Microbubble Dispersion Process Intensification Using Novel Internal Baffles

A bubble generator is a crucial component in the flotation system, and the bubble size is directly related to bubble mineralization. This paper focused on the microbubble size control of a swirl flow microbubble generator. The computational fluid dynamics coupled population balance model (CFD-PBM) was developed to evaluate the flow characteristic and the bubble generation performance of the microbubble generator with five novel internal baffles. The results showed that the baffle could improve the bubble dispersion without extra energy loss, and the single helical baffle could generate tiny bubbles with a Sauter mean diameter of 0.36 mm at a liquid flow rate of 2000 L/h. The baffle could limit the positive axial velocity and hinder the tangential velocity effect in the straight pipe section, weakening the swirl flow effect. Hence, although the baffle slightly reduced the pressure gradient magnitude and the turbulent intensity, it still presented an effective improvement in the bubble dispersion.