Confined fluidised bed porosity in the light of bubbling-bed models

Abstract

Abstract Based on hydrodynamic data, Kato-Wen and Kunii-Levenspiel bubbling-bed model parameters, supplemented with assumptions characteristic for tested confined fluidised bed, were analysed. The calculated bubble diameters and the bed composition proved essential influence of inter-particle space of packed compacted component onto fluidisation character. The usability of the conducted model analysis was also confirmed. Finally, it can be concluded that Kunii-Levenspiel and Kato- Wen models with characteristic assumptions (for the tested bed) can be applied for calculation of the confined fluidised bed layer porosity. Discrepancies of ε f value, determined on the basis of the above mentioned bubbling-bed models do not exceed 8% of the error. The model parameters obtained from the matching the model relations to experimental data εf = f(u0) allow an analysis of the fluidisation character as well as gas velocity regime and the fluidised bed structural composition identification. A description of the regime of the process in which confined fluidised bed is characterised with an increase of mass and heat transfer rate is also possible using relation (17) derived in the present study.