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capturing the energy from kilns

updated sat 20 nov 04

 

Louis Katz on wed 17 nov 04


My understanding is that draft vs temperature (differential) when
plotted comes to an asymtope ( sp) somewhere well below cone 10 and
that you could cool down your gases quite far without affective draft
much. I bleive I got this idea from Pioneer Pottery (Cardew). It might
make more sense to use waste heat to preheat combustion air during the
firing. After the firing in the winter you could opena door between
your kiln room and studio to provide heat.
I would be careful of any system that puts a water line into the kiln.
steam especially real hot steam can be a real problem in large
quantities.
Louis
On Nov 17, 2004, at 3:26 PM, Darin Lang wrote:

> There is a limited amount of energy. If you take some away to do
> something else then you must put more fuel in. If you draw away the
> radiant heat from a cooling kiln, it will cool faster.
>
> That said, you could put a stainless coil in your flue, then pump water
> through the coil to a tank and store hot water for radiant heat, it
> would cool the exhaust gases and potentially slow the draft down, but
> that could be countered by a cheap fan. A large underground tank could
> store a great deal of hot water for use in a radiant heating system.
> If
> you have a concrete slab, but no radiant tubing it could be installed
> by
> laying out the hoses which are not very expensive on the existing slab
> and then pouring a thin slab maybe 2 inches thick to cover. With
> regular
> firings you wouldn't need a supplemental boiler to drive the system.
> And
> you could really reduce your power bill by heating the slab to 65 F to
> achieve the same effect as heating the air to 70 F.
>
> Darin Lang
>
> Les Elford wrote:
>
>>
>>
>> Is anyone conssidering capturing the energy from kilns. Turning it
>> into a source of steam or some other usable source of energy?
>>
>> 2000 plus degree kilns that cool for hours could have a better use.
>>
>> Any Ideas?
>>
>> Good day to you all from the BIG SKY COUNTRY!
>> Les
>> ______________________________________________________________________
>> ________
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>
> _______________________________________________________________________
> _______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
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>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
>
Louis Katz

Question Questioning

Darin Lang on wed 17 nov 04


Another idea. I was just reading that 36% of the heat generated in a
good kiln is lost through the flue. That's alot of heat.

Get a radiator with an electric fan out of a junkyard, a water or bilge
pump, and a stainless steel coil. You could use it to build a forced
draft system with preheated combustion air for the kiln, or just to heat
a building. You could probably pump the water quite a distance,
switching to copper pipe, once outside the flue.

Or what about putting a bisquing kiln back to back with a firing kiln
and running the exhaust gases through it? Bisque one load while firing
another. Temperature could be controlled with a damper if it tended to
get too hot.

Darin Lang

Les Elford on wed 17 nov 04







Is anyone conssidering capturing the energy from kilns. Turning it into a source of steam or some other usable source of energy?

 

2000 plus degree kilns that cool for hours could have a better use.

 

Any Ideas?

 

Good day to you all from the BIG SKY COUNTRY!

Les


William Melstrom on wed 17 nov 04


Is anyone conssidering capturing the energy from kilns. Turning it into =
a source of steam or some other usable source of energy?

I have heard that some people run their gas lines through their stacks, =
thereby pre-heating the gas before it enters the kiln.
-- William Melstrom

Darin Lang on wed 17 nov 04


There is a limited amount of energy. If you take some away to do
something else then you must put more fuel in. If you draw away the
radiant heat from a cooling kiln, it will cool faster.

That said, you could put a stainless coil in your flue, then pump water
through the coil to a tank and store hot water for radiant heat, it
would cool the exhaust gases and potentially slow the draft down, but
that could be countered by a cheap fan. A large underground tank could
store a great deal of hot water for use in a radiant heating system. If
you have a concrete slab, but no radiant tubing it could be installed by
laying out the hoses which are not very expensive on the existing slab
and then pouring a thin slab maybe 2 inches thick to cover. With regular
firings you wouldn't need a supplemental boiler to drive the system. And
you could really reduce your power bill by heating the slab to 65 F to
achieve the same effect as heating the air to 70 F.

