The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Chenghang Zheng - One of the best experts on this subject based on the ideXlab platform.
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predicting Particle Collection performance of a wet electrostatic precipitator under varied conditions with artificial neural networks
Powder Technology, 2021Co-Authors: Chenghang Zheng, Zhengda Yang, Yuxiang Cai, Ye Jiang, Riyi Lin, Deshan Sun, Xiang GaoAbstract:Abstract The prediction of Particle Collection is important in designing and operating an electrostatic precipitator (ESP). In this work, a three–layer artificial neural network (ANN) was developed to predict the wet ESP performance under various conditions. The mean square error (MSE), standard deviation error (SDE), and variance account for (VAF) were used to evaluate the ANN model. The univariate analysis method was used to determine the contribution weight of each parameter. The MSE, SDE, and VAF for the trained ANN model were 0.0027%, 0.0362%, and 97.95%, respectively. The current decrease with operation time accounted for the inaccurate evaluation of wet ESP performance. The operating voltage, corona current, gas temperature, and residence time contributed 61.53%, 36.65%, 1.26%, and 0.56% to Particle Collection respectively. Furthermore, current and voltage dominated the Particle Collection in different regions. The research findings provide a valuable research approach to retrofit the design and operation of wet ESPs.
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correlations between Particle Collection behaviors and electrohydrodynamics flow characteristics in electrostatic precipitators
Aerosol and Air Quality Research, 2020Co-Authors: Chenghang Zheng, Zhengda Yang, Ye Jiang, Riyi Lin, Deshan Sun, Yang Yang, Xiang GaoAbstract:ABSTRACT Electrostatic precipitators (ESPs) are widely used to eliminate particulate matter emissions from industrial sources. However, the complex electrohydrodynamics (EHD) flow in ESPs can cause controversial conclusions on Particle Collection. This paper established an ESP model with an additional source term added to the equation of gas momentum conservation. Correlations between Particle motion behaviors and EHD flow characteristics were investigated regarding various discharge voltage, Particle size, and electrode position. Results show that the EHD flow presented a back-and-forth distribution between the electrode and plate. The peak value of vy can be as high as 0.15 m s–1. The EHD flow can cause four possible types of Particle motion status. The dominant factor for Particle motion switched between the electric force and drag force along with the Particle motion trajectory. There existed an escaping window at the ESP inlet. Particles released from this window penetrated through the ESP rather than be collected. Modifying the ESP geometry and increasing voltage can narrow the escaping window. When the ESP channel width was narrowed from 0.06 to 0.05 m, the maximum NEHD could increase by 73.4% from 0.94 to 1.63. Consequently, the Collection efficiency was significantly improved. The Collection efficiency can even amount to 100% for Particles sized 2.5 μm.
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balance and stability between Particle Collection and re entrainment inawide temperature range electrostatic precipitator
Powder Technology, 2018Co-Authors: Chenghang Zheng, Zhiyang Shen, Zhengda Yang, Chengsi Liang, Shaojun Liu, Yishan Guo, Yongxin Zhang, Xiang GaoAbstract:Abstract In an electrostatic precipitator, Particles migrate to the collecting plates through electrostatic force. Simultaneously, the effect of gravity and hydrodynamic drag force will cause these Particles to vacate the plates. Emission concentration and removal efficiency gradually stabilize after the Particles pass through multiple electric fields, and this stability value determines the high limit of electrostatic precipitation capacity. In this study, the balance between Particle electrostatic trapping and air re-entrainment was investigated through a closed-loop electrostatic precipitator system, and the behavior of the Particles deposited into the collecting plates was qualitatively analyzed. The Particle emission concentration was reduced significantly when residence time was within 40 s. The Particle concentration reached its limit and remained relatively stable after remaining stable for 100 s in the electric field. The applied voltage, velocity of flow, and temperature are the influencing factors considered in this study, here it was found that the decreased flow velocity, temperature and rising voltage were benefiting to Particles removal efficiency. The ultimate emission concentration gradually decreased from 13.14 mg/m3 to 7.19 mg/m3 while the velocity of the flow decreased from 0.376 m/s to 0.240 m/s at the temperature of 700 K. The ultimate emission concentration gradually increased from 6.24 mg/m3 to 1.79 mg/m3 while the temperature decreased from 800 K to 400 K when the flue gas velocity was 0.376 m/s, and the applied voltage was at its maximum which can be used at the corresponding temperature. The ultimate emission concentration gradually decreased from 19.5 mg/m3 to 6.0 mg/m3 when the flue gas temperature was 400 K, and the velocity of the flow was 0.376 m/s, with the increase in voltage from 14.9 kV to 32.5 kV. In addition, Particles of different size segments and specific resistances exhibited various characteristics in this study because the electrostatic and van der Waals forces were significantly affected by the Particle size.
