Numerical simulation of air and particle motions in bubbling fluidized bedof small particles

Air and particle motions in a bubbling fluidized bed of about 100,000 parti cles of 310 mu m in diameter, which are classified as the B particles in th e Geldart map, are numerically simulated. Particle-particle interactions we re calculated, using the three-dimensional distinct element method (DEM). T he Navier-Stokes equation and the Lagrangian type particle equation were si multaneously solved, where the drag and lift forces on particles, the multi -body collisions among particles and the mutual interaction between air and particles were taken into account. The corresponding experiments were also performed. It was found that the calculated results describe well the expe rimental instantaneous particle positions, and enable us to know the mechan isms of bubble formation, bubble coalescence and bubble disruption in a bub bling fluidized bed. (C) 2000 Elsevier Science S.A. All rights reserved.