Appropriate Technology

["Lawrence F. London, Jr." <lflj AT intrex.net>]

Rocket stoves use twigs to cook food quickly, efficiently - Boing Boing
<http://www.boingboing.net/2008/06/26/rocket-stoves-use-tw.html>
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Rocket stoves use twigs to cook food quickly, efficiently
Posted by Mark Frauenfelder, June 26, 2008 2:59 PM | permalink
rocket-stove.jpg

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 diameter before 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 NOT to produce more gasses or charcoal than can be cleanly burned at the powerlevel 
desired.

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