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Particle removal enhancement in a high temperature electrostatic precipitator for glass furnace
Powder Technology, 2017Co-Authors: Chenghang Zheng, Zhiyang Shen, Qianyun Chang, Mingjiang NiAbstract:Abstract The flue gas generated from glass furnaces contains Particles with high concentrations of alkali metals and hazardous heavy metals, which could reduce the lifespan of selective catalytic reduction (SCR) catalysts and lead to catalyst deactivation. Removing the Particles before SCR could improve system operation reliability and reduce nitric oxides (NOx) emission. In this paper, the characteristics of fly ash from glass furnaces and the Particle removal properties in the electrostatic precipitator (ESP) from 363 K to 623 K were studied. The Particle Collection efficiency was found to decrease with increasing temperature. A method of enhancing Particle removal was proposed and tested through Particle conditioning in a lab-scale experiment. In order to change the characteristics of the fly ash, calcium carbonate powders were used as conditioning Particles and the Particle Collection efficiency increased from 65.8% to 87.6% at 623 K. This method was further applied in an industrial high-temperature ESP for a glass furnace. When the ratio in mass between the Particles from the glass furnace and from the conditioning proportion was 1:1.5, the Particle Collection efficiency of the ESP was improved significantly and the outlet Particle concentrations decreased from 103.23 mg/Nm3 to 39.25 mg/Nm3.
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effect of electrode configuration on Particle Collection in a high temperature electrostatic precipitator
Separation and Purification Technology, 2016Co-Authors: Xi Xu, Chenghang Zheng, Yi Wang, Mingjiang NiAbstract:Abstract This study investigated the influence of electrode configuration on corona discharge and Particle Collection from 300 K to 900 K. Electrodes of different shapes (rod, saw, and screw), diameters (3, 5, and 8 mm), and intervals (55, 110, and 165 mm) were tested in an experimental-scale electrostatic precipitator (ESP). Results showed that a high current was generated with a saw electrode and increased the Particle Collection efficiency, particularly for fine Particles (diameter smaller than 0.1 μm), with the best Particle Collection efficiency being 99.8% at 300 K. However, with an increase in temperature, the rod electrode obtained an applied voltage higher than those of other electrode types and, as a result, generated relatively high Particle Collection efficiencies at 700 K and 900 K. Increasing the electrode diameter from 3 mm to 5 mm improved the applied voltage, whereas increasing this diameter from 5 mm to 8 mm reduced the discharge current. Among electrodes with different diameters, the electrode with a diameter of 5 mm achieved the best Particle Collection efficiency (87.4%) at 900 K. The applied voltages of the electrodes with different intervals were almost similar, but the discharge currents varied significantly. The best Particle Collection efficiencies were achieved by the electrode with an interval of 55 mm at 300 K and 500 K, but at 700 K and 900 K, the electrode with an interval of 110 mm obtained the best result. The interval between electrodes should be expanded with an increase in temperature to avoid the offsetting of electric field between neighboring electrodes.
Jerzy Mizeraczyk - One of the best experts on this subject based on the ideXlab platform.
