Simulação e experimentação da secagem de tijolos cerâmicos vazados.

Abstract

With application in various sectors, the materiais can be used for the manufacture of household goods, building materiais and even coating of spacecraft. In the manufacture of bricks (for example, the conformation and / or drying) may cause damage to structural cracks, distortion and warping that diminish the quality of the final product. Drying is a thermodynamic process, which is reducing the moisture content of the solid, by providing energy to it. Through the study of computer simulations can predict the behavior of variables such as moisture, temperature and stress inside the bricks, you can get a drying process faster and optimized, avoiding wastage of raw materiais and fuel economy. Seeking improvements to the drying process of clay bricks, this paper presents a numerical and experimental study of the drying process of a hollow brick. A three-dimensional transient mathematical model is presented to predict the mass transfer and heat to simulate the distribution of moisture content, temperature inside the solid, considering the symmetry around the center of the solid, constant thermophysical properties and volume change (shrinkage). For validation of the numerical experiments were carried out with drying hollow bricks industrial donated by eight holes "Cerâmica Cincera", located in Santa Rita-PB. In the experiments, were used drying temperatures of 50, 60, 70, 80, 90 and 100°C. It was found that for temperaturas of 50 and 60°C and relative humidity of 20,8% and 13,5% respectively the drying rate is lower, reducing the risks of product defects. Already at the drying temperatures of 80,90 and 100°C, there are high gradients of temperature and humidity inside the brick tensionally thermal water, causing large cracks and broken, especially in the corners and the inner walls of the holes especially in the initial process, apparently reducing the processing time because thecon tractions of the outer layer and above.