A 3D computational fluid dynamic modeling of atomization and fluidization of urea was simulated in an external mixing, bottom spray, fluidized bed granulator. The Eulerian–Lagrangian approach was used to predict the mean diameter of melt urea droplets similar to the droplets produced by an industrial scale two-fluid nozzle under hot atomized air. Temperature changes and evaporation of water content from droplets were determined during simulations. Furthermore, three-phase fluidization was simulated in the Eulerian approach whereby the bed expansion of the granulator was predicted. The mean diameter of droplets and bed height were found in good agreement with the empirical correlation and the real bed height, as characterized by a level transmitter instrument in the industrial granulator, respectively. The important features of this study included solving mass, heat and hydraulic equations simultaneously, as well as simulating a real urea fluidized bed granulation unit.

在外部混合，底部喷雾，流化床制粒机中模拟了尿素雾化和流化的3D计算流体动力学模型。欧拉-拉格朗日方法被用来预测熔融尿素液滴的平均直径，类似于工业规模的双流体喷嘴在热雾化空气下产生的液滴的平均直径。在模拟过程中确定了温度变化和水滴中水分的蒸发。此外，在欧拉方法中模拟了三相流化，由此预测了制粒机的床膨胀。分别以工业造粒机中的液位变送器为特征，发现液滴的平均直径和床高与经验相关性和实际床高高度吻合。