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recent progress in experimental studies of electro hydrodynamic flow in electrostatic precipitators
Journal of Physics: Conference Series, 2013Co-Authors: Jerzy Mizeraczyk, Janusz Podlinski, A. Niewulis, A BerendtAbstract:Many experimental, theoretical and numerical works were devoted to the electrohydrodynamic (EHD) flow generated in electrostatic precipitators (EPSs). The generally accepted conclusion from these studies is that the EHD flow plays an important role in the Particle Collection in ESPs. However, despite of the recent fast progress in numerical simulation and experimental techniques used in the ESPs studies many problems related to the influence of the EHD flow on the performance of ESPs are unsolved. In particular, the influence of the turbulent EHD on submicron Particles transport and deposition in ESPs is ambiguous. This problem and other related to the Particle Collection in ESPs are objectives of this paper, basing on the recent progress in experimental investigations of the EHD flow in ESPs.
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Electrohydrodynamic secondary flow and Particle Collection efficiency in spike-plate multi-electrode electrostatic precipitator
IEEE Transactions on Dielectrics and Electrical Insulation, 2013Co-Authors: Janusz Podlinski, A Berendt, Jerzy MizeraczykAbstract:In this work the results of electrohydrodynamic (EHD) secondary flow measurements in a spike-plate type electrostatic precipitator (ESP) are presented. In the investigated ESP two-sided and one-sided spike electrodes were used as a discharge electrodes. The results of 2D PIV measurements showed that flow pattern obtained for a different spike tips positions in respect to the primary flow direction significantly changing the flow structures in the ESP duct. The submicron dust Particles Collection measurements in this ESP were also performed. The obtained results showed that the Collection efficiency of submicron dust Particles depends on the generated EHD secondary flow.
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Electrohydrodynamic secondary flow and Particle Collection efficiency in a one-sided spike-plate type electrostatic precipitator
IEEE Transactions on Dielectrics and Electrical Insulation, 2011Co-Authors: Janusz Podlinski, A. Niewulis, V. Shapoval, Jerzy MizeraczykAbstract:In this work, results of electrohydrodynamic secondary flow and Particle Collection efficiency measurements in an electrostatic precipitator under positive and negative voltage polarity are presented. The electrostatic precipitator had two plate collecting electrodes and a single spike discharge electrode. The spike tips were only on one side of the discharge electrode, therefore called a one-sided spike electrode. The electrohydrodynamic secondary flow pattern and Collection efficiency measurements were carried out for two one-sided spike electrode positions: with the spike tips directed either upstream or downstream the primary flow. The results of the flow pattern measurement showed different flow patterns for different spike tips positions in respect to the primary flow direction. The electrostatic precipitator Collection efficiency measurements clearly showed difference in the Particle Collection for both spike tips positions. Since the other electrostatic precipitator working parameters were the same, it can be concluded that the observed change of the electrohydrodynamic secondary flow was the main reason of the difference in the electrostatic precipitator Collection efficiency.
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electrohydrodynamic flow and Particle Collection efficiency of a spike plate type electrostatic precipitator
Journal of Electrostatics, 2009Co-Authors: Janusz Podlinski, A. Niewulis, Jerzy MizeraczykAbstract:In this work, the results of electrohydrodynamic (EHD) secondary flow and Particle Collection efficiency measurements in a spike-plate type electrostatic precipitator (ESP) are presented. The EHD secondary flow was measured using 2- and 3-dimensional Particle image velocimetry (PIV) method under the negative DC voltage. The PIV measurements were carried out in several cross-sectional planes along and across the ESP duct. The results show a complex and turbulent flow structure in the ESP. The EHD secondary flow significantly depends on applied voltage and measuring cross-sectional plane position in respect to the spike tip. The partial Collection efficiency of the ESP was measured for negative and positive DC voltage. The Particle concentration with and without discharge was measured at the ESP exit using an optical aerosol spectrometer.
