[chistyakov1971]

Photo of the device of the inverter of 18 kw made in China.
The price of 4000 dollars :-)



The inverter made in China. The description device, the description of lacks, is a lot of photos.
on Russian
http://www.chernetsov.ru/projects/ch...wer_supply.htm
http://uploadbox.com/files/7b15f8b7aa

[Hernangonzalez]

HI to all , welcome Tim! good luck with your new bussines!

this is picture of my 3.5 kw 40Khz IH for research .I use a PIC 16F877 board ( 8 channel analog input and various digital outs... ) to control the cooling system temperature, PLL inverter board , start secuence and stepper motor automatic L match gap adjust for all kind of load materials.I enclosed all in the same cabinet. the furnace and water radiator are away from the cabinet.

I have the idea to build 10KW coreless Induction furnace too !

[chistyakov1971]

Made in China

[chistyakov1971]

Crucible formation, thickness of a crucible in quartzite

The fused steel of 2 kg, capacity of the furnace of 3-3.5 kw. Failure in furnaces, a bottom burn-out

capacitor

[siamon99]

Can you help me in building the electrical part of the induction melting furnace capacity
15KW running with input 440 volts 3 phase 60HZ for melting alumnium.

[chistyakov1971]

Melting Aluminium ,
further
Centrifugal moulding of pipes and engines for rockets,
further
Assemblage of rockets.
Further
To fire rockets of the American soldiers
Joke


Induction channel furnaces.
The book on Russian, is drawings, formulas for calculation.
It is necessary to download a file *pdf
http://window.edu.ru/window/catalog?p_rid=28488
From electronics - one transformer :-)

[orjan_nilsson]

It started with a busted high pressure washer.
A little aluminium peece worth < 1$, rendering the washer out of order.
How hard can it be to make such a detail?
Got a christmas present titling "How to make a metal lath out of scrap in your garage".
Studying charcoal based aluminum melters. One year later, 5KW charcoal aluminium furnace.
It melts 3 litres of aluminium in about 1 hour. Smoky and load(big vaccum cleaner in reverse).
Tired of standing in the coold and melting aluminium and
trying to make use of my PWM high power audio bass loudspeakers knowledge I set to understand
how to use induction heating to melt aluminium?
Now I got a prototype consuming about 2.4KW of power from 240AC/10A.
Estimate that about 2KW is delivered into the stainless-steel crucible.
The contraption is made of IGBT-half-bridge(FGL60N100BNTD)-inverter and transformer/LCL.
Now the question. Experimented with different diameter cruisables and
found that if the iron-metal crucible was larger than a certain diameter I could not get ZCS.
Looking at your induction furnace coil chistyakov1971 I believe that I'am using a to large
crusiable compared to other diameter of the coil.
Experimented with LTC design programs for power electronics I discovered that,
in LCL designs there is a limit of hard you can load the resonant LC-circuit and still achieve
ZCS(switch voltage when current pass throw zero, correct on this if I'am wrong,
feel this is confusing, as I believe that sometimes they talk about ZCS and really mean ZVS and VS).
As I'am understanding this, IGBT are good at switching high voltage at moderate currents.

---
And as long as you understand my jibberish I will not excuse me writings.
PS: My background is large-scale software systems with a foot in embeded systems.
It's OK to use micro-controller if you do not put it in the PLL-control-loop.
More like controlling impedance matching circumstances and displaying values.

Sorry for not being able to compress my thoughts even more this is a to long input.

[chistyakov1971]

Excuse, I badly know English.
The difficult childhood, shirked English lessons, drank vodka and played a balalaika.
I use computer transfer

The parity of the sizes coil and a heated up body is a big problem.
1. It is necessary to provide the minimum backlash
2. It is necessary to provide good isolation.
It contradicts each other. It is necessary to search for the compromise. There are recommendations
For a steel one decision.
For fusion of nonferrous metals - other decision.
Correct choice of frequency of a current.
Variant for the aluminium fusion, special crucibles. They are issued by various firms
http://mammut-wetro.de/

Parametres of my coil, for fusion steel
Height of 100 mm, internal diameter of 120 mm, number of coils 8
The sizes of a liquid steel
Height 100-120мм
Average diameter of 40-45 mm
Stuffing of crucible FINMIX 0,5

It is laboratory installation for small experiences
===================

I use a consecutive resonant contour
And adjustment of capacity by frequency

[orjan_nilsson]

And now some cool(or not so cool) pictures. About 2KW of induction heating into a stainless steel crucible with vermiculite isolation.
http://www.cnczone.com/gallery/showg...0&ppuser=14974 and http://www.cnczone.com/gallery/data/...PC170508_s.JPG.

