Computational Fluid Dynamics Modeling Of Airflow patterns around a Room-and-pillar mining face area

In this study, Computational Fluid Dynamics Modeling (CFD) was applied to model a room-and-pillar mining working area to investigate the airflow patterns for dust control. Room-and-pillar mining is a conventional underground mining technique used for the extraction of coal by cutting excavations called rooms using a continuous mining machine and leaving the remaining coal as pillars for supporting the coal seam. The FLUENT software was used to analyze the airflow in the mine whose structure was designed and meshed in GAMBIT. The analysis was carried out in four different stages. First, airflow patterns were studied in the roadway without any equipment. Next, a line curtain, which extends along the height of the coal seam, was simulated in the roadway to direct the flow of air towards the active mining face. In the third stage, a continuous miner was inserted between the mining face and the end of the line curtain. Three and six meters deep box and slab cuts were simulated and the airflow patterns were investigated. In the final stage, a wet scrubber was simulated as an integral part of the continuous miner and the effect of the scrubber on the airflow in the box and slab cuts were studied. Dead zones (areas with limited airflow) and recirculation areas were observed using velocity distribution contours. A parametric study was conducted to evaluate the effects of distance of the curtain from the pillar rib (Dcr), scrubber pressure (Psc) and height of the coal seam (Ho). The data were plotted as functions of selected dimensionless variables. It was seen that wet scrubber increased the air in the LOXC (Last open cross cut) by 7.6% and was also proved that extension of line curtain along with the cut. The results of these studies are being used to develop guidelines for dust control in the face area