Re: History of very small true gasifier units

["Paul S. Anderson" <psanders@ilstu.edu>]

Stovers,

I am forwarding Dan's recent comment to me.  Very interesting.

Dan's note says "Most had some way to draw
or force air through another hole and introduce it directly to the
coals."  Therefore, that would not be a gasifier (pyrolysis)
unit.  

I will also add that if the "Mormon stove" with 2 holes
in the ground was BOTTOM lighted, then it be more akin to regular burning
pits or to the Rocket stove.

Paul

At 08:40 PM 10/23/02 -0400, you wrote:
> In a message dated
> 10/23/02 11:05:19 AM Eastern Daylight Time, psanders@ilstu.edu
> writes:
>
> > Dan's comment's 
>
> > Ron, any info about the "Mormon
> > stove" that you mentioned was made of 2 
> > holes in the ground?  It could CLEARLY be an early gasifier if the
> > holes 
> > were connected at the bottom, with primary air going down one hole and
> > then 
> > up in the hole with the fuel.  And top lighted??  Before I dig
> > holes in my 
> > yard, I hope someone can send me further information.
> >
> > By the way, considering the poverty conditions in Mozambique and in
> > refugee 
> > camps and elsewhere, this "Mormon stove" two-holes in the
> > ground method 
> > DOES have potential for 21st century applications.
> >
> > Paul
>
> > Paul, 
>        Glad you're back. I don't have any
> specific info on the Mormon stove you speak of. I can however, state that
> many historic metal working operations dating back to Egyptian pyramid
> time used a hole in the ground concept. Most had some way to draw or
> force air through another hole and introduce it directly to the
> coals.  There is now some evidence that hot ironworking
> experimentation was well underway by then. 
>        The earliest above ground metal
> heating stoves were carved into the side of a cliff. Sandstone was the
> preferred rock type as it was easy to carve and the perfect natural
> refractory.  I have walked through an early 1800s (built in the
> 1820s?) blast furnace in south central Ohio that was carved out of a 30ft
> sandstone cliff. This furnace had tunnels CARVED around it close enough
> to pick up preheat for the air intake. I believe this shows the
> importance of preheating over forced air. Many air forcing techniques had
> been developed by then.  Ohio was just a primitive outback state
> then. 
>        We can mimic this technique of
> digging into a compacted mound of clay or carving into a rock outcrop. Or
> we can use a sandstone boulder just small enough to move and carve a lot
> of weight out of it. If the sandstone is available "just out the
> back door."  
>        My guess is that there was some
> knowledge of the benefit of the steam reforming reactions involved in
> these designs. The moisture being drawn out of the earth and preheated to
> steam temperatures prior to introduction into the coals. I am also
> suspicious that with the addition of some steam, the exhaust was lighter
> and produced a stronger draft. 
>        This is a very important factor not
> to be underestimated ;-). 
>        Dan Dimiduk

Paul S. Anderson, Ph.D.,  Fulbright Prof. to Mozambique 8/99 - 7/00

Rotary University Teacher Grantee to Mozambique >10 mo of 2001-2003

Dept of Geography - Geology (Box 4400), Illinois State University

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