Air Dispersion and Bubble Characteristics in a Downflow Flotation Column

Bubble Sauter mean diameter and aeration rate of a gas-liquid system in a laboratory downflow flotation column were explored. Both critical coalescence concentration and Sauter mean diameter decreased with increasing superficial liquid velocity, and also the Sauter mean diameter was found to obviously increase with the increase in the sampling height under low dodecylamine concentration. The aeration rate increased as the dodecylamine concentration increased at a constant valve opening degree and also linearly increased as superficial air velocity increased at a constant superficial liquid velocity of 11 cm/s. Compared to the superficial air velocity, the dodecylamine concentration was found to present a larger effect on the Sauter mean diameter but a smaller one on the aeration rate within the studied ranges of the dodecylamine concentration and superficial air velocity.