Electrostatic Precipitator Performance Research Articles

Application End Evaluation of Electrostatic Precipitation for Control PM and NOx Emissions from Small-Scale Combustions

Electrostatic precipitators (ESPs) have shown promise in reducing particulate matter (PM) emissions, but their potential for simultaneous NOx reduction in small-scale combustion systems remains underexplored. This study focuses on using non-thermal plasma generated in a corona discharge to reduce PM and NOx emissions from small-scale combustion. ESP was specifically designed for a commercially available 15 kW boiler with wood pellet combustion and used with both positive and negative discharge polarity to control emissions without any chemical additives. ESP performance was evaluated across a range of specific input energies (SIE) in terms of particle mass and number concentrations and NOx concentrations obtained by continuous gas analysis. ESP ensured the reduction in PM concentrations from 48 mg/m3 to the magnitude of PM content in the ambient air. The highest precipitation efficiency was observed for particles in the 20–200 nm range. Concurrently, NOx emissions were reduced by up to 78%, from 178 mg/m3 to 39 mg/m3. These results were achieved at specific input energies of 36 for positive and 48 J/L for negative corona, which is significantly lower than those reported for many existing separate PM and NOx control systems. This study demonstrates the potential of ESPs as a compact, energy-efficient solution for simultaneous PM and NOx removal in small-scale combustion systems, offering promising implications for improving air pollution control technologies for small-scale combustion systems.

Influences of voltage allocation and magnetic field introduced position on the dust removal performance of multi-electric field ESP

Improving the removal efficiency of PM2.5 particles is significant for the limitation of particle emissions from coal-fired power plants. This work reports a multiple electric field electrostatic precipitator (ESP) enhanced by magnetic confinement effect to efficiently remove PM2.5 particle from flue gas. Firstly, the electromagnetic dust removal mechanism of PM2.5 capture in multi-electric field ESPs is revealed, and the theoretical and numerical models of the multifield coupling under the effect of magnetic field are established. Secondly, the potential distribution law under different working voltages and the dust removal performance for PM2.5 are analyzed, and the magnetic field effect under the optimal voltage allocation is numerically simulated. Finally, the best magnetic field introduction position under the optimal voltage allocation is investigated. The numerical results show that the optimal voltage allocation and the best magnetic field position are determined to achieve the full effect of magnetic field to improve the PM2.5 dust removal efficiency in the multi-electric field ESP under the premise of ensuring the decrease of voltage load. The relevant results can provide ideas and references for greatly reducing PM2.5 emissions and voltage power consumption in thermal power plants.

Enhanced high-temperature particle capture through an electrostatic precipitator with assistant electrodes

High-temperature electrostatic precipitators (ESPs) are a potentially effective technology for purifying high-temperature gases. In this study, a comprehensive numerical model was developed to investigate the electric field and particle migration characteristics of an ESP at temperatures ranging from 400 to 600 °C. Moreover, an optimized ESP with assistant electrodes for improved high-temperature particle capture was proposed. The electric field, flow field and particle capture characteristics of the two types of ESPs were compared to demonstrate the superiority of the optimized ESP. Results indicated that high temperatures had a negative impact on ESP performance. As the temperature increased, the operating voltage of the ESP decreased, leading to decreases in both the electric field strength and space charge density. The effective migration velocity of the particles also decreased with increasing temperature, and the inhibitory effect of high temperature on particle capture increased with increasing particle size. The optimized ESP with assistant electrodes exhibited more favorable electric field and flow field characteristics for particle capture compared to those of the conventional ESP. The optimized ESP exhibited higher electric field strength, which increased the electric field force on the particles and promoted particle capture. Meanwhile, the space charge density of the optimized ESP was lower, effectively inhibiting the occurrence of back corona. Moreover, the optimized ESP enhanced the ionic wind downstream of the discharge electrode, thereby promoting particle migration towards the collection electrode. Consequently, the ESP with assistant electrodes effectively improved the collection efficiency.

