Induction Heating

(redirected from Inductive heating)
Also found in: Dictionary, Thesaurus, Medical, Legal.
Related to Inductive heating: Induction heater

induction heating

[in′dək·shən ¦hēd·iŋ]
(engineering)
Increasing the temperature in a material by induced electric current. Also known as eddy-current heating.

Induction Heating

 

the heating of current carriers through the generation of electric currents in them by an alternating electromagnetic field. The power released in a conductor by induction heating depends on the dimensions and physical properties of the conductor (specific electric resistivity and relative magnetic permeability), as well as on the frequency and intensity of the magnetic field. In induction heating the electromagnetic field is supplied by induction heaters.

Induction heating is characterized by the nonuniform release of power in the object being heated. Eighty-six percent of the power is released in the surface layer (the so-called penetration). The penetration of the current Δ (in meters) is Δ = Induction Heating where ρ is the specific electrical resistivity in ohms • m, μ, is the relative magnetic permeability, and f is the frequency in hertz (Hz).

Low-frequency (50 Hz), medium-frequency (up to 10 kHz) and high-frequency (over 10 kHz) currents are used in induction heating to generate an alternating electromagnetic field. Mechanical and static converters, as well as tube oscillators, are used to supply medium- or high-frequency current to induction heaters.

Induction heating is most widely used in the melting of metals, zone melting, and heating for pressure shaping. Induction heating is the most advanced contactless method of transmitting electrical energy to the object being heated, converting electrical energy directly into thermal energy. A schematic diagram of a device using induction heating is shown in Figure 1.

Figure 1. Schematic diagram of an induction heating device: (1) power supply, (2) capacitor, (3) induction heater, (4) lined crucible, (5) object being heated

REFERENCES

Babat, G. I. Induktsionnyi nagrev melallov i egopromyshlennoe primenenie. 2nd ed. Moscow-Leningrad, 1965.
Vysokochastotnaia elektrotermiia: Spravochnik. Moscow-Leningrad, 1965.
Elektrotermicheskoe oborudovanie: Spravochnik. Moscow, 1967.

A. B. KUVAIDIN

Induction heating

The heating of a nominally electrical conducting material by eddy currents induced by a varying electromagnetic field. The principle of the induction heating process is similar to that of a transformer. In the illustration, the inductor coil can be considered the primary winding of a transformer, with the workpiece as a single-turn secondary. When an alternating current flows in the primary coil, secondary currents will be induced in the workpiece. These induced currents are called eddy currents. The current flowing in the workpiece can be considered as the summation of all of the eddy currents.

In the design of conventional electrical apparatus, the losses due to induced eddy currents are minimized because they reduce the overall efficiency. However, in induction heating, their maximum effect is desired. Therefore close spacing is used between the inductor coil and the workpiece, and highcoil currents are used to obtain the maximum induced eddy currents and therefore high heating rates. See Core loss

Induction heating is widely employed in the metalworking industry for a variety of industrial processes. While carbon steel is by far the most common material heated, induction heating is also used with many other conducting materials such as various grades of stainless steel, aluminum, brass, copper, nickel, and titanium products. See Brazing, Heat treatment (metallurgy), Soldering

The advantages of induction heating over the conventional processes (like fossil furnace or salt-bath heating) are the following: (1) Heating is induced directly into the material. It is therefore an extremely rapid method of heating. It is not limited by the relative slow rate of heat diffusion in conventional processes using surface-contact or radiant heating methods. (2) Because of skin effect, the heating is localized and the heated area is easily controlled by the shape and size of the inductor coil. (3) Induction heating is easily controllable, resulting in uniform high quality of the product. (4) It lends itself to automation, in-line processing, and automatic-process cycle control. (5) Startup time is short, and standby losses are low or nonexistent. (6) Working conditions are better because of the absence of noise, fumes, and radiated heat. See Electric heating

induction heating

In piping, the heat treatment of completed welds by the heat generated by the use of induction coils around the piping.
References in periodicals archive ?
Due to the expanding of the exterior structure, during the inductive heating process, its interior diameter will grow, allowing the introduction in this phase of an interior cyllindrical structure, Fig.
Extension of research for the next period will focus on inductive heating and complex shapes (square, hexagon), where the effect comes through.
Infolytica customers include leading electronics, telecommunication, motor and inductive heating manufacturers such as: General Electric, NTT, ABB, Toshiba, Sony, Inductotherm, Northrop Grumman, General Motors, Samsung and Harman Motive.
A full product range of standard power modules will be available including: 600 & 1200 volt PT IGBTs, for the ultimate in a high switching speed IGBT module, NPT IGBTs for SMPS and high performance motor drive applications, and Power MOS 7(R) MOSFETs for high frequency applications such as inductive heating and inverters for arc welding.
The two companies have independently pursued the development of therapeutics based on non-invasive inductive heating of prosthetic devices and injectable targeted-nanomaterials.
Thermonix, Inc, is based in Minneapolis, Minnesota, USA, and is a leader in the development of therapeutics based on non-invasive inductive heating of prosthetic devices, directed at various inflammatory diseases such as arterioscleroses and cancer.
Its products include: insulated trays and components: pellet and inductive heating systems; specialized delivery, holding and rethermalization carts; and a range of ancillary equipment for cook-chill catering systems.
Its products include: insulated trays and components: pellet and inductive heating systems; specialized delivery; holding and rethermalization carts, and a range of ancillary equipment for cook-chill catering systems.
Its products include: insulated trays and components; pellet and inductive heating systems; specialized delivery, holding and rethermalization carts; and a range of ancillary equipment for cook-chill catering systems.
These high energy devices are typically used for filtering, protection, switching and discharge in applications such as mass transit, cardiac defibrillators, industrial converters, inductive heating and electric vehicles.