- #1
Metallus
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 you pass alternate current at high frequency. This generates a (oscillating?) magnetic field that points towards the center of the coil (according to right hand rule). If you put an object inside, called susceptor, it gets heated.
1) Why does this happen? What happens exactly at a microscopic level in the susceptor to justify the generation of heat? I always imagine alternating two magnets on a rod of iron and I can't fathom how this would heat it.
2) Does this work with any object or just metals/graphite and why? What would happen if I put, eg, my hand inside an induction coil powered to heat graphite at 1000C? What if I put an insulator?
3) I am amazed that the coil can heat graphite to 3000C without melting, considering that copper melts at 1083C. Yes, there is a cooling fluid circulating, but considering the graphite die is usually 1cm away from the coil, that seems really insane cooling. Or am I underestimating the effect of the insulator between the coil and the graphite die?
Thanks
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 you pass alternate current at high frequency. This generates a (oscillating?) magnetic field that points towards the center of the coil (according to right hand rule). If you put an object inside, called susceptor, it gets heated.
1) Why does this happen? What happens exactly at a microscopic level in the susceptor to justify the generation of heat? I always imagine alternating two magnets on a rod of iron and I can't fathom how this would heat it.
2) Does this work with any object or just metals/graphite and why? What would happen if I put, eg, my hand inside an induction coil powered to heat graphite at 1000C? What if I put an insulator?
3) I am amazed that the coil can heat graphite to 3000C without melting, considering that copper melts at 1083C. Yes, there is a cooling fluid circulating, but considering the graphite die is usually 1cm away from the coil, that seems really insane cooling. Or am I underestimating the effect of the insulator between the coil and the graphite die?
Thanks