A study of spray granulation in vibrated fluidized bed with internal heating tubes

Abstract

The granulation process in a vibrated fluidized bed with immersed horizontal heating tubes was studied in this paper, with small monoammonium phosphate particles as the initial particles and monoammonium phosphate solution sprayed on them. The concrete influences on the granulating performance of the immersed horizontal heating power, fluidizing gas velocity, vibration frequency and amplitude had been analyzed theoretically. The results show that appropriate vibration intensity is a preferred condition for the growth of partials, but the fine dust will become much more along with prolonged vibration. Increasing the heating power is beneficial to raise the growth rate. Particles will grow faster if the fluidizing gas velocity is higher, but this will cause more fine dust. The optimized condition of A=0.002 m, f=6.67 Hz, u=1.4 m/s was given after the analysis of the experimental results. In the end, a semiempirical formula was derived from the experiment data, and the calculation results show good agreement with the experimental data.

Key words： vibrated fluidized bed; immersed horizontal; horizontal heating tubes; spray granulation; particle growth model

Acknowledgements

The authors wish to acknowledge the experimental help of Weiliang Chen, Yabing Qi, and Chong Lin of Sichuan University.

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