chimnies

[jrgpots]

I'm sorry about another kiln builder's question......BUT....

 

I picked up a small 3 1/2 cubic foot electric kiln dirt cheep and want to convert it to a downdraft gas. I had seen Simon Leach's and others' conversion on YuoTube. Most put the chimney on the inside of the chamber. Is there any advantage other than ease of construction to place the chimney inside the chamber? I thought about placing the chimney outside of the chamber and reclaiming some of the chimney's heat then reintroducing that heated air back into the kiln. ANY Thoughts?

[Biglou13]

I'm sorry about another kiln builder's question......BUT....

 

I picked up a small 3 1/2 cubic foot electric kiln dirt cheep and want to convert it to a downdraft gas. I had seen Simon Leach's and others' conversion on YuoTube. Most put the chimney on the inside of the chamber. Is there any advantage other than ease of construction to place the chimney inside the chamber? I thought about placing the chimney outside of the chamber and reclaiming some of the chimney's heat then reintroducing that heated air back into the kiln. ANY Thoughts?

 

 

I've been doing tons of research on kiln building. I haven't seen chimney inside ware chamber? Can you post a link? I have seen exhausted routed via small chimney outside Of chamber.and out of top of chamber. Why take up space inside, and loose interior kiln space.

 

I have seen designs where air intake for kiln is heated via chimney exhaust, the re introduced a heated air source for combustion .... Very efficient.however this is not direct reintroduction of exhaust to intake. But a system of intake tubes routed through chimney to use that heat to pre heat intake air.

 

I'm questioning the the reintroduction of exhaust to chamber, unless some muffle tube type system. But either option turns into complicated build.

[Mark C.]

I'm sorry about another kiln builder's question......BUT....

 

I picked up a small 3 1/2 cubic foot electric kiln dirt cheep and want to convert it to a downdraft gas. I had seen Simon Leach's and others' conversion on YuoTube. Most put the chimney on the inside of the chamber. Is there any advantage other than ease of construction to place the chimney inside the chamber? I thought about placing the chimney outside of the chamber and reclaiming some of the chimney's heat then reintroducing that heated air back into the kiln. ANY Thoughts?

 

 

I've been doing tons of research on kiln building. I haven't seen chimney inside ware chamber? Can you post a link? I have seen exhausted routed via small chimney outside Of chamber.and out of top of chamber. Why take up space inside, and loose interior kiln space.

 

I have seen designs where air intake for kiln is heated via chimney exhaust, the re introduced a heated air source for combustion .... Very efficient.however this is not direct reintroduction of exhaust to intake. But a system of intake tubes routed through chimney to use that heat to pre heat intake air.

 

I'm questioning the the reintroduction of exhaust to chamber, unless some muffle tube type system. But either option turns into complicated build.

 

 

I see zero reason to put it inside-as it eats up firing space which is at a premium in a small kiln.

Outside makes the most sense no matter who or how many do it on u-tube.

Mark

[neilestrick]

If you try to put a chimney inside a kiln that small you won't have any room left for pots! Shelves won't fit right, either. You can use the heat from the chimney to preheat the intake air, but you can't use the actual air from the chimney as it will not have enough oxygen left in it to aid combustion.

[jrgpots]

I'm sorry about another kiln builder's question......BUT....

 

I picked up a small 3 1/2 cubic foot electric kiln dirt cheep and want to convert it to a downdraft gas. I had seen Simon Leach's and others' conversion on YuoTube. Most put the chimney on the inside of the chamber. Is there any advantage other than ease of construction to place the chimney inside the chamber? I thought about placing the chimney outside of the chamber and reclaiming some of the chimney's heat then reintroducing that heated air back into the kiln. ANY Thoughts?

 

 

I've been doing tons of research on kiln building. I haven't seen chimney inside ware chamber? Can you post a link? I have seen exhausted routed via small chimney outside Of chamber.and out of top of chamber. Why take up space inside, and loose interior kiln space.

 

I have seen designs where air intake for kiln is heated via chimney exhaust, the re introduced a heated air source for combustion .... Very efficient.however this is not direct reintroduction of exhaust to intake. But a system of intake tubes routed through chimney to use that heat to pre heat intake air.

 

I'm questioning the the reintroduction of exhaust to chamber, unless some muffle tube type system. But either option turns into complicated build.

 

 

I see zero reason to put it inside-as it eats up firing space which is at a premium in a small kiln.

