Ceramic Tuyeres for Smelting?

> I have been trying to run down the kiln shelf supports that we used for
> the air intake in the smelting furnace. However, I am told the round
> ones are not made any more and now they make triangular, square ones
> Do you know a source that makes and sells these round kiln posts?

I get the supports from a place in Kitchener ON. This is an outlet of a
larger company:

the Pottery Supply House
1120 Speers Road
Oakville ON, L6L 2X4
800-465-8544

mail@pshcanada.com
www.pshcanada.com

The units I purchase are:
FRP12 - 12" T175 Round Post (at $6 CDN plus taxes each)
The company does do mail order via phone or web site using credit cards.

These are supports for a PORCELIN kiln - higher temperature, I thnk
rated for 1150 C. You can contact the company direct and they may be
able to refer you to an American supplier (although these mail easy enough).

Now, I suspect that the interior diameter as round and at 1" size is the
critical thing. Likely the exterior shape does not matter. The artifact
samples are all cylinders or more commonly conical. This is mainly
because how they were made. You take a blob of clay and work it around a
stick with your hands and then either burn or more likely just pull out
the stick.
If you used a square or triangle shape, I'd suggest placing it so one of
the edges was uppermost - rather than one of the flats. Watch the
minimum wall thickness too. I can see a circle inside a triangle perhaps
leaving a thin side wall.

Ideally the air blast is cooling the tuyere material and keeping it from
melting. So with a constant blast from a mechanical blower the tube
shape may be of less importance.