The Terminal Velocity of Compound Drops in Flotation Units: E ect of Inner Bubble Size

The behavior of the terminal velocity of gas-liquid compound drops was studied experimentally. The e ect of the size of the internal bubble was analyzed, covering a wide range of relative sizes. The bubble signi cantly increased the buoyancy e ects, particularly for denser external uids. The terminal velocity increases with the size of the internal bubble, suggesting that the motion is governed by the geometry of the compound drop. A mechanistic model was proposed, and it showed a good agreement with the measurements.