StoveTec Rocket Stove with bellows

This was a test of a Rocket Stove with bellows for an 8th grade science project. Hypothesis was that forced air delivered by a simple bellows would decrease the time required to boil 5 liters of water on a StoveTec woodburning rocket stove. In this test, it took 43% less time to boil water in the bellows-assisted stove (21:33 minutes versus 37:55 in the control). Fuel consumed was comparable. Have not measured emissions.

The bellows used are similar in design to those used by blacksmiths in Africa for thousands of years using hollow logs and animal skins.

A widely adopted, more efficient woodburning stove could reduce human CO2 emissions, diseases caused by open fire pollution, and reduce time spent and risk of wood-gathering in undeveloped countries. This design is our small contribution to the effort.

Areas of future development should be:
- screens to prevent bellows from blowing ash out of stove and into pot
- optimizing size of bellows
- more durable...but still cheap...bellows design

Images of simple bellows in use in Africa for metalworking:

http://travel.webshots.com/photo/1511868379032256692oYuNDt

http://www.google.com/images?hl=en&source=imghp&biw=1305&bih=616&...

Category:

Science & Technology

Tags:

• rocket stove
• bellows
• StoveTec woodburning stove
• water test
• science project
• DIY
• carbon emissions

[SunnyMoon2010]

Did it use more fuel with the bellows ?

[mhee2b]

@SunnyMoon2010 No. All things equal, a hotter fire is more efficient and releases more energy from the same quantity of fuel. In this experiment, we burned wood in the two stoves for an equal number of minutes. The amount of wood burned in each was nearly equal. However, since the stove with the bellows brought water to boil faster, it took less wood with the bellows to achieve 10 minutes of boiling. Forced air > more efficient combustion > less wood needed > fewer emissions.

[apples13able]

I made a blower using a 2 liter plastic soda bottle with square hole cut into side and 12V computer fan metal taped to hole. Easily solar powered and/or car battery or smaller. Not super powerful but enough for cooking. Try it!

[mhee2b]

@apples13able Good thought. How much panel area and what cost for solar to run a 12V computer fan?

[mhee2b]

Good input. Thanks.

[mhee2b]

Thank you. The "why" is to investigate ways to make wood-burning stoves use less fuel, less polluting, and more attractive to the billions of people who cook over open fires, today. Forced air is one avenue of investigation in this quest. ("The way to have a good idea is to have a lot of ideas.") To learn more, google:

aprovecho research center why cleaner cookstoves

[TheOriginalStevenH]

it took 1/2 hour to boil water, not my cup of tea I rather use alcohol

[apples13able]

@apples13able One last thing, I used a hair dryer on cool on the woodgasstove and heated 30 gal of water to 140 F using a 5/8 copper coil. Took 3 hours of constant fuel feeding. I want to refine the system. Need a camera! Eventually!

[apples13able]

@apples13able I bilt a heineken rocket stove & while camping a fren had a foot air pump for his raft. We would sit near the stove and occasionally pump the air to increase flame & btus.I wanna bild a Jtube rktstove for less effort w fuel feed. Great that your teaching kids! I think the solar panel was under $25. But you could maybe hook up 8 D 1.5v batteries in series and hook a $25 solar panel to it altho the 2 AA solar charger is more compact... I like cheap & recycled/sustainable/effective­!

[apples13able]

@mhee2b I made it for my 1 gal paint can (plus a tomato can) woodgas stove. I powered it with a car booster pack which is basically a car battery and I would keep it charged with car batter solar panel, quite small. But it could run on smaller. At woodgascampstove site you can get a 2 AA solar battery charger which powers their stoves (I had 2 of them until I got smart and started making them) Just don't leave them out in the rain! My other panel can handle rain. Those flex panels work too.

[jjsjeffjjsjeff]

One thing you might want to be aware of is that when galvanized steel is welded on (heated) it can produce zinc oxide fumes.  You might want to use plain steel or another metal.