Liquid Circulation and Swarm Dynamics in Bubble Columns with Internals


Liquid Circulation and Swarm Dynamics in Bubble Columns with Internals

Möller, F.; Hampel, U.; Schubert, M.

Bubble column reactors are apparatuses of choice for many gas-liquid and gas-liquid-solid reactions due to their superior mixing, heat and mass transfer behavior as well as their simple design without any moving part. In particular, they are often used for exothermic reaction processes such as methanol synthesis, Fischer-Tropsch synthesis etc. Hence, the heat has to be removed out of the system in order to guarantee safe operation at optimal reaction conditions. For this purpose a variety of heat exchangers e.g. internal heat exchanging tube bundles, which can also be used to generate steam, are applied. However, the effects of heat exchanger installation in bubble columns on the gas-liquid flow are still fragmentary.
This contribution focusses on the effect of internals on liquid circulation and swarm dynamics. Internal longitudinal flow heat exchanging bundles with various tube pattern configurations (triangular, and square pitch) and tube diameters between 8 and 13 mm while covering a cross sectional area of ~25% are subject to hydrodynamic and mixing studies in a column of 100 mm diameter.
Wire-mesh sensors with measurement points suitably distributed in the cross-section between the internals’ tubes were installed at different axial positions to study liquid mixing and dispersion in the bubble column as well as lateral fluid exchange between sub-channels. Tracer studies were performed and suitable transfer functions were applied for the determination of the liquid dispersion coefficient. It was found that bubble columns with tube bundle internals show similar behavior as airlift reactors. In addition, ultrafast X-ray tomography is applied to study the effect of the internal configurations on the axial bubble size distribution and gas fraction evolution as well as on the prevailing flow regimes.

  • Poster
    Jahrestreffen Bingen 2016 - Fachgruppen Agglomerations- und Schüttguttechnik, Mehrphasenströmungen und Computational Fluid Dynamics (AGG, MPH, CFD), 29.02.-02.03.2016, Bingen, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-24327
Publ.-Id: 24327