jimwig - 19-6-2009 at 09:32
here is a recently found article on induction furnaces.
well once again foiled as i am unable to paste a diagram from the article i am speaking of......Journal of Chemical Education p1999 year 1929.
entitled high frequency heating.....or such...
the diagram (if pasted) would show a very simple diagram for inductiion furnace -- mainly just four parts --- the transformer, the spark gap, a
capacitor and the crucible holder (the furnace its self). if one were to use a silicon crucible then it would seem very high temperature inert
atmsphere reactions (even vacuum types) could be attempted......
i have long sought this type of basic approach to induction heating. and more to the point its utilization in high temperature/rapid heating of
chemical reactions......etc.
i would like to make this article available to anyone interested but where to place for conveinience (sp) for the membership?
i have space with the honorable mad hatter but seems like it there might be a better place --- please i do not know.
kindly excuse my inability to write in a coherent manner. i hope this is somewhat understandable........
and thanks for your patience understanding......
[Edited on 19-6-2009 by jimwig]
12AX7 - 19-6-2009 at 13:23
No problem, that's trivially easy to do. Also a good way to get the FCC's attention, too. There's a good reason spark gap transmitters went out of
style about 120 years ago.
Self excited oscillators of the tube or transistor type are almost as simple, much quieter, much more efficient, and only a little less reliable. For
that last bit of efficiency and reliability you really do need a "full assed" control and driver circuit, which is what I've been persuing.
Tim
merrlin - 19-6-2009 at 16:51
What is the maximum operating temperature that you require?
jimwig - 20-6-2009 at 08:18
you know i really don't do things like normal beings
that is to say i see some project that looks interesting and then, application or nil, i go for it.
but since you asked melting metals has always been in mind. i am a sculptor (occasionally) and aluminum in a liquid phase would be a minimum. but cast
iron sounds good too.
i am appreciative of the FCC notice...... and you know those JCE articles were in the 20's and or the 30's..... so thanks...
oh yes also phosphorus and other high temp reactions have held my interest....
[Edited on 20-6-2009 by jimwig]
merrlin - 20-6-2009 at 10:33
Induction heating can have some interesting side effects. I once used induction heating in vacuum for an experimental package assembly that I was
brazing with zinc. Shortly after the zinc melted, I was surprised when the chamber lit up with a blue/purple glow. The zinc vapor pressure had been
sufficient to produce an inductively coupled plasma. At shutdown, the interior of the bell jar was accumulating a thin zinc film. You mentioned vacuum
as a furnace environment. If you are going above 2000 Celsius in vacuum, graphite electrodes attached to water cooled copper tubing work well.
12AX7 - 20-6-2009 at 12:50
Indeed, and a furnace consisting of a graphite heater is described in Brauer, for use up to 2000C.
Tim