Novel ventilation for dust suppression and dilution of gas: A synergistic approach to front-split vortex-air curtains

In order to solve the problem of excessively high dust and gas concentration in continuous mining face, this paper puts forward a front split air technology which can control gas concentration while reducing dust pollution on the basis of not affecting on-site coal mining operations, summarizes the on-site dust and gas pollution diffusion law, and reveals the dust control mechanism of front split air technology. It provides a strong support for the safe and efficient production of coal face. The results show that too small pressure air volume will lead to less air flow in the head area, and a large amount of air flow will be absorbed by the fan, resulting in dust deposition, but the gas concentration is as high as 1.88 %. The increase of pressure air volume will increase the vortex and wind curtain intensity in the head area, and the increase of pressure air volume will lead to the increase of dust in the breathing belt at the front and back of the roadway, which will increase to 249.6 mg/m³. If the pressure pumping ratio is too small, the eddy current intensity will increase, and the dust will be inhaled by the fan. If the pressure pumping ratio is too large, the dust diffusion distance will gradually decrease to 6.5 m, and almost dust will be distributed behind the roadway, but gas will accumulate at the front end of the roadway, and the concentration will be as high as 2.27 %. Under the optimal ventilation conditions, the gas concentration on the continuous mining face is limited to less than 0.6 %, and the dust concentration at the back end of the roadway is controlled to less than 4.0 mg/m³. Compared with the traditional ventilation mode, the dust control efficiency at the back of the roadway is increased by more than 98 %, and the gas and dust concentrations on site are effectively controlled. This study will provide a new feasible research scheme for ventilation technology to solve the dust and gas pollution of continuous mining working face.