Two-phase hydrodynamics and aerosol mass transfer characterization in pool scrubbing: A simultaneous measurement technique

The bubbling of particle-contaminated gases through a liquid pool, called aerosol scrubbing, is a reliable, robust, and efficient collection technique to retain harmful aerosols from industrial processes or hazardous incidents. In this multiphase mass transfer phenomenon, the two-phase flow mechanics strongly influences the particle transport from the gas in the bubble to the surrounding liquid. The numerical and experimental studies have primarily focused on ideal flows and separate test effects. Here we developed a new experimental approach to assess the aerosol mass transfer and two-phase flow hydrodynamics simultaneously via tomographic conductivity measurements using a Wire-mesh sensor and an electrolytic aerosol scrubbed in a prototypical water column. The bubble phenomenology and size distribution can be effectively captured, and the aerosol deposition coefficient can be determined by measuring the electrolytic concentration increase in the liquid phase. Our integral results of the total retained mass in the column are compared with the aerosol mass concentration determined with filter measurements showing good agreement. We study the influence of the position and presence of the wire-mesh sensor on the results. The location has minor effects due to the high mixing level of the liquid phase. It is observed that the wire-mesh sensor could increase the mass transfer by not more than 5–10 %. We finally compare our mass transfer results with algebraic model predictions and suggest improvements to detect and study the mass transfer at the local bubble scale.