EFFECT OF FEEDING METHODS ON THE RICE HUSK ASH QUALITY IN A FLUIDISED BED COMBUSTOR

In this study, the effects of feeding methods on the combustion characteristics of rice husk andtheir resulting ash quality were investigated. Two methods of feeding were employed, namelyinclined feeding and inclined, tangential feeding. Experimental results showed that fly ash fromboth experiments were amorphous and almost similar in terms of residual carbon content(1.9 wt %). The major differences were that when feeding was done through the inclined feedingport, most of the ash was collected as fly ash and the size were coarser in the form of slightlybroken skeletons. The tangential velocity component in the combustor arising from the tangentialfeeding route caused the ash to be trapped at the swirling flow region above the bed, therebyretaining most of the ash particles as bottom ash. Further, the high degree of turbulence at theswirling flow region, coupled with the high degree of rice husk penetration in the bed, resulted infly and bottom ashes finer in size. It was concluded that combustion of rice husk by inclinedfeeding method was more desirable due to the stable, uniform combustor temperatures and ease inash collection.