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The article addresses the issue of the occurrence and creation of hexavalent chromium during the smelting of chromium-containing refractories in electric arc furnaces. The designs of gas cleaning systems for chromium-containing gases from electric arc furnaces DS-0.5 and DSP-1.5 are presented. The gas cleaning system of the electric furnace DS-0.5 consists of a cyclone, two scrubbers, and electrostatic precipitators. On the other hand, the gas cleaning system of the DSP-1.5 electric furnace is composed of a cyclone, an adjustable Venturi, converging scrubbers, and two BVKO electrostatic precipitators. The article demonstrates that industrial production of melt-molded chromium-containing refractories can be carried out safely by utilizing the specified dust and gas cleaning systems. [ABSTRACT FROM AUTHOR]

Due to the carcinogenic nature of diesel particles, these particles will pose a serious threat to human health. In order to meet this challenge, the attention of researchers and government agencies around the world is focused on achieving an economical and safe technology to control these particles. Given that electrostatic precipitators are one of the most important treatment technologies, this paper deals with the mathematical modeling of a cylindrical electrostatic precipitator and the prediction of the collection efficiency of diesel conductive particles in its various conditions. This sediment consists of a grounded cylinder with a circular cross-section and an excited electrode with negative direct current voltage installed in the center of the cylinder. Using the analytical response of Poisson equations and current conservation, ion spatial charge density, electric potential distribution and electrical volume forces in the electrostatic precipitator channel will be calculated. In this paper, COMSOL software is used for three-dimensional modeling of cylindrical electrostatic precipitators and solving turbulent air flow equations considering volume electric force. The particle charge and motion equations have been implemented in COMSOL software using particle routing physics and the results have been analyzed.

High enrichment of airborne viruses during sampling is critical for their rapid measurement and requires a high sampling flow rate (or velocity), small collection areas, and high collection efficiency; however, high collection efficiency can rarely be achieved at high flow velocities and in small collection areas in electrostatic sampling. Herein, we present improved measurement of airborne viruses using a two-stage highly virus-enriching electrostatic particle concentrator (HEPC) with wire electrodes and high values of the-inlet-velocity-to-collection-electrode-width ratio. This sampler was evaluated using MS2 viruses and 0.05–2.0 µm diameter polystyrene latex particles at 20 liters/min. Computer simulations and experiments agreed well, showing that the wire electrodes increased collection efficiency (by up to 37 % than the without-wire-electrodes case) without high viability losses through local electric field enhancement for high-flow-velocity regions over the collection electrode and minimization of local corona discharge. The relative infectious virus concentrations of the HEPC were 41–70 times higher than those of the BioSampler. Airborne influenza A viruses at field-level concentrations (1.8 × 105 and 2.6 × 104 copies/m3) were also detected at 10-min sampling due to the high enrichment capability of HEPC. The HEPC has strong potential as a rapid airborne virus monitoring system in the field. [Display omitted] • Electrostatic air sampler with wire electrodes (HEPC) was presented. • HEPC operated at high values of the inlet velocity to electrode width ratio. • The wire electrodes increased collection greatly without high viability losses. • The viable virus concentration of HEPC was 41–70 times higher than that of the BioSampler. • Airborne influenza viruses at field level concentrations were detected at 10-min sampling. [ABSTRACT FROM AUTHOR]

• Honeycomb ESP was designed to control NO x and PM emissions from 15-kW boiler. • ESP reduced NO x by 78 % while PM were reduced to a magnitude of ambient air. • ESP removal efficiency was studied in terms of ESP technological parameters. This work investigates the potential of corona discharge to control particulate matter and NO x emissions from small-scale biomass combustion. The electrostatic precipitator (ESP) was designed and used to suppress emissions from a 15-kW heating unit. The ESP was operated at different power modes at both polarities and demonstrated the capability to reduce NO x emissions with a removal efficiency of 78 % while PM concentration was reduced to a magnitude of particle content in ambient air. The efficiency of ESP was evaluated considering the technological parameters, namely the reduced electric field, Nt-product, and specific input energy. The growth in NO x abatement was observed when the energy input exceeded 1 J/L for both polarities and Nt-product exceeded 4.5 × 108 s/cm3/1 × 109 s/cm3 for negative/positive corona. The results of this work may contribute to understanding the processes in corona discharge and optimising corona discharge systems for various applications. [ABSTRACT FROM AUTHOR]

Coaxial (wire-cylinder) electrodes arrangements are widely used for electrostatic deposition of dust particles in flue gases, when a high voltage is applied to electrodes immersed in air and provide a strongly non-uniform electric field. The efficiency of electrostatic filters mainly depends on the value of the applied voltage and the distribution of the electric field. In this work, a two-dimensional computer simulation was constructed to study the effect of different applied voltages (20, 22, 25, 26, 28, 30 kV) on the inner electrode and their effect on the efficiency of the electrostatic precipitator. Finite Element Method (FEM) and COMSOL Multiphysics software were used to simulate the cross section of a wire cylinder. The results showed that the velocity of the liquid and the charge accumulation of the particles increased with the increase of the applied voltage and also the efficiency of the precipitator increased and reached 100% with an applied voltage of 30 kV.

