摘要
针对微波反应釜搅拌混合均匀性问题,设计具有不同桨型组合的双层搅拌结构微波反应釜,其组合方式上下桨为推进式搅拌桨A100(A1)、上桨A200下桨A100(A2)和上桨A100下桨A200(A3)。基于计算流体力学CFD(Computational Fluid Dynamics)方法,采用层流模型、组分扩散模型和多重参考系方法对微波反应釜内醇油混合液的流动混合特性进行数值模拟,获得了具有3种不同组合桨反应釜内混合液的流动特性和不同加料位置下的混合时间特征。结果表明:组合桨A1釜内上下桨间存在一个轴向速度趋近于零的环流面,该面影响了釜内混合液的轴向流动混合;而组合桨A2、A3,改善了该环流面上的轴向速度分布,其最大轴向速度分别是组合桨A1的1.22,2.28倍,增强了上下桨间混合液的轴向迁移能力;加料点的位置会影响反应釜内混合液的混合时间,在理想加料点B加料时,组合桨A3的混合时间最短。
In order to investigate mixing uniformity in microwave reactor,the microwave reactors with dual stirring structure were designed,combined by the upper and lower impellers A100(A1),the upper impeller A200 and lower impeller A100(A2),and the upper impeller A100 and lower impeller A200(A3). Based on Computational Fluid Dynamics(CFD)method,laminar model,component diffusion model and multi-reference frame method(MRF)were used to simulate flow mixing characteristics of the alcohol-oil mixture in these microwave reactors.The flow characteristics of the alcohol-oil mixture and mixing time characteristics at different feeding positions in these microwave reactors were obtained.The results showed that there was a circulation flow surface with axial velocity approaching zero between the upper and lower impellers in microwave reactor with combined impeller A1,which affected the axial flow mixing of the mixture.The combined impeller A2 and A3 improved the axial velocity distribution on circulation flow surface,with the maximum axial velocity 1.22 times and 2.28 times of the combined impeller A1,respectively.Meanwhile it enhanced the axial migration capability of mixture between the upper and lower impeller.The position of the feeding point could affect the mixing time of mixture in microwave reactor.The combined impeller A3 obtains the shortest mixing time at the ideal feeding point B.The study provided a practical theoretical reference for the design,selection and application of the microwave reactor combined impellers.
作者
张玉
金光远
崔政伟
宋春芳
陈海英
ZHANG Yu;JIN Guang-yuan;CUI Zheng-wei;SONG Chun-fang;CHEN Hai-ying(Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology,Wuxi,Jiangsu 214122,China;School of Mechanical Engineering,University of Jiangnan,Wuxi,Jiangsu 214122,China)
出处
《食品与机械》
CSCD
北大核心
2018年第11期82-88,共7页
Food and Machinery
基金
国家自然科学基金资助项目(编号:21606109)
中央高校基本科研业务费专项资金资助(编号:JUSRP51634B)
江苏省研究生科研与实践创新计划项目(编号:SJCX18_0629)
关键词
微波反应釜
组合桨
组分扩散
混合时间
计算流体
力学
环流
microwave reactor
combined impeller
component diffusion
mixing time
computational fluid dynamics
circulation flow
