Simple rocket stoves for Africa (and beyond)

I'm working with a nonprofit to design rocket stoves to replace the filthy 3-stone cooking used by billions.  Our goal is a rocket stove that is ultra-affordable and can be made everywhere with local material.  We want any brick maker to be able to easily make these stoves.

We are working on two designs - an L and J rocket stove.

While I'm sure we are far from the final designs, I'll give our latest designs below.

L Rocket Stove
Attached is the latest design.  We are limited to materials that are cheap and locally available everywhere.  So no insulation, no steel, no firewood rack, no ....  Just the clay mix used by local brick makers.  We use a broken brick to elevate the firewood into the fire chamber.  We have tested prototypes of this design and they work pretty well.  Not as well as commercial rocket stoves but much better than 3-stone.

We are testing different sizes for the center hole, different brick heights and additional air holes at the bottom of the bottom brick.

If we are successful in this design, we should be able to give brick makers the pipes for their molds and quickly teach them how to make the 2-brick stoves.  They should be able to make and sell the stoves for under US$1.


J Rocket Stove
We haven't yet tested a prototype of the J rocket stove.  The design is attached.  This is designed for the 11cm pvc pipe and 25x25x10 cm brick mold that one of our volunteers in Africa already has.  I expect that 11cm is too narrow.  I have a number of other concerns about this design, but we'll test it out.  Other volunteers should have access to larger pipes so we can test them later.

All suggestions are welcome.  Again, we hope these can be made without metal, without insulation, without firewood racks, etc..  (Adding insulative material to the clay is preferable but for now we want a design that can be used universally.  Depending one what is available locally, brick makers can add insulation (rice hulls, sawdust) to their clay.)

Aprovecho have done lots of work on stove design, also donkey32.proboards.com where you probably know you can find much information. One point is, have you asked the potential users what they want? Is a heavy brick structure going to provide for their needs. Can they get suitable wood for running a J tube?  There are lots of questions to ask and unless you have the answers to work with, success may be difficult.

I am faced with a similar problem. I've become associated with an orphan school in Kenya that is currently using the traditional three stone hearth. I want to advise my African partner on how improve this. We have almost no funds for this and so I am asking about local material like stones. (I need him to send me a picture of the stone kilns they use for pottery.) I've been researching the technology behind rocket stoves and how best to adapt to local conditions.

A note for Kevin: I have found in my research that a smooth chimney throat is less effective. Turbulence in the fire column gives more complete combustion, a square stack of bricks will give a more complete burn than round stovepipe.

May I use your plan to make my own rocket stove? I want to use it for my own nefarious purposes.

Any updates on this?

I'm thinking more about institutions. Schools are cooking with inefficient wood stoves. The pots they're using are sometimes over 2ft in diameter. How can this be handled with rocket powered stove?

Ronnie Akena wrote:Any updates on this?

I'm thinking more about institutions. Schools are cooking with inefficient wood stoves. The pots they're using are sometimes over 2ft in diameter. How can this be handled with rocket powered stove?

The Lorena style stove was developed for institutional cooking. It surrounds the cooking pot with hot gasses straight out of the heat risers. Permies has 3D plans for one style of Lorena
.

The Lens style stove uses a lot more wood because of the large space it is heating up and the increased distance between the fuel and the pot.

I've seen lots of organizations try to improve the African hearth. Guess what,  they like the one they've got. Ergonomics: the women want to cook squatting. They do it their whole lives and that's what they like. Secondly a rocket stove has only one input opening. The African women like to precisely control the position of their 3 sticks to variate fire placement on the pot and intensity. Thirdly,  they cook on large ROUND bottom cauldrons that lodge securely on the stones. In many areas of Africa the main dish is thick a grain mush that takes some very strong stirring. A flat or round surface does not offer the same holding strength.

If you REALLY want to interfere in an African woman's kitchen, start with what she uses and consider small modifications for improvement of air quality,  etc. And solicit feedback along the way.

Thank you Nathanael. I had been thinking of saying something similar asking about cultural context--your answer, small, undoubtedly beneficial modifications that harmonize with the traditional ways, seems like it could be one way forward that is easy to accept. Sometimes an outsider perspective is really helpful for this, at other times though it isn't seeing all there is to see. It's possible there are complex practical, cultural, even cosmological factors that the "indigenous mind" can see clearly, though they might not align with Western views of energy efficiency or mitigating pollution, they might feed into the cultural framework in ways that support the whole. I could be projecting though, as I don't have any direct experience of the African situation, but it's just extrapolating based on other indigenous perspectives and my experience of life.

I don't want to belittle the designs in any way though! These could be of great use in many regions of the world and I might end up taking inspiration for them myself.

Also, have you looked at the Dakota fire hole? It is almost a sort of original rocket stove, its tube built right into the ground.

This site has a good diagram. https://www.artofmanliness.com/skills/outdoor-survival/how-to-make-a-dakota-fire-hole/


Another site https://modernsurvivalblog.com/survival-skills/advantages-of-the-dakota-fire-hole/

It's maybe something like a hybrid between the three stone and a rocket stove? And from what I'm reading there's very little smoke and one could probably fuel it with corn cobs or other common residues.

I made one myself, once, but didn't delve into it too seriously.

Maieshe, I'm definitely not indigenous, but I've observed alot. I would be curious to know is if the people proposing a transition from three stones to a rocket stove use either on a consistent basis.

The transition that most African women I know would like to make is from a wood fire to a gas stove.