Conditions for Accurate CFD Modeling of Spray-Drying Process

摘要

The paper presents concluding results of extensive experimental and theoretical research on confident CFD modeling of spray drying.An earlier developed experimental method to determine spray-drying kinetics in a lab scale allowed us to find a critical material moisture content and to determine generalized spray-drying curves.The generalized drying curves,identical in shape in the laboratory and pilot plant units,were used in the CFD model of spray drying process.Extensive simulations for spray drying of 10,30,and 50% of initial solid content of maltodextrin proved high accuracy of the predictions of discrete(particle size distribution,particle moisture content,particle velocity,spray temperature)and continuous-phase parameters(gas temperature and humidity).Maximum error of the predictions of discrete-phase parameters was on the level of 20%,which is probably close to the current capacity of the CFD technique for modeling of spray-drying process.Comparison of experimental measurements and theoretical results shows that incorporation of realistic spray-drying kinetics into the CFD model and correct definition of initial drying and atomization parameters enable reliable simulations of spray-drying process.