摘要
循环射流混合槽作为一种高效的混合装置在化工过程强化处理技术中具有潜在的工业应用前景。由于缺乏对其内多相体系流动和混合行为的研究,制约了循环射流混合反应器的优化设计与工业化应用。本文选取水和二甲基硅油两相体系,采用计算流体力学软件ANSYS FluentV16.1中Eulerian-Eulerian多相流模型和SST k-ɷ湍流模型,对两种不同加料方式下循环射流混合槽内液液两相射流中心线速度、离析强度、拉伸率等参数进行研究。研究结果表明:分散相浓度(α_(d))增大射流卷吸能耗增大,在l/s<0.4内α_(d)=1.80%和2.86%量纲为1的射流中心线速度衰减趋势与α_(d)=6.00%相比减弱51%和21%;在低分散相浓度时,量纲为1的射流中心线速度随Re的增大衰减趋势变化小,在l/s<0.24内Re=6346、9519和12692量纲为1的射流中心线速度衰减趋势与Re=3173相比分别减弱2.60%、2.87%和12.69%。离析强度随混合时间的增大而减小,随周向角度增大呈W形变化趋势。在相含率和雷诺数相同时,对称球状较圆柱状加料达到混合时间减少65.5%;不同喷嘴之间的拉伸率随迹线长度的增大而增大,jet1和jet9位置处的拉伸率与其余喷嘴相比较大;相同喷嘴之间拉伸率随Re的增大而增大,Re=6346、9519和12692的拉伸率与Re=3173相比分别提高289%~320%、418%~454%和607%~667%。
As a kind of efficient mixing device,the circulating jet mixing tank has the function of chemical process intensification and has potential industrial application prospect.Insufficient study of the flow and mixing performance of multiphase system in the reactor restricts the optimal design and industrial application.In the present study,the two-phase flow of water and dimethyl silicone oil was considered.The Eulerian-Eulerian multiphase flow model and SST k-ωturbulence model in the computational fluid dynamics(CFD)software ANSYS Fluent V16.1 was adopted to investigate the dimensionless jet centerline velocity,segregation intensity,stretching rate of the liquid-liquid two-phase in the circulating jet mixing tank by two feeding methods.It is found that the energy consumption of jet entrainment increases with the increase of dispersed phase concentration(α_(d)).For l/s<0.4,the attenuation of dimensionless jet centerline velocity at α_(d)=1.80%and 2.86%weakens by 51%and 21%compared with that at α_(d)=6.00%,respectively.At low dispersed phase concentration,the increase of Re has little effect on the dimensionless jet centerline velocity.For l/s<0.24,the attenuation of dimensionless jet centerline velocity at Re=6346,9519 and 12692 weakens by 2.60%,2.87%and 12.69%in comparison with that at Re=3173,respectively.The segregation intensity decreases with the increase of mixing time.With the increase of circumferential angle,it presents a W shaped trend.Under the same conditions of dispersed phase fraction and Reynolds number,the mixing time in the CJT feed by the symmetrical spherical shape was reduced by 65.5%compared with that of the cylindrical shape.The stretching rate at different nozzles increases with the increase of the path line,and the stretching rate at the positions of jet1 and jet9 were larger than that of the other nozzles.The stretching rate of Re=6346,9519 and 12692 increased by 289%—320%,418%—454%and 607%—667%compared with that of Re=3173,respectively.
作者
孟辉波
刘振江
禹言芳
张平
吴剑华
MENG Huibo;LIU Zhenjiang;YU Yanfang;ZHANG Ping;WU Jianhua(School of Mechanical and Power Engineering,Shenyang University of Chemical Technology,Shenyang 110142,Liaoning,China;Liaoning Key Laboratory of Chemical Technology for Efficient Mixing,Shenyang University of Chemical Technology,Shenyang 110142,Liaoning,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2021年第11期5939-5948,共10页
Chemical Industry and Engineering Progress
基金
辽宁特聘教授计划(辽教函[2018]35号)
国家自然科学基金(21476142)
辽宁省教育厅项目(LQ2019003,LJKZ0429)
辽宁省“百千万人才工程”项目(201892151)
辽宁省自然科学基金(2019-ZD-0082)
沈阳市中青年科技创新人才计划(RC200032)。
关键词
循环射流混合槽
计算流体力学
两相流
混合
拉伸率
circulating jet tank
computational fluid dynamics(CFD)
two-phase flow
mixing
stretching rate