Conical Fluidized Bed with Arc Design for Improved Performance of Gas Distributor

Abstract

Particles distributions along a conical fluidized bed were predicted by an alternative arrangement of the minimum fluidization velocity equation. The proposed approach introduces two new equations which present the particle diameter in the bed as function of: height in the bed (Z), angle of inclination of the fluidized bed wall (θ), input flow rate (Q_o), and gas distributor diameter (D_o, 2r_o). A novel arc-shaped design of the gas distributor was suggested, which provides enhanced distribution of the gas and enables greater control on the direction of the gas inlet. The model showed that the inclination of the fluidized bed wall should not exceed a critical angle, which can be determined with the set of equations specially developed for this purpose, to prevent inhomogeneous fluidization across the bed and accumulation of particles along the walls.

By applying the Box Wilson Method, theoretical data were obtained for constant column diameter at the base (0.05 m), and varying bed height, Z, (range: 0.5 to 1.5 m), velocity of gas inlet, U, (range 0.25 to 1 m s^-1), and balance factor, a, (range: 0.5 to 1, a new factor), respectively. The angle of inclination of the wall was first predicted based on the above parameters, and subsequently, the particle size distribution along the column was determined. Theoretically the novel arc-shaped distributor design has shown the potential of generating homogeneous fluidization regimes along the bed.