Liquid-liquid dispersion and flow characteristics in a miniaturized annular rotating device

Abstract

Liquid-liquid microchemical processes suffer from the problems of small handling capacity and large pressure drops. In particular, process intensification is highly required for high phase ratios of the dispersion phase to the continuous phase and high- viscosity conditions. In this study, we reported a novel microdispersion device named miniaturized annular rotating device (m-ARD), which is a novel microdispersion device with a large handling capacity, small pressure drop, and relatively narrow droplet distribution, even at a low phase ratio of the continuous phase to the dispersion phase and under high-viscosity conditions. Various parameters were studied to determine the dispersion of the generated droplets and the flow pattern, average droplet diameter, pressure drop, and hold-up of the dispersion phase. Two typical droplet generation routes, namely, dripping and jetting, and typical flow patterns, i.e., helical and annular flows were also obtained. Transition maps of the droplet generation route and flow pattern were constructed. The average droplet diameter and handling capacity were up to 380 μm and 30 mL/min, respectively. A small pressure drop was observed in the m-ARD. Furthermore, two dimensionless equations were developed to calculate the average droplet diameter and hold-up of the dispersion phase. This work provides a promising dispersion technology for the process intensification of liquid–liquid mass transfer and reactions.