(70bk) A 2D DEM study of Geldart group A particle bed fluidization behaviour

A Lagrangian-Eulerian fluidised bed model employing the Discrete Element Method for the particulate phase (Kafui, Thornton & Adams, 2002) has been used in studying the fluidisation behaviour of a 2D Geldart Group A particle bed. Simulations have been carried out for particles without and with interparticle cohesion based on the JKR ( Johnson, Kendall & Roberts, 1971) model of surface energy. In each case, a wide range of fluidising gas velocities were utilised in order to identify the various regimes: fixed, fluidised, bubbling, turbulent and fast.

Visualisations of the fluidisation behaviours, pressure drop fluctuations and the relative standard deviations of the pressure drop fluctuations have been used in the qualitative and quantitative analysis of the simulations.

A description of the fluidisation behaviours as the fluidising gas velocity increases and the delineation of the various regimes based on the qualitative and quantitative simulation results will be presented. The effect of interparticle cohesion on the fluidisation behaviours and the regimes will also be highlighted. Comparisons with some empirical correlations in the literature will be offered.

References

Kafui, K.D., Thornton, C., & Adams, M.J. (2002). Discrete particle-continuum fluid modelling of gas-solid fluidised beds. Chemical Engineering Science, 57, 2395-2410.

Johnson, K.L., Kendall, K., & Roberts, A.D. (1971). Surface energy and the contact of elastic solids. Proceedings of The Royal Society of London A, 324, 301-313.