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驻极体材料在持续使用过程中过滤性能会发生变化,为研究其机理,对驻极体材料在不同加载条件下的过滤性能进行了测试。采用熔喷和电晕驻极方法制备了驻极体聚丙烯熔喷非织造材料,通过TSI8130过滤效率检测仪测试了加载时间、材料自身性能和气溶胶流速对加载过滤效率和过滤阻力的影响,通过SEM对加载不同时间的熔喷材料表面形貌进行了表征,并对加载过滤机理进行了分析。结果表明:随着加载时间延长,驻极体熔喷材料过滤效率在开始阶段逐渐下降并在第8 min时达到最低值98.04%,随后过滤效率呈上升趋势并在第29 min时趋于稳定,此过程中过滤阻力逐渐增大。其机理主要是加载过滤开始阶段以静电吸引作用为主,驻极体材料上的电荷被捕获颗粒中和导致静电吸引作用减弱,因此过滤效率下降;随着捕获颗粒增多,机械过滤作用增强使过滤效率逐渐上升;此外,材料自身性能和气溶胶流速等也会影响加载过滤性能。
Abstract：The filtration performances of electret materials will change during the continuous use. In order to investigate the mechanism, the filtration performances of electret materials are tested under various loading conditions. The polypropylene melt blown nonwovens of electret materials are prepared by the melt blown and corona charging technologies, and the influences of loading time, material characteristics and aerosol flow rate on the loading filtration efficiency and pressure drop are tested by the TSI8130. The SEM method is used to evaluate the surface morphology of the electret melt blown nonwovens after loading different time, and the filtration mechanism is further analyzed. The results reveal that the efficiency of electret melt-blown nonwoven initially presents a decreasing trend, and reaches the lowest value of 98.04% after 8 minutes, followed by an increase and reaches a constant value after loading 29 minutes.Meanwhile, the pressure drop increases gradually. The main reason for this is the electrostatic attraction plays an important role at the initial stage, and the charges on the electret material are neutralized by the captured particles, which results in the filtration efficiency decrease. As more and more particles are accumulated, the mechanical filtration is enhanced and it results in the filtration efficiency increase. In addition, the material characteristics and aerosol flow rate will also affect the loading filtration performances.
[1]索丹凤，曾三武.空气细颗粒物PM2.5对人体各系统危害的研究[J].医学信息.2019,32(18):32-34.
[2]LIU C,HSU P,LEE H,et al.Transparent air filter for high-efficiency PM2.5capture[J].Nature Communications,2015,6(1):6205.
[3]CHANG D Q,TIEN C Y,PENG C Y,et al.Development of composite filters with high efficiency,low pressure drop,and high holding capacity PM2.5filtration[J].Separation and Purification Technology,2019,212:699-708.
[4]王添颢，王雪，朱廷钰，等.细颗粒物过滤过程中沉积与捕集机理的研究进展[J].环境工程，2016,34(Sup1):507-511.
[5]TIAN X J,OU Q S,LIU J X,et al.Influence of pre-stage filter selection and face velocity on the loading characteristics of a two-stage filtration system[J].Separation and Purification Technology,2019,224:227-236.
[6]JOUBERT A,LABORDE J C,BOUILLOUX L,et al.Modelling the pressure drop across HEPA filters during cake filtration in the presence of humidity[J].Chemical Engineering Journal,2011,166(2):616-623.
[7]RENGASAMY S,MILLER A,VO E,et al.Filter performance degradation of electrostatic N95 and P100 filtering facepiece respirators by dioctyl phthalate aerosol loading[J].Journal of Engineered Fibers and Fabrics,2013,8 (3):155892501300800.
[8]WALSH D C,STENHOUSE J I T.The effect of particle size,charge,and composition on the loading characteristics of an electrically active fibrous filter material[J].Journal of Aerosol Science,1997,28(2):307-321.
[9]WANG Q,LIN X L,CHEN D R.Effect of dust loading rate on the loading characteristics of high efficiency filter media[J].Powder Technology,2016,287:20-28.
[10]李丽，王娇娜，李从举.静电纺PA6/PET复合膜的制备及其空气过滤性能[J].环境化学，2012,31(10):1575-1579.
[11]CHEUNG C S,CAO Y H,YAN Z D.Numerical Model for particle deposition and loading in electret filter with rectangular split-type fibers[J].Computational Mechanics,2005,35(6):449-458.
[12]QIAN F P,HUANG N J,LU J L,et al.CFD-DEM simulation of the filtration performance for fibrous media based on the mimic structure[J].Com puters&Chemical Engineering,2014,71:478-488.
[13]BARRETT L W,ROUSSEAU A D.Aerosol loading performance of electret filter media[J].American Industrial Hygiene Association Journal,1998,59(8):532-539.
[14]ELME T D,TRICOLI A,GRUNWALDT J,et al.Filtration of nanoparticles:evolution of cake structure and pressure-drop[J].Journal of Aerosol Science,2009,40(11):965-981.
[15]KASPER G,SCHOLLMEIER S,MEYER J.Structure and density of deposits formed on filter fibers by inertial particle deposition and bounce[J].Journal of Aerosol Science,2010,41(12):1167-1182.
[16]YANG Y J,ZHANG S C,ZHAO X L,et al.Sandwich structured polyamide-6/polyacrylonitrile nanonets/beadon-string composite membrane for effective air filtration[J].Separation and Purification Technology,2015,152:14-22.
[17]SALEEM M,KRAMMER G.Effect of filtration velocity and dust concentration on cake formation and filter operation in a pilot scale jet pulsed bag filter[J].Journal of Hazardous Materials,2007,144(3):677-681.
[18]陶然，李水清，杨萌萌.细颗粒在滤料中沉积和穿透特性的机理研究[J].工程热物理学报，2015,36(8):1721-1724.
[19]ZHANG S C,TANG N,CAO L T,et al.Highly integrated polysulfone/polyacrylonitrile/polyamide-6 air filter for multilevel physical sieving airborne particles[J].ACS Applied Materials&Interfaces,2016,8(42):29062-29072.
基本信息:
DOI：10.12194/j.ntu.20191018003
中图分类号:TS176
引用信息:
[1]张海峰,梁小鹏,张星,等.驻极体聚丙烯熔喷非织造材料加载过滤性能研究[J],2020,19(03):61-67.DOI:10.12194/j.ntu.20191018003.
基金信息:
南通市科技计划项目（MS12018005）