[Stoves] large camp stoves

[David G. LeVine]

>We need to build about 7 wood institutional stoves for varying size 
>large pots for a campsite and school in Madagascar.
>
>The pots have sloping sides (aluminium cocottes) rather than 
>straight sided. Most designs seem to be for straight sided.

Skirts help a lot.  Taking a right cylinder of insulated metal and 
directing the hot gasses close to the pot will improve heat transfer, 
if that is possible in your environment.

>We don't have access to ceramic making. We have bricks and cement 
>available, and some metal.

I bet you do have clay (as in pottery) and can make things with that, 
however.  Clay pottery IS a ceramic.  There are better ones, but clay 
pottery is remarkably good.

>We also want to include chimneys as they are surrounded by smoke. 
>Also a hot water providing system.

Hot water is easy if either you have soft tubing (like annealed 
copper) or a tank that can be attached to the body or chimney.  Just 
run copper tubing through the exhaust (chimney)  and be sure the 
chimney continues to be hot enough.  A hot water tank is wise to 
protect the "heat exchanger" (copper tubing in the chimney), just 
have an overpressure valve in case it gets too hot.  Thermosiphon 
(aka thermosyphon) technology is good here, ask anyone who has 
experience with old stationary engines (like Listers.)

If the water does not need to be potable (drinkable), the metals 
choices are wider, but for drinking, be sure the metals do not cause 
heavy metals poisoning.  Lead solder is pretty safe, but lead free 
solder is MUCH better.

David G. LeVine
Nashua, NH  03060