Large and small bubble breakup in gas–liquid centrifugal pumps

The present work studies bubble breakup in gas–liquid centrifugal pumps. Different inlet gas-fraction conditions are considered to provoke bubble-to-bubble, slug-to-bubble, and slug-to-slug pattern transitions. Results are presented for different mixture velocities and pump rotation frequencies. Data on mean equivalent bubble diameter and slug unit properties (length, passage frequency) are introduced. For small bubbles, a simple phenomenological theory is developed for the prediction of mean diameters. A discussion on the dynamics of small bubbles in the impeller region is also presented.