Multi-phase computer modeling and laboratory study of dust capture by an inertial Vortecone scrubber

Abstract

Dust generated in mining and tunneling activities is hazardous to health of persons and safety of operations. These projects employ pick-milling machines to extract minerals and rock by mechanical breakage. The machines are equipped with flooded-bed scrubbers that encase dust particles within fine water films as particles encounter a flooded wire-mesh screen. A major disadvantage is that the screen gets clogged when particles become trapped within the wire mesh, reducing airflow through the scrubber and increasing ambient dust concentrations. Thus, the system requires frequent maintenance or replacement. The application of a Vortecone scrubber as an improved alternative to conventional fibrous type scrubbers is investigated. A Vortecone forces dust-laden air and water to follow a complex, rapidly swirling motion. The momentum drives dust particles towards the periphery where they are captured by the water film. The operating characteristics of a reduced-scale physical model of a Vortecone, with its primary axis mounted in the horizontal orientation, was analyzed numerically and experimentally. Computational fluid dynamics (CFD) models depicting the spraying action and multi-phase air/water flows using the volume of fraction (VOF) approach, are presented. Experimental results, utilizing an optical particle counting technique to establish the dust-cleaning capabilities of the model, are also described.

Keywords

• Computational fluid dynamics (CFD)
• Process safety
• Multi-phase flows
• Volume of fraction (VOF)
• Dust-capture
• Cleaning efficiency