单螺杆挤出机螺槽内混合特性的数值模拟  

Numerical simulation of the mixing ability of the channel in a single-screw extruder

作　　者：宗原[1] 戴干策[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200037

出　　处：《中国科技论文在线》2009年第3期207-213,共7页

摘　　要：将单螺杆挤出机简化为三维方腔,利用粒子轨迹跟踪技术和有限元法研究了螺杆转速和螺槽深度对内其混合特性的影响。研究表明,聚合物在螺槽中的流动形式介于活塞流和全混流之间,其混合机理主要基于剪切作用。相比于螺杆转速,螺槽的几何构型对螺槽内的混合性能影响较大,但由于物料在单螺杆挤出机中始终沿着单一流线运动,导致其混合效果不佳。因此,在改进单螺杆挤出机混合特性时,应从增加流体界面取向及延长形变历程考虑。The single-screw extruder is simplified as a 3D rectangle cavity and the flow field is simulated by means of FEM and particle tracing technology in order to determine its mechanism of mixing and evaluate the effect of the screw speed and channel depth on the mixing performance.The results show that the flow pattern in the screw channel is between plug flow and CSTR,and the extruder adopts primarily a shearing mechanism.Compared with the screw speed,the geometry of the screw channel has greater effect on the mixing ability of the extruder.Since the material points always stay on their streamlines in the extrusion processing,the effectiveness and efficiency of mixing in the single screw extruder is reduced.Therefore,strengthening the interface reorientation and elongation the strained time should be combined to improve the mixing ability of the single screw extruder.

关 键 词：高聚物工程 混合特性 有限元数值模拟 单螺杆挤出机 

分 类 号：TQ320.663[化学工程—合成树脂塑料工业]