Theory Behind Design

[larsmith]

The theory behind my design had to do with comments I read about possibly having a "flatter" design to the air flow ( as opposed to circular or square, as in the inner workings of many ( most ? ) rocket heaters.

If I remember correctly, I read that possibly a more rectangular heat flow channel would work better, due to the fact that less air would collect in the "middle" of the air flow, while at the same time, more hot air would come in contact with the brick walls.

With that in mind, I laid aside the "traditional" 6" square heat channel thru the rocket heater brick and opted for 4.5 by 9.

Any of you who've handled fire brick know that 4.5 X 9 is a common firebrick size.

I'm wondering if the apparent success of my heater is due in part to the above mentioned heat channel and look forward to other comments and/or experiments with this design.

I also was influenced by the work done by Peterburg with his "bell" design. If I'd had enough brick, I'd perhaps have built on to the back end of my heater an upward exhaust channel resulting in my exhaust exiting from the top of the heater. Alas, not enough brick.

[peterberg]

Jan 1, 2009 13:08:34 GMT -8 larsmith said:

I also was influenced by the work done by Peterburg with his "bell" design. If I'd had enough brick, I'd perhaps have built on to the back end of my heater an upward exhaust channel resulting in my exhaust exiting from the top of the heater. Alas, not enough brick.

Consider yourself lucky. The flat updraft channel you mentioned here would have act as a warm chimney only.

In order to have the full benefits of the bell principle you could build another, but otherwise empty, stovelike thing (for lack of a better word) behind the first one. Built out of ordinary red bricks and, most importantly, with the input and exhaust port both at ground level at opposite sides. Preferably, with the input port of the two slightly higher in the bell.

The "bell" itself would be a dead end, but the top would become hot nevertheless. And after firing the stove itself long enough the whole of the thing would become quite warm.
This setup is a very effective solution to lower the chimney temp.

[Donkey]

Could a steel drum be used with the same arrangement of input/output as the bell design?
The drum wouldn't be a very good storage media but it may be quite good at radiating heat evenly.

And Larsmith.. You could save yourself quite a bit of money on brick by building the "bell" out of cob.

[peterberg]

Yes, I do think so. The bell principle still applies, whatever material it is built of.
In theory, even a real bell could be used for this purpose.