On the measurement of local gas hold-up and interfacial area in gas–liquid contactors via light sheet and image analysis

Particle image velocimetry techniques coupled with advanced image processing tools are receiving an increasing interest for measuring flow quantities and local bubble-size distributions in gas–liquid contactors.Aim of this work is that of providing a numerical procedure able to reconstruct local gas hold-up and specific interfacial area from images obtained by laser sheet illumination. A correction for measured quantities accounting for laser sheet thickness is proposed and tested by means of Monte Carlo simulations. The algorithms proposed are robust and independent of any measured parameters of the actual bubble size distribution.