ATTRITION OF COAL ASH PARTICLES IN A FLUIDIZED-BED

In this work, an attrition study has been carried out using a fluidized bed of coal ash. Experiments were carried out in a cold fluidized bed 0.14 m in diameter and 2.20 m in height. The effect on attrition of the following variables has been studied: bed particle size, static height of bed, time of attrition and fluidizing velocity. It was concluded that attrition is mainly due to abrasion, resulting in the removal of fines of a size smaller than 50-mu-m. The size distribution of fines produced is independent of the original particle sizes. The attrition rate varies linearly with the parameter (U - U(o)). It was observed that the variation of the static bed height has no effect on the attrition rate under steady-state conditions.