Design and Experimental Results of a DC Induction Heater Prototype for Aluminum Billets

The advantages of dc induction heating in high efficiency and good heating quality have been proved and studied worldwide in past decades. In this paper, a laboratory-scale dc induction heater with iron yoke for aluminum billets is designed and tested in detail. The billet to be heated is placed in the air gap of the yoke and is driven by a motor. The magnetic field in the gap is built up by copper windings with direct currents. The whole heating processes under different conditions are observed. Various surface temperature distributions have been achieved by changing several heating parameters including heating time, rotating speed, and dc magnetic field. Numerical analysis for calculating the heating process is also carried out in a commercial finite-element software. Results show that all the heating parameters will affect the final heating effects. Also, the numerical results agree well with the experimental results.