Linear non-equilibrium thermal and deformation transport model for hematite pellet in dielectric and magnetic heating

Abstract

A linear non-equilibrium thermal and deformation transport model for hematite pellet in dielectric and magnetic heating was developed to demonstrate the drying behavior and mechanical performance. The moisture ratio profiles, temperature distribution and deformation fitted the experimental values well with reasonable deviations. The collapses and cracks were apt to appear along the circumferential directions of the hematite pellets. The pumping phenomenon occurred during the microwave drying according to the variation of the water saturation at the pellet surface. The maximum water saturation at the sample surface was 0.79, which also confirmed that no existence of water drops or films on the pellet surface. The heat flux driven by polarization relaxation could weaken the heat transfer during the whole drying process. The heat flux driven by the polarization relaxation at the higher electric and magnetic field intensities (3 × 103 − 6 × 103 V m−1, 10–20 A m−1) regions was higher than that at the lower ones (103 − 3 × 103 V m−1, 4–10 A m−1), and the electric-thermal effects also decreased with both the decreasing of the moisture content and electric field intensity in the sample.