大叶片搅拌器在EVOH聚合釜中的数值模拟  

Numerical Simulation of Large-blade Agitator in EVOH Polymerization Reactor

作　　者：岳相丞 石艳 廖映华 罗一 林峰 YUE Xiang-cheng;SHI Yan;LIAO Ying-hua;LUO Yi;LIN Feng(College of Mechanical Engineering,Sichuan University of Science&Engineering,Yibin 644000,China)

机构地区：[1]四川轻化工大学机械工程学院,宜宾644000

出　　处：《科学技术与工程》2023年第27期11739-11746,共8页Science Technology and Engineering

基　　金：四川省科技厅重点研发项目(2022YFG0068)。

摘　　要：乙烯-乙烯醇共聚物(ethylene vinyl alcohol copolymer, EVOH)聚合是伴随放热的固-液两相湍流的复杂反应过程,在工程聚合中容易产生固体颗粒增大、颗粒间粘连和颗粒沉淀等影响颗粒聚合的理想悬浮状态,并且过程控制难以实现。为掌握EVOH聚合釜内的复杂运动规律,确定最佳聚合反应工艺参数,利用多重参考系(multiple reference frame, MRF)模拟非标新型大叶片EVOH搅拌聚合运动、欧拉模型模拟固-液两相流、湍流状态以标准k-ε湍流模拟和Wen-Yu模型的颗粒间作用,模拟仿真了颗粒直径为0.1~0.3 mm、转速为100~300 r/min区间范围的聚合反应过程。结果表明:新型大叶片搅拌下釜内漩涡区域明显增多、湍流程度加剧;叶片斜边处与底部的交接处,流速最大,湍流程度增加,减轻了颗粒沉积;固相体积分数随着颗粒直径增大逐步减小。在转速为100 r/min和颗粒直径0.1 mm时,聚合釜内各处固相体积分数接近原比例,有利于颗粒悬浮。EVOH polymerization is a complex reaction process accompanied by exothermic solid-liquid two-phase turbulence,making process control challenging.In attempting to comprehend the intricate motion law in EVOH polymerization reactor and determine the most productive polymerization reaction parameters,MRF(multiple reference frame)was employed to simulate the stirred polymerization motion of non-standard novel large-blade EVOH,the Euler model simulates solid-liquid two-phase flow,and the turbulent flow state simulates the interparticle interaction of standard k-εturbulence and Wen-Yu model.Additionally,particles with a diameter of 0.1~0.3 mm and a speed of 100~300 r/min were used to mimic the polymerization reaction process.The results demonstrated that the vortex area in the new large-blade stirring reactor,as well as the degree of turbulence,increased dramatically.The highest flow velocity,greatest turbulence,and lowest particle deposition are all observed at the junction of the beveled edge and the base of the blade.The polymerization reactor's solid phase volume fraction is close to the original proportion which is conducive to particle suspension at a speed of 100 r/min and a particle diameter of 0.1 mm.

关 键 词：EVOH聚合反应 固-液两相流 数值模拟 大叶片搅拌器 

分 类 号：TQ027[化学工程]