[Stoves] School/Educational material

[rongretlarson at comcast.net]

James (with ccs) 

I am not aware of anything that is general - and especially been approved by any educational community group. Jock and Kelpie are several who have done something already in classrooms and may be able to help - more on making charcoal, though. 

I think you will find quite a bit of good video stove material that you can draw from. 

The key concepts (came to me in random order - you can get a better order) I think you should try to get across are: 

a. The chemistry of combustion. - a biomass (looking like C6H12O6) + O2 giving CO2 and water. Should be able to find test procedures to show the magnitudes as 21% oxygen is reduced. 

b. The fact that biomass combustion occurs in two steps - first pyrolysis (with not much oxygen needed) and then gasification of the charcoal (with a lot more air needed). Understanding the flame and char-making in a match is a good place to start. Need to get across the idea of gases exiting the fuel (making CO at first) , preventing combustion of the remaining material (char). 
Might want to insert the idea of retorts in here. Maybe the idea of starting fires with a magnifying glass - and how fuel size factors in. 

c. Something about chimneys - that height and temperature are important for moving the needed O2.. The advantage of enough chimney can help avoid soot on the pot. 

d. That one can control primary air and secondary separately. Maybe here something on top-lighting vs bottom lighting and the movement of pyrolysis fronts (speed as a function of primary air supply. Maybe something on preheating secondary air. Showing a video on Worldstove's Lucia (TLOD - with non-combustible gas flow, Venturi effect, etc) can get across a lot of stove ideas - but probably not in 90 minutes. 

e. Something on fuels - and how excess moisture can kill any stove. How the size and shape of fuels controls air flow. Get in the concept of flow resistance. How making charcoal inefficiently is harmful to the environment (producing carcinogenic gases like those in cigarette smoke). 
How to start a stove fire is important. Tinder, small pieces of fuel - why important? 

f. Something on how excess air can lower temperature to the cookpot - one can bring in too much air. (as in all 3-stone fires) 

g. Something on coupling the exhaust gases to the cookpot - the use of convection shields. Maybe something on different shaped pots. The impact of pot lids. 

h. Something on stove materials. from three stones to all clay/bricks (heavy), tin cans (light), etc. 

i. I think you should try to get in some health statistics. (check with PCIA - www. pcia online.org/ ) How charcoal-using stoves have caused many deaths. How open fires have caused many burns, etc . The best authority in this area is Kirk Smith (UC Berkeley). 

Obviously you are looking at a lot to get across - and 90 minutes can't even do half of the above. But most ofl the ideas can be mentioned. Making and testing a simple TLUD and a simple rocket can be assigned as a homework assignment (comparing to three stones, electric ranges (where you can measure kWh), candles, alcohol stoves, etc.). 

More than the above is at most of Tom Miles' lists - not just the stoves list. You will find a lot of good stove material also on the biochar, gasification, digestion and maybe otherquickly lists. 

This is as close to a total data dump as I could do - I look forward to seeing/hearing what else could be accomplished in a 90 minute unit. Best of luck. 

Ron 

----- Original Message -----
From: "James Robinson" <jamesrobinson77 at gmail.com> 
To: "Discussion of biomass cooking stoves" <stoves at lists.bioenergylists.org> 
Sent: Monday, July 11, 2011 9:04:41 AM 
Subject: [Stoves] School/Educational material 

Hi all, 


I've got to give a workshop at a local school here in Johannesburg to a group of 13-14 year old kids - so does anyone know of some existing educational materials on combustion, biomass and stoves that I could use? A mixture of theory and hands-on would be good. It doesn't need to be too in depth as I've only got 90 minutes, although we can leave a training pack with the teachers. 


Cheers 
James 

-- 




James Robinson 

Basic Energy Specialist and Laboratory Manager 

SeTAR Centre 

University of Johannesburg 

Bunting Road Campus 

Republic of South Africa 

Desk: +27 11 559 1901 

Cell: +27 71 153 1485 



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