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Application of a transient heat conduction model for design of urea prilling tower

The studies mentioned above are more complicated to apply due to using many parameters and equations. The aim of this work is to propose a simple model based on the slowthermal conductivity of a spherical particle with appropriate assumptions and conditions to determine the height of the prilling tower. | Application of a transient heat conduction model for design of urea prilling tower Vietnam Journal of Science and Technology 56 (2A) (2018) 43-50 APPLICATION OF A TRANSIENT HEAT CONDUCTION MODEL FOR DESIGN OF UREA PRILLING TOWER Vu Hong Thai, Ta Hong Duc, Vu Dinh Tien* School of Chemical Engineering, Hanoi University of Science and Technology, No.1 Dai Co Viet Road, Ha Noi, Viet Nam Email: tien.vudinh@hust.edu.vn Received: 1 April 2018; Accepted for publication: 10 May 2018 ABSTRACT Urea has highest nitrogen content up to 46.65 % in comparison with other fertilizers. Therefore, it is used widely in agriculture, forestry and additives for animal feed. Recently, Vietnam has 04 urea manufacturing plants in Bac Giang, Ninh Binh, Phu My and Ca Mau with total production estimated in 2014 to be 2,660 million Ton/year. Except for Ca Mau plant using granulator to produce urea granular, other plants are using prilling tower to produce prill urea. In a prilling tower, molten urea is sprayed form the top distributor. The droplets fall along the tower to exchange heat with countercurrent air flow for cooling and solidification. Until now, there is not any Vietnam engineering company having ability to design a prilling tower due to lack fundamental knowledge. In this paper, a transient heat conduction model was applied to determine the engineering parameters like cooling time and prilling tower high. Keywords: transient heat conduction, urea fertilizer, prilling tower, solidification. 1. INTRODUCTION In recent years, Vietnam has been one of the leading exporters of agricultural products such as rice, coffee, tea, pepper, etc. In order to obtain that achievement, there is scientifically contribution of Vietnam fertilizer industry. For nitrogenous fertilizer, Vietnam currently has four plants with advanced technology and equipment imported from abroad. Phu My fertilizer plant and Ca Mau fertilizer plant have designed .