What are the structure and composition characteristics of the induction coil of medium frequency induction heating equipment?

The induction coil is an important part of the medium frequency induction heating equipment and is necessary for the heat treatment of the workpiece. Therefore, whether the induction coil design is reasonable, whether the production quality is excellent, and whether the installation is in place, directly affects whether the equipment works normally. Our more common induction coil is made of extruded rectangular copper tubes and wound on a special mold. It not only ensures the rigidity of the coil, but also has a large conductive cross-section.

The coil material selected according to the IS0 431-1981 standard can obtain the smallest copper loss and achieve the highest electromagnetic conversion efficiency.

After the induction coil is wound and formed, it is dip-coated with high-temperature-resistant and high-voltage-resistant insulating paint, and then dried in a vacuum. The insulation level must reach H level (the withstand voltage of the insulation layer is greater than 7000V). Before assembly, the induction coil must undergo a water pressure withstand test of approximately 1.2MPa (12kg(f)/cm2) for 24 hours and a voltage withstand test of 7000V.

The upper and lower parts of the induction coil are equipped with stainless steel water-cooling rings to ensure that the furnace lining is corroded and heated evenly, and there are also Faraday short-circuit rings to fully absorb the leakage magnetic flux at the upper and lower ends to prevent the equipment from heating.

The induction coil is powered by large-section water-cooled cables with side leads. The coil pressing device uses stainless steel pull rods to tighten up and down. It is easy to disassemble and assemble, and it is convenient to replace the coil.

Usually, the inside of the induction coil and the gap between the turns are coated with refractory clay (about 10-15mm) with good insulation properties, which can facilitate the tamping of the furnace lining and prevent the cold and hot deformation of the furnace lining from affecting the service life of the furnace lining.