Analysis of electrostatic precipitators plate-wire type in reducing dust emissions for sustainable environment

The current global environmental trend is that the world has agreed to go towards net zero emissions. Consequently, waste-producing-industries must comply with these provisions to achieve the mission of sustainable development and green production, including cement industry. This study aims to investigate the factors that affect the performance of the Electrostatic Precipitator (EP) as a dust collector in grinding cement raw materials. The method used was measuring the static-dynamic pressure at the poking hole closest to the EP inlet, measuring EP efficiency using the Matts-Ohnfeldt equation based on secondary data obtained from the Crane Information Management System (CIMS), and calculating the corona power to determine how strong the ion space is created between the discharge electrode and collecting electrode and determine the critical voltage and application voltage needed to generate the corona. The observations and calculations show that several factors can affect EP performance, such as inlet temperature gas discharge, concentration of dust from the chimney, and maximum concentration of chimney outlet. The maximum temperature gas discharge that EP can accept is 105°C. The maximum concentration of chimney outlet dust is 50 mg/Nm3 and maximum CO concentration is 2000 mg/m3.

Numerical study of the influence of using crenelated collecting plates on the electrostatic precipitators

Electrostatic precipitators (ESPs) are extensively used in industry to remove undesirable particles from flue gases using corona discharge. The particle collection efficiency of the ESPs is greatly affected by the optimization of collecting plates and corona electrode configurations. Different researchers are working to improve standard models in various ways to obtain a better performance of ESPs. This paper investigates the influence of using crenelated plates (CrPs) with five designs of collecting electrodes by changing the geometries of the crenelated part (the amplitude and the wavelength) and comparing them with flat plates (FPs) on the electrical proprieties of a single-stage ESP. The particle collection efficiency of the ESP and the dust particles’ transport behavior were enhanced using the crenelated collecting plates (CrPs), especially when using case E, which provides the highest collection efficiency for all particle sizes (0.01-5) μm. For instance, the particle collection efficiency of the CrP E type is 76%, which is 8% higher than the CrP D type for particles of about 0.1 μm. At the same time, 88% for CrP E with 0.05μm, which is 10% greater than the CrP D type. In addition, the influence of changing the amplitude (A) has more significant than changing wavelength (λ) on the particle collection efficiency and the dust particles’ transport behavior.

Performance evaluation of an electrostatic precipitator with a copper plate using an aerosolized SARS-CoV-2 surrogate (bacteriophage phi 6)

The global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has reminded us of the importance of developing technologies to reduce and control bioaerosols in built environments. For bioaerosol control, the interaction between researchers and biomaterials is essential, and considering the characteristics of target pathogens is strongly required. Herein, we used enveloped viral aerosols, bacteriophage phi 6, for evaluating the performance of an electrostatic precipitator (ESP) with a copper-collecting plate (Cu-plate). In particular, bacteriophage phi 6 is an accessible enveloped virus that can be operated in biosafety level (BSL)-1 as a promising surrogate for SARS-CoV-2 with structural and morphological similarities. ESP with Cu-plate showed >91% of particle removal efficiency for viral aerosols at 77 cm/s of airflow face velocity. Moreover, the Cu-plate presented a potent antiviral performance of 5.4-relative log reduction within <15 min of contact. We believe that the evaluation of ESP performance using an aerosolized enveloped virus and plaque assay is invaluable. Our results provide essential information for the development of bioaerosol control technologies that will lead the post-corona era.

