Induction Furnace Request for Bids
Open Source Induction Furnace
See also the Open Source Induction Furnace Project page.
You may have heard us talk about recasting civilization from scrap metal. Metal is the basis of advanced civilization. Scrap metal in refined form can be mined in abundance from heaps of industrial detritus in junkyards and fence rows. This can help us produce new metal in case of any unanticipated global supply chain disruptions. This will have to do until we can take mineral resources directly and smelt them to pure metal.
I look forward to the day when our induction furnace chews up our broken tractors and cars – and spits them out in fluid form. This leads to casting useful parts, using molds printed by open source ceramic printers – these exist. This also leads to hot metal processing, the simplest of which is bashing upon an anvil – and the more refined of which is rolling. Can we do this to generate metal bar and sheet in a 4000 square foot workshop planned for Factor e Farm? We better. Technology makes that practical, though this is undeard-of outside of centralized steel mills. We see the induction furnace, hot rolling, forging, casting, and other processes critical to the fabrication component of the Global Village Construction Set.
We just got a $5k commitment to open-source this technology.
Furnaceicon
The program for delivering an induction furnace involves a high frequency, high-power supply (between 20 and 50 kW (the latter can be gotten for $1600 on Ebay), and the melting chamber proper. Well, we could buy a turnkey system perhaps for $5k total used, and run it from the LifeTrac generator. The only disadvantage to this route is that if it breaks we’re dead-in-the-water – either with the impossibility of fixing closed-source technology, or a high repair bill. A single component which blows and is inaccessible for fixing could in principle turn a working power supply into worthless junk. Thus, it is worthwhile to tame this technology by open-sourcing the design.
It is more robust and cost effective to open-source the high power induction power supply. We would like to exactly this – which is mature technology. The question is finding a consultant or developer. We are thus making a call for bids. We are offering between $100 and $3000 for a design – depending on its level of completion. We will post this on eLance and other outsourcing sites.
If you are qualified to produce a design, please submit a bid by emailing opensourceecology at gmail dot com. We’re open to other suggestions on tactical and strategic aspects.
The bids will be judged on the demonstrated competence of the bidder, and upon the extent of design completion. The complete design would include all of the following:
- Design of an induction furnace circuit scalable up to 50 kW in units of 1 or 5 kW
- Design allows for power and frequency selection
- Power source may be either 1 or 3 phase electrical power.
- Specifications of a cooling or heat dissipation system
- Adaptable design specifications for primary coil windings
- Geometical design of melt chamber and basic power transfer calculations
- Melt chamber includes provisions for loading and pouring.
- Complete bill of materials
- Fabrication files for circuit and other components
- Sourcing information for components
- System design and process flow drawings
Serious bidders only, please. Naysayers on feasibility of this proposal will be either dismissed summarily, or our design criteria will be modified accordingly.
With up to $3k allotted for design work, we believe that the remaining $2k would suffice for parts for the actual device: about $1k for the electronics, and $1k for the furnace chamber.
Responses
Benny
I just read that you plan to build up an induction furnace. That´s a an interesting and exciting plan.While reading the aricle some remarks came to my mind.
But before I want to introduce myself:
I am Benny from Germany, Hannover. I am diploma engineer for electrotechnology and working at the university. I am dealing with some induction heating/ melting applications like induction melting of glasses (that is possible!) and induction furnaces for cast iron.
Some remarks from my point of view:
1. It is possible to build up a low cost furnace with the mentioned parameters. 2. The frequency of 9,6 kHz is much to high. The efficiancy will be so bad, that it will be hardly possible to melt steel or iron. Due to the small penetration depth of about 2 mm with this frequency and this electrical resistance. So it needs a really small diameter of the crucible, and thats not helpful. Also the refractory material will be strained too much, so that a small lifetime is given. This will raise the cost for the operating. 2. 50 Hz or 60 Hz is a better solution. And you can save the cost for the hf-converter. 3. How much material do you want to cast at one time? The maximum, what i expect to be possible with 50 kW will be about 50 to 60 kg. 4. What kind of raw material should be charged? It is important for the starting, because the initial density should not be too small (packing density). And the other question is, what kind of scrab it will be. There are so many problems known with content of zinc (hot zinc dipped) and other materials. The lifetime of common refractory material is really small. And what is more important the security for the personal is not given without a strong exhaust system, due to the toxic steam. I expect this as a strong cost factor.