Study On The Spatial Distribution Of Dust And Dust Removal Technology In Fully Mechanized Face

Coal is China's basic energy source.In recent years,with the improvement of coal mine mechanization,the danger of underground dust has become increasingly serious.As one of the main sources of underground dust production,fully digging face produces a lot of dust during the production process,which seriously threatens the physical and mental health of underground workers.Aiming at the problem of dust control in comprehensive mining,this paper studies the wind flow field and dust spatial distribution of the first comprehensive mining face of Pingmei No.10 Mine through a combination of on-site testing,numerical simulation and theoretical analysis,and formulates the dust according to the underground conditions Comprehensive prevention measures.By arranging measuring points in the driving roadway,the dust concentration at each location is measured to study the spatial distribution of the dust in the comprehensive tunneling.And further study the dispersion degree of the dust collected at the position of 4m in front of the fully digging face,and fit the R-R distribution function of the fully digging dust:(4_?9?=0⁽?-??9/46??1.59?,as The following research provides the necessary parameters.In order to propose reasonable dust-reduction measures for fully digging face,this paper systematically studies the wind flow field and dust movement law of fully digging face through CFD simulation based on interface mixed grid.According to the analysis of the wind flow field,it can be seen that at the 5m position,part of the wind flow on the return side flows upwards.During the flow process,the wind flows to the inlet side due to the influence of the roof.When the wind flow moves to the 20m position,the wind flow is in a relatively stable state.And the post-processing software is used to analyze the dust particles transiently.After 10s,the dust can be transported to the back of the roadheader.At the same time,the dust on the air inlet side of the roadheader diffuses along the wind flow to the return air side.At the front end of the roadway,due to the presence of eddy currents,dust accumulates in the vortex area,and high concentration dust accumulation occurs after 30s.At the same time,in order to study the influencing factors of dust movement,this paper systematically analyzes the dust through three aspects:wind current,dust source location and dust particle size.Aiming at the current situation of the existing simulation of spraying dust with surface dust sources in the research process of tunneling face,this paper builds a mobile dust source through UDF and studies the influence of mobile dust source on the dust distribution in the roadway.According to the status of comprehensive excavation dust and underground conditions,comprehensive prevention measures for the working dust are proposed.First of all,according to the current situation of the comprehensive excavation surface,three pressure-pressing schemes were developed.By comparing the dust concentration at the pedestrian side and the driver's position of the roadway under different pressure conditions,it was concluded that the air pressure at 470 m³/min is most beneficial to the dust in the roadway of discharge.Secondly,by installing a water curtain to further capture the dust in the roadway,in order to improve the water curtain's dust-reducing ability,the atomization and dust-reducing effects of different aperture nozzles under5Mpa conditions were compared through experiments,and the 1.5mm nozzle was the best nozzle Aperture.At the same time,through simulation,it is concluded that the fog droplets generated by the water curtain at the position of 25m of the roadway can effectively cover the cross section of the roadway and capture the full cross section of the dust.Finally,in order to improve the ability of water-based media to capture dust,the efficiency of mist drop dust reduction is improved by preparing active magnetized water underground.Through measures such as optimization of ventilation,installation of water curtains and improvement of water-based media,comprehensive prevention and control of dust from comprehensive excavation was carried out.The dust reduction efficiency of all dust and exhalation reached 81.3%and 78.4%,effectively reducing the dust concentration in the roadway and improving underground operations surroundings.The paper has 54 pictures,16 tables,and 86 references.