The Damru Chulha is a thermally efficient wood
cookstove which saves 30-50% of fuelwood. This improved chulha is simple in
design and could be easily fabricated by the local potters. It can be made
portable as well as stationary.
The Damru Chulha has the shape of the cooling tower of a thermal power
station. The double conical shape of the chulha can either be cylindrical or
double-conical with uniformly thick walls. The chulha is made of clay with
various additives to prevent cracking and provide better binding and
porosity. A clay ring is used to shield the cooking vessel to prevent heat
losses during windy periods.
Wooden moulds or sheet iron can be used to attain the inside shape. The
chulha body and the heat shield for cooking vessels are moulded separately.
The heat shield must be made of tired clay whether the body is fired or not.
An iron grate, carrying the firewood, improves the combustion as the air
enters from under the grate and passes through the fuelbed. The thorough
mixing of the air and fuel initiates the combustion of volatile gases, even
before they enter the space above the fuel bed. The grate and double conical
shape, both, guarantee improved combustion even without any chimney.
The total time taken by the Damru chulha to boil three and half litres of
water is twenty minutes as compared to the 23 minutes taken by a gas stove.
Rahul Parikh, Suruchi
Vasahat, Krishi Yantralaya, Bardoli, Gujrat