Specifics of Electrostatic Precipitation of Fly Ash from Small-Scale Fossil Fuel Combustion

This paper investigates the removal efficiency of a honeycomb electrostatic precipitator (ESP) applied to control particulate matter (PM) emissions from a small-scale boiler with combustion lignite and hard coal. The specifics of the precipitation of emissions from small-scale boilers are discussed, and the design principles for relevant ESPs are presented and used. The ion-induced nucleation of sulfuric acid occurred, causing the drastic penetration of 19 nm particles through the ESP. Despite this, the overall collection efficiency was sufficient to meet the EU’s Ecodesign Directive requirements. Back corona was not detected. The optimal ESP performance is defined with further parameters: a current density of 0.5 mA/m2 at an electric field strength of about 2.7 × 105 V/m; a minimal specific collecting area of ESP (SCA) of 60 m2/(m3/s); and Nt-product of 4.5 × 1014 s/m3. Such parameters of ESPs should ensure adequate PM emissions control for any type of boiler with similar emissions characteristics. The composition of collected fly ash particles was analysed, and a method for fly ash utilisation was proposed. This research may be helpful for designing ESPs to control PM emissions for small-scale units with fossil fuel combustion.

Numerical study of the effect of temperature and H2O concentration on the electrostatic precipitator characteristics at high temperatures

In this study, a numerical model of an electrostatic precipitator (ESP) suitable for high-temperature flue gas was established using COMSOL Multiphysics, and the effects of temperature and H 2 O concentration on the high-temperature ESP performance were studied. The results showed that, at the same voltage, increasing the temperature increased the negative ion density, thereby improving the particle charge and collection efficiency. However, increasing the temperature led to a decrease in the maximum operating voltage of the ESP, which reduced the negative ion density and electric field intensity at the maximum operating voltage and weakened the diffusion and field charges of the particles, leading to a further decrease in the maximum collection efficiency. Increasing the H 2 O concentration in the flue gas increased the negative ion density and, thus, enhanced the diffusion charge of the particles, which helped improve the collection efficiency. • A modified ESP model suitable for high temperature gas was established. • The plasma model was used to simulate corona discharges in the ESP. • The effect of temperature on ESP performance was studied numerically. • The effect of H 2 O concentration in flue gas on ESP performance was studied.

Effect of the Surface Treatment Process of Filter Bags on the Performance of Hybrid Electrostatic Precipitators and Bag Filters

Hybrid electrostatic precipitators consisting of electrostatic precipitation (ESP) and a bag filter are potential devices for ultralow emissions. The ESP captures and charges the particles; subsequently, the charged particles that escape enter the bag filter. The charged particles can cause the electric field of the filter bag to develop, thereby enhancing the filtration efficiency due to the force of the electric field. Experiments based on the coupling-reinforced electrostatic–fabric integrated precipitator system were conducted to investigate the outlet total dust concentration, dust removal efficiency, pressure drop, energy consumption of bag filter, and hybrid electrostatic precipitators with various filter bags. The measured results demonstrate that the removal performance of filter bags with smaller fiber diameters was superior. However, the pressure drop and energy consumption were high due to the increased filtration resistance. Compared to bag filters, hybrid electrostatic precipitators had lower total and grade dust mass concentrations at the outlet, higher total and grade dust removal efficiencies, a minor average pressure drop variation per minute, and lower total energy consumption. Consequently, the quality factor was utilized to comprehensively evaluate the overall performance of dust collectors. The hybrid electrostatic precipitators had a significant greater quality factor; their overall performance was superior to that of bag filters. Overall, a smaller filter bag’s fiber diameter resulted in more effective dust removal capabilities. Hybrid electrostatic precipitators with various filter bags were significantly better than bag filters in terms of dust removal performance, cycle life, and energy consumption.

Investigation of pollutant‐removal performance and energy efficiency characteristics of wet electrostatic precipitator

