Wireless Measurement of Float-Sink Motion of Variously-shaped Objects in Gas-Solid Fluidized Bed

Koshi Uemoto, Shohei Narita, Shusaku Harada, Yuya Sakamoto, Takuya Tsuji, Jun Oshitani, Hirokazu Kajiwara, Kei Matsuoka

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.

Advanced Powder Technology

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