Particle Dispersion Behaviors of Dense Gas-Particle Flows in Bubble Fluidized Bed

Abstract EN

An Euler-Euler two-fluid model incorporating a developed momentum transfer empirical coefficient is developed to study the particle dispersion behaviors of dense gas-particle flows in gas-fluidization reactor.

In this model, the four-way couplings among gas-particles, particle-gas, and particle-particle collisions are fully considered based on kinetic theory of granular flows and an improved smooth continuous drag coefficient is utilized.

Gas turbulent flow is solved by large eddy simulation.

The particle fraction, the time-averaged axial particle velocity, the histogram of particle fluctuation velocity, and the wavelet analysis of pressure signals are obtained.

The results are in good agreement with experimental measurements.

The mean value and the variance of axial particle velocity are greater than those of radial particle velocities.

Particle collision frequencies at bubble vibrant movement regions along axial direction are much higher than those of radial direction and attenuated along height increase.

Low-frequency component of pressure signal indicating the bubble movement behaviors in the center of reactor is stronger than wall regions.

Furthermore, the negative values represent the passed bubble and positive peak values disclose the continuous motion of single bubble.