Induction oven, ferromagnetic

fluidistic

I do not understand why ferromagnetic materials are more easily heated by an induction oven than a non/low ferromagnetic material such as copper or aluminum.
Are Eddy currents more easily induced into a ferromagnetic material than a conductor lacking a high ferromagnetic property? Why is it so?

Enthalpy

An induction cooker for instance creates losses by magnetic hysteresis. It works only with iron pans, not copper.

Some other induction heaters are designed for other materials, work at other frequencies, and prefer simple conductive material.

fluidistic

Quote by Enthalpy

An induction cooker for instance creates losses by magnetic hysteresis. It works only with iron pans, not copper.

Some other induction heaters are designed for other materials, work at other frequencies, and prefer simple conductive material.

According to wikipedia,

Quote by wiki

In an induction cooker, a coil of copper wire is placed underneath the cooking pot. An alternating electric current flows through the coil, which produces an oscillating magnetic field. This field induces an electric current in the pot. Current flowing in the metal pot produces resistive heating which heats the food. While the current is large, it is produced by a low voltage.

and they are talking about

Quote by wiki

a cooking vessel must be made of a ferromagnetic metal

.
And also

Quote by wiki

Some additional heat is created by hysteresis losses in the pot due to its ferromagnetic nature, but this creates less than ten percent of the total heat generated

.
So this does not seem to be the answer. I'm still clueless as why a ferromagnetic material heats much faster than a non/low ferromagnetic material.

Enthalpy

Possible explanations:
- Wiki botched it. It does happen.
- Losses result from induced current, but only because the skin effect increases the resistance, and the skin is made much thinner in ferromagnetic materials.
Why shouldn't you try to put some figures at it? Search for "Kelvin effect". Cookers use high frequencies, like >20kHz.

pumila

Ferromagnetic materials switch their internal magnetism back and forth with every switch of the external magnetic field. However the process has hysteresis, that is it is not completely reversible. The internal magnetic domains lag behind the changing external field, so the sweep back and forth describes a hysteresis loop. The larger the area in this loop the greater the loss on each cycle. This loss turns up as heat. Look up 'hysteresis loop' for graphs and further details.

This effect does not exist in non magnetic materials.

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fluidistic Recognitions: Gold Member	Induction oven, ferromagnetic I do not understand why ferromagnetic materials are more easily heated by an induction oven than a non/low ferromagnetic material such as copper or aluminum. Are Eddy currents more easily induced into a ferromagnetic material than a conductor lacking a high ferromagnetic property? Why is it so?

Enthalpy	An induction cooker for instance creates losses by magnetic hysteresis. It works only with iron pans, not copper. Some other induction heaters are designed for other materials, work at other frequencies, and prefer simple conductive material.

Enthalpy	Induction oven, ferromagnetic Possible explanations: - Wiki botched it. It does happen. - Losses result from induced current, but only because the skin effect increases the resistance, and the skin is made much thinner in ferromagnetic materials. Why shouldn't you try to put some figures at it? Search for "Kelvin effect". Cookers use high frequencies, like >20kHz.