利用粒子成像测速法(PIV)和电子低压冲击仪(ELPI),研究实验室规模的电除尘器(ESP)内电场强度、电晕放电功率和气流场等因素对PM10(粒径小于10 μm 的颗粒物)分级收尘效率.电除尘器为线-板式电极结构,其中板-板间距为200 mm,高电压电极为单根或双根.实验颗粒物采用艾灸烟作为示踪粒子,气体流量85 m3/h,颗粒物初始质量浓度33 mg/m3左右.实验结果表明,随着电场强度或电晕放电功率的增加,在高压电晕极线周围气流场从有规律的单个涡旋发展为相互作用的多个涡旋,优化电晕放电离子风分布是提高PM10收集效率和降低电耗的关键.从颗粒物个数浓度、外加电场或电晕放电功率看,可将电除尘器性能以电场强度为3 kV/cm 为界分为2 个区域.当电场强度低于3 kV/cm 时,分级除尘效率随着电场强度或电除尘指数的增加而增加.然而,当电场强度远大于3 kV/cm 时,收尘效率基本不变或降低.
This paper discusses PM10 (particle matter with a diameter less than 10 μm) grade collection efficiencies of a laboratory electrostatic precipitator (ESP) in terms of the electric field, corona discharge power, and gas flow patterns by means of the particle image velocimetry(PIV)and the electrical low pressure impactor (ELPI) technique. The wire-plate ESP has a plate-plate distance of 200 mm, together with a single or two high-voltage electrodes. Moxa-moxibustion smoke is used as the tracer for evaluation of the gas flow and particle grade collection efficiency. Experiments, performed in air with a total gas flow rate of 85 m3/h and initial particle mass concentration of around 33 mg/m3, show that with increasing the field strength or corona discharge power, the flow changes from regular vortexes around the corona wire to multi-vortexes inter-reacting each other. As a result, optimizing the distribution of corona discharge ion wind is the key to increase PM10 collection efficiencies and reduce the power consumption. In terms of the particle number concentration and the applied electric field or corona discharge power, two ESP performance regions can be distinguished: Below 3 kV/cm, the grade collection efficiency increases with the rise of field strength or ESP index; it tends to saturate or drop when the field becomes higher than 3 kV/cm.
[1] Ohyama R, Urashima K, Chang J S. Numerical modeling of wire-plateelectrostatic precipitator for control of submicron and ultra-fine particles[J]. Journal of Aerosol Science, 2000, 31: 162-163.
[2] Mizuno A. Electrostatic precipitation[J]. IEEE Transactions on Dielectricsand Electrical Insulation, 2000, 7(5): 615-624.
[3] Blanchard D, Dumitran L M, Atten P. Effect of electro-aero-dynamicallyinduced secondary flow on transport of fine particles in an electrostaticprecipitator[J]. Journal of Electrostatics, 2001, 59(51/52): 212-217.
[4] Mizeraczyk J, Kocik M, Podlinski J. Flow diagnostics using particle imagevelocimetry method[J]. Laser Technology VIII: Applications of Lasers,2007, 6598: 1-9.
[5] Mizeraczyk J, Kocik M, Dekowski J. Measurements of the velocity fieldof the flue gas flow in an electrostatic precipitator model using PIVmethod[J]. Journal of Electrostatics, 2001, 59(51/52): 272-277.
[6] Podlinski J, Dekowski J, Mizeraczyk J. Electrohydrodynamic gas flow ina positive polarity wire-plate electrostatic precipitator and the relateddust particle collection efficiency[J]. Journal of Electrostatics, 2006, 64(3/4): 259-262.
[7] Podlinski J, Niewulisa A, Mizeraczyk J. ESP performance for variousdust densities[J]. Journal of Electrostatics, 2008, 66(5/6): 246-253.
[8] Mizeraczyk J, Dekowski J, Podlihnski J. Laser flow visualization andvelocity fields by particle image velocimetry in an electrostaticprecipitator model[J]. Journal of Visualization, 2003, 6(2): 125-133.
