Numerical and experimental characterization of the hydrodynamics and drying kinetics of a barbotine slurry spray

Spray drying is a basic unit operation in several process industries such as food, pharmaceutical, ceramic, and others. In this work, a Eulerian-Lagrangian three-phase simulation is presented to study the drying process of barbotine slurry droplets for the production of ceramic tiles. To this end, the simulated velocity field produced by a spray nozzle located at the Institute of Ceramic Technology in Castello (Spain) is benchmarked against measurements obtained by means of laser Doppler anemometry in order to validate the numerical model. Also, the droplet size distribution generated by the nozzle is obtained at operating conditions by means of laser diffraction and the data obtained are compared qualitatively to those found in the literature. The characteristic Rosin-Rammler droplet size from the distribution is introduced thereafter in the three-phase simulation to analyse the drying kinetics of individual droplets. The model predicts the theoretical linear evolution of the square diameter (D-2-law), and the temperature and mass exchange with the environment. The proposed model is intended to support the design and optimization of industrial spray dryers. (C) 2018 Elsevier Ltd. All rights reserved.