Low cost efficient wood burning stove designed by Ashvini Kumar Hulithala
In countries like India, people living in villages mostly use biomass as cooking fuel but there are no cheap and efficient wood-burning stoves. As a result, smoke and particulate matter generated by this stove become an environmental hazard. At the same time, it will have bad effects on the health of the cook, mostly the woman of the house. Since the smokey stoves are not efficient they consume more fuel, draining on forest resources and producing dirty gasses. These stoves need constant blowing by mouth to maintain the fire, draining the energy of the cook.
To solve all the above problems, the following criteria were kept in mind while designing the simple low cost wood burning stove:
- The stove should be efficient
- It should emit as little smoke as possible
- Fire should burn without much attending (i.e. blowing by mouth)
- It should be possible to build with locally available materials
- It should be possible to build the stove by an ordinary person or housewife using very simple skills
- It should be cheap to build (you can not ask one to invest $15 - $20 to build a stove in a country where the average income of biomass-burning people is less than $2 a day)
- As much as possible, the flame should be visible from outside, as house wifes tend to associates good burning with a good flame
- It should be possible to burn most biomass fuels with the stove
- It should be quick, i.e. should boil water quickly
- Easy for the user to light and tend the fire
This simple wood burning stove was designed, meeting all the above criteria to a large extent. The efficiency when used with blackened pot is at least 15--26% better than most wood-burning stoves. Instead of bricks, even mud or un-fired bricks can be used for construction, thus reducing outside products to only a few ¼ inch rods. Except the top portion (the draft tube) all other dimensions can be changed or modified without much change in efficiency. The stove boils 2.5 liters of water in 10- 12 mins while the ambient temperature is 17 degree centigrade, so it is comparable with gas stoves. As the inside of the combustion chamber and draft tube are insulated, all the heat produced by the fire is transferred to the pot more efficiently. As fire burns on a rod grid, more air is drawn into fire, making a more complete combustion that produces less smoke. Fire burns at a higher temperature, so a clean fire with more hot flue gasses transfers heat to the pot more efficiently. As the fire is hot, there is less chance of the fire getting extinguished, thus it needs less tending. The speed of flue gasses is higher compared to other stoves, so the flow breaks a stagnant barrier making hot gasses touch the pot, which further increases efficiency.
Ashvini Kumar Hulithala
P.B. No 113