The hydrodynamics of a gas-solid fluidized bed was studied using a combination of experiments and CFD simulations. Experiments were conducted with polypropylene particles (710-1000 mu m in diameter) as solid phase and air as gas phase. A multifluid Eulerian model incorporating the kinetic theory for solid particles is used to simulate the gas-solid flow. Momentum exchange coefficient was calculated using the Gidaspow drag model. Effects of gas velocity, type of sparger, presence of draft tube on solid hold-up distribution and solid circulation pattern have been investigated. The presented experimental data and comparison with CFD predictions provide useful basis for further work on understanding bubbling fluidized beds. (C) 2008 Elsevier B.V. All rights reserved.