Small scale · Work package b and c
A transparent single-bubble column consisting of a 5 cm internal-diameter cylindrical test section surrounded by a square outer container, equipped with a controlled gas injection system and a two-camera stereoscopic imaging setup, designed to track individual bubbles and quantify their three-dimensional volume evolution with high spatial and temporal resolution. The square outer section provides flat optical interfaces around the cylindrical column, reducing image distortion during stereoscopic acquisition.
The facility is designed to investigate gas–liquid mass transfer at the single-bubble scale under well-controlled operating conditions. Individual bubbles are generated reproducibly and followed during their rise through the liquid phase. Two synchronized high-speed cameras observe the bubble from different viewing directions, while a controlled backlighting system provides high-contrast bubble contours. Following stereo calibration, the simultaneous images are combined to reconstruct the three-dimensional bubble geometry and determine its instantaneous volume, shape, position, and rising velocity.
Tracking the progressive decrease in bubble volume during CO₂ absorption provides a direct measurement of the gas transfer rate and enables the estimation of the liquid-side mass-transfer coefficient, independently of integral column-scale measurements. The facility therefore provides well-defined experimental data for investigating the coupling between bubble hydrodynamics, deformation, and mass transfer, as well as for the development and validation of single-bubble and CFD-based mass-transfer models.
Measurement set-up
