Performance evaluation of a fluidized bed reactor by studying the hydrodynamics and thermal properties of different solid particles

High heat transfer rate as one of the important advantages of fluidized bed reactors is attributed to hydrodynamic mechanisms. In this research the important hydrodynamic parameters such as minimum fluidization velocity, pressure drop, bed height, bubble formation and flow regime were investigated experimentally and numerically. The two-fluid model coupled with the kinetic theory of granular flow and two different drag models of Gidaspow and Syamlal-O'Brien were applied in the present simulation. The results showed that by using the Gidaspow drag model in numerical solution, the minimum fluidization velocity with an approximate error of 13.8% and the bed height with an average error of 9% are predictable in comparison with the experiments. In order to investigate the effects of particles properties on temperature distribution of a bubbling fluidized bed, several solid particles with different densities and thermal diffusivities were investigated. Finally, to demonstrate the advantages of fluidized beds to receive the required hot air in industrial units, temperature distribution and required height of a bubbling fluidized bed reactor were compared with a similar constant surface temperature simple channel. The results showed that the outlet air temperature of a bubbling fluidized bed is about 28 degrees Celsius higher than a similar simple channel.