[metalations]

Hi all
I am new to this forum. You say that a 5 Kw induction heater will melt 5Kg of steel in one hour. I contacted a company in china that makes induction heaters and they recommend I use a 120 Kw unit if I want to melt 3Kg of stainless steel. I don’t know why you guys want to make induction heaters when you can buy a new 18 Kw units from China for less than a thousand dollars.
Regards
Marcel

Id love to see this link.

[gombault]

Hi JBV
Thanks for that info. Could you also please explain what the difference is of a low, medium and high frequency induction heater? The link: http://www.tradekey.com/ks-induction-heating-machine/

[JBV]

Check this out:
http://en.wikipedia.org/wiki/Skin_effect#Examples

So roughly i would say:
Low = melting big loads of metal.
Medium = melting smaller loads of metal.
High = Surface hardening.

[stud]

Hello...everybody there

Here some more videos :

http://www.indutherm.de/engl/video/video.html

MC 15 model looks cool...

[JBV]

A friend asked me to design a water cooling assembly for his 2 new Celem CPRI300 power capacitators The blocks is aluminium because he have suitable material at hand. The coil is soldered to the copper blocks!
(The coil is just for illustration)

[svenakela]

Hello...everybody there

Here some more videos :

http://www.indutherm.de/engl/video/video.html

MC 15 model looks cool...

Indeed, the MC15 i awesome. I really could live with one of those!

[ilkkahy]

I think new thread should be made dedicated only for induction furnace theory.

[NinerSevenTango]

JBV,

About your energy calculations --

Don't forget, if you are going to melt something in 30 minutes, as the load gets hotter, it radiates and conducts heat away faster. So there will be considerable losses to the surroundings to account for.

[vallabesan]

Hi warpspeed,

Your design is fantastic, but normally all the melting systems are controlled by power because no one can control both power and voltage. and you are not any triping while system have run in some errotic condition.if i want make the system with 2.5kw and 1 phase what may be the best solution

thanks lot
vallabesan

[JBV]

Well if i cant get over 25% TOTAL efficiency i will go with gas instead... :P

[NinerSevenTango]

JBV,

Expect about 80 - 90% efficiency into the metal with any load larger than a thimble full, if your power supply tracks the frequency of the load and if the output circuit is properly tuned. Beyond that, you have to put power into the metal faster than it radiates or conducts away. You can help that with good thermal insulation (refractory material).

My point was that 30 minutes is a long time to wait for a melt, and your total power in KWHrs will be a lot more if the load is sitting there at elevated temperature for a long time, radiating heat into the room like an incandescent light bulb. So if you only calculate the heat that it takes to raise the temperature of the material and use that amount of power, mother nature won't let you reach the desired temperature because heat loss due to radiation goes up with temperature difference. And the longer the metal stays at high temperature, the more it oxidizes if exposed to air, at least if it is iron or steel.

You can melt a thimble full of any common metal with 5 KW at a frequency of 30-450 KHz. And it's cute to watch it levitate in the coil.

[Fierroy]

Hello to the members of CNCzone forum!

I am a retired technical instructor and I am attentive to the experiences of the partners of the forum. I have very good experience in mechanical constructions and it interests me a lot that exposed on inductive heating by the experts in the forum.

Greetings for all

Fierroy

Paraguay

South America

[Fierroy]

Hello to all

I am experiencing with the capacitores construction made of cans of beer. I have some thousand in my deposit and to build one schemes to cut them and to obtain about 1800 mm2 approximately. I plan to use had mylar of varnish for high temperature and high tension, as dielectric.
Capacitores can be built for high tension and high current.

Some suggestion?

Greetings.

Fierroy.

[NinerSevenTango]

Sounds interesting, let us know how it works out for you.

[Fierroy]

Hello NinerSevenTango

Thank for your replies.

I was building some prototypes of Condensers (Capacitores). Experience with different dielectricos, from paper absorbed with oil for transformer, until this movie for transformers that we call "mylar" had with varnish for high tension and high temperature (approximately 450 ºC). I have built a small device to test the rupture voltage, for the dielectrics, which gives a rupture tension for the dielectric of this material at approximately 5 KV. A can of beers provides a sheet of approximately 1800 to 1900 mm2, with a thickness average of 0.3 mm, imagine 300 or 400 of this sheets associated in parallel. This thickness and area, associates in a Condenser, it can support the necessities easily for the Induction Melting Furnace.
In this part of the world, the cheap and accessible materials are very strange, mainly for unknown technologies. This is one of the factors that impel me to build cheap and easy accessories to building.
A first analysis factor is that most of the "Hobbyster" prefers to build its own elements or devices, "gold rule", independently of the costs.
I am building a "cutter" for cans of beer cheap and when has it finished, I will expose the planes in the forum. Then I will build a Capacitor prototype, included the refrigeration systems and I will wait for suggestions.
I am not an expert in this topic, but I want to build an Induction Furnace with the directive.
I believe that the design of Warpspeed is appropriate, but the one has not sent up-to-date information of its achievements.

Greetings for all.

Fierroy

P.D. Sorry, my English is not good.

[NinerSevenTango]

If you can succeed at this, there would be many applications beyond just induction heating.

It occurs to me that one challenge will be how to remove sharp edges from your cut aluminum. And another will be cooling. Then there will be the question of how the dielectric properties change with age in the cooling medium (oil?).

Your English is quite good!

--97T--

[Fierroy]

Thank you for your attention.

I have solved the mechanical part of the cut of the cans of beer. They don't present sharp borders. My it schemes it embosses the cut borders easily. I have inconveniences to clean the surfaces of electric contacts in the electrodes, but I believe that it is question of method and time, to offer a good solution. I believe that the contact of the badges and the terminals will be made between two by pressure screwed badges. Simple and easy.
Regarding the refrigeration, I believe that you have an error in your analysis, because I plan to act in an exchange of heat in the terminals (contacts) of the Capacitor, not in the change of oil of the dielectric.

Greetings

Fierroy

[chroniccodez]

First of all, I'd like to say that this thread has been very helpful to me and I would like to thank everyone who has contributed thus far.

Anyways, to the point. I am in desperate need of a small, simple induction foundry for melting mainly gold, silver, and aluminum. It seems that alot of the designs I have come across are geared towards the "extreme!" I have no need to melt steel or iron.

I would like it to be as simple as possible. I am a true DIYer and love to figure out ways of building things with little to no cost. Is it in any way possible to build a induction furnace using parts from various appliances such as microwaves, TVs, dryers, etc.?

I already have the enclosure for the furnace itself. An 8 inch diameter (inside diameter) ductile cast iron cylinder that is 1 inch thick. I plan on putting a layer of high temp cement inside and casting so that I can easily secure the work coils in a spiral pattern.

Any suggestions or comments would be much appreciated.

[NinerSevenTango]

The easiest and cheapest way is to buy something at an auction or used. Starting from scratch is complicated and expensive. Almost everything in an induction heater has to be made special. If you can prove that wrong, you can make a fortune!

[Fierroy]

Hey 97T

You are right. I believe that the idea of the forum is to share experiences, to expose some collaboration, to show some advance. With regard to cutter of the cans I am making the images to hit them in the site. I hope they are not too many extensive. I should consult with my assistant (my twelve year-old daughter) that manages much better than me those questions. Please some patience.

Greetings.

Fierroy