In India, 80 per cent of the total population lives in villages. The major energy demand of rural population is for cooking which contributes to about 98 per cent of their total energy consumption.
Wood, agricultural waste and biomass are used as fuel in rural kitchens. Conventional stoves (chulha) take more time for cooking, more difficult to fire and consume more fuel.
Traditional stoves They also waste a lot of energy and pose many pollution hazards. Most traditional stoves can utilise only 2 – 10 per cent of the energy generated by the fuel.
The growing gap between availability and demand for firewood caused by traditional stoves forced technologists to concentrate their attention on improving the thermal efficiency of stoves.
In view of this the department of Bioenergy at the Tamil Nadu Agricultural University, Coimbatore has developed a single-pot chulha.
The single-pot chulha has a double wall with a gap of 2.5 cm. It has a grate at the bottom of the combustion chamber. The ash can be collected below the grate. The outer wall has two rectangular secondary air openings on both sides at the lower portion.
The inner wall has 1cm diameter holes which maintain a triangular pitch of approximately 3 cm. Separate mounds are provided for holding bigger and smaller vessels.
The secondary air enters through the rectangular opening in the outer wall, gets heated in the annular chamber and distributed through the holes in the combustion chamber. The preheated air helps in proper burning of the fuel.
Double pot Another one called double pot portable chulha (chimney-less) is made with two walls with an air gap of 2.5 cm. There are two secondary air inlets, one on the outer wall with rectangular shape (17 cm x 1 cm) near the combustion chamber and the other a circular hole of diameter 5 cm at the bottom of the second pot. A cast iron grate is placed at the bottom of the combustion chamber.
Those interested can contact the department for further details and availability of the chulhas.
(Dr. S. Kamaraj, Professor and Head, Department of Bioenergy, TNAU, Coimbatore, Phone: 0422-6611276 (O), 94439 34139 (M))
