Development and evaluation of a biomass-fuelled furnace

Abstract

The paper describes the development and testing of concentric-vortex type, agricultural residue-fired furnace which can be used for heating the air to a grain dryer. Measurements were made of furnace combustion efficiency at various fuel feedrates and air flow rates. The highest furnace efficiency obtained was 85% at a feed rate of 82 kg/h and an air flow rate of 1810 kg/h. The temperature of the flue gas varied from 420 to 870°C at various feed rates and air flow rates. The maximum heat release occurred when the furnace was supplied with 310% excess air over that needed for complete combustion. The turndown ratio for the furnace varied from 3.1 to 1, on a wet basis moisture content.