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electrohydrodynamic gas flow in a positive polarity wire plate electrostatic precipitator and the related dust Particle Collection efficiency
Journal of Electrostatics, 2006Co-Authors: Janusz Podlinski, Jerzy Mizeraczyk, D. Brocilo, J. Dekowski, Jenshih ChangAbstract:Abstract In this paper, the results of the Particle image velocimetry measurements of the flow velocity fields in an intermediate spacing wire-to-plate type electrostatic precipitator (ESP) with a single positive polarity wire electrode are presented. The observation plane was placed perpendicular to the wire electrode at its half-length. The investigation showed significant influence of the electric field and charge on the flow patterns in the intermediate spacing ESP under an extreme large electrohydrodynamic (EHD) number. The EHD forces cause the formation of strong vortex pairs in the upstream and downstream ESP regions for Ehd/ Re 2 >1.
Kunihiro Fukui - One of the best experts on this subject based on the ideXlab platform.
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effect of ring shape attached on upper outlet pipe on fine Particle classification of gas cyclone
Separation and Purification Technology, 2015Co-Authors: Yuki Wakizono, Kunihiro Fukui, Tsuyoshi Maeda, Hideto YoshidaAbstract:Abstract The effect on Particle Collection efficiency of a ring attached to the upper part of the outlet pipe of a gas cyclone was examined by experiment and CFD simulation. From a visualization experiment using fine bubble foam and CFD simulation, the rotational recirculation region is at maximum near the upper plate and the region decreases to the lower position. For the tapered shape ring of type Dc, the cyclone pressure drop is minimum, because the rotational recirculation region is almost eliminated by use of this special ring. The 50% cut size of the tapered shape ring of type Dc shows a minimum value and maximum Particle Collection efficiency is obtained. For the tapered shape ring, the optimum wall thickness ratio of the upper part to lower part is 1.47 and maximum Particle Collection efficiency and minimum pressure drop is simultaneously realized by use of the type Dc ring. The average downward fluid velocity in the upper part of the cyclone for the type Dc ring is greater than that of the case without the ring. Particles tend to go toward the downward direction easily and high Particle Collection efficiency is achieved for this special ring. The experimental partial separation efficiency qualitatively agreed with the simulation results.
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the effect of a new method of fluid flow control on submicron Particle classification in gas cyclones
Powder Technology, 2005Co-Authors: Hideto Yoshida, Kunihiro FukuiAbstract:Abstract The purpose of this paper is to study the effects of a secondary flow injection method on submicron Particle separation in a cyclone. It is found that Particle Collection efficiency increased with an increased secondary flow rate in the upper cylindrical section of the cyclone.In order to achieve a high Particle Collection efficiency, the location of the secondary flow injection should be close to the upper plate and a high injection velocity should be used.The use of a newly developed cyclone (type A) resulted in a high Particle Collection efficiency. Nearly all Particles are collected by the secondary injection fluid flow. Three-dimensional simulation results are qualitatively agreed with the experimental data.
Chuenjinn Tsai - One of the best experts on this subject based on the ideXlab platform.
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numerical modeling of nanoParticle Collection efficiency of single stage wire in plate electrostatic precipitators
Aerosol Science and Technology, 2010Co-Authors: Chuenjinn TsaiAbstract:The numerical models for predicting the Collection efficiency of Particles in the size range of 0.3 ∼ 10.0 μm in electrostatic precipitators (ESPs) have been well developed. However, for nanoParticles, or Particles with the diameter below 100 nm, the existing models can't predict the Collection efficiency very well because the electric field and ion concentration distribution were not simulated, or charging models were not adopted appropriately to calculate Particle charges. In this study, a 2-D numerical model was developed to predict the nanoParticle Collection efficiency in single-stage wire-in-plate ESPs. Laminar flow field was solved by using the Semi-Implicit Method for Pressure-Linked Equation (SIMPLER Method), while electric field strength and ion concentration distribution were solved based on Poisson and diffusion-convection equations, respectively. The charged Particle concentration distribution and the Particle Collection efficiency were then calculated based on the convection-diffusion equati...
