Performance of Spouted bed on drying of Foliar fertilizer: Analysis of yield and powder retention

Abstract

Foliar fertilization is one of the most important management techniques used to improve crop productivity and quality. To increase the efficiency of fertilization, the fertilizer must be highly soluble. The drying of paste and solutions in spouted bed can change the powder structure, making it more soluble. However, depending on the operational conditions, the powder yield produced in this operation may be low. As such, the goal of this research was to investigate the impact of operational conditions on powder yield and powder losses caused by adhesion on the walls of the bed and cyclone, on the particle surface, on the exhaust tube, filter, and filter overflow. To accomplish this, a 23 factorial design was used. The results of powder yield (between 2.3 and 26.6%.) were like those obtained in other spouted bed applications, but lower when compared to spray-dryer. The higher powder retention occurred on the surface of the inert particles and at the bed wall. A high level of instability was observed during spouting, which may have increased the powder adherence at the equipment's walls. The powder obtained after drying was solubilized about 5.9 times fast than the original fertilizer, demonstrating that the technique is promising if the bed stability is maintained.