| In recent years,large-scale haze has frequently occurred in many areas of China.This not only causes inconvenience to people's travel,but also seriously threatens human health.The reason for this is the rapid development of the coal-based industry,which emits a large amount of fine particulates and causes air pollution.To this end,China's air pollution emission standards for boilers and thermal power plants have been revised several times,and ultra-low emissions have been promoted for coal-fired power plants.China's determination and efforts to control industrial dust emissions to control haze have continued to increase.Under this background,all thermal power companies launched a large-scale transformation campaign for ultra-low emission of flue gas from thermal power plants.Without changing the original dust removal system of industrial boilers,the introduction of high-efficiency,low-cost,small footprint,simple maintenance and operation of dust removal technology and industrial boilers original dust removal system work together to achieve industrial boiler dust emission standards.The super-gravity wet dust removal technology has organically coupled various dust removal mechanisms such as packing trapping,centrifugal trapping,and droplet capture,and solves the problems of high cost,high energy consumption,and low efficiency of current dust removal technologies.At present,traditional rotating packed beds cannot fully meet the strict criteria for ultra-low emissions.The CAS-RPB is a new equipment technology based on the enhanced membrane control mass transfer process.Its rotor is composed of mutually embedded packing rings.The adjacent packing rings can generate gas when they rotate in the reverse direction.The huge shearing action increases the degree of turbulence of the gas,and the body resistance elements constructed on the outer edge of the packing ring can promote the separation of the boundary layer of the gas,form a gas flow vortex,reduce the thickness of the boundary layer,and reduce the mass transfer resistance of the gas phase.Makes the bed more evenly distributed.Studies have shown that the increase of turbulent intensity in the gas phase has a significant role in the capture of fine particles.Based on this,this paper explores the dust removal performance of a gas-flow counter-rotating shear packed bed.In this paper,with reference to the dust concentration at the outlet of the industrial boiler water film dust collector,the fly ash from the second thermal power plant in Taiyuan was used to simulate low-concentration(200 mg/m~3)dust-containing gas,and the particle size distribution and average particle size of the simulated dust were measured;The air-flow counter-rotating shear packed bed is a dust removal device.The influences of rotation mode,super-gravity factor,gas velocity,and liquid-gas ratio on the dust removal efficiency were investigated,and the total dust removal efficiency and grading dust removal efficiency under appropriate operating conditions were determined.The dust concentration was changed to investigate the range of dust concentration suitable for CAS-RPB treatment;the gas pressure drop during the dust removal process of CAS-RPB was measured;and the influence of liquid properties on the dust removal effect of CAS-RPB was investigated.When CAS-RPB was used to remove low-concentration simulated dust-containing gas,the experimental results showed that the appropriate operating conditions were additive body resistance piece,the two rotating disks were reversed,the high-gravity factor was 101,the gas velocity was 1.33 m/s,and the liquid-gas ratio was 0.8 L/m~3.The total dust removal efficiency under this condition was as high as 98.47%,and the outlet concentration was only 3.06mg/m3.The classification efficiency curve of CAS-RPB shows that the cutting dc of CAS-RPB is 0.01?m.Under the suitable operating conditions,PM2.5 can be completely removed,and the removal rate of PM1.0 is as high as 92%.Through the research on the gas pressure drop of CAS-RPB in the process of dust removal,it is shown that the pressure drop of both CASC and RPB increases significantly with the increase of the high gravity factor and gas velocity,and the pressure drop of liquid to gas ratio The impact is relatively insignificant.When the wet bed is in reverse,the pressure drop across the two rotating discs is higher than that of the same revolution.The pressure drop below the appropriate operating conditions is about 500Pa,which is a low-energy dust removal device.The effect of changes in liquid surface tension on the removal efficiency of CAS-RPB was investigated by choosing sodium SDBS as an additive to change the liquid surface tension.The results showed that sodium SDBS was used at a concentration of 0.03%.After reducing the surface tension of the liquid,the total dust removal efficiency was increased to99.76%;the dust removal efficiency of the classification was also significantly improved,and the classification efficiency of PM1.0 reached 100%.By selecting glycerol as an additive to change the viscosity of the liquid,the effect of changes in liquid viscosity on the removal efficiency of the CAS-RPB was investigated.After increasing the viscosity of the liquid,the total dust removal efficiency of the two rotary disks showed a downward trend when they were both turned and reversed.The drop of the two turntables during the same rotation was very obvious.The total dust removal efficiency dropped from 95.63%to 78.87%,a decrease of 14.76%.When the two turntables were reversed,the total dust removal efficiency dropped from 98.47%to 93.3%,only a decrease of5.17%;The removal rate of PM2.5 was only 88.3%,and the removal rate of PM2.5 was still95.6%when the two rotary disks were reversed.In summary,applying CAS-RPB to the dust removal process has the characteristics of high dust removal efficiency,strong ability to remove fine particles,low energy consumption,etc.This study provides the basis for the selection of CAS-RPB parameters in dust removal applications for industrialization.Scale design,operation and operation provide basic data. |
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