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influence of impaction plate diameter and Particle density on the Collection efficiency of round nozzle inertial impactors
Aerosol Science and Technology, 2002Co-Authors: Cheng-hsiung Huang, Chuenjinn TsaiAbstract:This study has investigated the influence of impaction plate diameter ( Dc ) and Particle density on the Particle Collection efficiency of single round-nozzle inertial impactors numerically assuming incompressible flow. The study shows that computed i St 50 values range from 0.473 to 0.485, which are nearly independent of W/Dc ( W is the nozzle diameter) for the nozzle Reynolds number, Re > 1500, and when W/Dc 0.32, i St 50 will increase slightly. It increases from 0.483 to 0.507 (Re = 3000) or from 0.479 to 0.495 (Re = 1500) when W/Dc is increased from 0.32 to 0.48. When the nozzle Reynolds number is smaller than 1500, the influence of W/Dc on i St 50 is found to be much more pronounced. The effect of Particle density on the Collection efficiency has also been investigated. When Particle gravity is included, the res...
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Particle Collection efficiency of an inertial impactor with porous metal substrates
Journal of Aerosol Science, 2001Co-Authors: Cheng-hsiung Huang, Chuenjinn Tsai, Tung Sheng ShihAbstract:This study has investigated numerically the Particle Collection efficiency of an impactor with porous metal substrates. Two-dimensional flow field in the inertial impactor was simulated by solving the Navier–Stokes equations with the control volume method. Particle trajectories were then calculated to obtain the Collection efficiency at different Reynolds numbers, which are based on nozzle diameter, and at different K, which is the resistance factor of the porous metal substrate. This study shows that some air may penetrate into the porous metal substrate resulting in different Particle Collection efficiency than that predicted by the traditional theory. The Particle Collection efficiency for the impactor with the porous metal substrate is higher than that with the flat plate substrate below the cutpoint, and numerical results are in good agreement with the experimental data. The dimensionless parameter φ=(ρU0/2Kμt)(Dc/W)0.9 has been introduced to determine the excess Particle Collection efficiency, ηe, by the porous metal substrate in the limit of . The theory explains the experimental data of the excess Collection efficiency very well.
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solid Particle Collection characteristics on impaction surfaces of different designs
Aerosol Science and Technology, 1995Co-Authors: Chuenjinn Tsai, Yuhsiang ChengAbstract:The effect of solid Particle loading on the Collection efficiency of a single-stage impactor with different impaction surface designs has been investigated. Experimental results show that the time-varying Collection efficiency depends on the surface coating condition, thickness of Particle deposit, and impaction surface design. Deposited Particles change the surface condition such that the Particle Collection efficiency decreases with time for the coated impaction surface while it increases with time for the uncoated impaction surface. However, after heavy loading, the Collection efficiency eventually approaches nearly the same asymptotic value whether the impaction surface is coated or not. The impaction surface with an inverted conical cavity and an orifice plate alleviates Particle bounce and reentrainment problems during Particle Collection process, resulting in a much greater Collection efficiency than the conventional design, which uses flat impaction surface.
Xiang Gao - One of the best experts on this subject based on the ideXlab platform.
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predicting Particle Collection performance of a wet electrostatic precipitator under varied conditions with artificial neural networks
Powder Technology, 2021Co-Authors: Chenghang Zheng, Zhengda Yang, Yuxiang Cai, Ye Jiang, Riyi Lin, Deshan Sun, Xiang GaoAbstract:Abstract The prediction of Particle Collection is important in designing and operating an electrostatic precipitator (ESP). In this work, a three–layer artificial neural network (ANN) was developed to predict the wet ESP performance under various conditions. The mean square error (MSE), standard deviation error (SDE), and variance account for (VAF) were used to evaluate the ANN model. The univariate analysis method was used to determine the contribution weight of each parameter. The MSE, SDE, and VAF for the trained ANN model were 0.0027%, 0.0362%, and 97.95%, respectively. The current decrease with operation time accounted for the inaccurate evaluation of wet ESP performance. The operating voltage, corona current, gas temperature, and residence time contributed 61.53%, 36.65%, 1.26%, and 0.56% to Particle Collection respectively. Furthermore, current and voltage dominated the Particle Collection in different regions. The research findings provide a valuable research approach to retrofit the design and operation of wet ESPs.
