Experimental Study On Filtration Performance Of Filter Material For Bag Dust Collector

With the accelerating industrialization and urbanization process in China,the problem of environmental pollution has become increasingly prominent.Especially in recent years,many areas in China have experienced more serious haze,which has a great impact on people’s lives and health.The treatment of atmospheric pollutants,especially industrial particulate matter,is an urgent issue to be solved.Bag dust removal equipment is widely used in industrial dust removal because of its high dust removal efficiency,low cost and simple operation.Bag filter material is the core component of bag filter,and its filtration performance is related to the filtration efficiency and service life of the entire bag filter.Therefore,how to objectively evaluate the filtration performance of the filter material is a problem to be solved.Six kinds of filter materials commonly used in the market are selected as experimental objects in the paper.By designing static filtration performance experiments,dynamic filtration performance experiment and the experiment about relationship between the resistance of the filter material and the mass of particulate matter captured by the filter material to test the effect of wind speed on the filtration efficiency of different filter materials,the classification filtration efficiency and the dust filtration efficiency of different filter materials and the resistance increase of different filter materials in the filtration process.Obtaining a comprehensive evaluation of the filter material in the term of efficiency and resistance.The static filtration performance experiments result show:①the collection efficiency will decrease with the increment of filtration velocity especially for the particles whose diameters are 0.3μm;②the filtration efficiency of the membrane filter is much greater than non-membrane filter due to the film on its surface.③ As a whole,although the filtration efficiency of the glass fiber composite felt membraned filter material is low,the filtration efficiency of fine particles whose diameter is less than 0.5 μm is higher than that of the fiberglass cloth membraned filter and the aramid membraned filter material,for PPSPTFE blended(5/5)membraned filter,the filtration efficiency for each particle size is higher than other filter materials;The dynamic filtration performance experiment result show:①with the increasing of the number of blows,the residual pressure drop of filters increase and the time for each filtration period decrease,The residual resistance of the membraned filter material increases first and then increases slowly.The residual resistance of the non-coated filter material increases slowly and the increment is less than the membraned filter.During the stable filtration period,the injection cycle of the membraned filter material is reduced first and then decreased slowly.The injection cycle of the non-coated filter material floats between certain values without obvious increase or decrease.The residual resistance of the membraned filter material is higher than the residual resistance of the non-coated filter material,but the injection cycle is smaller than the injection cycle of the non-coated filter material.② The PM2.5 emissions of both the membraned filter and the non-film filter are relatively low,but the concentration of PM2.5 downstream of the non-coated filter material will increase significantly after the injection,while the concentration of PM2.5 downstream of the membraned filter did not change significantly.③in the term of the collection efficiency for the whole particles,the collection efficiency of membraned filter and the non-coated filter can reach 99.9%,the efficiency of membraned filter is slightly higher than that of non-coat filter.The result of experiment about relationship between the resistance of the filter material and the mass of particulate matter captured by the filter material show:① During the aging process,more dust particles enter the interior of the non-coated filter material,the mass of the particles inside the membraned filter are less,After 9000 injections,the mass of the particles entering the non-coated filter material is greater than 2g,The particles inside the membraned filter material are less than 0.9g.② The resistance increase of the membrane filter material is much larger than the resistance increase of the non-coated filter material,and the resistance growth rate of the membrane filter material is fast and slow,and the resistance of the non-coated filter material grows slowly.③the resistance change curve with weight gain of two non-coated filter almost coincide,the resistance increase of the non-coated filter material has little relationship with the characteristics of the filter material itself.The curves of the four membraned filter materials are greatly different due to the difference in the porosity of the filter material and the surface film.The resistance of aramid-coated filter media grows slowly,which is close to the trend of non-coated filter media.It indirectly indicates that the service life of aramid-coated filter media is higher than that of the other three film-coated filter media.