往复式单螺杆销钉挤出机典型螺纹元件混合性能研究

使用Polyflow有限元软件对往复式单螺杆销钉挤出机（简称Buss机）的三类典型螺纹元件内物料流动和混合过程进行了数值模拟。流场分析中使用了网格重叠技术。在得到流场速度分布后，基于粒子轨迹跟踪技术计算了物料微元在螺纹元件内的流动轨迹，并分析了Buss机螺纹元件内物料的动态混合过程。以分布混合指数和分隔比例为指标定量地对比了螺纹元件的分布和分散混合性能，在此基础上分析了加工条件、物料特性及销钉布置对Buss机混合性能的影响。数值模拟结果与前人研究有较好的吻合性。

Mixing Performances of Typical Screw Elements in Buss Kneader

In the present study, the flow and mixing characters of the typical screw elements in the reciprocating pin single-screw extruder were studied using a Polyflow finite element package. Based on the statistical treatment of the flow trajectories for a large number of the mass points which were located at the entrance of the screw element, the dynamic mixing process was analyzed. Furthermore, the distribution index and the segregation scale were applied to evaluate the distribution mixing and the dispersive mixing, respectively. At last, the effects of the operating conditions, material viscosity and the pins on the mixing performances of the extruder were also analyzed. Some of the numerical results were compared with previous results.