Investigation on the effect of geometrical parameters on the performance of a venturi type bubble generator

The venturi type bubble generator adopted in the fission gas removal system for the liquid-fuel thorium molten salt reactor plays a crucial role in strengthening the mass transfer rate. Aiming at clarifying how these three main geometrical parameters, including the injection hole diameter, injection hole number, and divergent angle, influence the bubble size distributions, an experimental study is carried out. The bubble size distribution is extracted from the images captured by the high speed visualization. Post processing algorithm is developed to detect the bubble edges and compute their Sauter mean diameters for each flow condition. By changing the value of each geometrical parameter, the variation of the bubble size distribution is obtained and discussed. It is shown that the injection hole diameter and number basically have little effect on the bubble size distribution while the divergent angle is proved to be sensitive. Finally, the reasons that account for the bubble size variation with three geometrical parameters are explained by the bubble turbulence breakup theory.