Use of discrete element method simulation in studying fluidization characteristics: influence of interparticle force

A discrete element method (DEM simulation is used to investigate the influe nce of cohesive interparticle Force on the characteristic behaviour of a ga s fluidized bed. The cohesive interparticle force is introduced in a genera l Form; it is increased step by step with an increment equivalent to a mult iple of the single particle buoyant weight. Simulations were performed usin g a two-dimensional bed (height 0.2 m, width 0.08 m) and 4000 particles. Th e particles used had a diameter of 1 mm and densities in the range 1590-265 0 kg/m(3). A carefully Formulated strategy is presented for establishing th e minimum fluidization and minimum bubbling velocities by DEM simulations. The influence of the magnitude of the cohesive interparticle force on fluid ization characteristics is analysed in terms of the change in the ratio of the minimum bubbling to minimum fluidization velocities. Imposing a cohesiv e interparticle force on particles which are initially Geldart Group D or B is found to bring about Group A characteristics. Most notable of these cha racteristics is the existence of non-bubbling fluidization for a range of g as velocities between the minimum fluidization velocity and the minimum bub bling velocity, (C) 2001 Elsevier Science Ltd. All rights reserved.