Effect of liquid phase properties and reactor geometries on the sauter mean diameter in a stirred tank reactor

Abstract

A stirred tank reactor have been used in various industrial fields due to its high yield and selectivity. Since mass transfer occurs at the interface of the droplets, predicting the size of the liquid droplets is important for the scale-up and modeling of the reactor. In this thesis, the factors influencing the size of the liquid droplets were analyzed by using a borescope method, and a correlation was made to estimate the Sauter mean diameter of the droplets. In addition, the size of the reactor increased from lab-scale to pilot-scale, thus the applicability of the study increased. In chapter 2, the effect of high pH and concentrated salt on the Sauter mean diameter was investigated. The density difference between two liquid phases was found to have a significant effect on the droplet size, and a correlation reflecting this effect was newly proposed to predict the Sauter mean diameter of the liquid droplets and mass transfer coefficient. Continue to chapter 3, by using the pilot-scale reactor, the effects of the dual impeller geometries on the Sauter mean diameter were analyzed. Therefore, the droplet size was measured with different impeller geometries, and the Sauter mean diameter correlation was newly proposed from the mean energy dissipation rate and the revised geometrical factor. In chapter 4, the effect of the liquid phase volume, impeller spacing, and the design and number of the multiple impeller on the Sauter mean diameter and the droplet size uniformity was investigated. It was verified that the impeller zone volume was inversely proportional to the Sauter mean diameter, if the area of the flow pattern produced by the impeller was assumed to be the impeller zone. In addition, droplet size uniformity was enhanced by increasing the diameter, blade angle, and number of the impeller.