David Hendley on fri 9 nov 07
From Pioneer Potter, page 210 in my 1973 British edition:
"Black smoke at the chimney...contributes nothing to the
reduction of the oxides in the setting - for which we have
said, a small preponderance of carbon monoxide is all that
is required. Black smoke is thus the enemy of reduction,
not a means to it. A continuous emission of smoke means
not only that a large part of the calorific value of the fuel is
being wasted but also that the temperature will not rise
until it is cleared."
David Hendley
Maydelle, Texas
david(at)farmpots(dot)com
http://www.farmpots.com
Gary Navarre on wed 14 nov 07
On Fri, 9 Nov 2007 22:40:51 -0600, David Hendley wrote:
>From Pioneer Potter, page 210 in my 1973 British edition:
>
>"Black smoke at the chimney...contributes nothing to the
>reduction of the oxides in the setting - for which we have
>said, a small preponderance of carbon monoxide is all that
>is required. Black smoke is thus the enemy of reduction,
>not a means to it. A continuous emission of smoke means
>not only that a large part of the calorific value of the fuel is
>being wasted but also that the temperature will not rise
>until it is cleared."
>
>David Hendley
>Maydelle, Texas
>david(at)farmpots(dot)com
>http://www.farmpots.com
And remember the next two sentences... "Careful control of the secondary
air shutter is necessary throughout the reducing stage. The mouseholes also
require continual attention to ensure that the bank of embers does not begin
to block the throat arch." One of my early clay pals, Jeff Cline, made that
apparent to me when he visited during my firing the Hobelectric and it was
stalled at about ^6. He had me cut (close) the primary and secondary air and
feed off the coal pile with air from the mousehole for an hour or so and it
started climbing with a blue flame. In this new kiln I've installed an
interesting mousehole system, one for the Hob and another for the Pignose.
Having that control option is another feature of the Bourry firebox that led
me to taking the time to design it into what I'm building. The shape fans
out to the width of the firebox floor from a much smaller hole in front of
the pignose. Give me air Scotty and stay in there aeh!
G in da U.P.
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