带齿形偏心捏合块双螺杆三维流场分析

Three-Dimensional Flow Field Analysis of Twin Screw with Tooth Eccentric Kneading Blocks

针对传统双螺杆挤出机的混合性能较差,提出了一种带齿形偏心捏合块双螺杆结构,用以提升双螺杆挤出机的挤出品质。运用SolidWorks建立对应的几何模型,并在ANSYS/CFX有限元分析软件中对其流道进行三维流场分析,重点对宏观压力场、速度矢量场、速度流线场、剪切应变速率与挤出量进行讨论,并和传统双螺杆进行对比。结果表明:新型双螺杆流道压差较小,增加了物料停留时间;齿形偏心捏合块的存在使速度矢量分布不均,速度流线紊乱,剪切应变速率增大,提升了物料的分散混合效果。研究结果表明,新型双螺杆在保证挤出效率的基础上改善了挤出品质。

A twin screw extruder design featuring tooth eccentric kneading blocks was suggested to enhance extrusion quality due to the inadequate mixing performance of conventional twin screw extruders.The corresponding geometric model was established with SolidWorks,and the three-dimensional flow field was analyzed in the finite element analysis software ANSYS/CFX.The study examined and compared the macroscopic pressure distribution,velocity patterns,streamline paths,shear strain rates,and extrusion capacity between the proposed twin screw extruder design and the conventional twin screw configuration.w.The results show that the pressure difference of the new twin-screw runner is smaller and the retention time of the material is increased.The existence of eccentric kneading block makes the velocity vector distribution uneven,the velocity flow line disorganized,the shear strain rate increased,and the dispersion mixing effect of the material improved.The results show that the new twin screw can improve the extrusion quality on the basis of guaranteeing the extrusion efficiency.