Adam Kowalski

Comparison of a networks-of-zones fluid mixing model for a baffled stirred vessel with three-dimensional electrical resistance tomography

Reliable models for the simulation of mixing vessels are important for the understanding of real-life mixing problems. To achieve these models, information about the mixing in the system must be measured to compare with the predicted values. Electrical resistance tomography has the capability to measure spatial and temporal changes within a vessel in three dimensions even in optically inaccessible environments. This paper discusses the creation of a network-of-zones model for the prediction of mixing within a vessel with a Cowles disc-type agitator. Solving of the network-of-zones simplified transport equations for the vessel predicts the concentration distribution of an inert tracer added to the vessel. The change in this distribution with time is calculated and compared with visual inspection of the vessel. The concentration distribution inside the vessel is also measured using electrical resistance tomography and shows good agreement with the predicted values.

Mass transfer and chemical test reactions in the continuous flow rotor-stator mixer

This work is on mass transfer in liquid-liquid two-phase systems. To study mass transfer in the continuous flow in-line rotor-stator mixer, a method based on experimental determination of the product distribution of a set of complex chemical reactions has been applied together with drop breakage experiments. Experiments were carried out using the high-shear rotor-stator Silverson mixer for both drop dispersion and intensification of mass transfer. Volume fraction of organic phase was in the range between 0.01 and 0.015. The product distribution of complex reactions was determined based on high-performance liquid chromatography measurements. The drop size distribution was measured with the Malvern MasterSizer just after the process. Results of modeling of mass transfer with chemical reaction were used to characterise energetic efficiency of mass transfer.