The effect of wetting liquid droplet size on the growth of agglomerates during wet drum granulation

Results of investigation of the effect of wetting liquid droplet size on the growth of agglomerates during wet drum granulation of dolomite flour of selected grain-size composition which guaranteed geometrical similarity were discussed. ocess of granulation was carried out batch-wise in a drum granulator 0.5 m in diameter and 0.4 m long at rotational speed 0.33 s−1 and constant volumetric drum filling degree ϕ=0.1. On the bed tumbling in the drum, the wetting liquid (distilled water) was supplied at a constant flow rate Qw=12×10−3 m3/h. The size of wetting droplets was changed using various air flow rates through pneumatic spray nozzles in the range Qa=1.0 to 3.0 m3/h and applying a sprinkler which supplied (drop-wise) the liquid uniformly along the entire drum length. In the whole experimental cycle, constant mean saturation degree of the feed equal to S=0.293 was used. Relationships determining the effect of wetting droplet size and particle size distribution of the raw material on the rate of agglomerate growth during drum granulation were developed.