[Cob] Question about the dimensions of Rocket stoves

[Shannon Dealy]

On Fri, 27 Mar 2009, Susan Hagan wrote:

> Can someone who has built a stove tell me the following. I am qouting 
> from Ianto's book
>
> 1. "D is the distance from the feed tube to the heat riser...optimum 
> proportion is about half the height of the heat riser"
>
> Here does "heat riser" mean a,b,c,or d and does "burn tunnel" mean 
> e,f,g,or h?

Hi Sue,

I'm assuming that your picture is the same as mine (it may not be, mine is 
an electronic prepublication copy from a couple of years ago), but the 
heat riser should be "E", the tall vertical tube down the center of 
the large barrel and the burn tunnel is what "D" is measuring the length 
of, the horizontal tunnel below the "D" measurement, running from the feed 
tube to the heat riser.

> 2. How important is the dug out ash pit at the bottom of the feed tube?

Very important.  Ash and coals accumulate during each fire in the ash pit 
at the bottom of the feed tube, without it, these will migrate into the 
burn tunnel and obstruct the flow of air and volatile gases from the fire.
It's preferable if this is several inches deep, to shallow and ash and 
coals will end up in the feed tube on every firing.

> Would an ash pit where the pipe exits from the barrel be sufficient?

No.


Shannon C. Dealy      |               DeaTech Research Inc.
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