Figure 11 The percentage of the binary breakup. (a)
versus drop diameter; (b) versus dimensionless diameter
(d/dmax) and compare with the experimental
result in a pulsed disc and doughnut
column 44.
Breakup rate
The drop breakup rate was determined experimentally based on Equation 1.
Figure 12 shows the results of the drop breakup rate using the drop
diameter as the abscissa. It can be seen from Figure 12a-c that breakup
rate monotonously increases with increasing drop diameter. Moreover,
Figure 12a,b indicated that the breakup rate gets larger for the larger
rotating speed and lower interfacial tension. The reason is that
increasing the rotating speed can strengthen the disruptive stress, as
is shown in Equation 4,5, which leads to an increase in the drop breakup
possibility. Besides, it is illustrated in Section 4.1 that the breakup
time is almost independent of the rotating speed, making the breakup
rate monotonously increases with the increase of rotating speeds. For
the lower interfacial tension and larger drop diameter, the interfacial
stress σ I = 6σ /d of a drop is
smaller, leading to the weaker ability to maintain drops without
deforming. Thus, the breakup rate is larger for the smaller interfacial
stress. Figure 12c shows the combined influences of interfacial tension
and dispersed phase viscosity. As the interfacial tension is little
different for the System No.1 and 5, the big distinction of the breakup
rate is attributed to the different dispersed phase viscosity.