Modeling of the spray zone for particle wetting in a fluidized bed

In a spray agglomeration process the particle wetting influences the agglomerate growth and particle dynamics in the granulator. The mass of binder liquid that is deposited on single particles affects the amount of energy dissipation during particle contacts. For the agglomeration of colliding particles the whole impact energy has to be dissipated due to viscous and capillary adhesion forces in the liquid film and plastic deformation of the material. Therefore, a detailed knowledge of the particle wetting is necessary to model the agglomeration process. This contribution uses a coupled DEM-CFD approach to describe the spray zone of a two-fluid nozzle in a fluidized bed agglomerator. Droplets modeled as discrete elements showed the formation of a spray zone with a conical shape. Simulations of the spray zone and the wetting of single particles are in good agreement with experimental results. A coupled DEM-CFD approach is used to describe the spray generation of a two-fluid nozzle and the wetting of single particles. Valuable information to describe particle collisions of wetted particles is generated that are necessary to simulate fluidized bed processes, i.e. agglomeration and granulation.

Subjects

Computational fluid dynamics

Discrete element method

Droplets

Fluidized bed

Particle wettin

Spray

DDC Class

540: Chemie

More Funding Information

Nestec S.A.

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Modeling of the spray zone for particle wetting in a fluidized bed