同向啮合双螺杆挤出机挤出过程的计算机模拟

计算机模拟研究了聚苯乙烯在TSE-35A型同向啮合双螺杆挤出机的挤出过程.计算得到不同喂料速率与不同转速下的停留时间分布,并与在线荧光法测量值对比,二者基本相符.确定了停留时间与螺杆转速及喂料速率之间的函数关系式.模拟结果还预测了喂料速率、螺杆转速等工艺参数对双螺杆内流场变量,如温度、填充率、压力及粘度等的影响.模拟计算有助于了解双螺杆挤出机内部聚合物材料流动状态及停留时间长短,从而指导实际聚合物生产.

COMPUTER SIMULATION OF EXTRUSION PROCESS OF INTERMESHING CO-ROTATING TWIN SCREW EXTRUDERS

Numerical simulation of the extrusion process of polystyrene in a intermeshing co-rotating twin screw extruder was carried out to compute the residence time distribution(RTD) of the material particles and other flow field parameters in various processing conditions.The computed RTD was compared with the on-line measurement results,and a fairly good agreement was reached between them.Moreover,based on the numerical results,a definite relationship was determined for the influence of the screw rotation speed and feed rate on the residence time of the polymer melt.Numeric simulation results also predicted the profile of the flow field parameters such as temperature,filling ratio,pressure and viscosity along the axis of the screw under various processing conditions.The computer simulation method helps to investigate the internal flow state and residence time of the polymeric melt in a twin screw extruder and therefore helps to optimize the production.