Mechanical control of foaming in a bubble column

This study was performed to evaluate the effects of the air sparge rate, working liquid volume, liquid feed rate onto the disk, and disk diameter on the foam-breaking performance of foam-breaking apparatus with a rotating disk (FARD) installed in the bubble column. Experimental results showed that the smaller the air sparge rate and working liquid volume were, and the larger the liquid feed rate and disk diameter, the lower the critical disk rotational speed required for reduced foam-breaking. The presence of the effective ranges of the disk diameter and liquid feed rate for foam breaking was also confirmed. Furthermore, the quantitative predictions of the upper limits of the liquid feed rate, foam-breaking regions, and the required foam-breaking power were carried out, based on the results obtained above. Comparison of the FARD with two conventional mechanical foam-breaking spray-type apparati also demonstrated the highest level of the FARD in respect not only to foam-breaking performance but also to power requirements.