# What is Induction heating: Definition and 31 Discussions

Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, through heat generated in the object by eddy currents. An induction heater consists of an electromagnet and an electronic oscillator that passes a high-frequency alternating current (AC) through the electromagnet. The rapidly alternating magnetic field penetrates the object, generating electric currents inside the conductor, called eddy currents. The eddy currents flowing through the resistance of the material heat it by Joule heating. In ferromagnetic (and ferrimagnetic) materials like iron, heat may also be generated by magnetic hysteresis losses. The frequency of current used depends on the object size, material type, coupling (between the work coil and the object to be heated) and the penetration depth.
An important feature of the induction heating process is that the heat is generated inside the object itself, instead of by an external heat source via heat conduction. Thus objects can be heated very rapidly. In addition there need not be any external contact, which can be important where contamination is an issue. Induction heating is used in many industrial processes, such as heat treatment in metallurgy, Czochralski crystal growth and zone refining used in the semiconductor industry, and to melt refractory metals that require very high temperatures. It is also used in induction cook-tops for heating containers of food; this is called induction cooking.

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1. ### Inductive Heating of a Non-Conductive Reactor's Contents

Hi! I have been working with home-made reactor to do ambiant pressure, high temperature pyrolysis experiments that use an induction heating coil wrapped around the outside to heat the entire reactor. The contents are heated indirectly through their contact with the reactor. This worked well for...
2. ### Transformer frequency contradiction on induction heating

As a transformer freq bet higher, inside induction get more efficient i.e. less loss: 1. Hysteresis loss = η * Bmax^n * f * V. 2. Eddy current loss( proportional to B2mf2Bm2f2 )Now it seems that losses increases with increase in efficiency... But the above equations are valid when max flux...
3. ### I Induction heating vs Current heaing

I've been thinking and can't come up with a satisfying answer. Would there be a difference in the amount of heat generated in a given time in a metal rod if it was heated by a) induction b) current passing through the same length of rod Given that the current is the same amperage and...
4. ### Efficiency of heating up aluminum vs steel by induction

Summary: In a heating by induction experiment performed, the idea was to determine the efficiency of heating up a small steel cylinder, an aluminum cylinder and then compare the two efficiencies. The cylinder was surrounded by a metall coil that alternating current was going through...
5. ### Induction heating internal splines

I want to surface heat internal splines with induction heating with an internal diameter coil. It is a cylinder, uniform shape, and the teeth are 1mm wide and 2mm deep. The inside diameter of the hollow section is 19mm and the length is 55cm. I was wondering when calculating power/resistance...
6. ### Induction heating flat spiral springs

Summary: is it possible to heat a coiled spring If I had a spirally coiled spring like inserted pic, spiral coiled spring approx. 300mm dia and spring section +-12mm dia with +-1mm gauge wire, with a total length of spring approx. 4mtr-6mtr , is it possible to heat this with induction heating...
7. ### Electronics Temperature Sensing to Switch on/off an Induction Heater

Hello, I'm having trouble thinking of ways that I can measure the temperature of an object that I am heating using an Induction Heater. A little background: The coil and workpiece will be submerged in liquid, and due to most thermometers being metal it won't work with the induction heater. I'm...
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### Questions about induction heating

Hi there, I'm a material chemist, currently working on ceramics. I know the very basics of physics, but I have many doubts about electromagnetism. How does induction heating exactly work? I understand that you use a hollow coil of copper with a cooling fluid circulating inside, through which...
9. ### Induction Heating: Calculating Magnetic Field from Temperature

Hi everyone, I'm conducting an experiment where I place a ferrous material rod inside a solenoid to measure it's temperature due to induction heating, as shown in the video below: The aim of my experiment is to calculate the magnetic field from the temperature of the ferrous material rod. Is...
10. ### Induction Heating Coil Design: Rectangular vs. Spiral Shape

Goodmornig everybody, I'm working on the design of a power converter for high frequency induction heating. The induction coil should be a flat spiral (pancake) with a rectangular shape, but my customer would like to design it as shown in the following picture. I think it will not work because...
11. ### Induction Heating Calculation

I would like to get a clue of how to arrive at the power and frequency for an Induction heater. I am planning to heat a graphite rod upto 1200 degC and also to provide a heat flux of 1 MW/m2. The graphite rod dimension will be for one case Dia 5 and length 100 mm and in the second case will be...
12. ### Induction Heating Process Characterization

Hi All, I'm working on a process involving induction heating. I'm heating up an irregular shape ss die to make a bond. My dilemma is in my understanding of where the eddy currents will be that generate the heat (based on skin effect). The clam shell die is pictured below. The right hand...
13. ### Understanding relationships in Induction Heating circuits

Hi Everyone, I will try to keep this short as I can and to the point, there is a bit of a back story, so bear with me. For the last 18 months (on and off as life allows), I have been trying to develop an induction heating assisted machine for 2 reasons. 1 - To learn as much as I can by doing...
14. ### In Induction Heating, what does the heat output depend on?

