Bed symmetry in the fountain confined conical spouted beds with open-sided draft tubes

Bed symmetry has been analysed in fountain confined conical spouted beds operating with fine particles. Thus,
vertical particle velocities and the spout shape have been determined in a wide range of spouting air velocities
and bed configurations. Bed symmetry is widely accepted in the spouted beds without draft tubes or with nonporous
ones, but this is not the case when open-sided draft tubes are used. Thus, radial particle velocity profiles
differ depending on the cross-sectional angular plane considered in the open-sided draft tubes. The spout expands
preferentially along the tube opened surface, and is wider as spouting air velocity and aperture ratio are
increased. The literature correlations proposed for the average spout diameter have been analysed and no one
is valid for estimating this parameter in the whole range of spouting air velocities and configurations analysed
in these systems operating with fine particles.