Bill Merrill on tue 21 jun 11
There is a lot mentioned about chimney height during conversations on
clay art. If you followed Bernard Leach's formula for a chimney it
would be over 40 feet tall. Most stoneware kiln chimneys don't need to
be over 10-12 high. The flue opening is oversized in most instances. I
have a 50 cubic foot kiln and the flue opening is "9 x 5" and I still
have the damper closed to about 1" open + - a fraction of an inch. I
have a slight flicker of a flame out of the bottom spyhole which is
about 5" from the bottom of the kiln floor. I use a different floor
system than most kilns. It is shown on my Flickr account:
http://www.flickr.com/photos/25594880@N04/
=3D20
=3D20
Wally Schwab has a 40 cubic kiln that has a flue opening of 35 or less ,
using Alfred burners and that kiln fires beautiful pots.
http://wallyschwab1.home.comcast.net/~wallyschwab1/apprentice1.htm
=3D20
=3D20
J.T. Abernathy had a kiln with no chimney. He opened up the brick door
at the top to let gases escape from the kiln
http://www.ibremsenpotter.com/abernathy.html
The kiln design is shown on the site listed above.
=3D20
Bill Merrill
=3D20
=3D20
=3D20
=3D20
Bonnie Staffel on thu 23 jun 11
Your mention of J.T's kilns reminded me of my visit to his studio in Ann
Arbor many years ago when I was new to clay. Here in the middle of town,
with stores surrounding his building, he had an impressive kiln so large =
=3D
one
could park a car inside. I then heard that it took two men to carry the
shelves to load the kiln. The door was also on wheels for ease in =3D
closing.
Then it was said there was no chimney but that there were openings in =3D
the
ceiling of the building which acted as his exhaust of the kiln fumes.
Amazing man. He also had developed powerful wheels and where two potters
would work on the same pot. If you are ever in Ann Arbor, (I hope they =3D
are
still there) are tree planters made by him. The planters were huge. JT =3D
had
his ups and downs during his career, but he certainly had an impact on =3D
the
growth of interest in studio clay works. HE was also generous with
information to us newbies as well. His innovations in constructing =3D
equipment
for the potter was also ingenious. I recall (I hope correctly) that Norm
Schulman patterned my first electric wheel after some of his ideas. It =3D
was
very powerful but also loud because of the motor used. But after twelve
years at a stand up treadle wheel, it was my gateway to my own ease in
working with clay.=3D20
=3D20
I am thankful I have at least one of JTs early pots to give me some nice
memories.=3D20
=3D20
Regards,
=3D20
Bonnie
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
DVD Throwing with Coils and Slabs
DVD Introduction to Wheel Work
Charter Member Potters Council
=3D20
Steve Mills on fri 24 jun 11
For many years I've used Fred Olsen's calculations as my guide on Flue/Stac=
k=3D
proportions, but more recently have opted for taller stacks with a large-i=
s=3D
h chamber at the base with several passive dampers. The idea being to promo=
t=3D
e an "after-burner" effect by allowing some (controlled) air in at the bott=
o=3D
m to burn off the excess unburnt gasses. This decreases the amount of visib=
l=3D
e smoke from the stack exit, if you like a "visual clean-up".=3D20
This works pretty well in practice, with no detriment to the actual firing.=
=3D20=3D
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my Ipod touch
On 21 Jun 2011, at 21:16, Bill Merrill wrote:
> There is a lot mentioned about chimney height during conversations on
> clay art. =3D20
douglas fur on fri 24 jun 11
Bill
(and the community)
Olsen repeats these chimney rules. Leach attributes them to Matsubaiyashi.
They are based on massive hard brick kilns of the 19th C. Olsen gives a rul=
e
of thumb for gas requirements with the demand of IFB at 5/8ths of DFB. Thi=
s
suggests the draft requirement of a soft brick kiln should be 5/8ths of har=
d
brick.
Query- how to apply this? For soft brick kilns should the height be 5/8ths
the height calculated using Matsubaiyashi's rules or the crossection area
5/8ths or should they both be 5/8ths?
I've seen a couple of successful atmosperic burner kilns with chimneys only
as high as the top of the arch.
