Research On The Adaptability Of Spray Dust Reduction Systems In Coal Mine Drivage Faces

As mechanization and automation of coal mining continue to improve,the problem of dust pollution in underground work environments is becoming increasingly serious,and the occupational health of coal miners is receiving high attention from the government.Although dust-reducing technology in comprehensive mining workspaces has made progress,the technology for dust control in excavation workspaces cannot fully meet the needs for dust prevention and control.In this study,theoretical analysis,numerical simulation,and experimental testing were used to design and study a dust suppression system for excavation workspaces that has multiple adaptability.Different excavation workspaces,including comprehensive mining workspaces and continuous mining excavation faces at different locations,were tested for dust suppression effects.During on-site investigations of dust control in excavation workspaces,it was found that the cutter head and shovel of the excavation machine produce the most severe pollution.The turbulence in the air flow caused by the cutter head is one of the main reasons for dust accumulation.Therefore,dust suppression technology was used to capture dust in this area and moisten coal to prevent excessive dust concentration and dust generated during coal transport.A modular design was used for comprehensive mining workspaces and continuous mining excavation faces,and atomization performance requirements were determined based on actual water pressure,wind pressure,and installation position.Two types of eight nozzles were chosen for atomization characteristics experiments,and the macroscopic and microscopic atomization parameters of each nozzle were compared and measured.A spray test system was built to verify the simulation of the nozzle spray field.A wide-angle circular air atomizing nozzle was used for dust suppression in the comprehensive mining workspace,and a circular swirl nozzle was used for continuous mining excavation faces.The nozzle positions were calculated and device structure design was based on the number and location of the nozzles used.The airflow distribution in the excavation workspace was analyzed using grid independence verification for comprehensive mining workspaces and continuous mining excavation faces.Due to the position of the air duct and the proximity of the excavation machine to the coal wall,there was a vortex region in the cutter head area that required additional treatment to collect dust.Under actual working conditions for continuous mining excavation faces,the effects of the airflow on the sprayed field with the nozzles placed were simulated and analyzed.It was found that under the influence of the airflow,compared with no wind conditions,the droplet size in the spray field composed of multiple nozzles would increase,and under the same injection distance conditions,the larger the wind speed,the larger the droplet size under the wind flow perturbation.The feasibility of the dust suppression equipment for multiple adaptability in excavation workspaces was tested by installing dust suppression systems on the 2304 rib transport crosscut comprehensive mining workspace at Weiqiang Coal Mine and the 25212 continuous mining excavation face at Hongliulin Coal Mine for underground dust suppression effect testing and analysis.Compared with the dust removal technology originally used by the mines,the dust removal rates for total dust and respiration dust for the operator’s position in the comprehensive mining workspace were increased by 28% and 30.3%,respectively.At the operator’s position in the continuous mining excavation face,the overall dust removal rate was increased by27.2%,and the respiration dust removal rate was increased by 23.1%.Figure [69] Table [11] Reference [86]...