双螺杆挤出机内聚合物和终止剂混合过程的数值模拟  

Numerical Simulation on Mixing Process of Polymer and Terminator in Twin Screw Extruder

作　　者：安澍 李伟龙 王连文 廖祖维[1] 黄正梁[1] 王靖岱[1] 阳永荣[1] AN Shu;LI Weilong;WANG Lianwen;LIAO Zuwei;HUANG Zhengliang;WANG Jingdai;YANG Yongrong(College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China;Yellow River Delta Jingbo Chemical Research Institute Company Limited,Binzhou 256500,China)

机构地区：[1]浙江大学化学工程与生物工程学院,浙江杭州310027 [2]黄河三角洲京博化工研究院有限公司,山东滨州256500

出　　处：《化学反应工程与工艺》2021年第3期203-210,共8页Chemical Reaction Engineering and Technology

摘　　要：针对聚合物在双螺杆挤出机中的流动及混合问题,通过有限元软件Polyflow对双螺杆挤出机中聚合物和终止剂的流动及混合特性进行数值模拟,获得了双螺杆挤出机内的压力分布、流体流动情况以及高黏聚合物和终止剂的混合过程。模拟结果表明:压力沿着挤出方向阶跃式升高,反向螺杆元件前产生高压区,随后压力突然下降;在径向截面处的剪切速率由大到小依次是螺棱>筒壁>螺杆表面。根据混合指数分布发现:在物料双螺杆挤出机的筒壁处主要承受剪切作用,而双螺杆表面和筒壁表面之间的部分,物料同时承受着剪切和拉伸作用。采用混合效率(α)表征终止剂加入挤出机内之后的混合程度,结果为α先快速升高,后升高的速率减慢,在900 mm之后保持稳定。For the flow and mixing performance of polymer in twin-screw extruder,the mixing process of polymer and terminator in twin-screw extruder were simulated by computational fluid dynamics(CFD)software Polyflow.The pressure distribution,flow state and mixing process of high viscosity polymer and terminator in twin-screw extruder were obtained.The simulation results showed that the pressure increased step by step along the extrusion direction,and a high-pressure zone was formed in front of the reverse screw element,and then the pressure dropped suddenly.In the radial section,the order of shear rate from large to small was flight,cylinder wall and screw surface.By the mixing index distribution,it was found that the shear flow was dominant in the wall of twin-screw extruder,and the material between the surface of twin-screw and the wall of cylinder bore shear and tensile action.The mixing efficiency was used to characterize the mixing degree after the terminator was added to the extruder.The result was that the mixing efficiency increased rapidly in the beginning,then increased more slowly,and finally remained constant after 900 mm.

关 键 词：双螺杆挤出 高黏度聚合物 流动混合特性 

分 类 号：TQ330.4-4[化学工程—橡胶工业]