CFD simulation with multiphase flows in porous media and open mineral storage pile

Abstract

In open storage piles in bulk solids port terminals, power stations and cement factories, not only the solid and porous barrier behaviour in front of the pile is important, but also the effect that porous and solid barriers produce when they are behind the pile.Considering the dust propagation behind the pile, the solid barriers are more effective than the porous ones. But, the effect of the porous barriers on the wind velocity distribution, mainly in zones between the barriers and the piles should be taken into account, regarding the total dust emission to the atmosphere and its propagation.In these studies, wind and dust concentration measurements in laboratory and field were carried out. A hot-wire anemometer (Velocicalc Plus (TSI)) was used in the wind study and two dust collectors (E-Sampler, Met One Instruments, Inc., Oregon, USA) were used to measure the dust concentration (Total Particle like PM10); a meteorological station (E-Sampler, Met One Instruments, Inc., Oregon, USA) attached to a PM10 collector was also employed.All these measurements were used to adjust the 3D CFD computational model (Ansys CFX 10.0): In the wind case through a k-epsilon turbulence model and the dust case by Lagrangian method.These adjusted models allow us to carry out several simulations combining the effect of solid and porous fences in front of and behind the pile, as well as pile shape modifications and behaviour analysis according to the dust emission from several special configurations and its relation to the wind gust preferential directions.

Experimental and numerical study of fence effects on dust emission into atmosphere from open storage piles

“…When modelling a 37° angle cone, it is observed that the recovery zone of the wind flow velocity is smaller, 9H becoming 8H. The choice of these slope angles is based on former research by TORAÑO et al [12], TORAÑO et al [7], TORNO et al [5], TORNO [3] and DIEGO et al [8], in which they determined that for the use of standard EPA emission formulas [29], a 0.2 relation between the radio and the pile height was necessary. This relation has been used by STUNDER and ARYA [20] which is the same as the one used in our studies, (11 m high and 37° angle).…”

“…For each type of fence, solid fence (ε=0%), porous fence (ε=30%) and no fence (ε=100%), 183 wind velocity measurements with hot-wire anemometer and 60 dust concentration measurements, measuring Total Particle and PM10, were developed. Some turbulence models used by the authors in other studies [5,[7][8]12] were included again in these simulations, carried out by 3D CFD (Computational Fluid Dynamics) code ANSYS CFX-10.0 [18−19]. These simulations were validated by the measurement programmes mentioned above, determining that the vortex, which is produced between the fence and the pile, diminishes its velocity when a solid fence is changed for a porous fence (ε=30%).…”

Dust emission reduction for open storage mineral piles by fences: CFD modelling

“…Firstly, the effect of the porous barriers at 30% adjacent to the pile has been studied, achieving an emission reduction produced to windward of pile due to the solid barrier effect over the wind flow (Torno et al [7]). …”