[9] Podlinski J, Dekowski J, Kocik M, et al. Measurement of the flowvelocity field in multi-field wire-plate electrostatic precipitator[J].Czechoslovak Journal of Physics, 2004, 54(3): 922-930.
[10] Podlinski J, Dekowski J, Mizeraczyk J. EHD flow in a wide electrodespacing spike-plate electrostatic precipitator under positive polarity[J].Journal of Electrostatics, 2006, 64(7/9): 498-505.
[11] Podlinski J, Niewulis A, Mizeraczyk J. Electrohydrodynamic flow andparticlecollectionefficiencyofaspike-platetypeelectrostatic precipitator[J]. Journal of Electrostatics, 2009, 67(2/3): 99-104.
[12] Niewulis A, Berendt A, Podlinski J. Electrohydrodynamic flow patternsand collection efficiency in narrow wire- cylinder type electrostaticprecipitator[J]. Journal of Electrostatics, 2013, 71(4): 808-814.
[13] Niewulis A, Podlinski J, Kocik M. EHD flow measured by 3D PIV ina narrow electrostatic precipitator with longitudinal- to- flow wireelectrode and smooth or flocking grounded plane electrode[J]. Journalof Electrostatics, 2007, 65(12): 728-734.
[14] Niewulis A, Podlinski J, Mizeraczyk J. Electrohydrodynamic flow patternsin a narrow electrostatic precipitator with longitudinal or transversewire electrode[J]. Journal of Electrostatics, 2009, 67(2/3): 123-127.
[15] Podlinski J, Niewulis A, Mizeraczyk J. Electrohydrodynamic turbulentflow in a wide wire-plate electrostatic precipitator measured by 3DPIV method[C]//Proceeding of the 11th International Conference onElectrostatic Precipitation. Hangzhou: Zhejiang University Press,2008: 134-139.
[16] Podlinski J, Niewulis A, Mizeraczyk J. Electrohydrodynamic flow in awire-plate non-thermal plasma reactor measured by 3D PIV method[J]. The European Physical Journal D, 2009, 54(2): 153-158.
[17] Zouzou N, Dramane B, Moreau E. EHD flow and collection efficiencyof a DBD ESP in wire-to-plane and plane-to-plane configurations[J].IEEE Transaction on Industry Applications, 2011, 47(1): 336-343.
[18] Sattar S A. Influences of geometrical parameters upon electrostaticprecipitator efficiency[J]. The International Journal for Computationand Mathematics in Electrical and Electronic Engineering, 1991, 10(1): 27-43.
[19] Chang C L, Bai H. Effects of some geometric parameters on theelectrostatic precipitator efficiency at different operation indexes[J].Aerosol Science and Technology, 2000, 33(3): 228-238.
[20] Yang X, Kang Y, Zhong K. Effects of geometric parameters and electricindexes on the performance of laboratory- scale electrostaticprecipitators[J]. Journal of hazardous materials, 2009, 169(1): 941-947.
[21] Kim S H, Lee K W. Experimental study of electrostatic precipitatorperformance and comparison with existing theoretical predictionmodels[J]. Journal of Electrostatics, 1999, 48(1): 3-25.
[22] Glover W, Chan H K. Electrostatic charge characterization ofpharmaceutical aerosols using electrical low-pressure impaction (ELPI)[J]. Journal of Aerosol Science, 2004, 35(6): 755-764.
[23] Hsieh Y K, Chen L K, Hsieh H F, et al. Elemental analysis of airborneparticulate matter using an electrical low-pressure impactor and laserablation/inductively coupled plasma mass spectrometry[J]. Journal ofAnalytical Atomic Spectrometry, 2011, 26(7): 1502-1508.
[24] Zhu J B, Zhao Q X, Yao Y P, et al. Effects of high-voltage powersources on fine particle collection efficiency with an industrialelectrostatic precipitator[J]. Journal of Electrostatics, 2012, 70(3): 285-291.