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correlations between Particle Collection behaviors and electrohydrodynamics flow characteristics in electrostatic precipitators
Aerosol and Air Quality Research, 2020Co-Authors: Chenghang Zheng, Zhengda Yang, Ye Jiang, Riyi Lin, Deshan Sun, Yang Yang, Xiang GaoAbstract:ABSTRACT Electrostatic precipitators (ESPs) are widely used to eliminate particulate matter emissions from industrial sources. However, the complex electrohydrodynamics (EHD) flow in ESPs can cause controversial conclusions on Particle Collection. This paper established an ESP model with an additional source term added to the equation of gas momentum conservation. Correlations between Particle motion behaviors and EHD flow characteristics were investigated regarding various discharge voltage, Particle size, and electrode position. Results show that the EHD flow presented a back-and-forth distribution between the electrode and plate. The peak value of vy can be as high as 0.15 m s–1. The EHD flow can cause four possible types of Particle motion status. The dominant factor for Particle motion switched between the electric force and drag force along with the Particle motion trajectory. There existed an escaping window at the ESP inlet. Particles released from this window penetrated through the ESP rather than be collected. Modifying the ESP geometry and increasing voltage can narrow the escaping window. When the ESP channel width was narrowed from 0.06 to 0.05 m, the maximum NEHD could increase by 73.4% from 0.94 to 1.63. Consequently, the Collection efficiency was significantly improved. The Collection efficiency can even amount to 100% for Particles sized 2.5 μm.
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balance and stability between Particle Collection and re entrainment inawide temperature range electrostatic precipitator
Powder Technology, 2018Co-Authors: Chenghang Zheng, Zhiyang Shen, Zhengda Yang, Chengsi Liang, Shaojun Liu, Yishan Guo, Yongxin Zhang, Xiang GaoAbstract:Abstract In an electrostatic precipitator, Particles migrate to the collecting plates through electrostatic force. Simultaneously, the effect of gravity and hydrodynamic drag force will cause these Particles to vacate the plates. Emission concentration and removal efficiency gradually stabilize after the Particles pass through multiple electric fields, and this stability value determines the high limit of electrostatic precipitation capacity. In this study, the balance between Particle electrostatic trapping and air re-entrainment was investigated through a closed-loop electrostatic precipitator system, and the behavior of the Particles deposited into the collecting plates was qualitatively analyzed. The Particle emission concentration was reduced significantly when residence time was within 40 s. The Particle concentration reached its limit and remained relatively stable after remaining stable for 100 s in the electric field. The applied voltage, velocity of flow, and temperature are the influencing factors considered in this study, here it was found that the decreased flow velocity, temperature and rising voltage were benefiting to Particles removal efficiency. The ultimate emission concentration gradually decreased from 13.14 mg/m3 to 7.19 mg/m3 while the velocity of the flow decreased from 0.376 m/s to 0.240 m/s at the temperature of 700 K. The ultimate emission concentration gradually increased from 6.24 mg/m3 to 1.79 mg/m3 while the temperature decreased from 800 K to 400 K when the flue gas velocity was 0.376 m/s, and the applied voltage was at its maximum which can be used at the corresponding temperature. The ultimate emission concentration gradually decreased from 19.5 mg/m3 to 6.0 mg/m3 when the flue gas temperature was 400 K, and the velocity of the flow was 0.376 m/s, with the increase in voltage from 14.9 kV to 32.5 kV. In addition, Particles of different size segments and specific resistances exhibited various characteristics in this study because the electrostatic and van der Waals forces were significantly affected by the Particle size.