SIMULATION OF UREA PRILLING PROCESS: AN INDUSTRIAL CASE STUDY

A local industrial urea prilling tower with a rectangular cross-sectional area under the operating conditions of free convection was mathematically modeled. In this model the prilling process has been simulated by simultaneous solution of the continuity, hydrodynamic, and thermal equations. Temperature distributions of the particles and the cooling air along the height of the tower were calculated from the model. The air temperature profile predicted by the model was compared with the measured air temperature along the tower. The data predicted by the model were almost in agreement with the plant data, indicating the validity of the model. The result of this study suggests that an increase in heat transfer from the particles using installation of induced fans can reduce the temperature of produced prills and hence reduce caking tendency of the prilled urea.