Study on the Shape and Behavior of the Formed Bubbles in a Pressurized Fluidized Bed : Simulation for the Behavior of Formed Bubble from Single Nozzle

By using numerical analysis in the present study, we found that the size of formed bubble increased with air-flow rate and pressure in a solid-gas pressurized fluidized bed. But frequency of production was almost kept a constant without changing pressure. Calculation were based on DEM code where have taken a new approach concerning the air void rate and accuracy of convergence. To verify the bubble behavior, the experimental observation on the shape and flow characteristics of the formed bubble was carried out in the distributor with a single nozzle in the pressurized solid-gas fluidized bed. Experimental data were obtained from the visualized image of the bubble using the shadow-graph method and later were analyzed. Those results indicate that the size and rising velocity of the bubble increased with added rate of nozzle flow and these bubble behaviors directly correspond to increase of pressure in the bed. Also the growth rate of first produced bubble was agreed with the previous works in theoretical and experimental.