Darin Lang

Les Elford wrote:

>
>
> Is anyone conssidering capturing the energy from kilns. Turning it
> into a source of steam or some other usable source of energy?
>
> 2000 plus degree kilns that cool for hours could have a better use.
>
> Any Ideas?
>
> Good day to you all from the BIG SKY COUNTRY!
> Les
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org You may look at the archives
> for the list or change your subscription settings from
> http://www.ceramics.org/clayart/ Moderator of the list is Mel Jacobson
> who may be reached at melpots@pclink.com.

Pfeiffer, Dan R (Dan) on wed 17 nov 04


I am planning on putting copper pipe in my vent hood to heat water for the
studio.
This should be of some use but in the long run it will not do much as I need
water
a lot more often then I fire the kiln. The problem with most all energy
recover schemes
is storing the energy until you need it. But it is easy if you fire gas and
have lots of heat going
up the flue !

Dan in Elkmont Al

>> Is anyone conssidering capturing the energy from kilns. Turning it into
a source of steam or some other usable source of energy?

2000 plus degree kilns that cool for hours could have a better use.

Any Ideas?

Les <<

John Rodgers on wed 17 nov 04


There is a device known as a "Stack Robber" that is often installed in
smoke stacks and exhaust stacks from furnaces, kilns, etc.

Stack Robbers are usually a box like device that has an input port and
an exhaust port, and a series of tube that pass completely through the
stack robber. A fan is often mounted on one side to draw/blow air
through the tubes, which in turn is heated by the hot gases passing the
tubes on the way out the exhaust stack. This system is an energy
recovery device that provides additional heating for work spaces in
colder climates.

I have seen a few Stack Robbers modified to heat water for transport to
other areas.

The most interesting variation of this theme I ever say was one winter
while visiting in the Athapascan Indian village of Grayling on the Yukon
River. Must have been about 35-40 degrees below zero, and the family in
their little house had a 55 gallon steel drum sitting in an upright
position on cinder blocks serving as a heating stove. A door had been
fashioned on one side to serve for loading wood into it. Wrapped around
that steel drum were several turns of copper tubing. A steel tub, filled
with water, sat to one side, with the bottom turn of the copper tube
passing through the bottom side of the tube, and the end of the top turn
of tubing sticking down just under the surface of the water. Over time
the water in the coils slowly heated and a thermo-siphon action would
get started, and eventually the entire tub of water was heated nicely.
This water was used for bathing, cloths washing, etc. Very ingenious.
Cloths drying was done out doors in spite of the cold. At those
temperatures, the clothes freeze almost instantly, but the ice
sublimates quickly and soon the clothes are completely dry. Interesting
process. Freeze Drying the clothes to get the water out for wearing.
Smart people, those Athapascans.

Regards,

John Rodgers
Chelsea, AL

Les Elford wrote:

>
>
> Is anyone conssidering capturing the energy from kilns. Turning it
> into a source of steam or some other usable source of energy?
>
> 2000 plus degree kilns that cool for hours could have a better use.
>
> Any Ideas?
>
> Good day to you all from the BIG SKY COUNTRY!
> Les
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org You may look at the archives
> for the list or change your subscription settings from
> http://www.ceramics.org/clayart/ Moderator of the list is Mel Jacobson
> who may be reached at melpots@pclink.com.

Ivor and Olive Lewis on thu 18 nov 04


Dear Les Elford,
I have seen a heat exchanger put in the flue stack so that the =
combustion air can be preheated. If you search back through CM annual =
and collective indexes you should e able to find a superb technical =
article on this.
Alternatively, why not put a water circulator into the stack and use the =
heat to warm up the pool in winter. Or channel it around the house.
Andrew is coming this arvo. He is a conservation engineer. See what he =
can suggest in addition to these notions.
Best regards,
Ivor Lewis.
Redhill,
S. Australia.

