EFFECT OF THE IMPELLER SHAPE ON THE PERFORMANCE OF THE MIXER-TYPE DISPERSER

The performance of the mixer-type disperser has been studied experimen tally with particular attention to the effect of the impeller position and the blade angle. The experimental results showed the relatively h igher position and narrow impeller were better for attaining good perf ormance. The variation of the dispersion efficiency was well correlate d by a newly introduced parameter, a non-dimensional residence time. T he non-dimensional parameter represents the amount of recirculating fl ow in the vessel, because it was inversely proportional to a non-dimen sional air flow rate, which is defined by the ratio of the discharged air flow rate to the flow rate exhausted from the impeller. It was con cluded that the best disperser has no recirculating flow. As for the e ffect of the angle, the blade perpendicular to the bottom attained the best performance as a result of no short cut particles and no recircu lating particles.