Definition of Thermal Energy and the BTU

[sm0ky2]

i suck at art, but here goes

[sm0ky2]

Ok so,
We have 4 basic dimensions in the earlier versions of this tech


D is the one that doesn't always fit a set proportion, it is sometimes close,
But seems like an arbitrary value for the height of the burn chamber.
I went with 10-inches here, which is within the 2.5 inches from the value A
As the dimension D was always with a range of 2.5in +/- of A


B = 1/4 A
A = 1/4 C
C is the total height from the bottom of the burn chamber to the top aperature
The chimney gets narrower from the top of the chamber towards the top.
I didn't find any set angle, some were conical, some were angled-flat sides.
The size and shape of the top opening varied drastically as well.


I've built mine for the 4th time recently (overheats and destroyed itself)
It gets too hot for plaster, so I went back to clay. This time mixing sand and
crushed (used) plaster as an aggregate. Hoping this will help.
I think the clay I used he first time had too low ceramic content, so I went with a different
type of colliche, also found locally in the ground.
I'm making some clay extracted from crushed granites.
To test the heat tolerance. If that holds well, I may use that for my next one.


I tried playing with the dimensions of the (later advancement) upper chamber
Mostly because I didn't have enough materials to make that large of a box.
I tried 1/2 A, the vortex is still present but the air flow went way down, and it doesn't no get as hot.
With this new mod it takes about 20 mins to heat up, and barely will melt aluminum.
(got hot in under 2 mins before)
So I will knock the little box off and try again.

I want to try 1/3 A, but if that do sent work I will collect the materials to build the 3A dimension
used by the ancients. (Cube oven)
I assume it had a removable door, as the top vent was too small to insert a crucible.
My current top-box has no lid, and no door.
I drop the crucible in from above.
I think it constricts the airflow too much, still hums the same tune
But the flame-jet dropped to 3-4 inches out the top, instead of the original 4-feet into the air


I'll update this thread when I get the new chamber built

[sm0ky2]

Sorry, my drawing is missing a detail


The front part of that shape is open
So you can put the wood or coals in
I drew it there but forgot to go back and
erase the front side of the chamber
It's a 3-sided shape

[madddann]

Hi!
Thanks for the details.
What should be the dimensions of the front opening? Should the width be A or A+2B? What about the height and shape of the opening?

Wish you good luck with the construction and testing.

[sm0ky2]

Basically, the front is A, as if A was missing
And the B's stand as pillars at the corners
I think it's to form the boundaries of the side A's
The height is the same as the chamber height on
the examples I saw.


It looked like a separate piece that the chimney
and outer structure was built around.
I built my base first then sort of stuck the chamber
inside as I got close to the inner dimension.
I just framed it with wood paneling, and burnt it out
after the clay hardened.


Mine didn't turn out nearly as pretty as the ancient
promethian culture.
not sure their techniques, but they were better at it
than my first attempt. my surface is all cracked with
pits and whatnot. I just kinda fill it in as it falls apart.