Experimental Study on Inductive Heating Characteristics and Motion Behaviors of Metal Particles under Alternating Magnetic Field

Induction heating, characterized by rapid and clean heat generation, has seen emerging applications in industrial processing, such as heating and sterilization in the food industry. Currently, the primary method for fluid heating involves heat transfer through metal pipe walls, which suffers from significant temperature inhomogeneity. Heating metal particles within pipes can substantially improve thermal uniformity but encounters challenges of lower heating efficiency that hinder industrial adoption. Therefore, this study systematically investigates the induction heating power and energy conversion efficiency of metal particles with various properties under different excitation conditions, while also analyzing particulate flow behavior under alternating magnetic fields. The results show that the heat power and efficiency of nickel-coated iron particles increase with the excitation current, particle diameter, and bed mass and are superior to those of copper particles. However, due to magnetization caused by the alternating magnetic field, the fluidization behavior of nickel-coated iron particles deteriorates as the excitation current increases. In contrast, the motion of copper particles under an alternating magnetic field shows little difference compared to their behavior without the magnetic field, resulting in better fluidization performance than nickel-coated iron particles.