Research On Respirable Dust Separation Technology And Separator Based On Virtual Shock Principle

In recent years,the number of occupational diseases in China has remained in 20,000 to 30,000 cases,of which more than 20,000 cases of pneumoconiosis have accounted for more than 84%.The main cause of pneumoconiosis is respiratory dust,which reaches the deep part of the human respiratory tract and the alveolar area.The industries with the most serious pneumoconiosis are coal mining and washing industry,and non-ferrous metal mining and dressing.Strengthening continuous online monitoring of the concentration of respirable dust emissions from coal mines is the key to preventing pneumoconiosis,separators for the separation of respiratory dust must be able to achieve continuous separation and meet the "Determination of Sampling Efficiency of Respirable Dust Meters"(MT394-1995),Existing respiratory dust separators are difficult to achieve continuous separation of respiratory dust.Therefore,the research on continuous separation technology of respiratory dust and separator is of great significance for the prevention of dust occupational hazards,and provides technical support for enterprises and regulatory authorities to control the effects of dust damage.This paper analyzes the principles of traditional inertial impact separation technology,ceramic separation technology,cyclone separation technology and virtual impact separation technology,the status quo at home and abroad and the problems of corresponding separator under continuous separation conditions,combined with the reality of continuous separation of respiratory dust.The preliminary design of the virtual impactor was completed by referring to the traditional inertial separation technology theory.The original structure size was corrected by numerical simulation results,so that the separation efficiency satisfies MT394-1995.According to this,the physical sample is processed,the experimental system is set up,and the separation performance test is carried out.Through research,the following conclusions are drawn:(1)The virtual impactor can achieve continuous separation of respiratory dust.(2)Through numerical simulation,the velocity,dynamic pressure,static pressure,turbulent kinetic energy and turbulent energy dissipation rate of the gas field of the virtual impactor are distributed in the radial direction.The separation efficiency of the particle size of 2.2?m is 85.98% and the particle size is 3.9.The separation efficiency of ?m is 70.88%,the separation efficiency of particle size 5?m is 47.25%,the separation efficiency of particle size 5.9?m is 25.31%,the separation efficiency of particle size 7.1?m is 4.73%,and the separation efficiency error of 5 particle sizes is less than 5%.(3)The virtual impactor samples were produced according to the numerical simulation of the structural dimensions.The separation performance of the virtual impactor was tested by aerosol test.The separation efficiency of the particle size of 2.2 ?m was 93.85%,and the separation efficiency of the particle size of 3.9 ?m was 69.21%.The separation efficiency of 5 ?m is 47.34%,the separation efficiency of particle size 5.9 ?m is 31.27%,the separation efficiency of particle size 7.1 ?m is 3.12%,and the separation efficiency error of 5 particle sizes is less than 5%.