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Induction stove

  1. Dec 20, 2005 #1
    Can someone explain to me how an induction stove works? I know it has something to do with magnetism, but how the casserole can get hot while the surface of the stove itself does not blows my mind!

  2. jcsd
  3. Dec 20, 2005 #2


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    Last edited: Dec 20, 2005
  4. Dec 21, 2005 #3
    In short, there's a coil if wire near the casserole pan. A current of electrons whizzes round in the coil and creates a field around it. When that field hits the pan it 'pushes and pulls' the electrons around inside the material it's made of. As the electrons in the pan get pushed and pulled around they heat up the pan, just like a piece of wire gets hot if you try to put too much current through it. That's why the pan has to be metal, or something else that's conductive, the coil has to be able to move the electrons around in things to make it hot. Because you don't want to have to plug in your pans to heat them up, the oven -couples- onto them with a magnetic field to achieve the same effect.

    The coil doesn't care what is put in it so long as it can move electrons around. So ceramics won't heat up because they're excellent insulators, at room temperature anyway; a lot of the best superconductors are ceramics but need to be at cryogenic temperatures before they take on the weird properties of superconduction.

    If you stove was powerful enough it could melt the metal containers you put on it. The food inside is acting like coolant, or radiator fluid, soaking up the heat from the metal.

    Ovens just like your's, but much more powerful, are used industrially to melt metal. They're often used for metals that would be contaminated by normal flame heating or that need very specific cooking times and temperatures (annealing, meaning to soften, as well as tempering, to harden).

    You can see some good video clips of induction heating being used industrially here;
    http://www.ameritherm.com/videoindex.html (Notice how quickly the parts heat up)

    The Precison Induction Heating video is the best to watch first. The rest are examples of the company's work.
    Last edited: Dec 21, 2005
  5. Dec 21, 2005 #4


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    We also use induction heaters to heat bearing assemblys before installation id the shaft fit is tight enough.
  6. Dec 21, 2005 #5
    Induction heating is also extremely widely used in heat treating metals. A given alloy has an optimum temperature for hardening (and also for tempering). Induction heating allows for precise control of the temperature to which the metal is heated before quenching. This has allowed for automated, consistant, mass heat treatment of parts.

    This has been particularly useful in the automotive industry. I once saw a figure for the number of different alloys of steel that go into the average car and was astonished. It was over a hundred, I think, each requiring heat treatment at a specific temperature.
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