permaculture

[Lawrence London <lfljvenaura@gmail.com>]

http://boingboing.net/2008/06/26/rocket-stoves-use-tw.html

When I visited Kelly Coyne and Erik Knutzen of Homegrown Evolution,
http://www.homegrownevolution.com/,  last week they showed me the
rocket stove they made in their backyard. Theirs is quite fancy
because it is made of bricks. They sometimes use their rocket stove to
fry a meal in a skillet.

The rocket stove was invented about 10 years ago by Dr. Larry
Winiarski at the Aprovecho Research Center in Oregon. It consists of
an elbow-shaped combustion chamber (usually made from metal cans)
surrounded by insulating material (often a large can filled with
sand). It uses twigs for fuel, so it's ideal for areas where the trees
have been depleted.

Here's a video from the Aprovecho Research Center that shows how to
make a rocket 
stove.http://www.aprovecho.org/web-content/media/rocket/rocket.htm

    200806261447.jpg Here are the first 3 of 10 rocket stove
principles, by Larry
Winiarski.http://www.bioenergylists.org/stovesdoc/Still/Rocket%20Stove/Principles.html

    1.) Insulate, particularly the combustion chamber, with low mass,
heatresistant materials in order to keep the fire as hot as possible
and not toheat the higher mass of the stove body.

    2.) Within the stove body, above the combustion chamber, use an
insulated,upright chimney of a height that is about two or three times
the diameterbefore extracting heat to any surface (griddle, pots,
etc.).

    3.) Heat only the fuel that is burning (and not too much). Burn
the tips ofsticks as they enter the combustion chamber, for example.
The object is NOTto produce more gasses or charcoal than can be
cleanly burned at the powerlevel desired.

Illustration from In the Wake, a cool website on various simple
off-the-grid tools. http://www.inthewake.org/b1cooking.html