Fundamentals of the hydrodynamic mechanism of splitting in dispersion processes
Article first published online: 17 JUN 2004
Copyright © 1955 American Institute of Chemical Engineers
Volume 1, Issue 3, pages 289–295, September 1955
How to Cite
Hinze, J. O. (1955), Fundamentals of the hydrodynamic mechanism of splitting in dispersion processes. AIChE J., 1: 289–295. doi: 10.1002/aic.690010303
- Issue published online: 17 JUN 2004
- Article first published online: 17 JUN 2004
The splitting of globules is an important phenomenon during the final stages of disintegration processes. Three basic types of deformation of globules and six types of flow patterns causing them are distinguished.
The forces controlling deformation and breakup comprise two dimensionless groups: a Weber group NWe and a viscosity group NVi. Breakup occurs when NWe exceeds a critical value (NWe)crit. Three cases are studied in greater detail: (a) Taylor's experiments on the breakup of a drop in simple types of viscous flow, (b) breakup of a drop in an air stream, (c) emulsification in a turbulent flow.
It is shown that (NWe)crit depends on the type of deformation and on the flow pattern around the globule. For case (a) (NWe)crit shows a minimum value ∼ 0.5 at a certain value of (NVi) and seems to increase indefinitely with either decreasing or increasing ratio between the viscosites of the two phases. For case (b) (NWe)crit varies between 13 and ∞, depending on NVi and on the way in which the relative air velocity varies with time, the lowest value refers to the true shock case and Nvi0. For case (c) (NWe)crit, which determines the maximum drop size in the emulsion, amounts to ∼1, and the corresponding values of NVi appear to be small. A formula is derived for the maximum drop size.