Subburaj Rahul, Tang Yali, Deen Niels G
Power and Flow Group, Department of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Eindhoven Institute for Renewable Energy Systems (EIRES), Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Ind Eng Chem Res. 2023 Sep 12;62(38):15656-15665. doi: 10.1021/acs.iecr.3c02352. eCollection 2023 Sep 27.
In the concept of a microstructured bubble column reactor, meshes coated with catalyst can cut the bubbles, which in turn results in high interfacial area and enhanced interface hydrodynamics. In previous work, we developed a closure model for the fate of bubbles interacting with a wire mesh based on the outcomes of energy balance analysis. In this paper, the model is validated using Euler-Lagrange simulations against two experimental cases of microstructured bubble columns. Before validation of the model, the definition of the deceleration thickness, as used in the calculation of the virtual mass term, is refined to introduce the effects of liquid viscosity and wire thickness. Proceeding with the validation, the inclusion of our cutting closure model results in an excellent match of the bubble size reduction by the wire mesh with the experimental data. Consequently, the simulations produce a more accurate prediction of the reactor performance for the gaseous reaction in view of the pH and gas holdup profiles. The effect of liquid viscosity on the bubble size reduction by the wire mesh is replicated accurately as well. Noticeably, the significance of bubble coalescence and breakup in bubble dynamics overperforms the role of bubble cutting at high superficial gas velocities; thus, further improvement is needed there. Finally, based on the validated cutting model, we share some perspectives on the design of wire meshes to increase the bubble interfacial area.
在微结构鼓泡塔反应器的概念中，涂覆有催化剂的网板可以切割气泡，进而产生高界面面积并增强界面流体动力学。在之前的工作中，我们基于能量平衡分析的结果，开发了一个用于描述气泡与丝网相互作用命运的封闭模型。在本文中，该模型通过欧拉-拉格朗日模拟针对微结构鼓泡塔的两个实验案例进行了验证。在模型验证之前，对用于虚拟质量项计算的减速厚度定义进行了细化，以引入液体粘度和丝网厚度的影响。在进行验证时，纳入我们的切割封闭模型使得丝网对气泡尺寸的减小与实验数据完美匹配。因此，考虑到pH值和气体持液率分布，模拟结果对气态反应的反应器性能给出了更准确的预测。液体粘度对丝网减小气泡尺寸的影响也得到了准确再现。值得注意的是，在高气速下，气泡动力学中气泡聚并和破裂的重要性超过了气泡切割的作用；因此，在这方面还需要进一步改进。最后，基于经过验证的切割模型，我们分享了一些关于设计丝网以增加气泡界面面积的观点。
