三层桨叶结构及组合形式对搅拌釜内气液分散的影响  

Influences of Three-Layer Impeller Structure and Combination on the Gas-Liquid Dispersion in Stirred Tanks

作　　者：谢楠楠 陈和 易鑫 叶光华[1] 束忠明[1] 傅送保 周兴贵[1] XIE Nannan;CHEN He;YI Xin;YE Guanghua;SHU Zhongming;FU Songbao;ZHOU Xinggui(State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;Institute of Chemicals&Advanced Materials(Beijing)Company Limited,CNOOC,Beijing 102209,China)

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237 [2]中海油化工与新材料科学研究院(北京)有限公司,北京102209

出　　处：《化学反应工程与工艺》2025年第1期134-142,171,共10页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金(22378115);中海油集团公司科技项目(KJZH-2022-0026)。

摘　　要：桨叶对气液搅拌釜式反应器的传质和反应性能起到至关重要的作用。本研究建立并验证了一种耦合欧拉双流体模型和群平衡模型的气液搅拌釜计算流体力学模型,并利用该模型研究了三层桨叶结构及组合形式对气液分散性能的影响规律。当径向六抛物面叶片圆盘涡轮桨(PDT)和六箭叶圆盘涡轮桨(ABDT)置于底部,轴向四宽叶轴流桨(KYA)、四宽叶翼型桨(WHD)和斜四叶开启式涡轮桨(PBT)置于上部时,形成的流场结构相近,但PDT+2KYA桨叶组合中KYA排液量大,相比其他桨叶组合更有利于釜底物料更新。由于KYA排液量大,ABDT破碎气泡能力强,有利于延长气泡停留时间,因而PDT+2KYA和ABDT+2PBT搅拌釜均有较高的气含率。ABDT+2PBT桨叶组合对应的气泡尺寸最小,容积传质系数最高,单从传质性能考虑该桨叶组合最优。随着搅拌转速的提高,ABDT+2PBT和PDT+2KYA桨叶组合的容积传质系数接近,并且前者搅拌功率更大。高搅拌转速下PDT+2KYA桨叶组合对应的单位功率气含率和单位功率平均容积传质系数更高,综合考虑PDT+2KYA桨叶组合最优。这些研究结果可以为气液搅拌反应器的桨叶设计优化提供一些理论指导。Gas-liquid stirred tanks are widely used as reactors in the industry,and impellers play a critical role in affecting mass transfer and reaction in this type of reactor.A computational fluid dynamics(CFD)model coupling Euler two-fluid model and population balance model for gas-liquid stirred tanks is established and validated,and this model is used to study the influent of three-layer impeller structure and combination on the gas-liquid dispersion performance.When the six parabolic blade disc turbines(PDT)and six arrow blade disc turbines(ABDT)radial impellers are placed at the bottom,and four wide blade axial flow impellers(KYA),four wide blade airfoil impellers(WHD)and oblique four-blade open turbine impellers(PBT)axial impellers are placed at the top,the flow field structures are similar.PDT+2KYA combination is more favorable than the other combinations in updating the fluid at the tank bottom,due to the strong circulation ability of KYA.In addition,ABDT performs well in breaking bubbles,which are both beneficial in extending the residence time of bubbles.Thus,PDT+2KYA and ABDT+2PBT combinations both show large gas hold-up.ABDT+2PBT combination gives the smallest bubble size and thus highest volumetric mass transfer coefficient,indicating this combination performs best in terms of gas-liquid mass transfer.With the increase of rotational speed,the volumetric mass transfer coefficients of ABDT+2PBT and PDT+2KYA are close,but the former has a higher power consumption.PDT+2KYA conducts higher gas holdup per unit power and average volumetric mass transfer coefficient per unit power under a high rotational speed.Therefore,PDT+2KYA combination is optimal.These results can provide some theoretical guidance for the design and optimization of impellers for gas-liquid stirred tank reactors.

关 键 词：气液分散 搅拌釜 桨叶 传质 计算流体动力学 

分 类 号：TQ027.2[化学工程]