Filtration of fine particles by multiple liquid droplet and gas bubble systems

The collection of small particles by a system consisting of multiple fluid spheres such as water droplets or gas bubbles was studied analytically. Kuwabara’s free vorticity model based on the solid particle system was extended to include the effects of induced internal circulation inside a liquid droplet or gas bubble system on the flow and the mass transfer rate. Using the resolved flow field, analytic solutions were obtained for the particle collection efficiencies due to diffusion and interception. The results were applied to the problem of particle capture by gas bubbles in liquid or by droplets suspended in gas. The results indicated that the particle collection efficiency by the multiple fluid sphere system is higher than that by a solid sphere system. This is due to the internal circulation which develops inside the fluid spheres