Simulação numérica via CFD da secagem de tijolos cerâmicos industriais.

Abstract

The manufacture of ceramic bricks involves the steps of extraction of the raw material, lamination, drying and burning of the material. Drying is one of the stages that has the highest energy consumption, and understanding this phenomenon and reducing energy expenditure becomes crucial. This work aims to study theoretically the drying of industrial cast ceramic bricks. An advanced mathematical modeling to predict heat and mass transfer in the material along the process, based on the liquid diffusion model, is presented. Results of moisture reduction and temperature increase kinetics inside the material are presented. The numerical solution of the model was obtained via CFX software. It was found that the mass diffusivity varies strongly with temperature and that the position of the brick inside the kiln directly influences the moisture and temperature fields inside the brick and, consequently, in the quality of the final product. This means that in addition to air velocity, temperature and humidity, the air flow direction also affects the heating and drying kinetics and the distribution of heat and moisture in the solid material.