膨化机小模孔模具物料挤出过程的流场数值模拟与分析  

Numerical simulation and analysis of flow field of extrusion process in micro die hole of extruder

作　　者：阮伟豪 武凯[1] RUAN Wei-hao;WU Kai(School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学机械工程学院,江苏南京210094

出　　处：《粮食与饲料工业》2023年第6期37-41,共5页Cereal & Feed Industry

基　　金：江苏省科技成果转化专项项目(BA2020071)。

摘　　要：为了提高螺杆挤出小粒径膨化颗粒的效率与质量,利用POLYFLOW软件对直径为0.4 mm模孔的螺杆挤出过程进行了等温流场数值模拟,分析了模前压力、模孔过渡段锥孔角度等因素对模孔内熔体流场的影响。研究结果表明,随着物料进入模具前所受压力的增大,物料熔体在模孔中的流动速率、剪切速率增加,黏度降低,产量增大;不同过渡段锥孔角度下,熔体在模孔内的流动状态差异较小,各物理量的变化趋势随锥孔角度减小有所减缓,有利于物料均匀挤出。在实际生产中,提高模前压力、使用锥孔角度较小的挤出模板可以在一定程度上提高小粒径膨化颗粒的生产效率和颗粒质量。In order to improve the efficiency and quality of screw extrusion of small diameter puffed particles,the POLYFLOW software was used to simulate the isothermal flow field of the screw extrusion process with a diameter of 0.4 mm die hole.The effects of factors such as pre die pressure and transition angle of the die hole on the melt flow field inside the mold hole were analyzed.The research results indicated that as the pressure on the material before entering the die increases,the flow rate and shear rate of the material melt in the die hole increased,the viscosity decreased,and the yield increased.Under different transition cone hole angles,the flow state of the melt in the die hole had little difference,and the trend of changes in various physical quantities slowed down with the decrease of cone hole angle,which was conducive to the uniform extrusion of the material.In actual production,the production efficiency and quality of small size expanded particles could be improved to some extent by increasing the pressure before the die and using the extrusion template with small angle of cone hole.

关 键 词：膨化机 小直径模孔 挤出性能 数值模拟 流场特性 

分 类 号：S969.421[农业科学—水产养殖]