Experimental and numerical study on the effect of an elevated spout on spout fluidized bed dynamics

In this paper the effect of elevating the spout on the dynamics of a spout-fluidized bed, are studied both numerically and experimentally. Positron emission particle tracking, particle image velocimetry and electrical capacitance tomography experiments were conducted in 2D and 3D spout fluidized beds. Moreover, a discrete particle model was used to perform full 3D simulations of the bed dynamics. In the spout-fluidization regime dead zones appear near the bottom of the bed as the spout is elevated. In the jet-in-fluidized-bed regime the background gas velocity is relatively high, producing bubbles that interact with the spout channel. As the spout is elevated, this interaction is shifted upwards in the bed, allowing the bubbles to remain undisturbed providing the motion of the particles in the annulus near the bottom of the bed. As a result, no dead zones are created and additionally, circulation patterns are vertically stretched.