三螺杆挤出机螺纹元件流场分析

基于三角形排列的三螺杆挤出机的研究开发实践,对螺纹元件所形成的流场,特有的三个啮合区和中心区流场进行了模拟研究。通过对流速、流向、剪切速率、剪切黏度等挤出特性的剖析,说明这种三螺杆挤出机具有较强的输送能力;三个啮合区较其他区域有高的速度梯度、剪切速率;中心区存在瞬态环流和回流。在计算条件下,中心区的物料中的95％会在5 s内流出中心区,其余物料在中心区的停留时间不会超过100 s。

Analysis of Velocity Field in Screw Element Region of A Triple Screw Extruder

A simulation study of the flow field in screw element region, especially in the three inter-meshing zones and the center region for a triple screw extruder with triangle configuration was carried out. Through the analysis of simulated data fitting for extrusion characteristic, such as the velocity profile , flow direction, shear rate and shear viscosity, etc, it was showed that the machine has powerfully pumping capacity along with higher speed gradient and shear rate in the intermeshing zone, there are instantaneously rotational drag flow and flow back in the center region. With the calculating condition, it was found that 95 percent of the materials in the center region could flow out in only 5 seconds and the stay time for the remains was less than 100 seconds.