Kiln Electric To Gas

[Wyndham]

I've got an old olympic 16 cu ft oval that I'd like tp convert to gas. Thought I'd throw out an idea for discussion.

Coming in from one end with 2 burners onto a bagwall about 6 to 8 in in and an exit flue on the other end.

Here's the area I'd like some thoughts on. I could put the exit flue at the far side with the first shelf about 6 in off the floor  or....

I could make a floor that has a channel  recessed from the middle running to the exit flue and the shelf 6 in above the floor or...

Have the channel as above but cover it over except for a exit point in the middle of the floor about the same sq in as the exit flue.

I'm trying to figure out which way gives me the best even heat distribution back to front and top down.

The channel would be hard brick and if I covered the channel, I'd use old kiln shelves cut to size.

The burners word be raku burners mr705? and the regulator is max 15ld high pressure but most likely only use about 3/4 lb per lb at max.

Hope I haven't left anything out

Thanks for any brainstorming

Wyndham

[Mark C.]

I suggest keeping the exit flue as low as you can that way the floor will be more even(not cold)

There has been a bunch of this old electric to gas conversions lately -you may want to see what others have done with the search button.

 

Force the flames up and then down for best heat distribution.

Mark

[Wyndham]

Thanks Mark.

What I was wondering about is which might be more effeicent . The floor channel open from mid point to exit flue, which would generally draw along the channel or close the channel and have an entrance to the channel at mid floor, much like an under the floor drain pipe for water. In this configuration the heat would be drawn down to the center floor of the kiln, under the floor and out the exit flue at the back and up the stack.

I've seen plans for both styles of downdraft.

Not a problem to try both ways as the covering over the floor channel would be easliy removed

Wyndham

[Mark C.]

I like to think like the flame-I think its better to pass through the load and over the load and when it exits thats the cool spot

Moving the exit into the center and up will leave a larger cool area-but hey only one way to know for sure.

All of these small conversion kilns fire with hot and cold spots so the main idea is to make them less with what you have.

The more burners the more even the longer the flame stays in the kiln/load the more even-the slower the fire the better for all reasons

Many try this for their 1st gas experience and struggle on design issues-these conversions always are a one of a kind deal

 

The folks I know who buy the smaller round  (what I call trash can kilns) usually have better results with more burners and some idea of how stacking affects the flame path and also what a damper and bag  walls or baffels do.There all tend to be updrafts and thay all have issues with hot and cold spots

 

Just remember that where the flame exit is usually is a tad cooler so thats why I suggested lower bottom as far away as you can get from the burners.

Mark

[Wyndham]

Yea, that's why I think the channel will help as it lowers the flame exit as low as possible. I'm looking for a smaller kiln for things like mugs that I can fire with a quick load & fire schedule. A stacking space of about 10 cu ft will get  special orders out as well. my other kiln takes several days to glaze and load where this should be glaze & fire in one day.

Now all I need is the time to do it, at least t will get answers in a firing or so.

Wyndham

[jrgpots]

Mark, I put the exit flue between my two burner ports in my conversion kiln. Did I make a fatal mistake? And should I change the exit flue to the opposite side of the kiln?

 

Sorry for the interuption. I just noticed you post above.

 

Jed

[Mark C.]

I cannot say. depends if the flame/heat can get right out.If you can force the flame out and away into the load before exiting then you are fine.

Most kilns the exit flue is some distance from the heat source

especially in  natural draft downdrafts

The exception to that are downdrafts that use forced air-with the burners are on each side of the chimney shooting towars the front door in bag wall trench.

In all the kilns I have built I have always used traditional designs that work so converting electrics to gas would be for me using the same principles just altering them for the differtent shapes and sizes.That said each one is unique and folks seem to try all types of designs.

Mark

[Wyndham]

Jed, welcome to the discussion.

I was thinking of using the config you are talking about, except that my burners for my larger kiln would fit nicely on my proposed oval kiln with out any extra plumbing. I also have a shed that makes me have to put the exit flue/chimney  across from my burners.

Wyndham

[jrgpots]

It sounds like you have a better plan anyway. I'll be working on my kiln today, setting brick for the chimney. I am converting my burners to power burners and making my kiln more airtight.

 

I look forward to hearing more about your project.

 

Jed