gnitseretni
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stainless steel heating elements
Does anyone know if stainless steel wire can be used for the heating element in a homemade furnace? I'd hook it up to 220V.
Your thoughts pls.
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watson.fawkes
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Quote: Originally posted by gnitseretni  | | Does anyone know if stainless steel wire can be used for the heating element in a homemade furnace? I'd hook it up to 220V. |
It will work, but won't last long if you heat it up very hot. Order some proper heater wire from Duralite. They have precoiled wire for a number of voltage/wattage combination, and they also have 50 foot bundles for $15. The straight wire is
cheaper, but will need to be formed before installation. Both are better priced than anything on eBay. If you don't know what to buy, go with Alloy
875 (eq. Kanthal A1) if you're operating in open air. If this answer confuses you, read more, search existing topics, and perhaps open a new thread.
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gsd
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I am surprised to learn that two critical properties of SS 304 and Kanthal are not very different.
Electrical Resistivity
SS 304 : 0.000116 ohm-cm
Kanthal A: 0.000145 ohm-cm
Coefficient of Thermal Expansion
SS 304 :18.7 µm/m-°C to 649°C
Kanthal A:14.0 µm/m-°C @ 20.0 - 750 °C
may be some other parameter warrants use of special alloy as a heating element.
gsd
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not_important
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Ordinary steels, even stainless, tend to oxidise away under furnace conditions. Wire for heating elements uses alloys that form tight low permeability
oxide scale that protects the underlying metal against further attack.
The sag temperature is also important, many steel compositions loss strength far below their melting points, so heating elements made from them weaken
and break at much lower temperatures than would be expected. For lower temperature ovens, such as drying ovens, steel will work although it still may
have a much shorter life than the commonly used heating element alloys.
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gnitseretni
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@watson.fawkes - eventhough $15 ain't much, since I really need to clean up the mess in and around the house, I prefer to use stuff I have already.
(like the approx. 20 firebricks and leftover furnace cement)
So I guess SS wire is out of the question.
What about the coiled wire inside one of those small heaters? Here's a picture of the same one I have: http://www.honeywellcentral.com/product_images/0-92926-34121...
I bet that wire is useless, right? I mean these heaters don't need to get that hot.
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Polverone
Now celebrating 21 years of madness
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Thread Moved
12-2-2010 at 12:20 |
watson.fawkes
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[Aside: Thank you, Polverone, for splitting this out.]
Generally, those
residential space heaters use nichrome (nickel-chromium alloys) wire. Nichrome is a reasonably refractory material. Like all such materials, there are
operating limits. So to know whether nichrome is suitable for your furnace, we'll need to know what you want to do with it, what your target
temperatures and durations are, and something about construction to know how to support your wire. It'll burn out pretty quick if you want to fire
porcelain to Cone 10, but for plenty of other applications it will work. So say more about what you're trying to accomplish.
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gnitseretni
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Sorry.. already started construction of a furnace that will burn used oil.
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Texium
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Thread Moved
19-11-2023 at 15:10 |
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