Conventional oven conversion questions

[ronyon]

I have a conventional oven I am converting to be a low mass wood fired black oven.
I have stripped the few inches of original insulation to make room for either mass or better insulation.
I plan on treating it like a bell,with the gasses entering and leaving from the bottom.
I'm concerned that the gasses will not stratify-it's a small oven.
The deflector plate and a "gas separator" could come together in a "T" to force the gasses up and prevent them short cutting to the exit.
That would take up room in the oven but it might be better to do that and skip surrounding the oven with mass.

So my questions:
-Mass surrounding the oven,or inside the oven? Or both?
-Do I need to worry about the gas short cutting to the exit and take steps to prevent that,or will it stratify on its own?
I will post a picture of the oven,and the inside dimensions when I get home...

[matthewwalker]

I think the answers to both depends on how you use it. I'd build it without the extra mass or deflector, try to cook whatever it was I was cooking, and go from there.

[drooster]

You can fill the empty oven with mass when not using it for cooking to get the most heat storage ...

[ronyon]

Resurrecting an old thread about an old project.

I've decided to pack perlite concrete into the space around the oven.

I need to size a rocket to drive it.

It's a small wall oven, just 5929 cubic inches(3.43 cubic feet,.0971 cubic meters) on the inside.

I want to hit 800°F in this oven, for 90 second pizzas.

The conversions I've seen use metal j-tubes, and don't hit those temperatures.

Im pretty sure that a properly insulated batch box or even a j could deliver higher temperatures.

I am planning on using a batch box, since they give more bang for the buck, but over heating is a concern.

I figure a bypass would help this,allowing me to vent the heat instead of stratifying it.

I also intend to include a pipe to introduce water onto a metal plate for steam.
This will be great for bread crusts,and it might be a way to cool the oven rapidly.

So, how big a rocket do you think I need?
Is a batch box the best choice due to the greater power,and shorter risers, or is the control that j tubes offer worth it?

[keithturtle]

I'm wondering if the wood fire is the best approach for your intended use. To get to 800*F will take a while, whilst the duration of the use is less than 3 minutes. Unless this is for a pizza shop with many being baked, you might do better the gas or electric. A low-mass oven with proper coils will get hot right now. I might be missing something

Turtle

[ronyon]

I bake in mass, for family and church. I can wait awhile to get to temp, letting a batch box runn a full load would give me time to work on the dough, etc.
I would not rule out gas or electric, this is kind of a test bed for ideas. I have a working TLUD I want to fire it with, with a long (90 mins?) burn time.
Practically speaking, gas is probably the way to go, but burning wood is a pleasure in and of itself.
That the fire be clean as possible and useful is what a rocket adds to the equation.

[keithturtle]

Jun 14, 2018 3:15:22 GMT -8 ronyon said:

Practically speaking, gas is probably the way to go, but burning wood is a pleasure in and of itself.
That the fire be clean as possible and useful is what a rocket adds to the equation.

Plus, the dry heat makes for a better crust (than gas).  Wood seems like the better option.

Turtle

[ronyon]

Another reason to go with wood is marketing. Wood fired,small batch,local,artisan bread ftw.

Any opinion on how big I should go?
I have been "designing" an 8" batch that would use cast slabs for the box and ceramic fiber for the riser.
8" is huge, but power is good, right? I could burn with less than a full load...
The oven sits on platform more than 3 feet off the ground, enough room for a even a 10" batch box, if we use the new shorter riser lengths.

[serg247]

Прочитай это. donkey32.proboards.com/thread/3312/normal-sauna-stove-ancient-furnace.
Может появиться любая мысль.