Wireless measurement of Float-Sink motion of Variously-shaped objects in Gas-Solid fluidized bed

Abstract

The float-sink motions of coarse objects in a gas–solid fluidized bed were investigated experimentally using a newly developed wireless sensor system. The Lagrangian sensor system developed by our previous study, which can measure the vertical position of a freely-moving object in an invisible system, was extended to measure the attitude angle and vertical position of variously-shaped objects simultaneously. The vertical motion of objects which have different shapes with the same mass and volume was measured using the Lagrangian sensor under the density conditions similar to the apparent density of the fluidized bed. The results demonstrate that the float-sink motions of objects in the gas–solid fluidized bed differ significantly depending on the shape of the object, even at the same density, in contrast to those in water. It was found that non-spherical objects tend to float more easily than spherical objects, which supports the numerical results shown in our previous study (Tsuji et al., Chem. Eng. Sci., 2022). Simultaneous measurement of the position and attitude angle highlights the importance of the angular motion of objects in terms of the float-sink motion. The interaction of the object with the media particles in the fluidized bed differs depending on the object shape, which indicates that each shape involves a unique float-sink mechanism.