Fuel efficient Rocket stove from cans and sand.

[Locke141]

Some of my students are going to a Maasai Bama (a village made up of one family) to help them with building projects. The Maasai are a nomadic people, but it is now getting harder to live a nomadic life here, so some communities are seedling while trying to preserve there way of life.

When you live in one place you need to be more resourceful with your locale resources. One way to do this is to use fuel efferent stoves in place of a pile of burning stick with 3 rock around it to hold up you pots. Below are some pic of a rock stove I made from 3 cans and some sand. I used hardly any wood and was easy able to get the water to boil in a reasonable amount of time. 

[Nephasth]

Does it play galaga?

[Generic Eric]

Do you have a shot of the 3 rocks before you put the pot on it?  Also, I'd be interested in seeing more photos from when you put the wood in, and how much sand you used.  How long is reasonable?

[Locke141]

Do you have a shot of the 3 rocks before you put the pot on it?  Also, I'd be interested in seeing more photos from when you put the wood in, and how much sand you used.  How long is reasonable?

I was all set to take the timer when I put the water on but didn't. I think it was about 5 minutes but there was not much water in the pot. I just got it all together and was excited to have it working. I'll do a more scientific run tomorrow and report back.

The sand was just used to fill the space between the larger outer can and the slimmer inner can, rocks or dirt would have done the same job. There's a horizontal can that run between the other two,thats where the wood is imputed. In this 3rd can is a peace of scrap metal that the wood burns on top of, under it air is suck in by the up draft.

This one isn't a supper efficient versions, just a cheep easy to do one. There are larger versions that do a better job of getting the most out of the wood. We are building one of those as well but it's not some thing the Maasai will be able to replicate. The gaol is to give the a few, show them how to make them, and have the woman adopt them in the larger community.

[Locke141]

I didn't get around to doing better testing before the stoves were packed up for the trip. I did how ever do some research on how they work and why they are more efficient. Its about air flow and insulation. Not all Rocket stove's are insulated, some depend on the up draft to make the fire burn hotter and faster I think . You can see some gems on you tube.

The air chamber feeds the fire from below, providing a steady one way flow of oxygen, while the earth insulation traps more of the heat raising the temp, making for a more efficient burn and directing much more of the heat to the cooking area. Thats how you can get much more heat with less wood.

On my second build I used a regular soup can for the wood/air input chamber, a short wide can for the burn chamber (similar to a nut can), and a 1.5'ish wide soda can for exhaust (like a read bull butt taller). The hole on the bottom of the exhaust, over the hole on top of the burn chamber, was made slightly smaller. Then I cut and bent fins in the exhaust to make the two hols match. This was done in an attempt to get the hot gas to spiral, giving it more time to completely combust. This second build worked well.


 
I have reseved a pic from the village where the students are now but you can barely see one in the back ground. I'll add more as I get them.

Note: I got some smoke out of the top at first but after it heats up a bit there was little to no visible smoke out of the top. Also you should be aware that at first it will be cool to the touch but will be come very hot inside and out.           

[jennifer]

     Im confused here, The light gauge tin that can is comprised of will only last about a week under those high temp conditions.... So your teaching them to repurpose trash? or is that a prototype your going to duplicate with real steel, (like an oil drum) because then you could get say a year or so of real use.

[Locke141]

That one (my V2) is hard packed with clay so it should hold its form after the can is long gone. or at least that is the plan. My first one is just sand with 3 cans inside and a large can oud side. It is simple enough to replace the internal parts as needed.

The students and teachers with them are teaching the locals to make there own from trash they can easily find in the community. The DT teacher is making a large scale version out of an old propane tank and some thick steel for larger scale cooking. That is something that can be replicated by local welders.

[pbj]

If they haven't figured out the miracle of fire by 2015.....

 

[Locke141]

If they haven't figured out the miracle of fire by 2015.....

 

They have fire, and cell phones, and face book. I've seen them start a fire with just sticks like in the movies. It's just the way they were using it is not sustainable. They used to just move on when things went scarce. Lots of communities made up of former nomadic people become deforested. 

[knave]

If they haven't figured out the miracle of fire by 2015.....

 

I think the idea is that these stoves use wood more efficiently than a regular cooking fire.

In any case I think it looks cool and want to build one...

[Locke141]

If they haven't figured out the miracle of fire by 2015.....

 

I think the idea is that these stoves use wood more efficiently than a regular cooking fire.

In any case I think it looks cool and want to build one...

Yep thats exactly right.

Things to keep in mind.

• After it heats up there should not be a lot of visible smoke coming out the top.
• The sides stare and stay cool for a while but will become very hot after time.
• A longer exhaust is better and the diameter seem to make a real difference

[Generic Eric]

@Locke could you elaborate?  Do those people use charcoal? 

[Locke141]

@Locke could you elaborate?  Do those people use charcoal?

Not traditionally and I've never seen a group using it, but I am sure some do. Usually it 3 stones and stick inserted in to the sides. It's not like you learned in boy scouts where you learned how the native Americans did it althorn I would think some group of NA did it the same way.

Charcoal is generally a big problem in the developing world as it is not use efficiently and is completely un regulated. Governments andNGO's spent lots of time and money trying to get people to adopt fuel efficient stoves.




Here you can see the the border of the Haiti (left) and the Dominican republic (right). As a result things like flooding and erosion are much worse in Haiti.