Simulation analysis of microwave sintering of recycled building bricks based on three-phase porous medium model

Abstract

The visualization and quantification characteristics of numerical simulation can overcome many obstacles caused by experimental conditions and contribute to the development of the microwave sintering mechanism of recycled building bricks (RBB). However, existing research has paid little attention to the numerical simulation of the microwave sintering of RBB. This study considers the phase transition and mass transfer of three-phase porous media, and establishes a fully coupled model of electromagnetic, heat transfer, and three-phase porous media to study the thermal behavior of RBB under microwave irradiation. The results indicate that the electric field inside the cavity exists in a non-uniform form with high and low energy regions. The addition of RBB will see a redistribution of the electric field in the cavity. The non-uniform distribution of electric field and the selective heating of microwaves result in the appearance of hot and cold regions inside RBB during sintering. Phase transition and mass transfer are beneficial for improving the uniformity of temperature field. The geometric size and position of RBB will affect the uniformity of the temperature field of RBB, and adding SiC board can be effective to improve the uniformity.