[chistyakov1971]

And now some cool(or not so cool) pictures. About 2KW of induction heating into a stainless steel crucible with vermiculite isolation. [Just want to insert this cool gloving image] OK I'am used to Motif and Unix systems and not how to insert a URL into response. Please help!

There are intermediate services for storage of images.
For example the Russian-speaking http://savepic.org/77850m.htm

[orjan_nilsson]

This is really cool. Being able to communicate with fellow metal-caster nerds.
My dream: Being able to a low price, manufacture broken stuff in my home.
I think we are tooo dependent on large scale manufacturing plants.
Knowledge roles!

[chistyakov1971]

My power module for the inverter of 30-40 kw

Control system, the driver - are already made and adjusted.
There was an assemblage in the case.
I will be engaged in assemblage after start of the module for fusion of a steel of 1.5 kg.

[siamon99]

My power module for the inverter of 30-40 kw

Control system, the driver - are already made and adjusted.
There was an assemblage in the case.
I will be engaged in assemblage after start of the module for fusion of a steel of 1.5 kg.

Is your power module based on IGBT or you have any designe for a 25 KW induction furnace i am intrusted in it.

siammon 99

[chistyakov1971]

siamon99
Look mail

I have this scheme for industrial use, serial release of inverters, for induction heating and an induction melting furnace
I have possibility to develop the scheme for your conditions, at professional level
Has 10 channels of protection
Drives on the ACPL-333
look post 234

[orjan_nilsson]

chistyakov1971, are you using parallel or series LC.
What do you think are better in view of melting metal?
When I look at commercial induction ovens they usably contain about 20-50 turns of copper tubes. I estimate that transfers to about 40uH to 200uH in the work-coil(correct me if I'am wrong). (I now use 11u/190mm-diam/8turns/150mm-hight work-coil and 8u capacitor= 17KHz resonance, crucible=90mm Diameter,2mm stainless steel), if I use a larger diameter crucible I can't reach ZCS=the switching occurs when current is large(=large switching losses).

[orjan_nilsson]

What do I see on the picture, chistyakov1971?
Heavy semiconductor assemblies on copper plate=large current/high voltage contraption?

[chistyakov1971]

for "crucible=90mm Diameter,2mm stainless steel"

coil d=130mm, h=aluminium

There is enough thermal protection of 2-2.5 sm

It is required the transformer on ferrite
Factor of transformation 1/10-1/20 at connection to a line in 220 volt

I recommend a consecutive resonance on a secondary winding

Thickness of a wall of a crucible 2mm - a little, look dependence of depth of penetration of a current on frequency in a steel
=============

OK, SEMIKRON
======
Enough copper tube in diameter of 8 mm.
Backlash between coils to 2 mm
Tube isolation is desirable.

The transformation factor steals up taking into account inverter loading
The core form is desirable III + III .

Specific capacity a minimum of 1 kw / kg

[orjan_nilsson]

At the moment I use a 2.5KG homemade ferrite core for transformer(now 1:1 coupled, it's made of crushed fly back transformers from scraped TV-sets... bound by silicon-rubber, gives about 0.13uH/n2, commercial IH-transformers gives about 3-6uH/n2) and a series inductance of estimated 50uH.
Is "consecutive resonance" series resonance? I use parallel LCL topology.
Because this gives small currents demands supplying the resonant large-current CL-circuit.

[elifarley]

Have you guys seen this project from Open Source Ecology?

They're offering from US$ 1k to 3k to the best induction furnace project submitted.

The project should include:

1. Design of an induction furnace circuit scalable up to 50 kW in units of 1 or 5 kW
2. Design allows for power and frequency selection
3. Power source may be either 1 or 3 phase electrical power.
4. Specifications of a cooling or heat dissipation system
5. Adaptable design specifications for primary coil windings
6. Geometrical design of melt chamber and basic power transfer calculations
7. Melt chamber includes provisions for loading and pouring.
8. Complete bill of materials
9. Fabrication files for circuit and other components
10. Sourcing information for components
11. System design and process flow drawings

You can learn more at their page.

[chistyakov1971]

Thanks for the reference.
I have all.
Only there is no desire to participate. My opinion: competitions it is swindle on gathering of schemes
Induction heating is very old theme for inventions.
To think up something new it is very difficult and it is unreal