小型可调间隙饲料制粒机设计与试验

摘要

Small-scale pellet mill has many advantages,such as small mass production,less energy and raw materials consumption and low costs.Recently many researches were focused on the pelleting experiments,but the lack of small-scale pellet feed machine had become a problem of the influence of different formulas and processing conditions on pellet feed quality.To solve the problem,a structure of small-scale pellet mill was designed,which consisted of ring die and its matching components,roller and its matching components,transmission mechanism,etc.The prototype was manufactured and the production experiment was conducted.The adjusting mechanism for the roller was located outside the chamber,so the gap between roller and ring die could be real-timely adjusted when the production was in process.The structure could ensure that the production of pellet feed would be non-stop.Based on elastic-plastic theory and continuum mechanics,the software Abaqus and its built-in Drucker-Prager Cap material model were used for the numerical simulation and analysis of the pelleting process.The simulation results showed that the gap between roller and ring die should be adjusted with the friction coefficient of raw materials;proper increase of raw materials' friction coefficient could avoid internal sliding and energy consumption,which could help to improve the yield and quality of pellet feed.Some suckling pig feed formula was taken as raw material to be produced,and the performance indicators of the pelleting mill were determined.The experiment results showed that the moisture content was 13.53％,diameter of the pellet feed was 3 mm,pellet durability index was 94.34％,hardness of pellet feed was 176.03 N,and productivity of the pelleting mill was about 42 kg/h.All the indexes met the design requirements,which could meet the production need of small-scale pellet mill.The design of the pelleting mill and experiment research provided reference for the pelleting technology and development of the similar equipments.%为实现小批量颗粒饲料生产,设计一种小型可调间隙饲料制粒机,包括环模及配套部件、压辊及配套部件、传动机构等.该制粒机特征为:压辊调节部件位于制粒机外部,能够在不停机的状态下实时调节模辊间隙,保证颗粒饲料的连续生产.同时设计了与该制粒机配套的控制系统.基于弹塑性理论,采用有限元分析软件Abaqus内置的Drucker-pragerCap本构模型对制粒机模辊挤压过程进行了数值模拟,模拟结果表明,模辊间隙的设置应与物料的摩擦因数相匹配,适当提高物料的摩擦因数能够避免物料内部滑移耗能,有利于提高颗粒饲料的产量和质量.制造样机并进行了生产试验,以某配方乳猪料为原料,进行制粒机作业性能指标的测定,结果表明:该制粒机生产的颗粒饲料成品含水率为13.53％,直径为3 mm,颗粒含粉率为3.27％,颗粒耐久度(PDI)为94.34％,颗粒硬度为176.03 N,生产率约为42 kg/h,各项指标均达到设计要求,满足小批量颗粒生产的要求.