Measurement and Simulation of Mass Transfer and Backmixing Behavior in a Gas-Liquid Helically Coiled Tubular Reactor
Measurement and Simulation of Mass Transfer and Backmixing Behavior in a Gas-Liquid Helically Coiled Tubular Reactor
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DOI：
10.1016/j.ces.2017.01.027
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发表时间：
2017-10
影响因子：
4.7
通讯作者：
M. Jokiel;L. Wagner;M. Mansour;N. M. Kaiser;K. Zähringer;G. Janiga;K. Nigam;D. Thévenin;K. Sundmacher
中科院分区：
文献类型：
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作者：
M. Jokiel;L. Wagner;M. Mansour;N. M. Kaiser;K. Zähringer;G. Janiga;K. Nigam;D. Thévenin;K. Sundmacher
采用两种不同的测量技术（氧光电管和氧敏染料的光学观察），测量了水平螺旋管反应器中细长泡状流态的体积传质系数（k L a）和Bodenstein数（Bo）。此外，气液传质和两相流的停留时间行为进行了描述与三维计算流体动力学（CFD）模型，也与一维两相模型。在这项研究中，16例涉及不同的气体和液体的体积流量产生的空气-水通过两个螺旋管的曲率比分别为δ 1= 0.093和δ 2= 0.3。表观气液雷诺数Re s，G和Re s，L以及气含率Re s，G分别为494 ~ 2483、1456 ~ 2713和0.46 ~ 0.81。传质实验表明，气液传质速率随液相表观速度和Re s，G的增大而增大。Bodenstein数随气相雷诺数的增加而减小，随液相表观速度的增加而增加。提出了描述传质和返混行为的关联式。计算结果与实验数据吻合良好。利用一维两相流模型，可以描述两相流在螺旋管中的停留时间行为。
Volumetric mass transfer coefficients (k L a) and Bodenstein numbers (Bo) for the elongated bubble flow regime in horizontal helically-coiled tube reactors are reported using two different measurement techniques (oxygen optodes, and optical observation of an oxygen-sensitive dye). Additionally, the gas-liquid mass transfer and the residence time behavior of the two-phase flow were described with a 3D Computational Fluid Dynamics (CFD) model, and also with a one-dimensional two-phase model. For this study, 16 cases involving different gas and liquid volumetric flow rates were employed to generate air-water flows through two helically coiled tubes with curvature ratios of δ 1= 0.093 and δ 2= 0.3, respectively. The superficial gas and liquid Reynolds numbers (Re s, G and Re s, L) and the gas hold-up (∊ G) are varied from 494 to 2483, from 1456 to 2713, and from 0.46 to 0.81, respectively. The mass transfer measurements show an increasing gas-liquid mass transfer rate with increasing superficial velocity of the liquid-phase and Re s, G. The Bodenstein number decreases with increasing gas-phase Reynolds number and increases with increasing superficial velocity of the liquid-phase. Correlations describing the mass transfer and backmixing behavior are proposed. The CFD results are in excellent agreement with the experimental data. With the 1D two-phase model it is possible to describe the residence time behavior of the two-phase flow through the helically coiled tube.