Basic experimental investigations on the hydrodynamics of bubble columns

Abstract

The aim of the present work is to investigate experimentally basic properties of the buoyancy-driven two-phase flow in bubble columns. The present report represents results from investigations on the turbulent liquid motion induced by the bubbles. The experimental hardware used was a small-scale bubble column with square-shaped cross section, oriented at the design from the Institute of Chemical Process Engineering (ICVT) of the University of Stuttgart. The capillary aerator produced bubbles with adjustable sizes of up to 5 mm. Gas void fractions up to around 3% were achieved. Measuring techniques employed were PIVILIF to get information about the gross-scale liquid and bubble motions, and LDA for acquiring data on the turbulent motion of the liquid. Results consist in spatial distributions of the mean velocities of the two phases, turbulence levels in the liquid, and power spectral density distributions at various locations in the flow field. These sets of information together yield insight into the turbulent behavior of this two-phase flow, which is of interest for various fields of process engineering.