Rates of mass transfer from water drops into cyclohexanol and from drops of cyclohexanol, isobutanol, and o-toluidine into water were measured. These experimental data were augmented by published results, to cover, at drop Reynolds numbers less than 10, a Peelet number range of 0.01 to 5,000,000 for non-circulating spheres and 700 to 24,000,000 for circulating spheres. Transfer rates, expressed as Sherwood numbers, were in substantial agreement with those predicted from a theoretical model. The contribution of natural convection, inherent in the measurements, but omitted in the model, was approximately accounted for. Data for circulating spheres verified the hypothesis that internal motion affects the external transfer rate. This effect depends on the ratio of continuous to disperse phase viscosity of the system; a four to six-fold enhancement of mass transfer due to internal circulation was found for water drops falling in cyclohexanol.
Les auteurs ont mesure les taux de transfert de masse a partir de gouttes d'eau dans le cyclohexanol et a partir de gouttes de cyclohexanol, d'isobutanol et de o-toluidine dans l'eau. On a ajoute aux resultats experimentaux en puisant a meme des resultats publies pour balayer, a des nombres de Reynold inferieurs a 10 pour les gouttes, un champ correspondant a un nombre de Peclet allant de 0.01 a 5,000,000 pour des spheres ne comportant pas de circulation, et de 700 a 24,000,000 pour des spheres avec circulation. Les taux de transfert, exprimes sous forme de nombres de Sherwood, s'accordent assez bien avec ceux que l'on a predits a partir d'un modele theorique. On a tenu compte, de facon approximative, de l'effet de convection naturelle inherent aux methodes de mesure mais omis dans le modele. Les resultats pour les spheres comportant une circulation interne verifient l'hypothese que cette circulation affecte le taux de transfert a l'exterieur. L'effet note depend du rapport de la viscosite de la phase continue a celle de la phase dispersee; on a trouve un accroissement, par un facteur allant de 4 a 6, du transfert de masse attribuable a la circulation interne pour des gouttes d'eau tombant dans le cyclohexanol.
[1]
F. H. Garner,et al.
Mass transfer from single solid spheres by free convection
,
1961
.
[2]
O. Trass,et al.
Mass transfer from fluid and solid spheres at low reynolds numbers
,
1961
.
[3]
R. E. Treybal,et al.
Mass transfer from a solid soluble sphere to a flowing liquid stream
,
1960
.
[4]
R. M. Griffith.
Mass transfer from drops and bubbles
,
1960
.
[5]
A. Hamielec,et al.
Mass transfer inside drops
,
1960
.
[6]
Y. Kitaura,et al.
Mass Transfer from Single Spheres
,
1960
.
[7]
L. Scriven,et al.
Interfacial turbulence: Hydrodynamic instability and the marangoni effect
,
1959
.
[8]
S. G. Terjesen,et al.
On the action of surface active agents on mass transfer in liquid-liquid extraction
,
1959
.
[9]
R. B. Keey,et al.
Mass-transfer from single solid spheres—I: Transfer at low Reynolds numbers
,
1958
.
[10]
A. Hamielec,et al.
End effect corrections in heat and mass transfer studies
,
1958
.
[11]
A. Acrivos.
Combined laminar free‐ and forced‐convection heat transfer in external flows
,
1958
.
[12]
A. I. Johnson,et al.
Mixing studies on a perforated distillation plate
,
1958
.
[13]
D. Haydon.
An investigation of droplet oscillation during mass transfer I. The conditions necessary, and the source of the energy for the oscillations
,
1958,
Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.
[14]
T. Sherwood,et al.
Interfacial Phenomena in Liquid Extraction
,
1957
.
[15]
Thomas Baron,et al.
Mass and heat transfer from drops in liquid‐liquid extraction
,
1957
.
[16]
F. H. Garner,et al.
Some factors affecting droplet behaviour in liquid-liquid systems
,
1955
.
[17]
F. H. Garner,et al.
Mass transfer in fluid flow from a solid sphere
,
1954,
Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.
[18]
R. Gunn,et al.
The Evaporation, Temperature and Thermal Relaxation-Time of Freely Falling Waterdrops.
,
1951
.
[19]
H. Kramers,et al.
Heat transfer from spheres to flowing media
,
1946
.