Coating of urea with an aqueous polymeric suspension in a two-dimensional spouted bed

In this work, a process of coating of urea with polymeric film was developed and analyzed experimentally in a two-dimensional spouted bed. An experimental design was utilized to investigate the effects of operational variables, e.g., air flow rate, air temperature, atomizing air pressure and coating suspension flow rate, on the efficiency of the process, particles growth, particles growth kinetics and physical properties. The results showed that the efficiency of the process and particle growth characteristics were strongly influenced by the operational variables. Coating of the polymeric suspension of Eudragit(R) improved up to four times the moisture holding capacity of coated urea in relation to uncoated urea. The bulk density, grain size and sphericity were found to be independent of operational conditions.