柱塞式压辊生物质成型机成型模具的设计

Design of molding die of plunger-type roller biomass molding equipment

[目的]对柱塞式压辊生物质成型机成型模具的设计方法进行改进,在此基础上探究成型孔入口结构和柱塞与成型孔啮合深度对成型效果的影响,为成型模具的设计与成型品质的提高提供支持。[方法]建立压辊柱塞相对于环模成型孔的运动轨迹数学模型,根据数学模型提出设计成型孔入口与柱塞结构尺寸的理论方法。利用理论方法设计柱塞与成型套筒并进行加工,以用于后续生物质成型试验。采用自主研制的液压驱动单柱塞生物质成型机,以柠条粉为原料,成型孔入口结构为变量设计单因素试验,探究成型孔入口结构对成型效果的影响,进而采用改进后的成型孔入口结构,以原料含水率、柱塞与成型孔啮合深度以及成型孔长径比为变量设计三因素三水平正交试验,探究啮合深度对提高成型块松弛密度和抗跌碎性的影响,并确定最佳成型工艺参数。最后在柱塞式压辊生物质成型机上进行验证试验,对单因素试验和正交试验结果进行检验。[结果]通过改进方法设计的柱塞与成型孔间不发生干涉,无需建模仿真验证,简化了设计步骤。采用阶梯形成型孔入口,并适当增加柱塞与成型孔啮合深度有利于改善成型过程,提高成型品质。正交试验确定的最佳成型工艺参数为:生物质含水率22%,啮合深度1 mm,成型孔长径比为4.2。[结论]改进的理论方法使成型模具的设计更加简便快捷,对成型孔入口结构和柱塞与成型孔啮合深度的分析和改进为生物质成型品质的提高提供了技术支持。

[Objective] In this study, the design of molding die of a plunger-type roller biomass molding equipment was improved, and the influence of structure of molding hole entrance and meshing depth of plunger with molding hole on molding effect was explored to provide support for design of molding die and improvement of molding quality.[Method] A mathematical model of motion trajectory of plunger relative to molding hole was established, and a theoretical method for designing structure and size of molding hole entrance and plunger was proposed according to a mathematical model.Plungers and molding sleeves were designed and processed by theoretical method for subsequent biomass molding experiments.Using an independently developed hydraulically driven single-plunger biomass molding equipment and Caragana korshinskii powder, a single-factor experiment was designed to investigate the influence of structure of molding hole entrance on molding effect.Using the improved molding hole entrance structure, a three-factor three-level orthogonal experiment was designed with moisture content of raw material, meshing depth between plunger and molding hole, and aspect ratio of molding hole as variables to investigate the influence of meshing depth on relaxation density and shatter resistance of the briquettes and determine the optimal molding process parameters.Finally, a verification experiment was performed on the plunger-type roller biomass molding equipment to verify analysis results of the single-factor experiment and orthogonal experiment.[Result] There was no interference between plunger and molding hole designed by the theoretical method, and the design steps were simplified because modeling and simulation verification was no longer required.Adopting the stepped molding hole entrance and appropriately increasing meshing depth of plunger with molding hole were conducive to improving molding process and quality.The optimal molding process parameters determined by orthogonal experiment were 22% for biomass moisture content, 1 mm for meshing depth and 4.2 for aspect ratio of molding hole.[Conclusion] The improved theoretical method made the design of molding die easier and faster.The analysis and improvement of structure of molding hole entrance and meshing depth of plunger with molding hole provide technical support for improvement of biomass molding quality.