The collision model between a single particle and a spherical cap bubble in a water medium

Abstract EN

A mechanistic model is developed to account for the collision between a single particle and a single bubble in a liquid medium.

Based on the model, two penetration criteria are established under which the particle is predicted to penetrate through the bubble if any of the two criteria is satisfied.

It is shown that the particle penetration is only a necessary, but not sufficient, condition for bubble disintegration in the case of single particle-single bubble collision.

The penetrated bubble is shown to deform into a doughnut shape and the subsequent bubble breakage is made through the necking mechanism of the doughnut-shape bubble.

Bubble disintegration occurs only if the penetrating particle has a diameter greater than the height of the doughnut-shape bubble.

The column is constructed of Plexiglas with an internal diameter 10 cm and a height of 180 cm.

Experiments are also performed for single particle-single bubble collision in water, using three different particles (2 mm, 3 mm glass beads and 3*3 mm PVC cylinder) with Reynolds no.

and Weber no.

are (953, 1512 and 840) and (5.68, 9.45 and 5) respectively.

Two markedly different collision phenomena are observed.

A small and / or light particle is unable to penetrate through the bubble and is ejected after collision.

A medium particle can penetrate through the bubble but may not break the bubble.

The two phenomena are all well predicted by the proposed model.