Collisional viscosity of FCC particles in a CFB

Particle velocity distributions were measured for a flow of 75-mu m FCC particles in a CFB using a new video-digital camera technique. From the spread of particle histograms, a random oscillating particle velocity was determined This random velocity was used to compute the powder viscosity with the help of dense-phase kinetic theory of granular flow. There was excellent agreement between this kinetic-theory measurement and previous macroscopic viscosity measurements. The dimensionless group kinematic viscosity divided by the oscillating velocity and particle diameter correlated all available data as a function of particle volume fraction.