Pressure Drop and Gas Holdup Studies in a Spout-Fluid Bed

摘要

Spout-fluid beds are used for a variety of processes involving particulate solids. They are employed where the particle agglomeration, dead zones, and sticking of particles to the vessel are the common problems in conventional spouted beds. Applications involved are granulation, coating, drying, combustion, and gasification. In this study, experimental studies have been carried out in a cylindrical Perspex column (0.094m internal diameter and 1.217m height) using glass beads and air. The effects of initial bed loading, spout velocity, and background (fluidization) velocity on pressure drop and gas holdup have been investigated. It is found that the minimum spout-fluidizing velocity increases with increase in initial bed loading. The pressure drop and gas holdup increase with increasing bed loading. In spout-fluid bed condition, at a constant spout velocity, as the background gas velocity increases, the gas holdup increases, and it is found to be high for smaller bed loading and is low for larger bed loading at higher velocities. The fountain height increases as spouting velocity increases and it decreases with initial bed loading. The total velocity required to fluidize the particles in spout fluidization is lower in comparison to spouted beds and fluidized beds.