Abstract
Combustion characteristics of high density briquettes produced from sawdust admixture at three moisture contents of 12%, 10% and 8% using screw press extruder were investigated in this work. The briquettes were burnt in free air and developed riquette stove and the combustion characteristics data collected and analysed. The burn characteristics investigated include ignition time, burn time, mass reduction, normalized burn rate, the effects of density on briquette characteristics and stove performance. The results indicated that briquettes?? self-ignition time in open air and stove was slow however burns with steady flame, when burning is established. The high density of the briquette was responsible for slow flame propagation resulting in longer time to burn out while lower density briquettes reaches burning phase faster than higher density briquettes. The normalized burn rate increases with increase in briquette density. The stove performance characteristics are largely dependent on fuel material quality. The stove thermal efficiency increases with increase in briquette material moisture content while the specific fuel consumption increases with decrease in moisture content. From this results, there is an inverse relationship between specific fuel combustion and thermal efficiency of the stove. The higher the briquettes particle moisture, the higher the specific fuel combustion and the lower the stove thermal efficiency and vice versa.
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