卧式单轴捏合反应器结构对流体流动与混合特性的影响  

Influence of the structure of horizontal single-shaft kneader on fluid flow and mixing characteristics

作　　者：杨立森 张先明[1] YANG Lisen;ZHANG Xianming(National Engineering Lab for Textile Fiber Materials and Processing Technology,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学纺织纤维材料与加工技术国家地方联合工程实验室,杭州310018

出　　处：《浙江理工大学学报（自然科学版）》2024年第2期161-173,共13页Journal of Zhejiang Sci-Tech University(Natural Sciences)

基　　金：国家自然科学基金项目(51973196);浙江省重点研发计划项目(2020C01010)。

摘　　要：为进一步分析卧式单轴捏合反应器内流体流动与混合特性,采用有限元方法与粒子示踪技术,通过数值模拟方法研究了高黏牛顿流体在不同结构卧式单轴捏合反应器内的流动与混合过程。首先,采用有限元方法对不同结构反应器内流体流动过程进行模拟,以分析反应器结构变化对流体速度分布、剪切速率分布和混合指数分布的影响规律;然后,采用粒子示踪技术对不同结构反应器内流体混合过程进行分析,以探究反应器结构变化对流体分布混合过程、拉伸率及混合效率的影响规律。结果表明:分布混合的实验结果与数值模拟结果吻合较好;高速度、高剪切区域的面积随捏合杆侧边长度的增加而增大;反应器内混合指数分布大于0.7所占的比例,随静态捏合杆数目和捏合杆侧边长度的增加而先增大后减小;增加静态捏合杆数目有利于强化分布混合过程;平均对数拉伸率随静态捏合杆数目和捏合杆侧边长度的增加而增大;平均时均混合效率随静态捏合杆数目的增加而先增大后减小,随捏合杆侧边长度的增加而增大。该研究得到的反应器结构变化对流体流动与混合特性的影响规律,可为卧式单轴捏合反应器的优化设计提供理论指导。To further study the fluid flow and mixing characteristics in the horizontal single-shaft kneader,the finite element method(FEM)and particle tracer technique were combined to study the flow and mixing processes of highly viscosity Newtonian fluid in a horizontal single-shaft kneader with different structures by numerical simulation.Firstly,the FEM was used to simulate the flow process of fluid in kneader with different structures,so as to analyze the influence of kneader structure changes on the fluid velocity distribution,shear rate distribution and mixing index distribution.Then,particle tracer technology was used to analyze the mixing process of fluid in kneader with different structures,so as to explore the influence of kneader structure changes on the fluid distributive mixing process,length of stretch and mixing efficiency.Results show that the experimental results of distributive mixing are in good agreement with the numerical simulation results;the area of high velocity and shear region increases with the increase of kneading bars side length;the proportion of mixing index distribution greater than 0.7in the kneader firstly increases and then decreases with the increase of the number of static kneading bars and the length of kneading bars;increasing the number of static kneading bars is beneficial to strengthening the distributive mixing process;the average length of stretch increases with the number of static kneading bars and the side length of kneading bars;the average time average mixing efficiency firstly increases and then decreases with the increase of the number of static kneading bars,and increases with the increase of the length of the side of the kneading bars.The influence law of kneader structure changes on fluid flow and mixing characteristics obtained can provide theoretical guidance for design and optimization of horizontal single-shaft kneaders.

关 键 词：单轴捏合反应器 数值模拟 反应器结构 分布混合 混合效率 

分 类 号：TQ320.5[化学工程—合成树脂塑料工业]