392-400High intensity ultrasonic vibrations are known to be
efficient at destabilizing stationary foams. In this paper, the effect of the
application of ultrasonic vibrations generated by an ultrasonic bath has been
studied on the drainage of static foam. The vibrations are found to enhance the
drainage rate of the foam and the model could be extended to correlate these
drainage rates. This model can also be used to predict the variation in the
foam cell size and shape factor during drainage. The effect of type of sparger
and column diameter on the drainage rate has been studied. The rate of foam
collapse depends on the foam cell size, which in turn depends on the sparger
used for foam generation. The foam drainage and collapse rates were found to
increase with the decrease in the column diameter