June 7th, 2019

Induction heating of wires, cables and tubular products

By Dr. Valery Rudnev

In the past four decades, heating by means of electromagnetic induction has become increasingly more popular. Growing environmental concerns in combination with the requirement of increasing production with reduced equipment footprint have
resulted in induction heating (IH) becoming the dominant method for heating ferrous and nonferrous wires, ropes, cables and tubular products in such applications as heat treatment, coating, drying, plating, bending, and others (Fig. 1). IH is also more energy efficient than most other heat sources.

The heating of tubes, pipes, and other hollow workpieces is somewhat different from the heating of solid bodies. With a solid
workpiece, there is considerable conduction of heat toward the colder core or centre of the heated workpiece. Besides, there are
no heat sources generated in the core regardless of the selected frequency when using solenoid-type coils, which are the most
popular designs.