(320e) Mixing and Age Distribution in Turbulent Jet Mixers

In this talk, mixing and age distribution in industrial turbulent jet mixers will be discussed. Spatial distributions of mean age and higher moments of age in the reactors are obtained from CFD solutions of the steady transport equations. The spatial distribution of mean age reveals details of the spatial non-uniformity in mixing. Variances of age and the degree of mixing discussed by Danckwerts and Zwietering are computed. Blend time can be estimated from the mean age probability density function curves. Two types of jet mixers, angled jet and vertical jet mixers will be considered. Both types are widely used in process industries. Mixing and age distribution in the angled jet mixers have been presented previously and the main results will be reviewed. The results showed that the predicted blend time using mean age method agrees well with lab experiments and existing correlations. On the other hand, there has been no blend time correlations for vertical down flow jet mixer. Mean age method will be used to predict blend time and the results will be compared with available experimental data in literature. A correlation will be proposed based on the predicted blend time.