FLOW FIELD ANALYSIS OF THE KNEADING DISK REGION IN A CO-ROTATING TWIN SCREW EXTRUDER
FLOW FIELD ANALYSIS OF THE KNEADING DISK REGION IN A CO-ROTATING TWIN SCREW EXTRUDER
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DOI：
10.1002/pen.760321903
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发表时间：
1992-10-01
影响因子：
3.2
通讯作者：
MANAS-ZLOCZOWER, I
中科院分区：
文献类型：
--
作者：
YANG, HH;MANAS-ZLOCZOWER, I
同向旋转啮合双螺杆挤出机广泛应用于聚合物的复合和共混。在同向旋转双螺杆挤出机的不同模块中，捏合盘是决定混合效率的主要部件。解决捏合圆盘区域流动问题的主要困难是由于圆盘旋转时复杂的几何形状和随时间变化的流动边界。本文采用流体动力学分析软件fidap对Werner&Pfleiderer ZSK-30同向旋转双螺杆挤出机捏合盘区域的流动模式进行了有限元模拟。通过选择一系列序列几何图形来表示一个完整的混合循环，解决了随时间变化的流动边界问题。流场的特征包括速度分布、压力分布、产生的剪应力和量化拉长流分量的参数lambda。后两个参数是分析混合效率最重要的参数。分析了设计变量（错开角、左、右构型）和加工条件（转速、轴向压力梯度）对流动特性的影响。
Co-rotating, intermeshing twin screw extruders are widely used in polymer compounding and blending. Among the different modules of the co-rotating twin screw extruder, the kneading discs are the dominant ones in determining mixing efficiency. The major difficulty in solving the flow problem in the kneading disc region arises from the complex geometry and the time-dependent flow boundaries as the discs rotate. In this work, a fluid dynamics analysis package-FIDAP-using the finite element method was employed to simulate the flow patterns in the kneading disc region of a Werner&Pfleiderer ZSK-30 co-rotating twin screw extruder. The problem of time dependent flow boundaries was solved by selecting a number of sequential geometries to represent a complete mixing cycle. The flow field was characterized in terms of velocity profiles, pressure distributions, shear stresses generated and a parameter lambda quantifying the elongational flow components. The last two parameters are the most important ones in analyzing mixing efficiency. The influence of design variables (stagger angle, right or left handed configuration) and processing conditions (rpm, axial pressure gradient) on the flow characteristics was analyzed.