SEPARATION OF FLY-ASH PARTICLE BY REVISED CYCLONE WITH HIGH-ACCURACY

Experimental studies were conducted on the separation of fine flyash particle by use of a revised type of cyclone with movable 50% cut size. The amount of unburned carbon in the separated particle was also measured. The 50% cut size of the cyclone was changed from 0.9 to 2.3 mu m by use of the vertically movable apex cone of the cyclone. When the apex angle of the apex cone was smaller, the amount of particle deposition decreased and high-efficiency particle separation was obtained. In the case where the 50% cut size becomes less than 1 mu m, the collection efficiency of the fine-particle side decreased and amount of unburned carbon increased in the fine- particle side. The reason why the unburned carbon increased in the fine-particle side is that coarse particles were smashed in the ring nozzle disperser and fine particles having a high unburned carbon content were introduced into the cyclone. When the 50% cut size becomes smaller, the unburned carbon amount in the coarse-particle side was nearly constant, but the value increased in the fine-particle side. The experimental data of the unburned carbon amount agreed well with the calculated results.