"Steve" <
[email protected]> wrote in message
news:
[email protected]...
> Andrew Mawson wrote:
>
> > Steve,
> >
> > You would be very welcome to call by and see it - the big 'Beast'
> > isn't connected up yet due to absence of big generator - I have a
> > little 'demonstrator' that I knocked up (250 watts as opposed to
> > 100KWatts) which doesn't melt anything (other than solder<G>), due
to
> > it's low power but shows the principle.
>
> Hi Andrew,
>
> Bit of a trip to see you specially, but its technically something
I'm
> interested in - can you heat things up to 1700 degrees by induction
> realistically ? I'd guess as 4-5 kW ?
>
> Steve
Upper temperature limit is not specifically limited by the power you
apply. There are two effects happening in an induction furnace:
A/ Magnetic hysterisis - happens up to the 'currie point' of the metal
(850 C for most steels) - the violent twisting of the magnetic domains
heats the metal. Above the currie point the metal is no longer
magnetic and this effect ceases.
B/ I (squared) R heating - the charge acts as a shorted turn in a
transformer with vast circulating currents heating the metal by
resistive losses. This effect is less in better conductors like copper
and aluminium and more in steels.
Power input and radiant and conductive losses limit the temperature
that you achieve - maximum temperature is when input power and power
loss are in equilibrium. Given good thermally insulating refactory
materials and enough power there is no problem reaching 1700 C.
My 'Beast' can dissipate 100Kw in a tiny 12Kgs of stainless steel
which should melt it in quick order (if I can find a suitably rated
and price generator !!!!!)
AWEM