Controlling ventilation currents to prevent layered methane accumulations in mines
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The authors have studied the shaping effect of grids on the velocity field and turbulent characteristics of air streams in mine workings.
The dependence of the diffusion coefficient of methane in an air stream on the distance to the grid in the case of complete coverage of the roadway cross section has been established. The degree of the effect of the increase of the diffusion coefficient in the area immediately beneath the roof, with partial coverage of the roadway cross section by a grid, has been determined.
The effectiveness of reducing the concentration of layered methane accumulations by shaping the air steam parameters by grids has been determined in mines. It has been established that the use of a single grid with a mesh size of 0.5–1 mm enables us to reduce greatly the methane concentration beneath the roof at a distance of up to 20–25 roadway diameters.
KeywordsDiffusion Coefficient Methane Concentration Mine Working Complete Coverage Pulsation Velocity
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