Mass transfer measurement in a square milli-channel and comparison with results from a circular channel

The results show that the bubble dissolution curves in square channels are relatively even while the dissolution curves for bubbles in circular channels show some noticeable change in the slope. Furthermore, it is shown that the calculated liquid side mass transfer coefficient based on the measured data show good agreement with the data predicted by the penetration theory when the contact time between two phases is defined as the ratio of bubble length to the relative velocity. In addition, the comparison of the results with the data for circular channels showed that despite the fact that the rise velocity of bubbles in square channel is about three times faster than in circular channel, the liquid side mass transfer coefficients are approximately the same.