Hank Murrow on sun 10 dec 06
On Dec 10, 2006, at 5:13 PM, jonathan edward byler wrote:
>
> Another option that I was thinking about with this sodium vapor kiln
> is to make the area around the burner ports where the soda is added
> out of hardbrick, and design this area to be easily removable for
> replacement. I have been told that much of the problems in a sodium
> vapor kiln form where the soda gets introduced into the firebox, and
> this then coagulates into a lump until it is vaporized, causing
> severe damage to the bricks underneath.
Dear Jonathan;
You might want to borrow a trick I learned while at Anderson Ranch in
the early 70's. Cast a reservoir out of good refractory(Pryor giggey
Flocast 30S or equivalent) to hold the molten sodium so it does not
seep into the cracks in the brickwork. Works a treat, and will be
replaceable in the event that the reservoir fails.
Cheers, Hank
www.murrow.biz/hank
jonathan edward byler on sun 10 dec 06
Hi luba,
I'm looking at the same stuff right now, and not really sure about a
decent answer. Just to pass on this information and my conclusion to
others, I am forwarding this to the clayart list also.
I was looking at using softbrick for the insides of the sodium vapor
kiln we want to build here at auburn. After talking with a friend
last night we were thinking that for the size (a little under 30 cu
ft.) we might want to use hard brick after all. I was considering
the energy savings of soft brick, but such a small kiln I fear might
cool off to fast. So I think we might be back to a hardbrick kiln
with some other refractory (kaowool, castable, softbrick) on the
outside for extra insulation. This would also solve the problem of
the bricks being eaten away so quickly. When We build this kiln, I
am going to try and do some extensive tests with ITC and other
coatings to see what they do do soft brick. I am a skeptic who would
like to believe, but I want some hard data before I commit to
something that I don't know will work. hard brick liners are a
proven thing, and since I want to fire the kiln, not build it over
and over, I am leaning strongly in this direction.
as to the high CaO content, when I looked at the data sheets I got,
all the bricks that they said were especially resistant to alkaline
atmospheres have 10% or more CaO content. I'm not a chemist or
anything, but that seems to make sense.
Another option that I was thinking about with this sodium vapor kiln
is to make the area around the burner ports where the soda is added
out of hardbrick, and design this area to be easily removable for
replacement. I have been told that much of the problems in a sodium
vapor kiln form where the soda gets introduced into the firebox, and
this then coagulates into a lump until it is vaporized, causing
severe damage to the bricks underneath.
the bricks from newcastle refractory are probably fine bricks. They
have slightly higher percentages of FeO and other impurities than do
the bricks from Thermal Ceramics. I'm not sure what this means in
terms of overall brick life, but the cost of getting the Thermal
ceramics bricks may be significantly higher. Also the thermal
conductivity of the Thermal Ceramics bricks appears to be lower for
comparable grades of bricks, but the ASTM standard used for testing
is not the same for each manufacturer. TC uses ASTM C 201 for this
test, New Castle uses ASTM C 182. I have not read these standards,
so could not tell you the difference.
Please post to us if you find any additional info, and I will try and
do the same as time permits.
best,
jon byler
jon byler
3-D Building Technician
Art Department
Auburn University
Auburn, AL 36849
On Dec 10, 2006, at 10:42 AM, MudFire - Luba & Erik wrote:
> Hi Jon,
>
> Quick question about your post on Clayart. You mentioned that the
> high CaO content in K26 bricks is more resistant to Alkaline
> atmopsheres... I'm building a soda kiln, which we will fire in mild
> reduction. I'm not great with chemistry... please help: is soda
> vapour the type of alkaline atmosphere this would be good for?
> Should I run not walk from bricks made by new castle refractory
> (ncrci.com) in PA which have less than 0.1%CaO?
>
> Any insight would be greatly appreciated! Thank you so much!
>
> Luba Sharapan
>
>
> MudFire Clayworks & Gallery
> Open Studio * Workshops * Exhibits
>
> 175 Laredo Dr, Decatur, GA 30030
> 404-377-8033
> www.mudfire.com
>
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