一种折流板单螺杆挤出机中流动与混合数值模拟  

Numerical Simulations of Flow and Mixing in a Baffled Single Screw Extruder

作　　者：冉可 喻慧文 陈金伟 谈灵操 黄卫扬 徐百平 RAN Ke;YU Huiwen;CHEN Jinwei;TAN Lingcao;HUANG Weiyang;XU Baiping(Key Laboratory of Intelligent Manufacturing of Polymer Materials,Wuyi University,Jiangmen 529020,China;Technology Development Center for Polymer Processing Engineering of Guangdong Colleges,Guangdong Industry Polytechnic,Guangzhou 510300,China;Guangdong Simcheng Plastics Machinery Co.,Ltd.,Foshan 528200,China)

机构地区：[1]五邑大学高分子材料智能制造重点实验室,广东江门529020 [2]广东轻工业职业技术学院广东省高分子材料先进加工程技术研究中心,广东广州510300 [3]广东仕诚塑料机械有限公司,广东佛山528200

出　　处：《塑料工业》2024年第6期89-96,共8页China Plastics Industry

基　　金：国家自然科学基金项目(11972023);广东省重点建设学科科研能力提升项目(2021ZDJS096)。

摘　　要：设计了一种折流板单螺杆结构,建立了熔体输送段几何模型。基于有限元叠加网格技术,采用Bird-Carreau纯黏性非牛顿流体本构模型,开展挤出过程三维流动与混合数值模拟研究。对比了机筒静止-螺杆正转与螺杆静止-机筒反转2种运动条件下的速度分布,发现两者的速度分布规律相同,证实2种运动条件下的流动特性与参考坐标系无关。相比普通单螺杆,新型折流板单螺杆的轴向速度沿程变化大,2种构型的挤出特性相似,相同压力梯度下,折流板单螺杆产量约降低20%。相同产量及螺杆转速条件下,折流板单螺杆混合指数提升、分离尺度减小,表明该结构进一步地提升了熔体输送段的分布分散混合能力。A baffled single screw structure was designed,and the geometric model of melt conveying zone was established.Based on the finite element method along with mesh superimposition technique(MST),the numerical simulations of three-dimensional flow and mixing in the extrusion process were carried out by using Bird-Carreau constitutive model of the purely viscous non-Newtonian fluid.The velocity distributions under the two conditions of static barrel and forward rotary screw,static screw and reversely rotary barrel were compared.The results show that the velocity distributions under the above assumptions are the same,proving that the flow characteristics are independent of the reference coordinate systems.Compared with the ordinary single screw,the axial velocity of the novel baffled single screw changes greatly along the axial direction.The extrusion characteristics of the two configurations are similar.Under the same pressure gradient,the output of the baffled single screw is reduced by 20%.Under the conditions of the same output and the same screw speed,for the baffled single screw,the mixing index increases and the segregation scale decreases.These results indicate that the baffled single screw further improves the distributive and dispersive mixing ability of melt conveying zone.

关 键 词：折流板单螺杆 数值模拟 分离尺度 混合指数 混合能力 

分 类 号：TQ320.66+3[化学工程—合成树脂塑料工业]