超声对受限撞击流微观混合性能的强化  

Effects of ultrasound intensification on micro-mixing performance in a confined impinging reactor

作　　者：杜强 陈律名 曾宏伟 陈冰冰[1] DU Qiang;CHEN Lyuming;ZENG Hongwei;CHEN Bingbing(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023,China)

机构地区：[1]浙江工业大学机械工程学院,浙江杭州310023

出　　处：《高校化学工程学报》2023年第5期740-748,共9页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(21908195)。

摘　　要：为了进一步提高受限撞击流反应器内纳米颗粒结晶性能,在反应器中引入超声场来强化反应器内入射流撞击区域上方“三角区域”流动与微观混合过程。采用Villermaux-Dushman平行竞争反应体系对超声强化的受限撞击流反应器内微观混合过程进行实验研究,使用离集指数、微观混合时间以及达姆科勒数对反应器内微观混合性能进行表征。结果表明:低频超声场通过诱导超声空化效应能有效地强化撞击流反应器内微观混合过程,低雷诺数时效果更为明显。与未施加超声相比,在超声作用下离集指数减小10.9%~23.5%,微观混合时间从0.00016~0.00043 s缩短至0.00014~0.00033 s。研究发现该反应器在所有工况下达姆科勒数均小于1,表明该化学反应由微观混合过程主导。In order to enhance the crystallization performance of nanoparticles in a confined-impinging jet reactor,an ultrasonic field was introduced to enhance the hydrodynamics and micro-mixing process in the"triangle zone"just above the impinging region in the reactor.The Villermaux-Dushman parallel competing reaction system was used to experimentally study the effects of ultrasound intensification on the micro-mixing performance in the confined-impinging jet reactor.The segregation index,micro-mixing time and Damkohler number Da were employed to characterize the micro-mixing performance of the impinging flow.The results show that low-frequency ultrasonic field can significantly enhance the micro-mixing process by inducing the ultrasonic acoustic cavitation in the reactor,especially when the Reynolds number is low.It is found that compared with the case without ultrasound,the segregation index is reduced by 10.9%to 23.5%under ultrasound irradiation.The micro-mixing time is also decreased from 0.00016-0.00043 s to 0.00014-0.00033 s with ultrasound.It is also observed that Da number of the reactor is always smaller than 1,which indicates the chemical kinetics is dominated by the micro-mixing process.

关 键 词：撞击流 超声强化 微观混合 离集指数 

分 类 号：TQ051.7[化学工程]