化工进展

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化工搅拌釜内流动测量技术的应用进展

杨 斌,高 凯,淡 勇,郝惠娣   

  1. 西北大学化工学院,陕西 西安 710069
  • 出版日期:2012-11-05 发布日期:2012-11-07

Development of the flow measurement techniques used in the experimental study of the chemical stirred tank

YANG Bin,GAO Kai,DAN Yong,HAO Huidi   

  1. School of Chemical Engineering,Northwest University,Xi’an 710069,Shaanxi,China
  • Online:2012-11-05 Published:2012-11-07

摘要: 搅拌釜内的物料混合是一个有限空间中的复杂非定常湍流问题,且常伴有强烈的传质、传热乃至反应过程。搅拌混合过程中影响因素多,理论分析难度大,实验获取搅拌釜内整场流动信息是其机理研究和搅拌混合设备优化设计的重要手段。本文归纳了在搅拌混合研究中传统流动测量技术的应用,分析其各自优缺点,着重探讨了新一代全场光学测速技术——粒子图像速度场仪(PIV)在搅拌混合实验中的应用,指出PIV在搅拌混合研究中具有广泛应用前景。PIV具有很高的空间分辨率和时间解析度,可以得到搅拌釜中混合流体的瞬时2D或3D速度场以及浓度场和温度场等信息,进行非定常湍流特性研究,有助于建立搅拌釜内多相流动模型,验证数值模拟结果,实现搅拌釜的优化设计,从而促进化工搅拌技术的进一步发展。

关键词: 搅拌釜, 混合, 湍流, 流场, 粒子图像速度场仪

Abstract: Mixing in a stirred tank is a complicated unsteady turbulent process,which occurs in a confined space,and often with the strong processes of mass transfer,heat transfer and even chemical reaction. Many factors affect the stirring and mixing process in a stirred tank,making it difficult to analyze the process theoretically. This paper reviewed the development of flow measurement techniques used to study the stirring and mixing process in past several decades. Advantages of conventional measurement implements for the flow rate were discussed in detail. In addition,Particle image velocimetry (PIV),a new optical whole field velocity measurement technique was introduced in this paper. PIV has higher space- and time-resolution. PIV technique could have the advantages of obtaining 2D or 3D instant velocity fields,density field and temperature field of the mixing flow,and development of turbulent structure in the flow. Experimental studies using PIV can provide great help for building multi-phase flow model in the stirred tank,validating numerical simulated results and performing the optimal design of the stirred tank. In summary,the application of PIV should advance the research of chemical stirring and mixing technology.

Key words: stirred tank, mixing, turbulence, flow field, particle image velocimetry(PIV)