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.