Mathematical model and numerical investigation of the influence of spray drying parameters on granule sizes of mold powder

In this work, the formation mechanism of the droplet-to-granule was investigated in detail based on mold powder manufacturing. A specific mathematical model of two-stage spray drying was established to describe droplet and granule motion, heat and mass transfer, and granule morphology during spray drying. Then, the relationships between spray drying parameters (inlet temperature, atomization pres-sure, slurry mass flow rate) and the properties of the drying tower (temperature and velocity fields) and mold powder granules (temperature, evaporation rates, moisture content, and diameter) were simulated and calculated using ANSYS/Fluent software. To ensure that the granule size of mold powder was controlled within the ideal range (0.2-0.6 mm) for producing granules with appropriate mechanical and metallurgical properties, the following optimum spray drying parameters were chosen based on the results of the numerical simulation: inlet temperatures, 873 K; slurry atomization pressure, 1.8 MPa; slurry mass flow rate, 0.05 kg s-1. Among these parameters, the slurry mass flow rate has the most significant effect on granule size.(c) 2023 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.