Abstract: A study has been carried out on the hydrodynamic performance of a fountain confinement device used in conical spouted beds for the treatment of Geldart A and B type particles. Stability and particle elutriation have been analysed for beds provided only with this device and those provided with this device and two types of draft tubes, namely, open sided draft tube and nonporous draft tube. Stability is greatly improved when only the fountain confiner is used, but the draft tubes are required for significantly avoiding bed elutriation in spouted beds. The modified conical spouted bed has been located in a map of operating conditions together with the remaining gas-solid contact regimes. The fountain confiner provides a dramatic increase in the applicability range of spouted beds. Thus, unlike the traditional use of spouted beds for Geldart D type particles, this device allows operation with Geldart A, B and D particles, with a small fraction of C particles.