Experimental Research On Dust Control Of Inner And Outer Double Cyclone Air Curtain In Roadway Heading Face

With the progress of coal mining machinery and automation,the mines accident rate has been decreasing,but mine dust disasters remain high.In particular,the high concentration dust in roadway heading face(RHF)seriously endangers the physical and mental health of miners and brings many hidden dangers to the safety production of coal mines.As one of the important research methods in the field of dust control,the air curtain dust control system(ACDCS)is favored by many scholars because of its non-pollution,non-blocking vision,harmless to human body and easy to use.In this paper,we utilize a combination of theoretical analysis,numerical simulation and experimental research to systematically study and analyze the newly proposed inner and outer double cyclone air curtain(IODCAC)dust control technology,which provides a theoretical basis for the application of ACDCS in RHF.In the experiment of dust migration and settlement in RHF,the effects of different particle size distribution,different morphology and different area size on dust migration and settlement are qualitatively analyzed.By means of multi-factor analysis of variance(ANOVA),the influence of distance of measuring point,shape of dust,particle size of dust and area of dust on the migration and settlement of dust is quantitatively analyzed.It is concluded that the particle size distribution of dust plays the most important role in the settlement of dust in RHF,but the influence of dust morphology on the settlement of dust can not be ignored.Aiming at the situation that the dust control efficiency of the existing ACDCS needs to be improved and the dust control research of the cyclone air curtain is relatively limited,the IODCAC is designed and proposed by taking the cyclone air curtain as the research object.Based on the similarity theory,the experiment platform of IODCAC is built and the flow field test is carried out.It is proved that the IODCA generator can form cyclone air curtain.Wind flow attenuation experiment is performed on the experiment platform,and the whirlpool attenuation formula is fitted by particle swarm algorithm.After opening the IODCAC,the total dust concentration decrease to 67.37 mg/m~3 and the dust reduction efficiency reach 85.00% at the 1.0 m dust measurement point from the air curtain generator;the exhalation dust concentration decrease to28.63 mg/m ~3 and the dust reduction efficiency reach 81.52%.Fluent software is utilized to simulate the IODCAC,and the laws of formation,migration,dust particle diffusion and different outlet velocities of IODCAC in RHF are obtained.The results show that the IODCAC generator can form an invisible swirl wind curtain under long pressure short suction ventilation mode,and effectively inhibit the diffusion of high concentration dust to the back end of the roadway.The air flow velocity at the floor is maximum and gradually weakens upwards.Compared with the outlet velocity of 30 m/s,when the outlet velocity is 35 m/s and 40m/s,it is obvious that there is a large amount of dust-containing air flow accumulation around the fully mechanized excavator and under the bridge reprinting machine,and this air flow field accumulation will lead to the accumulation of dust particles.Therefore,the outlet velocity of the jet cavity is not as large as possible.By analyzing two kinds of air curtain dust control devices based on plane jet,an improved modular air curtain dust control device based on plane jet is proposed.A module division method based on improved spectral clustering algorithm is proposed and applied to the module division of air curtain dust control device.The results demonstrate the effectiveness of the improved spectral clustering module division method and the uniqueness of the proposed improved modular air curtain dust control device.Through the modular optimization of the air curtain dust control device,the core components and general components are designed in a unified manner,avoiding the repeated work of iterative design of later series products.There are 93 figures,26 tables and 180 references in the dissertation.