场协同对PP/PS复合体系传热传质性能的影响

从动量和能量守恒方程出发,提出速度场与温度场的协同耦合作用对聚合物流动与换热具有重要影响,并以此为依据设计了新型扭转螺杆结构和场协同螺杆。以聚丙烯(PP)和聚苯乙烯(PS)为原料制备PP/PS复合材料体系,通过挤出试验对比研究了常规螺杆与场协同螺杆的传热传质性能。结果表明,相对于常规螺杆,设置有扭转螺杆结构的场协同螺杆的数均粒径更小、粒径分布密度和平均停留时间更大,提高了挤出机的混合能力;场协同螺杆的对流换热系数更大、径向温差更小,提高了挤出机的换热能力。

Effect of Field Synergy on Heat and Mass Transfer Performance of PP/PS Composite System

In terms of the conservation equations of momentum and energy,the synergy effect from the velocity and tem-perature fields was proposed as an important influence factor on the flow and heat transfer of polymer.A novel torsion screw configuration and field synergy screw were designed,and the heat and mass transfer properties of conventional screw and field synergy screw were studied through extrusion experiments for the polypropylene/polystyrene compo-sites.The results indicated that the field synergy screws with a torsion screw configuration had a smaller average particle size,a larger particle size distribution density and a longer average residence time compared to the conventional screw.This can improve the mixing capability of the extruder.The field synergy screws had a larger convection heat transfer co-efficient and a smaller radial temperature difference,which improved the heat transfer ability of the extruder.