ABSTRACT
Scaling rules for rotary kilns are obtained by non-dimensionalising the differential equations governing the behaviour of solids motion. The derived dimensionless groups include Froude number, pseudo-Reynolds number, pseudo-Euler number, kiln geometric ratios, kiln inclination, kiln fill percentage, size distribution of particles, and physical properties of particles and kiln wall such as restitution coefficient and elasticity modulus. At relatively low pseudo-Reynolds numbers, the effect of velocity fluctuations and hence granular temperature can be neglected; solids motion is in the quasi-static regime. At relatively low pseudo-Euler numbers, the effect of frictional contribution to the total stress tensor is negligible; particle motion is then in the rapid granular flow regime.
