In today’s demanding markets, our customers require equipment that
is efficient, affordable, and reliable. Hengyang Industry leads the
way in induction heating technology. Our goal is to bring induction
solutions to every application where thermal processing is
required.
If you’re looking for innovative solutions to match your production
needs, our experienced staff will work with you to provide a
cost-effective induction heating system.
Contact with us for more details if need other kind of drying plant
or calcination plants: +8615617816797
The basic of induction heating principle have been understood and
applied to manufacturing since the 1920s. During World War II, the
technology developed rapidly to meet urgent wartime requirements
for a fast, reliable process to harden metal engine parts. More
recently, the focus on lean manufacturing techniques and emphasis
on improved quality control have led to a rediscovery of induction
technology, along with the development of precisely controlled, all
solid state induction heating power supplies.
Induction heating takes place in an electrically conducting object
(not necessarily magnetic steel) when the object is placed in a
varying magnetic field. Induction heating is due to the hysteresis
and eddy-current losses.
Hysteresis losses only occur in magnetic materials such as steel,
nickel, and very few others. Hysteresis loss states that this is
caused by friction between molecules when the material is
magnetized first in one direction, and then in the other. The
molecules may be regarded as small magnets which turn around with
each reversal of direction of the magnetic field. Work (energy) is
required to turn them around. The energy converts into heat. The
rate of expenditure of energy (power) increases with an increased
rate of reversal (frequency).
Eddy-current losses occur in any conducting material in a varying
magnetic field. This causes heading, even if the materials do not
have any of the magnetic properties usually associated with iron
and steel. Examples are copper, brass, aluminum, zirconium,
nonmagnetic stainless steel, and uranium. Eddy currents are
electric currents inducted by transformer action in the material.
As their name implies, they appear to flow around in swirls on
eddies within a solid mass of material. Eddy-current losses are
much more important than hysteresis losses in induction heating.
Note that induction heating is applied to nonmagnetic materials,
where no hysteresis losses occur.
For the heating of steel for hardening, forging, melting, or any
other purposes which require a temperature above Curie temperature,
we cannot depend upon hysteresis. Steel loses its magnetic
properties above this temperature. When steel is heated below the
Curie point, the contribution of hysteresis is usually so small
that it can be ignored. For all practical purposes, the I2R of the
eddy currents is the only way in which electrical energy can be
turned into heat for induction heating purposes.
Two basic things for induction heating to occur:
- A changing magnetic field
- An electrically conductive material placed into the magnetic field
