DESCRIPTION
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.

CONSTRUCTION
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.

WORKING
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.

SOURCE

Rahul Parikh, Suruchi Vasahat, Krishi Yantralaya, Bardoli, Gujrat