Studies on a Two-layer Swirling Fluidized Bed (SFB)

Swirling Fluidized Bed is a newer development of fluidized bed in fluidization technology. A significant amount of research work has been carried out on swirling fluidized bed since 1990s. Even though Two-layer regime swirling fluidized bed has been discovered by previous researchers, a comprehensive understanding on its hydrodynamics characteristics with respect to different designed parameters has not been fully established. Increasing interest on determining the superiority of swirling fluidized bed over conventional bed becomes the driving force of further studying swirling fluidized bed hydrodynamics behaviors as a sequel to the earlier work of the past researchers, especially in Two-layer swirling fluidized bed. In fluidization processes, bed pressure drop is crucial as it determines the power required to achieve fluidization. Full-scale experiment were carried out by assigning the parameters such as particle size, bed weight and superficial velocity in order to study the effect of them on the hydrodynamics characteristics of Two-layer swirling fluidized bed behaviors. In the study, the author started the experiment by manipulating the superficial velocity up to approximately 4.0m/s and bed weight from 500g to 3000g, to find out the particular bed weight when Two-layer regime started appearing and ended the experiment in elutriation regime. Spherical particles of 4mm, 5mm and 6mm were be experimented at each time. Blades with overlap angle of 18¢ª and inclination of 10¢ª were used in the experiment. The studies show that due to the presence of frictions and electrostatic charge, more energy is required in larger bed weight to achieve fluidization. In addition, as the bottom swirling layer has better quality of fluidization, small bed loadings with lower bed height are encouraged to minimize the bed expansion hence reduce the effect of undesirable top conventional layer while maintaining high value of height of bottom swirling layer and height of top bubbling layer (S:B) ratio.