基于锥齿轮传动的变速三螺杆挤出机的三维流场分析

Three-Dimensional Flow Field Analysis of Variable Speed Three-Screw Extruder Based on Bevel Gear Transmission

针对传统三螺杆在豆粕加工过程中混合剪切性能较差的问题,基于锥齿轮传动设计了一种新型变速三螺杆的结构,旨在提高三螺杆挤出机的混合剪切性能。采用MATLAB软件的粒子群算法对螺杆的螺槽深度和螺距进行了优化处理。采用SolidWorks三维建模软件进行建模,基于有限元法ANSYS/CFX流道模块对豆粕在加工过程中的运动情况进行模拟,以传统三螺杆作为对照,分析其压力场、速度场和速度流线场等。结果显示,通过使用中性捏合块元件,可以有效减缓豆粕的流动速度,并对物料流进行多次分割和重新组合;内嵌变速装置的变速段螺杆起到了反向螺纹的作用,阻碍了物料的向前运输,且在与前段螺杆处产生回流。二者都使物料在流道中的停留时间延长,改善物料混合的均匀性。因此新型三螺杆挤出机相较于传统三螺杆挤出机,具有更优越的混合剪切性能。

In order to solve the problem of poor mixing and shearing performance of traditional three screw during soybean meal processing,a new variable-speed three-screw structure was designed based on bevel gear transmission,aiming to improve the mixing and shearing performance of the three-screw extruder.The particle swarm algorithm of MATLAB software was used to optimize the groove depth and pitch of the screw.SolidWorks three-dimensional modeling software was used for modeling.Based on the finite element method,the ANSYS/CFX flow channel module simulated the movement of soybean meal during processing.The traditional three-screw was used as a comparison to analyze its pressure field,velocity field and velocity flow.Line field etc.The results show that by using the neutral kneading block element,the flow speed of soybean meal can be effectively slowed down,and the material flow can be divided and recombined multiple times;the variable speed section screw with built-in variable speed device acts as a reverse thread,hindering the material flow.It is transported forward,and backflow occurs at the front screw.Both extend the residence time of materials in the flow channel and improve the uniformity of material mixing.Therefore,the new three-screw extruder has better mixing and shearing performance than the traditional three-screw extruder.