Experimental study of drop size distributions at high phase ratio in liquid–liquid dispersions

Effective interfacial area in agitated liquid–liquid continuous reactors

“…The failure of Eq. (2) in ÿtting the drop size data with a constant exponent of −0:6 was already reported by other authors, namely by Fernandes and Sharma (1967) for lower stirring range and more recently by Desnoyer et al (2003) that report the change of the Weber number exponent with the hold-up fraction for coalescent and non-coalescent systems. Desnoyer et al (2003) reported that this exponent decreases in absolute value with the increase of the hold-up fraction, assuming −0:6 only when hold-up fraction tends to zero, which conÿrms restrictions to this equation that depend also on composition.…”

“…am Ende, Eckert, and Albright (1995) studied the interfacial area of sulphuric acid and hydrocarbons dispersions using a stirred reactor and a constant cross-sectional area reactor, and concluded that interfacial area is dependent on hold-up fraction of the dispersed phase, on acid composition, on agitation speed and temperature and added that interfacial area reaches a maximum which depends on the volume of the continuous phase. Furthermore, these authors used image analysis and registered a bimodal distribution of droplets diameters that has been conÿrmed at high phase ratio by Desnoyer, Masbernat, and Gourdon (2003). This recent work also reports that, for the high phase ratio liquidliquid dispersions studied, the exponent on Weber number in Eq.…”

Representative drop sizes and drop size distributions in A/O dispersions in continuous flow stirred tank

“…Diameter of inviscid drop in correlation of Calabrese et al (1986a) A function of hold up in correlation of Desnoyer et al (2003) [−] K A constant in correlation of Rodger et al (1956) [−] n(ϕ)…”

“…This is not surprising considering that the drop size distributions in stirred liquid-liquid dispersions are highly system specific due to their being dependent on the physical properties of the phases, phase continuity, impeller type, mode of operation and geometric configuration of the mixer. Among the compared correlations, the correlation obtained with TBP containing organic as the continuous phase and an acidic phase as the dispersed phase (Desnoyer et al, 2003) exhibits the least deviation form the correlation given by Eq. (23).…”

“…Some of these studies are summarized in Table 1. Majority of them (Vermeulen et al, 1955;Rodger et al, 1956;Weinstein and Treybal, 1973;Mlynek and Resnick, 1972;Fernandes and Sharma, 1967;Brown and Pitt, 1974;McManamey, 1978;Calabrese et al, 1986a,b;Wang and Calabrese 1986;Nishikaw et al, 1987a,b;Laso et al, 1987;Chatzi et al, 1991;Zhou and Kresta, 1998;Pacek et al, 1999;Ruiz et al, 2002;Desnoyer et al, 2003;Giapos et al, 2005;Sechremeli et al, 2006) have been done on batch vessels. Only few of them have been done on continuous flow stirred tanks (Wienstein and Treybal, 1973;Fernandes and Sharma, 1967;Quadros and Baptista, 2003).…”