On the measurement of local gas hold-up, interfacial area and bubble size distribution in gas–liquid contactors via light sheet and image analysis: Imaging technique and experimental results

In this work a novel experimental technique for measuring local gas hold-up, interfacial area and bubble size distribution, in gas–liquid systems is proposed. The technique is based on advanced Image Processing coupled with experimental set-ups typically available for Particle Image Velocimetry. A fluorescent dye dissolved in the liquid phase allows to identify in-plane bubbles among all visible bubbles in the images. To this end, a suitable algorithm is proposed. The raw data so obtained are processed by previously developed statistical methods that result in a reliable reconstruction of actual dispersion properties. The technique is applied to the case of a gas-dispersed mechanically agitated vessel, and the data obtained are presented and discussed. •Original data about gas–liquid dispersion properties in stirred vessels are presented and discussed.•The experimental technique is based on the adoption of a laser plane and a fluorescent liquid phase.•Highly detailed data can be obtained without affecting the system fluid dynamics.•Data presented are in agreement with the literature.