Ivor and Olive Lewis on thu 18 nov 04


Heat Storage can be accomplished by having a large tank of several
thousand gallons capacity and filling it with cobble size lumps of
Quartzite, Granite or other similar solid rocks that have a high heat
capacity.
Remember that a thermo-syphon can be used to drive a low power turbine
generator and the electricity generated can be stored in accumulators,
pushed through invertors and transformers to give useable power at
110v or 240v
But never forget, Entropy Rules!
Best regards,
Ivor Lewis.
Redhill,
S. Australia.

Louis Katz on thu 18 nov 04


if the clothes are smooth and starched before they freeze is it
possible to have them "dry" already ironed? This would be very handy
for my socks, and shirts.

Would love to test this but my freezer is small.

Louis
:)

On Nov 17, 2004, at 6:52 PM, John Rodgers wrote:
> The most interesting variation of this theme I ever say was one winter
> ........ At those
> temperatures, the clothes freeze almost instantly, but the ice
> sublimates quickly and soon the clothes are completely dry. Interesting
> process. Freeze Drying the clothes to get the water out for wearing.

Louis Katz
WIKI site http://www.tamucc.edu/wiki/Katz/HomePage

Bruce Girrell on thu 18 nov 04


Darin Lang wrote

> Or what about putting a bisquing kiln back to back with a firing kiln
> and running the exhaust gases through it? Bisque one load while firing
> another.

While it is certainly possible to heat your water or a swimming pool with
waste heat from a kiln, the infrequent firing cycle (for most) would require
that you use conventional heat sources for those purposes as well so now you
have to pay for two heating/piping systems instead of one, making the
payback of the heat recovery a very long term investment at best.

Darin's idea though, using the waste heat of a high fire process to
accomplish a lower temperature process, has some merit I think. Production
of ware for the bisque would be easy to keep at a rate that matched the
firing of the glaze kiln so the intermittent usage would match the output of
the individual potter. Physically arranging the two kilns would not be that
difficult. You'd need a bypass to adjust the temperature and terminate the
firing of the bisque. And you'd have to tinker a bit to keep good oxidation
in the bisque if you had reduction going in the glaze kiln.

Perhaps we're just tweaking a noborigama, but the idea sounds interesting.

Bruce "insert catchy internym here" Girrell

Lee Love on thu 18 nov 04


Darin Lang wrote:

> Another idea. I was just reading that 36% of the heat generated in a
> good kiln is lost through the flue. That's alot of heat.

I have seen the noborigama ground hot air balloons sailing over
the sky above it. Very scary! I thought we were going to have to
squeegee people off the ground.

Aren't there any old Whole Earth Catalog or Co-Evolution
Quarterly readers here? (Or has Mel's disparaging comments about
"Hippies" made you keep your mouth shut? ;^) )

Probably, anagama (which are not your most efficiently
design in wood kilns. You could build a more efficient kiln and use
the saved wood to fuel a wood stove), that are embanked with earth
would be the best situation for capturing heat. I have seen plans for
use in earth insulated houses with a green house at the southern end,
where heat sinks are made behind the house that are filled with crushed
stone, and then conduit is used with a blower to transfer the heat from
the greenhouse to the gravel heat sink., which is drawn upon at night to
heat the house.

The same principle could be used with a kiln, but using pipe
filled with water that could be used to carry heat to the heat sink.
With an anagama, you could also have a run from the kiln to the chimney
underground, with a heat sink on each side of the run to capture the heat.

You could also use co-generation to make electricity that you
could store in batteries. This might work well in conjunction with
windmills.

I would like to build a kiln with oya building stone. It is
used in this region for foundations in buildings, wall,s and for the
walls in storehouses. I have though you could build the outside
structure of the kiln with oya, and then line it with insulation
brick. The mass would hold heat for a long time. Would be a
disadvantage in the summer though.

--
Lee in Mashiko, Japan http://mashiko.org
http://www.livejournal.com/users/togeika/ WEB LOG
http://public.fotki.com/togeika/ Photos!