AbstractEnergy conservation and efficiency enhancement are the options to achieve carbon neutrality in coal‐fired power plants. Wet electrostatic precipitator (WESP) is an important pollutant removal and energy consumption equipment in coal‐fired power plants, which emits a large amount of CO2 indirectly and has a great potential for emission reduction. In this paper, the emission reduction characteristics of multiple pollutants and energy consumption were analyzed by collecting 158 datasets of WESP. The results showed that WESP was effective at removing PM, PM2.5, SO3, droplets, and Hg with the following concentrations at the outlet: 1–10, 3, 1–5, 15, and 5 µg/m3, respectively. The emission factors of different pollutants were sorted in the descending order of size as droplets (average value 51.59 g/MWh), PM (19.15 g/MWh), SO3 (17.32 g/MWh), PM2.5 (8.21 g/MWh), and Hg (9.74 mg/MWh). Specific power/water/alkali consumptions were found as 0.5–2.5×10–4 kWh/m3, 10 × 106 t/m3, and 0.06–9.79 ×10–8 t/m3, respectively. These consumptions were negatively correlated with the inlet concentration of PM/SO3. The average annual emission of CO2 per unit installed capacity by the application of WESP was found to be 13.88 t/MW. It was estimated that the CO2 annual emissions by using WESP in coal‐fired power plants in China were 1.68×106 t. The CO2 annual emission reduction of 7.33×105 t could be achieved through grade 2 energy efficiency WESP (7.83 t/MW) of GB/T 37484‐2019. A further reduction of 3.18×105 t could be achieved if it could be controlled at grade 1 (5.20 t/MW). This study can provide a valuable reference for the subsequent operation of ultra‐low emission units to conserve energy and reduce CO2 emissions. © 2022 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.

Numerical Simulation and Analytical Evaluation of the Collection Efficiency of the Particles in a Gas by the Wire-Plate Electrostatic Precipitators

In this study, a numerical simulation model and an analytical method are introduced to evaluate the particle collection efficiency and transport phenomena in an electrostatic precipitator (ESP). Several complicated physical processes are involved in an ESP, including the turbulent flow, the ionization of gas by corona discharge, particles’ movement, and the displacement of electric charge. The attachment of ions charges suspended particles in the gas media. Then, charged particles in the fluid move towards the collection plate and stick on it. The numerical model comprises the gas flow, electrostatic field, and particle motions. The collection efficiency of the wire-plate type ESP is investigated for the particle diameter range of 0.02 to 10 µm. It is observed that electric field strengths and current densities show considerable variation in the solution domain. Meanwhile, changing supply voltage and charging wire diameters significantly affect the acquired charges on the electrostatic field and particle collecting efficiencies. Simultaneously, the distance between the charging and collecting electrodes and the main fluid inlet velocity has an important effect on the particle collection efficiency. The influence of the different ESP working conditions and particle dimensions on the performance of ESP are investigated and discussed.

Experiment and numerical simulation on the fine particle migration behaviors for the collection efficiency enhancement of a wire-plate electrostatic precipitator in pig house

In this paper, an integrated numerical model is presented and validated to investigate the particle charging and migration behaviors in a wire-plate electrostatic precipitator (ESP) for the collection efficiency (η) enhancement of the ESP in the piggery. Calculations of the RNG k-ε model, corona model, and particle tracking model are coupled in our model by utilizing MATLAB and COMSOL Multiphysics. This model is used to investigate the influence of various factors, such as the particle diameter (dp), flow velocity (u), and applied voltage (V), on the performance of ESP. Simultaneously, a visual experimental platform for PM2.5 migration is established for verification. The calculated results show that the predicted values of potential distribution, u distribution, and η are in good agreement with the previously reported experimental data. Moreover, the calculated results indicate that two elliptical shapes are produced by a relatively high electric potential and space charge density in the surrounding of the discharge corona wires. Furthermore, η first decreases with the increase of dp, remains unchanged in the range of 0.1–1.0 μm, and then increases until became constant in the range of 1.0–10 μm, revealing the interaction between diffusion charging, electric field charge, and fluid drag. In addition, the experimental and calculation results indicate that the η of PM2.5 increases with the decrease of u and increase of V. Notably, η of 2.0 μm is 100% at u = 1 m/s, V = 50 kV. Therefore, both the migration behavior solution method and the rules of η dependence on PM2.5 provide a scientific parameter control method for improving the air quality in pig house.

