(712c) Impact of Internals Size and Configuration On Bubble Dynamics in Bubble Columns

Slurry bubble columns have been used in wide range of applications in industry such as the Fisher-Tropsch synthesis and Liquid phase methanol synthesis among others. The effects of dense internals with different diameters and covering the same cross-sectional area and hence configuration on bubble properties are lacking in the open literature. Therefore the focus of this study is to investigate the effects of dense internals with different diameters and covering the same cross-sectional area and hence configuration on the bubble dynamics such as; specific interfacial area, local and overall gas hold-up, axial bubble velocity, bubble passage frequency and bubble chord lengths using four-points optical probe. The experimental work was carried out in 0.14 m diameter Plexiglas bubble column for an air-water system. The superficial gas velocities applied based on both total cross-sectional area as well as free cross-sectional area available for the flow were in the range of 0.03 to 0.45 m/s covering the bubbly flow regime through churn-turbulent flow regime. The internals used were both Plexiglas rods of 0.5-inch diameter and 1-inch diameter occupying 25 % of column cross- section area. The experimental data obtained suggest that 0.5-inch internals gave consistently higher overall and local gas holdup, specific interfacial area, and bubble passage frequency than the 1-inch internals or empty column particularly at the column center. The variation was insignificant for the gas holdup, particularly in the churn turbulent flow regime. While lower axial bubble velocity was obtained with the smaller diameter internals. Details of the results will be discussed during the presentation.