对饲料粉体、秸秆颗粒等松散物料环模制粒过程的非连续多次压制特征,提出了一种基于光滑粒子流体动力学(SPH)方法的环模制粒成形数值模拟方法,并针对单个模孔内物料的多次压制过程进行了仿真分析,研究了成型过程中物料的流动情况、密度变化情况以及多次挤压对压制力和颗粒密度的影响,并将仿真结果与已有研究中的结论相对比。结果表明,该成型过程经过4次压制后进入稳定状态;在进入稳定挤压状态前,模孔入口处物料的密度更大。该方法可应用于饲料粉体、秸秆颗粒等松散物料的模压成型数值模拟中。

Ring die pelletizing is a widely used process in the feed industry,biomass energy and other fields.The core of the process is the discontinuous extrusion of the material in a single die hole.A numerical simulation method of ring die pelletizing based on the smooth particle hydrodynamics(SPH) method was proposed for the discontinuous multiple pressing characteristics during the ring die pelletizing process of loose materials such as feed powder and straw pellets.And the simulation analysis was carried out for the multiple compression of the material in a single die hole to investigate the flow of the material during the forming process,the density change and the effect of multiple compression on the compression force and particle density.The simulation results were compared with the findings of existing studies.The results showed that:the molding process entered a steady state after four pressings;the density of the material at the entrance of the die hole was greater before entering the steady extrusion state.The method could be applied to the numerical simulation of loose materials molding such as feed powders and straw pellets.