Numerical simulation on magnetic confinement characteristics of internal vortex electrostatic cyclone precipitator under different working voltages

Aiming at improving the capture performance of internal vortex electrostatic cyclone precipitator (ECP), a theoretical model with mechanics-electric-magnetic coupling was established, the collection efficiency of magnetic confinement ECP under different working voltages was simulated, and the influence of magnetic flux intensity on the removal performance of submicron particles was explored. Results show that the number of particles escaped from the cyclone is greatly reduced after the introduction of magnetic field and electric field, indicating that charging effect and magnetic confinement are more conductive to trap submicron particles in the internal vortex ECP. The lower the working voltage is, the worse the charging lifting effect is, but the stronger the magnetic confinement characteristics are. Furthermore, the contributions of charging effect to collection efficiency and magnetic confinement characteristics are more obvious at a weaker magnetic flux density. The research results can provide a practical new idea for the innovative design of ECP.

A holistic performance assessment of duct-type electrostatic precipitators

Epidemiological surveys have shown a significant association between indoor airborne particle exposure and adverse health effects. Duct-type electrostatic precipitators (ESPs) are effective in controlling airborne particles in buildings. Although several studies have examined the initial performance of duct-type ESPs, there are no comprehensive data on the holistic performance of commercially available ESPs. In addition, there are no published comparisons of the performance of ESPs with and without dielectric coatings considering the impact of dust loading and washing. In this study, laboratory tests were conducted to determine the holistic performance including initial, dust-loaded, and postwashing filtration efficiencies and ozone emission rates of ESPs with and without dielectric coatings. ESPs with dielectric coatings showed enhanced removal efficiency of submicron particles, with overall efficiencies comparable to those of F7 filters and 85% lower energy consumption. The removal efficiency of the ESP with dielectric coatings was superior to those of ESPs without dielectric coatings, but the higher energy consumption of the former led to slightly lower comprehensive performance. The filtration efficiency for submicron particles differed most between the two types of ESPs and was more suitable for evaluating their performance. The ozone emission rates were almost 2–7 times higher for ESPs without dielectric coatings than for the ESP with a dielectric coating (5.9 ± 2.2 mg/h). Based on the initial comprehensive quality factors of the ESPs, the maximum reductions caused by dust loading and washing were 55.3% and 17.5%, respectively. This study demonstrates the importance of considering multiple criteria when evaluating the performance of duct-type ESPs.

Factors Affecting the Performance of Dry Electrostatic Precipitator: A Review

Factors Affecting the Performance of Dry Electrostatic Precipitator: A Review

Performance of Electrostatic Precipitator as Air Cleaner in Water Production Process from Humid Air

Humid air as a source of water can be utilized by using a condensation system called the Atmospheric Water Maker (AWM) in order to overcome the problem of limited drinking water supply. However, to maintain water quality and production capacity, the AWM requires an air filtration system with minimum flow resistance. In this work, an electrostatic precipitator (ESP) was used as an air filter for AWM application. Thus, this study aimed to investigate the performance of ESP in terms of particle collection efficiency and water quality produced by AWM. In order to evaluate the performance of ESP, wire to cylinder type ESP was designed and three experimental activities were performed i.e., smoke filtration test, dust filtration experiment, and AWM water quality assessment. The performance of ESP was studied at various voltages ranging from 5.8 kV to 9.7 kV and two wire mesh sizes. The results showed soot particles were successfully removed by the ESP for all applied voltages with both 1 mm and 4 mm wire mesh. The effect of ESP voltage could be observed in dust filtration experiments in which the particle collection efficiency increases with the increase of voltage. The highest particle collection efficiency was observed at a voltage of 9.7 kV with a wire mesh of 1 mm. The results also showed that the use of ESP for AWM application offered a positive effect on the quality of condensed water in which the water physical and chemical properties satisfy the WHO standard for drinking water.

