Critical fluidization velocities and maximum bed pressure drops of homogeneous binary mixture of irregular particles in gas–solid tapered fluidized beds

Abstract

Recently, tapered fluidized bed has become more attractive because of the problems associated with conventional (cylindrical) beds like fluidization of widely distributed particles, entrainment of particles and limitation of fluidization velocity. There have been some investigations on hydrodynamics of uniform single size particles but there have been no detailed studies of homogeneous binary mixture of particles of different sizes and different particles in tapered beds. In the present work, an attempt has been made to study the hydrodynamic characteristics of homogeneous binary mixture of irregular particles in tapered beds having different tapered angles. Correlations have been developed for important characteristics, especially critical fluidization velocities and maximum bed pressure drops of homogeneous binary mixture of irregular particles in gas–solid tapered fluidized beds. Experimental values of critical fluidization velocities and maximum bed pressure drops have been compared with the developed correlations. Graphical abstract In the present work, an attempt has been made to study the hydrodynamic characteristics of homogeneous binary mixture of irregular particles in tapered beds having different tapered angles. Correlations have been developed for some characteristics, especially critical fluidization velocities and maximum bed pressure drops of gas–solid tapered fluidized beds of homogeneous binary mixture of irregular particles (coal, iron ore and dolomite). Experimental values of critical fluidization velocities and maximum bed pressure drops have been compared with the developed correlations. Fairly good agreement was found to exist between the calculated and the experimental values. Experimental set-up 1. Compressor. 2. Receiver. 3. Silica gel tower. 4. Bypass valve. 5. Line valve. 6. Rota meter. 7. Bed materials. 8. Fluidizer. 9. Pressure tapping to manometer.