Performance estimation of a venturi scrubber and its application to self-priming operation in decontaminating aerosol particulates

To understand the performance of a venturi scrubber operating in self-priming mode, the present study develops a computational model to simulate the interacting three phase flow occurring in the venturi scrubber. The computational model is based on an Euler- Lagrangian framework where parcels of droplets and aerosols are tracked throughout the flow domain. The model incorporates the effect of droplet collision and increased momentum source in the regions of high liquid concentration. Additionally, the droplet inertial effects on the shear induced multi-jet breakup is included to predict the evolution of the droplet size distribution. The predicted local liquid loading, pressure drop and the collection efficiency were found to be in good match with the cited experimental values. The jet penetration and the droplet mean diameter is combined to form a unique dimensionless number, called the Performance Parameter, to quantify the multi-jet characteristics in the throat section of the scrubber. Higher values of Performance Parameter corresponded to higher efficiencies of the scrubber, hence serves as an analytical tool to assess the performance of the scrubber. Based on the parametric study for different throat gas velocities, liquid injection velocities, changing throat length and changing orifice diameter, the applicability of such a scrubber to self-priming mode is discussed. Further, for transients incurring lower gas velocities and lower operating height, the advantages of multi-stage injection and variable injection diameter are presented.