Wasn't sure whether to post this here or in EE forum. I've been learning about induction heating for the past few hours and scoured every video on youtube and every web article I could come across and I still lack an understanding of how to determine the heat output of an induction heater. I...
15. ### Induction heating by AC magnetic field-magnetic hyperthermia

Hi, I want to heat magnetic nanoparticles in an AC magnetic field. I need a uniform and a magnetic field about 15- 25 mT ) . I have thought about some designs, can you tell me which one is the most suitable design for creating a uniform alternating magnetic field? I need this system for...
16. ### Magnet configuration for spinning permanent magnet induction heating

Watch this video: Permanent magnets moving relative to a stationary copper tube generate Eddy currents which result in Joule heating of the copper. Simple enough. Let's change the problem to a rotor with 4 (circumferential) permanent magnets rotating inside a stationary (aluminum or...
17. ### Enquiry on flexible-elastic induction heating

Hi, I am a designer currently working on alternative induction cooking methods. The question is, whether it is possible to have a flexible/elastic cooking surface (something like a mat, that would roll up, fold up, expand etc.) A project similar to this, is here...
18. ### Induction Heating Basics

I am idly curious about induction heating; specifically for heating 80L-100L of water from 20C to 100C as efficiently as possible with an emphasis on as little waste heat going to the surrounding environment as possible. I have done some precursory reading (...
19. ### Induction Heating for Outgassing the Beamline

Hi, I want to heat the FEL beamline for the outgassing process with an induction heater. What frequency should I use in the driver circuit of the heater? The geometry of the beam line as you can imagine is cylindrical. And do you have any experience about it? If its so, I will be...
20. ### Induction heating of non-magnetic metal?

I'm experimenting with induction heating, and made a simple ~100W device. Royer oscillator type, 200kHz frequency. It readily heats a steel blade to the point of incandescence. However, a piece of aluminium of a similar size doesn't even get warm. I understand that magnetic hysteresis...
21. ### How much power is needed to melt aluminum using induction heating?

How much power is needed to be able to melt aluminum using induction heating? So I have coil of copper wire around an aluminum cylinder. The aluminum is NOT touching the copper wire. the copper wire have a thickness of 0.5 cm. d = 0.5cm the copper wire is looped 20 times around. N = 20...
22. ### Induction heating theory clarification

Hi all, I'm trying to understand induction heating, specifically if there can be inductive heating without a coil, simply power applied through a hairpin-shaped resistor. Imagine a big hair-pin-shaped resistor with power applied to one leg - near the bottom of these legs are small metal...
23. ### Induction heating of a cylinder

Hello! I am making som calculations on induction heating of a metallic cylinder inside a solenoid through which an AC current passes, but the answer I get seems to be completely unrealistic (10 kW with a 50 Hz, 5 Amps, 230 V rms), but I can't seem to find my mistake. What I think is...
24. ### Induction heating modeling in Ansys

Hi I'm trying to preform a simple model of a ferromagnetic bar which has a coil wrapped around it. The bar has a 4×4 cm base and is 15 cm tall, the coil has an inside radius of 29 mm and outside radius 30 mm and a height of 10 cm. The goal is to find the eddy currents in the bar, generated...
25. ### Why is a high permeability desirable for induction heating?

The resistance per unit length of a conducting wire is proportional to the square root of the ratio of permeability to conductivity. The power generated as heat may be expressed as I-squared x R: also as V-squared / R. In induction, the EMF induced is determined by the rate of...
26. ### I want formulae for Induction heating

hi i want formulae for induction heating .. 1) dept of heating 2)power loss per unit volume also for dielectric heating please help me ..
27. ### Electrical DIY Induction Heating with pll

Hi there, I've been interested in this induction heating thing and would like to build one. Its quite a long time searching the net and experimenting to make it work. I've been stuck with the pll issue. My configuration is Hbridge which is fed from a simple power supply(not split) so the lowest...
28. ### Induction Heating Ice: How Does it Work?

Does anybody know how this works? https://www.youtube.com/watch?v=aLwaPP9cxT4
29. ### How to not short circuiting an induction heating coil

how to not short circuit an induction heating coil Just wondering about induction heating coils and how to not short circuit one. basically, if i hook up one end of the coil to the positive and one end to the negative (DC) i assume that i will be short circuiting the connection and also...
30. ### Temperature measurement induction heating aluminium

Is there a way to measure the temperature in an induction oven for melting of aluminium(700 C). The pyrometer I’m using can’t correctly display the temperature when the system is running because it interferes with the induction field. The non-contact IR-camera has been abandoned because of the...