Prilling and Granulation are finishing sections of urea production process. Prilling is defined as distribution of molten droplets into a column of rising air which removes the heat of fusion and yield a solid product. Two most important aspect of prilling are droplet formation and distribution of droplets over maximum cross-section area of prilling tower. The paper intends how the mathematical hydrodynamics, heat, and mass transfer between the urea and the cooling air are developed in natural prilling tower. The height of the prilling tower is about 80 meter to 140 meter according to plant load and weather condition.
Granules are larger, harder and more resistant to moisture as compare with prills urea. The aim of this paper is to build a mathematical model for a prilling process at in National fertilizers Ltd, Vijaipur (Guna (M.P.). with productivity of 3500 tons/day, located in India.