Date of Graduation

1988

Document Type

Thesis

Abstract

Mine face ventilation is generally regarded as the most effective tool for lowering the concentrations of respirable dust. A practical and economical way to gain more in-depth understanding of the relationship between mine face ventilation and dust dispersion is through scale model studies. Researchers have established that the results of these studies can be scaled-up as long as geometric, kinematic, and dynamic similitudes exist between the scale model and the full scale system. To better understand face ventilation and dust dispersion, a one-fifth scale model of room and pillar mine face was constructed. The model was then used to study the effects that line brattice distance (from the face) and air quantity had on dust dispersion. Sixteen combinations of brattice distances and air quantities were examined. The experiments utilized both methane and Arizona Road Dust for simulating the respirable coal dust. Methane or Road Dust concentrations were measured at 25 grid points for each brattice distance and air quantity combination. The tests were first carried out without face machines and the same conditions were repeated with the presence of face machines. Upon completion of the experiments the data were summarized and compared. Rates of reductions in methane or Road Dust concentration because of increased air quantities or brattice extensions were calculated. In addition, concentration isopachs were drawn to observe the trend of changes in concentration pattern. Differences between the dust simulation substances and the presence of face machines were also discussed. The correlation between the ventilation parameters and dust simulators was examined at each grid point. Also, the statistical functions for predicting the dust concentration at each grid point from different simulating substances were also constructed by using regression techniques. Recommendations were made in regard to controlling dust dispersion through increasing air quantity or extending line brattice. Consideration of face areas typically of high and low dust concentration was also recommended.

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