Testing of the Anila stove in India August 2010

The aim of this test was to finalise the design of the Anila stove, which had been produced in India ready for distribution to households to gather feedback from them about usability.
This is for the project:

Without wanting to change the design too much from the original plans, the following changes were deemed necessary –
- Adding a mud seal around the base join
- Increasing pan height
- Blocking 50% of holes.

All tests wood feedstock (approx 10-15cm x 2 x 2)

Test 1:
Sugarcane trash
All holes open – flame height high
No mud seal - very smoky
Pan height low (2.5cm – as per design) - smoky

Test 2:
Cajurina (Casurina equisetifolia) tree waste
50% holes blocked – flame height medium heigh
Mud seal – less smoky
Pan height increased – less smoky

Test 3:
50% of holes blocked.
1kg wood
400g sugarcane trash – 200g biochar produced (50% conversion)
2 litres was boiling in 10 minutes. Total burn time 50minutes, but still smouldering embers keeping hot for a further 10 minutes.

Test 4:
All holes open
1kg wood
900 g Cajurina tree waste – 400g biochar produced (44% conversion)
5 litres boiling in 13 minutes, then rolling boil for a further 28 minutes. Smouldering for 10 minutes, total 50 minutes.

Further tests can be done with adding just 300g of wood, and topping up with 200g later, to reduce the height of the flame. However adjusting the design allows more flexibility in the amount of fuel which the user wants to use, and makes the use of the wood more efficient. This method will be suggested to users, but if a significant amount of water to boil is the aim, it may not be possible with just 500g of wood. It also requires users to attend to the stove (to add extra wood), which would increase exposure to any smoke produced, and also requires extra effort – this is a potentially low fire maintenance intensive option.