聚丙烯环管反应器内颗粒粒径分析研究

摘要

Numerical simulation of the particle size distribution of propylene polymerization in the loop reactor was carried out by using computational fluid dynamics software. Based on the CFD-PBM coupled model, the fluid characteristics was simulated using quadrature method of moments (QMOM). The results indicated that in the reaction process, the particles were serious deposited in the fourth elbow. In order to improve the reaction rate and to theoretically explore the complicate flow behavior inside the reactor, the average particle size in three fluid cases, included particle aggregation, breakage and both coexisting, was discussed. When t = 40 min, the dynamic equilibrium between breakage and aggregation was reached, and the average particle size was about 283μm which coincided with data obtained from actual production. Therefore, this model could be used as a theoretical guide for improving the quality of industrial products.%利用计算流体动力学软件对环管反应器内丙烯聚合生成的颗粒粒径分布进行了数值模拟。以CFD-PBM耦合模型为基础，通过矩量法对反应器内流体流动行为进行模拟。结果表明，在反应过程中，颗粒在第四段弯管处囤积严重。为提高反应速率、从理论上探讨反应器内复杂的浆液流动情况,进一步研究了颗粒破碎、聚并以及破碎聚并这3种情况下颗粒的平均粒径变化情况。约40min后，颗粒在第四段直管段顶部达到破碎与聚并动态平衡时，平均粒径约为283μm，与实际生产数据相吻合。因此，该模型可作为提高工业产品质量的理论指导。