Experimental And Numerical Simulation Of Vortex Pneumatic Fog Screen For Dust Control

The fully mechanized face is one of the most important work place in the coal mine production.Due to the coditionality of roadheader cutting coal in single tunnel to make the dust concentration is usually highest underground,and the condition is the worst.In this thesis,a combination of theoretical analysis,simulation experiment and numerical simulation is adopted.A new type of dust control technology in fully mechanized face is studied from the macroscopic angle.By comparing the simulation experiment results with the numerical simulation results,the advantages and effectiveness of the vortex pneumatic screen dust control technology are confirmed.First of all,the thesis puts forward the shortcomings of traditional spraying dust control device which can not achieve the effective combination of dust separation and dust reduction.Therefore,the pneumatic vortex fog dust control technology has been proposed.The dust control technology achieves the second breakup of fog droplets on the basis of air curtain dust separation.In the limited working space,the dust control technology increases the probability of collision of dust coupling,effectively improves the dust collection efficiency of droplets.In addition,the various parts of the device are described in detail,meanwhile,the working principle and characteristics of the device are analyzed.Secondly,we developed a set of vortex aerodynamic fog curtain dust removal equipment,through the simulation platform,the experiment measured the optimum working parameters.When the water supply pressure is 8MP,the fan speed is 12m/s,the nozzle diameter is 0.3mm,nozzle angle is 75°,the spray coverage and dust reduction effect of equipment to achieve the optimal effect.Using CFD respectively analyzes the velocity field distribution of the fan and the particle crushing effect under the optimum operating parameters.The experimental data are consistent with the simulation results.Finally,through the simulation experiment,the first measurement of the rate of natural dust dust,traditional high-pressure spray and vortex aerodynamic fog dust.Through the above experiments we can draw the scroll pneumatic dust control technology of the average fog dust rate is 7.05 mg/(m3 · s),far more than the other two kinds of dust fall modes.Then through the comparative analysis of two kinds of dust control technology of dust removal efficiency,we can conclude that the vortex pneumatic fog curtain has greatly improved the effect of dust control compared with the traditional high-pressure spray dust control technology.The average dust reduction efficiency of full of dust and respirable dust respectively is 93.35%and 91.20%,and the effect is remarkable.The dust control device achieves the organic combination of dust separation and dust reduction.Scroll air curtain through vapor droplets combine to make droplets are broken more thoroughly,increasing the probability of dust particles and combined with water.Because the aerosol particles is small,so the inhibitory effect of respiratory dust has been further enhanced.Therefore,The fully mechanized face will effectively seal the fine dust.In addition,the device has the advantages of small size,low water consumption,wide spray coverage,simple structure,clear component,easy repair,etc.In order to further improve the working efficiency and improve the environment conditions of the fully mechanized face,it provides a strong support.