Hydrodynamics and Mixer-Induced Bubble Formation in Micro Bubble Columns with Single and Multiple-Channels

• Published in: Chemical engineering & technology Vol. 29; no. 9; pp. 1015 - 1026
• Main Authors: Haverkamp, V., Hessel, V., Löwe, H., Menges, G., Warnier, M. J. F., Rebrov, E. V., de Croon, M. H. J. M., Schouten, J. C., Liauw, M. A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.09.2006; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: Applied sciences; Bubble; Chemical engineering; Columns; Columns, Bubble; Exact sciences and technology; Flow pattern; Hydrodynamics of contact apparatus; Microprocess engineering; Microreactor; Cartography; Particle size; Two phase flow; Mixer; Prediction; Hydrodynamics; Flow field; Annular flow; Optimization; Design; Bubble; Particle size distribution; Flow regime; Bubble column; Gas liquid flow; Liquid flow
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.200600180

A hydrodynamic characterization of an industrially used gas‐liquid contacting microchannel device is discussed, viz. the micro bubble column of IMM. Furthermore, similar characterization of a gas‐liquid flow microchip of TU/e, with two tailored mixer designs, is used to solve fundamental issues on hydrodynamics, and therefore, to achieve further design and operating optimization of that chip and the IMM device. Flow pattern maps are presented in a dimensionless fashion for further predictions on new fluidic systems for optimum single‐channel multiphase operation. Bubble formation was investigated in the two types of mixers and pinch‐off and hydrodynamic decay mechanisms are observed. The impact of these mechanisms on bubble size, bubble size distributions, and on the corresponding flow patterns, i.e., the type of mixer design, can be decisive for the flow pattern map and thus, may be used to alter flow pattern maps. The bubble sizes and their distribution were improved for the tailored designs, i.e., smaller and more regular bubbles were generated. Finally, the impact of multi‐channel distribution for gas and liquid flow is demonstrated. Intermediate flow patterns such as slug‐annular flow, also found for single‐phase operation, and the simultaneous coexistence of flow regimes are presented, with the latter providing evidence of flow maldistribution. A hydrodynamic characterization of a micro bubble column, and of a gas‐liquid flow microchip with two tailored mixer designs is discussed, and used to solve fundamental issues on hydrodynamics, and, therefore, to achieve further design and operational optimization.