Computational Fluid Dynamics (CFD) Modelling of ZnO-SiO2 Composite Through a Consecutive Electrospray and Spray Drying Method

Abstract

Modelling of the droplet formation and drying process in the synthesis of Zinc Oxide-Silicon Dioxide (ZnO-SiO2) composite have been conducted through a CFD modelling. In general, modelling of spray drying only focused on exploring the drying chamber section. The phenomenon builds in a consecutive electrospray and spray drying method has been successfully studied in this paper. The influence of carrier gas flow rate (2 to 10 L/min), precursor flow rate (1 to 10 ml/h), drying chamber temperature and applied voltage (12 to 14 kV) were investigated systematically. Numerical modelling was conducted to describe the mechanism of the composite droplet formation through the jet shape of the electrospray. Evaporation of the initial composite droplet was considered in the modelling, accounting for its size evolution. Simultaneous mass transfer modelling due to the composite evaporation was solved in combination with a general dynamic equation solution. The modelling results show that the applied voltage and the precursor flow rate effectively affected the composite droplet size. While the carrier gas flow rate and the drying chamber temperature, influenced the effectiveness of the composite particle formation in the spray drying synthesis.