双层改进型推进式搅拌桨桨间距对 搅拌槽内流场的影响  

Effect of the Impeller Pitch of Double-layer Improved Propeller on Flow Field in the Stirred Tanks

作　　者：潘跃跃 杨其洲 徐阳 周勇军[1] PAN Yue-yue;YANG Qi-zhou;XU Yang;ZHOU Yong-ju(College of Mechanical and Power Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京211816

出　　处：《石油化工设备》2024年第6期8-14,共7页Petro-Chemical Equipment

基　　金：国家自然科学基金资助项目(52175171)。

摘　　要：采用粒子图像测速技术对不同桨间距C_(2)下双层改进型推进式搅拌桨槽内流场特性进行实验研究,并分别采用大涡模拟模型、标准k-ε模型以及RNGk-ε模型对搅拌槽内流场进行模拟预测。研究结果表明,桨间距C_(2)对搅拌槽内流型及速度分布有较大影响。当C_(2)=0.23H(H为液位高度)时,受上桨排出和卷吸作用的影响,下桨区域的旋涡无法成型,搅拌槽内物料混合效果不佳;当C_(2)=0.26H时,上桨叶区的高速区域较C_(2)=0.23H时增大了20%左右,下桨叶区高速区域增大了近25%,下桨叶区开始形成区域自循环;当C_(2)增大到0.29H时,两桨间逐渐出现低速旋涡和流动死区,同时混合效率降低。对比r/T(r/T为周向距离比)=0.4处的无因次化速度分布,发现采用大涡模拟模型得到的模拟结果与搅拌槽内流场的实验结果更接近。研究结果可为双层改进型推进式搅拌桨的实际应用提供参考。Particle image velocimetry was used to experimentally study the characteristics of the flow field in the stirred tank at different impeller pitches C_(2),and the large eddy simulation model,standard k-εmodel and RNG k-εmodel were used to simulate the flow field in the tank,respectively.The research results show that the impeller pitch has a great influence on the flow streamlines and velocity distribution in the tank.When the impeller pitch C_(2)=0.23H(H represents the liquid level height),affected by the upper impeller discharge and entrainment effects,the vortex of the lower impeller zone cannot be formed,and the mixing effect of materials in the tank would be poor;When the impeller pitch C_(2)=0.26H,compared with C_(2)=0.23H,the high-speed zone in the upper impeller zone increases by about 20%,the high-speed zone in the lower impeller zone increases by nearly 25%,and the lower impeller zone begins to form regional self-circulation.When the impeller pitch increases to C_(2)=0.29H,low-speed vortices and flow dead zone gradually appear between two propellers,meanwhile,the mixing efficiency decreases.By comparing the position at r/T(r/T represents the circumferential distance ratio)=0.4,it was found that the simulation results using the large vortex simulation model are closer to the experimental results of the flow field in the stirred tank.The research results provide a reference for the practical application of this stirring impeller.

关 键 词：推进式搅拌桨 搅拌槽 桨间距 粒子图像测速 大涡模拟 流场 

分 类 号：TQ027[化学工程]