Research And Application Of Wet-type Resonant Chord Filter Dust Collector In Mine

With the continuous development of mining production scale,dust hazards,occupational health and environmental pollution have become the focus of national and public concern.Dust hazard is one of the six natural disasters in coal industry.Its hazards are mainly reflected in two aspects:pneumoconiosis and environmental pollution.In this paper,theoretical analysis,numerical simulation and experimental research methods are used to systematically analyzed the influencing factors of wet resonance chord grating filtration,the similar numerical simulation of gas-liquid twop-hase flow in internal flow field,the performance parameters test of dust removal efficiency,and the manufacture and application of dust collector.The main contents and conclusions are as follows:(1)Based on the theory of spray Dust-fall and chord filtration and dust removal,the effects of single droplet and dust on collision,interception and diffusion are analyzed,and the empirical formula of the total dust reduction efficiency of each mechanism is obtained.By using the law of mass conservation,the formula of dust catching efficiency is obtained through analyzing the effect of droplet group and dust.The breakage,formation conditions and mechanical equation of the water membrane during the filtration process were deduced,and the formula for calculating the effective water membrane area of the chord grid filter cross section was deduced.(2)The physical model for numerical calculation of chord-grate filtration is established by Solidworks threedimensional modeling software,and the internal flow field of gas-liquid two-phase flow in chord-grate filtration is calculated by Fluent software;the Realizable k-?turbulence equation is selected for continuous phase(gas phase),and the DPM model for liquid phase(droplet)is selected to calculate and track the trajectory of gas-liquid two-phase flow in chord-grate filtration.On the premise of analyzing the filtration efficiency of single-row chord-grate,two-row chord-grate filtration models are selected to study systematically.The velocity and pressure distribution of gas phase in resonance chord-grate filtration,droplet distribution and filtration efficiency of internal flow field in chord-grate filtration under various calculation conditions are obtained.(3)Based on the grid filter dust removal experimental platform,the experiments of dedusting performance of resonant chordal grid under different nozzle diameters,different filter speeds and different spray pressures were carried out.The results showed that the dust removal resistance increased with the increase of filtration wind speed,and had little relationship with the water supply pressure.When the water pressure remains unchanged,the dust removal efficiency increases with the increase of the wind speed when the wind speed is between 1 and 2 m/s;when the wind speed is greater than 2 m/s,the dust removal efficiency increases only slightly with the increase of the filter wind speed.When the filtration speed is kept constant,the efficiency of dust removal increases first and then decreases with the increase of spray pressure.That is to say,the peak value of dust removal efficiency exists under the condition of optimal water pressure,and the corresponding water supply pressure of the optimal dust removal efficiency varies with the filtration speed of each nozzle.except(4)Based on the dust removal test results,a wet resonant chord-grid filter is designed and applied in the dust removal system reform project of the underground crushing chamber of Fankou LeadZinc Mine.After two dust collectors have been running for a period of time,dust sampling and analysis are carried out.The application results show that the dust removal effect of multistage wet resonance chord filter is good.The total dust concentration of No.1dust collector decreases by 9.3 mg/m~3,and that of respirable dust decreases from 2.5 mg/m~3 to0.17 mg/m~3.The total dust concentration of No.2 dust collector decreases by 8.23 mg/m~3,and the respirable dust is concentrated.It decreased from 2.7 mg/m~3 to 0.13mg/m~3.After modification,the dust concentration in the crushing chamber not only meets the standard requirements of the workplace,but also meets the requirements of the air quality of the underground air flow after dust removal and purification.