Induction heating is a process used to harden, bond, or soften metals or other conductive materials. In modern manufacturing processes, induction heating offers an attractive combination of speed, consistency, control, and energy efficiency.
Recently, the focus on lean manufacturing techniques and the emphasis on improved quality control have led to the rediscovery of induction technology in parallel with the development of solid-state induction power systems with advanced control accurate.
When an alternating current is applied to the primary of a transformer, an electromagnetic field is generated. According to Faraday’s Law, if the secondary of the transformer is placed inside the magnetic field, an electric current is induced.
In a basic induction heating equipment setup, a power supply generates an alternating current through an inductor (usually a copper coil) and the part to be heated is placed inside the inductor. The inductor acts as the primary of the transformer and the secondary circuit part. When the metallic piece is crossed by the magnetic field, Foucault currents are induced in said piece.
As shown in the image above, eddy currents flow against the electrical resistivity of the metal, generating precise, localized heat without any direct contact between the part and the inductor. This heating occurs with magnetic and non-magnetic parts, and is often known as the “Joule Effect” which refers to Joule’s first law (scientific formula that expresses the relationship between heat produced and electric current through a conductor).
Benefits of induction heating
Why choose induction heating over other methods such as convection, radiation or flame?
The main advantages that induction heating offers for manufacturing are summarized below:
Maximum productivity
Productivity rates can be maximized because induction is very fast: heat is generated directly and instantly in the part (e.g. more than 1000ºC in less than a second in some cases). Start-up for warm-up is virtually instant, no preheating or cooling required. The induction heating process is completed on the manufacturing floor, close to the hot or cold forming machine, rather than sending batches of parts to a remote or outsourced furnace.
Energy efficiency
This process is the only truly efficient one from the energy point of view. Converts the energy consumed into useful heat by up to 90%; batch ovens generally do it up to 45%. In addition, as it does not need preheating or cooling in work cycles, heat losses in stand-by (when not working) are reduced to a minimum.
Process control and automation
Induction heating eliminates the inconsistencies and quality issues that occur with flame, torch, or other methods. Once the system is calibrated and running, there is no room for drift, heating patterns are repeatable and consistent.
With GH induction power supply, precise temperatures are achieved that provide uniform results; the fountain can be turned on and off instantly. With closed loop temperature control, advanced induction heating systems have the ability to measure the temperature of each part individually. The speeds of increase, maintenance and decrease of temperature can be established in each case and the data is stored for each piece on which it works.
Product quality
With induction, the treated piece never comes into direct contact with a flame or other heating element, the heat is induced in the piece directly through an alternating current. As a result, product warpage, distortion and reject rates are minimized. To maximize product quality, the part can be isolated in a closed chamber with a controlled vacuum, inert or reduced atmosphere to eliminate the effects of oxidation.
Green energy
Induction heating systems do not burn like traditional fossil fuels. Induction is a clean, non-polluting process that helps protect the environment. An induction system helps improve working conditions for employees by eliminating smoke, excessive heat, toxic emissions, and noise. Heating is safe because it does not endanger the operator, and by not using an open flame, it does not obscure the process. Non-conductive materials are not affected so they can be placed close to the area where it is being heated without any damage.
Using induction melting furnace supplier induction solutions means improving the operation and maintenance of the induction installation since production stops are minimized, energy consumption is reduced and quality control of parts is increased.