The Effect of Corona Wire Position and Radius in a Duct-Type ESP with Wavy Collecting Plates

Electrostatic precipitators (ESPs) have become one of the most effective methods for removing harmful particles from various industries. Many investigations in this subject are constantly developing due to the inherent benefits of using an ESP, and there are many robust initiatives taking place today all over the world. Different configurations of collection and discharging electrodes must be investigated to improve the ESP performance of ESPs. Many studies are working to enhance existing models in different ways. The geometry of the electrodes and the collecting plates is one area that could be improved. This paper investigates the wavy designs of collecting electrodes with varied corona electrode radius (range of variable corona radius (0.07-0.6 mm)) and position in a single-stage ESP. Wavy plates (WPs) and Inverted wavy plates (InvWPs) are compared to flat plates (FPs) using a numerical simulation tool. The results of this work show the impact of changing the corona radius when wavy and inverted wavy collecting electrodes are used on the electric potential, electric field strength, current density, and space charge density distribution, and particle collection efficiency. When compared to InvWPs and FPs, WPs show the highest performance in this range of particles. Although InvWPs can be utilized to reduce current density or space charge density, they do not increase particle collection efficiency.

Characterization of electrohydrodynamic flow in a plate-plate electrostatic precipitator with a wire-cylinder pre-charger by data-driven vortex and residence time analysis

The two-stage electrostatic precipitator (ESP) is widely used for indoor air cleaning field, while both the Particle Image Velocimetry (PIV) observations and well-characterized quantitative descriptions are probably scarce. In this work, we propose to use vortex analysis, which is the main quantitative method for flow field, and the relative residence time method (RRT) to evaluate the electrohydrodynamic flow (EHD) in a plate-plate ESP. The effects of electrical energization, pre-charger polarity and primary gas flow velocity are studied. Two vortex indexes sort the particle flow as five patterns and increase almost linearly with applied voltage. Four final particle statuses, penetrated, collected, stagnant and back-mixed are clarified by RRT method. The data generated by RRT are utilized to derive the PIV index for further analysis of the ESP performance. The trend, which rises first and drops later, suggests PIV index is expected to pave a new way to clarify the relationship between the ESP flow patterns and particle collection efficiency.

Trapping PM2.5 particles from electrostatic precipitator equipped with magnetic field under different gas velocities

The aim of this work is to investigate the effects of magnetic field and ionic wind on the ability of a wire-plate electrostatic precipitator (ESP) to trap fine particles. A theoretical model of multi-field coupling between gas flow field, particle dynamic field and electromagnetic field was established, and a grid model was built by GAMBIT software. The collection efficiency under different gas velocities was calculated in FLUENT software where the electric field force and the magnetic field force were introduced by User Defined Function (UDF). The numerical results indicate that both ionic wind and applied magnetic field can effectively improve the PM2.5 collection efficiency in a wire-plate ESP, and the smaller the particle size, the more obvious the improving effects are. With the increase of gas velocity, PM2.5 collection efficiency has a nonlinear declining trend, but the contribution of ionic wind or magnetic field to the collection efficiency increases. The trapping performance of the wire-plate ESP under the combined action of the two factors is better than that of considering one of them separately. The research results can open up a new design idea and direction for the performance upgrading of the wire-plate ESP.

Simulation Research on Particle Collection Efficiency of Electrostatic Precipitators

Electrostatic precipitators (ESP) have been widely used to remove particles from exhausted gases in many industrial processes. The performance of ESPs is affected by operating parameters such as inlet velocity, applied voltage and other factors. A numerical method of multi-field coupling is used to study the influence of different factors on the distributions of electric field and flow field in an ESP. The results show that the particle collection efficiency of 0.1–10 µm particles has a U-shaped distribution relationship with particle size. With the increase of applied voltage and electrode length, and the decrease of inlet velocity and anode-cathode distance, the particle collection efficiency increases. The established numerical model and corresponding conclusion can provide some guidance for the optimal design of ESPs.