Entrainment Behaviour of Particles Induced by A Half-Submerged Horizontal Rotary Drum

This paper presents the development of a two dimensional computational model which
describes the entrainment of buoyant solid spherical particles into the thin liquid film
adjacent to the surface of a half-submerged rotating drum (RD). The flow is presented by
two dimensional model equations neglecting the end effects of the RD and solving by
finite volume method. Generation a grid of order of micron covering a curved surface,
solving the flow equations on this grid, has difficulties in terms of stability and
convergence. The film free surface is captured by volume of fluid, VOF, (validation
presented by Khan, 2003). The flow behaviour in the rectangular tank is also validated
against LDV (Laser Doppler Velocimetry) data and presented by Khan (2003). A reason
for modeling the half-submerged rotating drum system is to determine the dispersion
characteristics of buoyant particles (BP) in the plunging region of the rotating drum. It was
found that for particles smaller than 100 microns in diameter can be dragged up by the
liquid formed on the RD. The model presented is applied to water only, but applicable to
any Newtonian fluid.