This seems to imply that the shortest possible chimney has the slowest draf=
t
speed and therefore the most time for heat to be transfered from the
combustion gasses to the ware. I think your trough design works similarly
in that the restriction slows the gasses in the kiln.
Thanks for the links
DRB
Seola Creek
On Tue, Jun 21, 2011 at 1:16 PM, Bill Merrill wrote:
> There is a lot mentioned about chimney height during conversations on
> clay art. If you followed Bernard Leach's formula for a chimney it
> would be over 40 feet tall. Most stoneware kiln chimneys don't need to
> be over 10-12 high. The flue opening is oversized in most instances. I
> have a 50 cubic foot kiln and the flue opening is "9 x 5" and I still
> have the damper closed to about 1" open + - a fraction of an inch. I
> have a slight flicker of a flame out of the bottom spyhole which is
> about 5" from the bottom of the kiln floor. I use a different floor
> system than most kilns. It is shown on my Flickr account:
> http://www.flickr.com/photos/25594880@N04/
>
>
>
>
> Wally Schwab has a 40 cubic kiln that has a flue opening of 35 or less ,
> using Alfred burners and that kiln fires beautiful pots.
> http://wallyschwab1.home.comcast.net/~wallyschwab1/apprentice1.htm
>
>
>
>
>
> J.T. Abernathy had a kiln with no chimney. He opened up the brick door
> at the top to let gases escape from the kiln
> http://www.ibremsenpotter.com/abernathy.html
>
> The kiln design is shown on the site listed above.
>
>
>
> Bill Merrill
>
>
>
>
>
>
>
>
>
gary navarre on fri 24 jun 11
That's what I was wondering about Steve, by intuition I put 4 soap sized ho=
=3D
les up the stack but so far only used the one above the active damper for t=
=3D
hat afterburner effect and the lowest one below the active damper to see co=
=3D
nes placed at the exit flue. My feeling is the draft is increased by adding=
=3D
that air instead of cooling and slowing. Maybe opening the lower one would=
=3D
cool the stack below the active damper thereby slowing the draft. I haven'=
=3D
t done that yet.=3D0A=3D0AGary Navarre=3D0ANavarre Pottery=3D0ANavarre Ente=
rprises=3D
=3D0ANorway, Michigan, USA=3D0Ahttp://www.NavarrePottery.etsy.com=3D0Ahttp:=
//www.=3D
youtube.com/GindaUP=3D0Ahttp://public.fotki.com/GindaUP/=3D0A=3D0A=3D0A--- =
On Fri, =3D
6/24/11, Steve Mills wrote:=3D0A=3D0A> From=
: St=3D
eve Mills =3D0A> Subject: Re: [Clayart] kiln=
c=3D
himneys etc=3D0A> To: Clayart@LSV.CERAMICS.ORG=3D0A> Date: Friday, June 24,=
201=3D
1, 4:14 AM=3D0A> For many years I've used Fred Olsen's=3D0A> calculations a=
s my=3D
guide on Flue/Stack proportions, but more=3D0A> recently have opted for ta=
ll=3D
er stacks with a large-ish=3D0A> chamber at the base with several passive d=
am=3D
pers. The idea=3D0A> being to promote an "after-burner" effect by allowing =
so=3D
me=3D0A> (controlled) air in at the bottom to burn off the excess=3D0A> unb=
urnt=3D
gasses. This decreases the amount of visible smoke=3D0A> from the stack ex=
it=3D
, if you like a "visual clean-up". =3D0A> This works pretty well in practic=
e,=3D
with no detriment to=3D0A> the actual firing. =3D0A> =3D0A> Steve M=3D0A> =
=3D0A> =3D0A=3D
> Steve Mills=3D0A> Bath=3D0A> UK=3D0A> www.mudslinger.me.uk=3D0A> Sent fro=
m my Ipo=3D
d touch=3D0A> =3D0A> On 21 Jun 2011, at 21:16, Bill Merrill L.ED=3D
U>=3D0A> wrote:=3D0A> =3D0A> > There is a lot mentioned about chimney heigh=
t duri=3D
ng=3D0A> conversations on=3D0A> > clay art.=3DA0 =3D0A>
| |
|
