Model for HoldUp Measurements in Liquid Dispersions Using an Ultrasonic Technique

The spherical droplet correction time-averaged (SDTA) model is proposed, which permits estimation of the dispersed-phase holdup from the transmission time of the ultrasound wave through the dispersions. The SDTA model considers the effects of spherical and polydispersed drops on the path length of ultrasound wave transmission and the physical properties of both phases. This analysis also suggests that an estimate of phase inversion holdup can be made. The validity of this model is investigated for the two chemical systems of saturated water with toluene and saturated 0.2 M nitric acid solution with 30 vol % tributyl phosphate in n-dodecane. Experimental results show that the true holdup can be accurately measured with a relative error range between 0% and 7.7%. It is also shown that the ultrasonic technique can be employed on steel wall vessels of an extraction unit in a noninvasive and nonintrusive manner for continuous and safe monitoring.