In thermal gasifier, the fuel wood is converted into fuel gas by efficient thermal conversion;fuel gas is burnt in a special burner emitting high intense flame similar to lpg. The intensity of flame can be reduced or increased by instantaneous movement of valve. Thermal gasifiers conserve firewood substantially because of 70% conversion efficiency. The thermal gasifiers are advised at places where firewood is presently used for the generation of heat. This thermal gasifier finds its applications in: baby boilers, bakeries, ayurvedic pharmacies, small kilns, glass industry, large kitchens of hospitals/residential schools/ industrial canteens, hotwater boilers in hotels, waste disposal incinerators, ovens, hot-air dryers, and aluminium melting furnaces. Following are some of the technical features of this thermal gasifier which include: heat output of the gasifier is 50,000 kcal/hour and it consumes 25 kg of fuel-wood per hour at full capacity; heat can replace 5 litres of diesel oil when diesel oil burners are used. When used for cooking, this unit can cater up to 600 persons; payback period is said to be less than two years when used for 10 hours/day at full capacity; in addition, 100% income tax depreciation is allowed in the first year; are non-conventional energy devices which qualify for central government subsidy. Burners can be one, two or three depending upon the heating application.
