Mixing Rules for Powder Mixing

systems.

in the rolling mode to fully cascading ows consistent with industrial comminution

successfully scales up mixing con gurations spanning slowly rotated drums operated

Mixing Mechanisms

three mixing mechanisms are then achieved via the Entrainment number. The theory

dominated, and (iii) intermediate (both shear and advection). Scale-up rules of the

that classify mixing into three categories: (i) shear dominated, (ii) advective

Focussing on shear and advective mixing, we isolate the corresponding energy signatures

forced-to-free entrainment|The Entrainment Number.

the governing equations yields a set of dimensionless numbers, including the ratio of

and basal interface) and full velocity eld. Subsequent non-dimensionalisation of

(PEPT) measurements con rms the successful recovery of bed geometry (free surface

transient and non-uniform ow conditions. Positron Emission Particle Tracking

free surface e z(x), basal interface z e (x), and depth-averaged velocity u(x) under arbitrary

subsequent balance of mass, momentum and energy yields di erential equations to the

dense, viscoplastic granular rheology of (da Cruz et al., 2005; GDR MiDi, 2004), a

spanning rolling-to-fully-cascading ow regimes. Starting with the linearised form of

of rotating drum ows that facilitates scale-up of the dominant mixing mechanisms

The Entrainment Number (^ !)|from a fundamentally-derived granular ow model

In our third phase of the project we identify a suitable dimensionless number|

Executive Summary