Ind. Eng. Chem. process Des. Dev, lg83, 22, 135-143 135 liquid-liquid dispersion. Since equal power per unit mass results in equal drop size, this implies that a bigger impeller can be employed to produce the same final drop size faster using the same amount of energy. Conclusion 1. Unsteady-state drop size, ita distribution, and the minimum transition time required to reach steady state during the initial period of liquid-liquid dispersion have been measured by using a microphotographic technique and a light transmittance method.2. The average drop size was found to follow the exponential decay rule.3. The drop size distribution changes from a very wide (multi-modal) distribution to a narrower (normal) distribution to, finally, a very narrow (skewed or log-normal) distribution as drop size becomes smaller and smaller.4. The minimum time required to reach a steady state is very strongly dependent on impeller size and speed and on tank size. At the same power input per unit mass, a larger impeller is more efficient. Nomenclature a = interfacial area per unit volume, m-l DI = impeller diameter, m DT = tank diameter, m d = particle or droplet diameter, m ds2 = Sauter mean droplet diameter defined by eq 2, m dS2* = Sauter mean droplet diameter at steady state, m I = emergent light intensity Io = incident light intensity ml, m2 = constants used in eq 1 n = number of drops N = impeller stirring speed, rpm T = fractional light transmittance = I/&,, dimensionless AT = fluctuation in T readings, dimensionless t = time, min t, = minimum transition time required to reach steady-stateGreek Letters a, 6 = constants used in eq 4 y = constant defined in eq 5 t = rate of energy dissipation per unit mass of fluid, W/kg p = viscosity, N.s/m2 p = density, kg/m3 9 = Kolmogoroffs length scale, m u = standard deviation based on dS2, m ' $d = volume fraction of dispersed phase, dimensionless Literature Cited Coulakglou, C. A.; Tavlarides, L. L. AIChE J . 1976, 22, 289. Lee, J. M. Ph.D. Dlssertatlon, University of Kentucky, Lextngtm, KY, 1978. McCoy, B. J.; Madden, A. J. Chem. Eng. Sci. 1969, 24, 416. Narslmhan, G.; Ramkrishna, D.; Gupta, J. P. A I C M J . 1980. 2 6 , 991. Roger. W. A.; Trlce. V. G., Jr.; Rushton, J. H. Chem. Eng. Prog. 1956, 52, Ross, S. L.; V e h f f , F. H.; Curl, R. L. Ind. Eng. Chem. Fundam. 1878, 77, Ramkrishna, D. Chem. Eng. Scl. 1974, 2 9 , 987. Skelland. A. H. P.; Lee, J. M. Ind. Eng. Chem. Process Des. Dev. 1978, Skelland, A. H. P.; Lee, J. M. AIChE J . 1981, 27, 99. Sprow. F. B. A I C M J . 1967, 73, 995. Vermeulen, T.; Williams, G. M.; Langlols, 0. E. Chem. Eng. Prog. 1955, 57, drop size, min 515. 101. 77, 473. 85-F.A strategy of model building In complex catalytic reaction systems is described based on the deployment of different types of laboratory reactors and independent measurement of pore diffusion within a single-pellet diffusion cell. The approach is applied to the kinetic modeling of simultaneous isomerlzation and disproportionation of a mixture of xylenes over a commercial silica-alumina catalys...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.