In Eq.2, represents the number of breakup events within time in unit
volume for droplets within size interval from to . represents the
duration of the measurement. The droplet diameter is determined by in
the 2D images after measuring the long axis a and short axisb of the droplet. After and are counted from the video captured
by the high speed camera, DBFF can be determined.
The DBFF obtained above is then applied to determine the value of DIFT
by regression method based on Eq. 3, which was established in our
previous work based on systematical experiments 37.
The value of DIFT changes with the column height since the DBFF measured
at every height is different, because the mass transfer condition varies
along the column.