Experimental Study on the Mixing Process of Binary Mixtures in
Three-dimensional Fluidized Beds Using Capacitance Probe
Abstract
Measuring the particle mixing parameters at multi positions in
three-dimensional fluidized beds continuously remains a challenging
task. A novel measurement method for the mixing and segregation of
particles inside three-dimensional fluidized beds is developed based on
capacitance probe. The measurement error is generally below 7%. The
particle mixing parameters and dispersion coefficients at
multi-positions of the three-dimensional fluidized bed are acquired. The
effect of convection and diffusion mechanism on particle mixing is
discussed. Results show that the governing mechanism of particle mixing
at center and top of the bed is convection; meanwhile the governing
mechanism for particle mixing at bottom and near the wall is diffusion.
The radial dispersion coefficient at half-radius of the bed is mainly
between 0.0038 and 0.026 m2/s, which is about 1.5 times that near the
wall. The axial dispersion coefficient is mainly between 0.004-0.056
m2/s, which is about 2.3 times that in radial direction.