Aw. Pacek et al., VIDEO TECHNIQUE FOR MEASURING DYNAMICS OF LIQUID-LIQUID DISPERSION DURING PHASE INVERSION, AIChE journal, 40(12), 1994, pp. 1940-1949
Studies on the dynamics of phase inversion available offer limited inf
ormation due to the difficulty of following the transient mean and dro
p-size distribution. A new technique developed provides such data. A s
tereo microscope with a very shallow depth of field attached to a vide
o camera gives sharp images of droplets in intensely-agitated, immisci
ble liquid dispersions by using a Strobotach pulsing at the camera fra
ming rate. Droplets from 40 mu m upward at concentrations up to 70% by
volume dispersed phase can be measured accurately. Droplets of contin
uous organic phase in aqueous drops can be seen. The pictures can be a
nalyzed semiautomatically using a computer and in-house software to gi
ve, using a variety of discretizations, cumulative and frequency distr
ibutions to any base and any mean size. Means and distributions are a
function of time for phase inversions generated in three ways. The tec
hnique gives a powerful tool for understanding fast, complex dispersio
n processes.