Re: Castings for engine project
- We regularly use coreless induction heaters all the way down to 60Hz. These only work on huge steel pieces, where the work itself acts as a core to some extent, and where the coil can be made with enough inductance (lots of turns around a large workpiece, lots of copper) that it has reasonable performance. Typical applications include billet heating, large melting furnaces, and coatings (think powder coating huge oil pipelines, fittings and whatnot).
Frequencies of a few hundred Hz are typical for power levels over maybe 50kW, mostly for pipe heating and melting purposes (low frequencies penetrate deep into the melt, stirring it well). 10kHz and up is typically used for general purpose heating, brazing, heat treating, surface hardening, etc. Very high frequencies (100+ kHz) are typically used where very shallow surface hardening is necessary, for brazing, and on physically small parts (occasionally, frequencies up to 13.8MHz and beyond are used for very small parts).
The highest design frequency I've heard of for a rotating generator is 100kHz:
Electronic means are of course more available for most any frequency, and the only way for >100kHz.
--- In firstname.lastname@example.org, Jim <jimmy163333@...> wrote:
> Is that frequency high enough for induction heating? I thought it had to be much higher than that.