平模成型机结构参数对成型过程的影响

Influence of structural parameters on flat mould plate

为了研究生物质材料在平模成型机制粒过程中的塑性变形情况,针对平模成型机制粒过程中呈现出几何非线性、材料非线性和边界条件非线性的问题,采用连续介质力学方法建立生物质材料的力学模型并确定其本构关系,应用非线性有限元分析软件ABAQUS及其内置的Drucker-Prager Cap粉体物料本构模型,对生物质材料在平模成型机的挤压成型过程进行有限元数值模拟。结果表明:平模模孔锥角处的生物质物料挤压应力较大,由此造成物料在该处的塑性变形较为明显;减小模辊间隙和压辊直径可以促进物料的塑性变形,减小模辊间隙、增加压辊直径可以提高物料的压进量。由此得出:在平模模孔锥角处应加固模具防止损伤,模具应尽量减小模辊间隙和压辊直径以促进物料成型,而当模辊间隙一定时加大模辊直径有利于提高物料的压进量。研究结果可为平模成型机的制粒工艺及模具结构的优化设计提供借鉴和参考。

The utilization level of biomass energy is lower than that of petroleum, coal and natural gas. As the fourth richest energy resource, biomass energy can promote the improvement of energy structure and the environmental quality to realize the sustainable development, and has great significance for raising the rural economic development. How to convert and utilize biomass energy effectively has become an important subject in the field of energy and ecological environment. Biomass pellet fuel plane-die briquetting machine is an important equipment in biomass briquetting technology with good application and is currently a research and development focus area. In this study, the plastic deformation of biomass material during the granulation in flat die molding machine was investigated. To solve the nonlinear problems occurred when biomass material is extruded, the biomass extrusion process in flat die molding machine is numerically simulated by using ABAQUS and its Drucker-Prager Cap constitutive model for powder materials. The results showed that the bigger the compressive stress on the material around the orifice of the flat die, the more the material is plastically deformed. Reducing the gap of the die rolls and the diameter of the pressure roller can promote the plastic deformation of the material. Reducing the gap between the die rolls and increasing the diameter of the pressure roller can promote the feed of the material. The results provided a reference for the granulating process of the flat molding machine and the structural optimization of the mold.