William Brouillard on wed 15 jul 98
Spin drafting burner placement and kiln design
Just a few comments on the burner configuration that was
discussed a few days ago. One burner in front and one in
the back of the kiln with the front burner on the left side of
the kiln and the back burner on the right side of the kiln.
I have always called that type of burner set up a Spin Draft.
I only have the experience of working with three kilns using
a spin type burner set up. The first was a round bodied kiln
built like a silo. It was a Ted Randle design and was in the
kiln room at Alfred University. There were two forced air
burners, one mounted in the rear and the other in front.
They were mounted at two different heights One rear lower
than the front( I think). It had a great deal of plumbing on it
and was set up to change from oxidation to reduction with
the pull of a lever. The burners created a tornado like spin
draft inside the kiln . It was a very even firing kiln in low or
high temperature.
The ceramic engineers had a combination metal, brick and
fiber spin draft that had one burner at the top of the kiln and
second mounted at the bottom. It was an opposing front to
back spin style configuration.
The third kiln was a spin draft ground hog style Salt kiln at
Penland School. The advantage of the spin draft
configuration as I under stand it is to create lots of
turbulence inside of the kiln.
It was an outgrowth of the old 3 T s of proper combustion
axiom, Time Temperature and Turbulence. The spinning
high velocity gases would circulate better though out the
kiln giving even temperature. AN added advantage of the
Spin Draft was that it gave better salt/soda distribution
though out a vapor kiln. It was the equivalent of putting a
big spoon in a mixing pot and stirring vigorously. The
combination of the front/back, spin configuration with the
addition of a forced air burner system gives any salt/soda
kiln a turbulent fluid flow and excellent vapor distribution
through out the kiln. You can stack tighter and still get the
same results as you would with a more open stack. Many
kiln designs are uneven in the early stages of the firing . A
spin set up helps even them out at low temperatures. If
there are some engineers out there you might want to add
your thoughts about whether Corollas (spelling) force
makes any real contribution and would dictate the burner
placement in terms of a clockwise or counter clockwise
spin. My guess would be that a forced air burner system
would override those kind of considerations. My two cents
for the week.
--
william brouillard
1011 literary road
cleveland,oh.44113
ch151@cleveland.freenet.edu
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