Bryan Hannis on sat 24 apr 99
I just finished a firing of a 24 cu.ft. alpine updraft kiln while using an
oxy probe for the first time and I had some weird readings?? In the lower
temps [1400F to 1800F] the readings seem to be very stable [.1 to .2] but
after a body reduction the readings started to be very eratic jumping from
.1 to .6 up until cone 10 went down?? The gas was set at about 2", damper at
2 1/4 ", fan speed at 3/4 open with side gates about 1/2 open, does anyone
see what went on?? any suggestions would be much appreciated.
Bryan Hannis
Nils Lou on sun 25 apr 99
What went on was your probe was responding to the ever changing atmosphere
in your kiln. Updraft designs are notorious for poor mixing conditions.
The Oxyprobe samples 3-7 times per second, so it was "seeing" the
variation of oxygen atoms going by. You may want to find another place to
position the probe, but that won't change the actuality of poor
turbulence, (read stratified atmospheric conditions) in your Alpine. If
you
are interested, I can suggest some modifications which will make your
Alpine fire significantly better. First, if it has the curved muffles over
the flame trench, remove them. Second, line the trench with 1" ceramic
fiber blanket-go up the sides 3-4" and up the back 8". Get rid of the
porcelain burner tips if they are perchance still in one piece. Spray the
interior with ITC 100. Call and tell me how pleased you are with the
subsequent firings. Call Alpine and tell them their kiln is fixed.
Nils Lou
PS. Install the fiber blanket AFTER you spray the kiln with ITC 100. The
reason is you want the friction of the fiber surface to break up the
flame.
On Sat, 24 Apr 1999, Bryan Hannis wrote:
> ----------------------------Original message----------------------------
> I just finished a firing of a 24 cu.ft. alpine updraft kiln while using an
> oxy probe for the first time and I had some weird readings?? In the lower
> temps [1400F to 1800F] the readings seem to be very stable [.1 to .2] but
> after a body reduction the readings started to be very eratic jumping from
> .1 to .6 up until cone 10 went down?? The gas was set at about 2", damper at
> 2 1/4 ", fan speed at 3/4 open with side gates about 1/2 open, does anyone
> see what went on?? any suggestions would be much appreciated.
>
> Bryan Hannis
>
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