Hydrodynamic correlations for bubble columns from complementary UXCT and RPT measurements in identical geometries and conditions

Many correlations have been developed to predict the hydrodynamics of bubble columns. Often, these studies are performed for incomparable systems in terms of column and sparger dimensions as well as physical fluid properties. In this work, a different approach is proposed comprising interrelated correlations for liquid velocity, gas holdup and bubble size. The correlations are developed on the basis of complementary experiments with non-invasive measurement techniques, namely, Ultrafast X-ray Computed Tomography (UXCT) and Radioactive Particle Tracking (RPT). The experimental setup consists of a bubble column equipped with a needle sparger. The developed correlations consider sparger dimensions, operating conditions and bubble size. The bubble size is applied as the characteristic length in the Reynolds and the Eötvös numbers, which are utilized for the gas holdup and liquid velocity correlations. In comparison with previous approaches, the developed correlations show better agreement with experimental data from this study as well as from the literature.