Multi‐impeller mixing performance prediction in stirred tanks using mean age theory approach

Abstract

The mixing performance and power consumption for four dual‐impeller configurations in a stirred tank are studied using the mean age theory (MAT) approach, the fully transient techniques (FTT), and experiments. A novel method is developed based on the scaled mean age probability distribution curve, allowing the MAT method to be applied to multi‐impeller systems for the first time. The MAT approach provides three‐dimensional tracer distribution within the vessel, which is confirmed by FTT and experiments. Compared to the experimental data, the predicted mixing time from the MAT approach shows a deviation within 20%. This is a good degree of accuracy compared to FTT and correlations. For steady‐state predicted power numbers, a 20% deviation from the experimental data is observed, while the transient approach exhibits a lower deviation at 10%. However, the computational time can be reduced significantly using the steady‐state MAT approach.

Investigation of the Mixing Time Distribution and Connected Flow Fields in Two-Stage Stirred Vessels

“…The second main difference between this study and the majority of investigations found in the literature is the tracer addition, which usually takes place at the liquid surface [16][17][18][19]. Here, the dye enters the system via a custom 3D-printed injection baffle.…”