Dave Finkelnburg on sat 28 dec 02
Hi Paul!
You wrote, "I am again thinking of preheating air. In the ³Energy
Efficient Potters²
book (whose authors i have not been able to communicate with) , the writer
uses nozzle mix burners because he claims that the integrity of the fuel is
destroyed by the preheated air...."
If the book author actually wrote that, he has written nonsense. The
fuel, even if it were "cracked," would still contain just as many carbon and
hydrogen atoms as before, just in more molecules. "Cracking" is the breaking
of hydrocarbon bonds to make shorter hydrocarbon chain molecules.
Personally, I don't think you'll crack much liquid propane anyway with your
preheated air at the operating pressure of your burners.
The chemical reaction you are concerned about is thermal oxidation, the
combining of the carbon and hydrogen atoms in the fuel with oxygen. Of
course, we usually call this particular reaction "burning."
You are worried about the right design issues for your burners. Good
luck with your design!
Dave Finkelnburg in unseasonably winter warm Idaho
Paul Taylor on mon 30 dec 02
Dear Dave
Thanks for your input .
I am glad I am not a beginner because the ramifications of this is that
nothing I have read can be taken as a certainty . In matters of philosophy
and politics I always doubt what I read , but my habit has always been to
take what is said in text books as gospel. I suppose one has to a bit. if
you question every thing in a book it is of little help to you.
I recently fond out that according to Olson for twenty five years I have
been using my venturi burners the wrong way up . He gives no explanation
why. they seem to work all right my way so I will ignore him.
The reference I mentioned in the Energy Efficient Potter is wrapped up in
some very firm rhetoric, and the article's author describes how to build a
nozzle mix burner avoid disintegrating the fuel . So I will not consider
myself stupid for taking it at face value. However I should have smelt a ra=
t
after trying in vain to follow the very inadequate instructions on building
the nozzle mix burner.
I think There is dam all known about gas burners in the public domain. ther=
e
is probably more exacting research done on dung beetles in the desert.
And until the price of fossil fuels in America doubles I suspect we will no=
t
see much research. Of all the books I have I have found Nils is the most
helpful.=20
I like the convenience of the minnesota flat top. it is a kiln that would b=
e
very easy to maintain apart from the roof. But in some ways a roof that
often needs replacing or repairing that is easy to replace is not half as
much hassle as an arched roof that seldom needs replacing but is near
impossible to repair.
Again thanks.
=20
-- =20
Regards from Paul Taylor
http://www.anu.ie/westportpottery
Those that live by rhetoric will lie by it
> From: Dave Finkelnburg
> Reply-To: Clayart
> Date: Sat, 28 Dec 2002 16:13:23 -0700
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: burner question. Paul Taylor, fuel cracking
>=20
> Hi Paul!
> You wrote, "I am again thinking of preheating air. In the =B3Energy
> Efficient Potters=B2
> book (whose authors i have not been able to communicate with) , the write=
r
> uses nozzle mix burners because he claims that the integrity of the fuel =
is
> destroyed by the preheated air...."
>=20
> If the book author actually wrote that, he has written nonsense. The
> fuel, even if it were "cracked," would still contain just as many carbon =
and
> hydrogen atoms as before, just in more molecules. "Cracking" is the break=
ing
> of hydrocarbon bonds to make shorter hydrocarbon chain molecules.
> Personally, I don't think you'll crack much liquid propane anyway with yo=
ur
> preheated air at the operating pressure of your burners.
> The chemical reaction you are concerned about is thermal oxidation, the
> combining of the carbon and hydrogen atoms in the fuel with oxygen. Of
> course, we usually call this particular reaction "burning."
> You are worried about the right design issues for your burners. Good
> luck with your design!
> Dave Finkelnburg in unseasonably winter warm Idaho
>=20
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