Kevin Black on fri 19 nov 04


Sorry if this sounds like a rant but given the world's dwindling fossil fuel
supply and the apparent connection between greenhouse gases and the ozone
layer, I believe that as significant energy users we should all 'do our
part' to reduce fuel wastage. Maximising the 'useful' energy we employ is
one step and I applaud moves by those companies within the ceramics industry
who have pioneered heat recovery systems and regenerative kilns such as
http://www.takasago-inc.co.jp/eg/rbk/regene.htm . Hopefully some of these
innovations will find their way into the world of studio pottery by some
enterprising kiln manufacturer. In the meantime I encourage everyone to
review your own practices. ITC coating, oxyprobes, kiln placement and even
efficient kiln loading all contribute in a small but significant way.

I'll get off my soapbox now and would be pleased to hear from anyone who
might like to share their own energy saving idea.

regards.. kevin

Located in New Zealand - yes sitting under the hole in our ozone layer!
email: kevin@i.am

John Rodgers on fri 19 nov 04


Louis Katz wrote:

> if the clothes are smooth and starched before they freeze is it
> possible to have them "dry" already ironed? This would be very handy
> for my socks, and shirts.
>
Louis, you crack me up!!!

I never met an Alaskan of any kind - Native or non-Native - that was
anal enough to be concerned about whether his shirts could be freeze
dried in a "Starched and Ironed" state, much less his socks!!!!! LOL!!

Nobody cares, my friend, in that environment. Thats a city thing. Get
out of Anchorage to find the real Alaska and the "Real" people, and they
don't care about such stuff. If it's warm, convenient, and wears well
.... that is the concern.

BTW, "Alaska Formal" is a Jac-shirt and a bolo tie with a Native-carved
ivory clip.

Regards,

John Rodgers
Chelsea, AL

Joyce LEE on fri 19 nov 04


ok
----- Original Message -----=20
From: Louis Katz=20
To: CLAYART@LSV.CERAMICS.ORG=20
Sent: Thursday, November 18, 2004 9:47 PM
Subject: Re: Capturing the energy from Kilns


if the clothes are smooth and starched before they freeze is it
possible to have them "dry" already ironed? This would be very handy
for my socks, and shirts.

Would love to test this but my freezer is small.

Louis
:)

On Nov 17, 2004, at 6:52 PM, John Rodgers wrote:
> The most interesting variation of this theme I ever say was one =
winter
> ........ At those
> temperatures, the clothes freeze almost instantly, but the ice
> sublimates quickly and soon the clothes are completely dry. =
Interesting
> process. Freeze Drying the clothes to get the water out for wearing.

Louis Katz
WIKI site =
http://www.tamucc.edu/wiki/Katz/HomePageHomePage>

=
_________________________________________________________________________=
_____
Send postings to =
clayart@lsv.ceramics.org

You may look at the archives for the list or change your subscription
settings from =
http://www.ceramics.org/clayart/

Moderator of the list is Mel Jacobson who may be reached at =
melpots@pclink.com.

Lee Love on fri 19 nov 04


Bruce Girrell wrote:

>Perhaps we're just tweaking a noborigama, but the idea sounds interesting.
>
People have been doing this. I wanted to build a second chamber for
my kiln, but I didn't have the time (I had only 2 months to build the
kiln, buy supplies, and make my first work.).

MacKenzie's kiln is a two chambered noborigama and he used to bisque in
the second chamber. But it was difficult to keep up with and he now
bisques in electric. He converted his front chamber into a car kiln
and the second chamber is not used. This configuration might work
best in a communal studio situation. Someday, I might be able to
work far enough ahead to have my green ware ready to fire during the
current glaze firing...

I think the first mention of using waste heat to bisque is
Daniel Rhodes book on kilns. He has a diagram of a kiln that has a
wall in the back with an opening at the top and the back space is used
for bisquing.

--
in Mashiko, Japan http://mashiko.org
http://www.livejournal.com/users/togeika/ WEB LOG
http://public.fotki.com/togeika/ Photos!