Outside makes the most sense no matter who or how many do it on u-tube.

Mark

 

 

The youtube clip from Simon Leach is

.

That being said, I don't want to intrude on my already tiny kiln space. When I saw this youtube video, it made me wonder if there were any good reason to place the chimney inside the chamber. Shortly after posting my first thread, I was reviewing the October issue of Ceramics Monthly and found an article about an heat exchange chimney. It was very complex. I don't want to spend so much time and effort for such a small space, 3.7 cu ft.

 

But, I thought about other ideas:

 

1. Wrapping 2 tubes around one another, like 2 snakes intertwined, one tube would be the flue while the other would be a heat exchange tube. It would not reintroduce exhaust, but would preheat outside air which would then be introduced into the kiln. This would be used during ramp up and turned off during reduction and cool down.

2. Creating a dead air space around the flue, then use that dead air space as a heat exchange to preheat outside air prior to going into the kiln. This would also be used for ramp up and turned off for reduction and cool down.

3. Or...Saying the heck with it. It's a small kiln anyway and will not take much fuel to fire it.

 

 

Jed

[neilestrick]

I vote for #3. Although this would be a great way to work out the bugs if you were planning on building a larger version in the future.

[jrgpots]

I vote for #3. Although this would be a great way to work out the bugs if you were planning on building a larger version in the future.

 

 

 

I tend to agree after sleeping on it... I am going to insulate the outside with kaowool and hard brich to get the slower cool down. It also makes it easier to support the outside chimney. I will be using two MR- 750 venturi burners. One could do the job, but two gives me better control....I hope.

 

Jed

[Mark C.]

I vote #3

After blowing 15 minutes on that painfull u-tube vid. (long on tube short on why)

I see even less reason to do this -

Top 10 list-

1# The lid will not last as long with a hole cut in it

2#The chimney will crack away from wall sooner than later on the inside

3# Easier to cut a hole in outer lower wall and build one outside strapped to outside of kiln-yes a few more bricks oh well.

4#shelves will fit and work better with all that outside.

5# over complicates a simple chimney

6# both require cutting 1 hole in 2 1/2 inches of soft brick-The side or lid take ones pick-I pick the side

7# can I ever get my time back from this bad idea on u-tube?NO I cannot

8# all shelves will need to be cut to have this inner chimney work for them.

9# square tires work best on cars as seen on u-tube -no parking brake needed saves on brake pads

10# drum roll This list will be read on Letterman later this week by someone famous

 

Anywone watch that 5 hour u-tube mystery on if the Titanic sank or just was swallowed in a fog bank never to be seen again untill the same people who faked the moon landing faked the underwater videos of the wreck?

Here's two traditional chimneys I shot at our place today-just make them way smaller-ones my salt kiln with the crooked stainless the straight stainless is my car kiln chim.

do not forget to have a dampner.

Mark

[jrgpots]

I vote #3

After blowing 15 minutes on that painfull u-tube vid. (long on tube short on why)

I see even less reason to do this -

Top 10 list-

1# The lid will not last as long with a hole cut in it

2#The chimney will crack away from wall sooner than later on the inside

3# Easier to cut a hole in outer lower wall and build one outside strapped to outside of kiln-yes a few more bricks oh well.

4#shelves will fit and work better with all that outside.

5# over complicates a simple chimney

6# both require cutting 1 hole in 2 1/2 inches of soft brick-The side or lid take ones pick-I pick the side

7# can I ever get my time back from this bad idea on u-tube?NO I cannot

8# all shelves will need to be cut to have this inner chimney work for them.

9# square tires work best on cars as seen on u-tube -no parking brake needed saves on brake pads

10# drum roll This list will be read on Letterman later this week by someone famous

 

Anywone watch that 5 hour u-tube mystery on if the Titanic sank or just was swallowed in a fog bank never to be seen again untill the same people who faked the moon landing faked the underwater videos of the wreck?

Here's two traditional chimneys I shot at our place today-just make them way smaller-ones my salt kiln with the crooked stainless the straight stainless is my car kiln chim.

do not forget to have a dampner.

Mark

 

 

Thank you very much. He does tend to ramble a bit. And it takes him a while to say anything....lol

 

Jed

[neilestrick]

I'm thinking if you want to do the heat-from-the-chimney-preheating-the-intake-air thing, you'll need to have power burners.