Aggregation Rate of Fine Particles in Turbulent Flows

Abstract

An aggregation rate equation for fine particle suspensions in a turbulent flow has been derived in this study on the basis of the Tchen equation and a Gaussian probability distribution of particle‐particle relative velocity, in which aggregation rate was correlated with a repulsive potential energy barrier. In the derivation, a capture efficiency term has been presented to estimate the correlation quantitatively. It has been found that capture efficiency depends on an initial aggregation rate constant, which can be represented by the slope of an E (aggregation degree) versus t (aggregation time) curve in a fine particle suspension at t → 0. Accordingly, capture efficiency could be experimentally determined through an aggregation kinetics test. In this work, this determination was tested with fine quartz and rhodochrosite suspensions in turbulent flows, and the results were compared with those obtained by computations based on the aggregation rate equation.

Keywords:

• Aggregation rate
• Potential energy barrier
• Fine particles
• Turbulent flows

Acknowledgment

Financial support for this work from the Consejo Nacional de Ciencia y Tecnologia (CONACyT) of Mexico under the grant #485100‐5‐38214‐U is gratefully acknowledged.