On Fri, 17 Oct 2014 20:06:13 +0000 (UTC), Jerry Peters
wrote:

Think porcelin like a sink or bath tub. It's firmly bonded to the
metal.

Well, let's do the math.
Coefficient of linear expansion for:
steel = 12*10^-6 m/m-K
alumina = 5.4*10^-6 m/m-K

http://www.engineeringtoolbox.com/linear-thermal-expansion-d_1379.html
From 25C to 100C (near the burner) on a 2 meter high tank, the steel
will expand:
12*10^-6 m/m-K * 2m * (100-25) = 1.8 mm
and the ceramic:
5.4*10^-6 m/m-K * 2m * (100-25) = 0.8 mm
1mm difference doesn't sound like much, but if both materials are
rigid, it could easily delaminate. The alumina ceramic is very rigid,
but the steel can bend. If the tank were allowed to bulge slightly in
the middle, it would work, if the alumina can survive being under
constant tension without cracking.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
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