An electrostatic precipitator (ESP) is an efficient device for removing fly ash from small-scale solid-fuel combustion. Under corona discharge, a gaseous medium becomes ionised, and particles become charged by colliding with ions. An electric field forces the movement of charged particles to remove gases and induces the movement of generated ions, causing secondary electrohydrodynamic flow. Thus, particle charge, the presence of neighbouring particles, an ESP electric field, and gas flow turbulence can enhance particle coagulation. Therefore, the ultrafine particle concentration in an ESP is expected to evolve under electrostatic removal and enhanced coagulation. In the present study, the contribution of coagulation is explored and confirmed using experimental measurements performed on an ESP used to control emissions from a 160-kW boiler with biomass combustion. The ESP was operated under several modes to obtain different coagulation conditions. Changes in particle concentrations were measured simultaneously using two techniques. It was found that coagulation could be responsible for up to 5% of the total removal efficiency, depending on the ESP operation parameters. The present study can promote a deeper understanding of the processes involved in electrostatic precipitation, and the obtained results can be useful for practical ESP engineering.

The Electrostatic Precipitator (ESP) is common equipment used in thermal power plants and industrial mining plants such as steel, copper, and cement. ESP is installed to capture the dust in the exhaust gas of boilers or furnaces. The availability of ESP is vital for plants since any interruption in this device causes serious process problems and environmental pollution. As a result, the availability of ESP is crucial, and a comprehensive study in this area must be performed for maintenance activities. This paper presents a novel method for assessing complex equipment availability, such as ESP, based on improved dynamic particle swarm optimization (IDPSO). To evaluate the availability of ESP, all related systems, sub-systems, and all components of ESP must be considered. Availability assessment of ESP, consisting of many series-parallel sections and components, can be challenging and time-consuming. An IDPSO is used to search for the most probable states among numerous possible states. In addition, IDPSO overcomes shortcomings of standard PSO, such as falling into local optimums. The proposed method is applied to the actual data of an ESP installed at a copper factory. The results show the proposed method achieved an accuracy of 99.54 % in availability assessment. [ABSTRACT FROM AUTHOR]

Electrostatic precipitators (ESPs) have been widely used to remove particles from gas. However, an additional gas pumping system should be utilized to pump the particle-laden gas. A self-pumped ESP is proposed, in which the ESP itself pumps particle-laden gas. The gas flow and particle collection characteristics are evaluated numerically. Results demonstrate that a nearly unidirectional ion wind stream can be generated with a suitable arrangement of electrodes. Particles significantly restrain the corona discharge current and decelerate the gas accordingly. Particles with a smaller diameter and a higher concentration exert a more significant influence on the corona discharge and gas flow. The average velocity of 0.5 m/s at the inlet of the ESP (area of 0.3 m2) is achievable with a voltage of 23 kV and a power consumption of 20 W. A collection efficiency of more than 99 % is achievable for particles with a diameter of 5 µm. • Self-pumped electrostatic precipitator with reasonable flow rate is designed. • Interaction between particles and ion wind is numerically evaluated. • High particle collection efficiency is achievable. • Gas velocity varies with the particle concentration and diameter. [ABSTRACT FROM AUTHOR]

Coaxial (wire-cylinder) electrodes arrangements are widely used for electrostatic deposition of dust particles in flue gases, when a high voltage is applied to electrodes immersed in air and provide a strongly non-uniform electric field. The efficiency of electrostatic filters mainly depends on the value of the applied voltage and the distribution of the electric field. In this work, a twodimensional computer simulation was constructed to study the effect of different applied voltages (20, 22, 25, 26, 28, 30 kV) on the inner electrode and their effect on the efficiency of the electrostatic precipitator. Finite Element Method (FEM) and COMSOL Multiphysics software were used to simulate the cross section of a wire cylinder. The results showed that the velocity of the liquid and the charge accumulation of the particles increased with the increase of the applied voltage and also the efficiency of the precipitator increased and reached 100% with an applied voltage of 30 kV. [ABSTRACT FROM AUTHOR]

Particulate matter, including airborne pathogens, is of particular concern because it can cause the spread of diseases through aerosol transmission. In this study, a new concept is proposed: on-demand antiviral electrostatic precipitators (ESPs) with electrothermal-based antiviral surfaces. We applied electrothermal-based antiviral surfaces to air-purifying applications and demonstrated that the proposed method is effective with regard to collecting airborne virus particles on collection plates in a two-stage ESP. With alternating current power, MS2 bacteriophage and H1N1 viruses were completely deactivated after exposure to 50 °C for 30 min. This remarkable antiviral performance via electrothermal effects indicates that on-demand platforms for self-antiviral surfaces can perform sterilization immediately without generating secondary pollutants, thus effectively preventing the spread of infectious microorganisms in public places. We believe that the results of this study can provide useful guidelines for the design and realization of practical and wearable devices for antiviral air-purifying applications. [ABSTRACT FROM AUTHOR]

Air quality and air pollution are important issues, and thus it is necessary to look at possibilities for how to decrease emissions in the atmosphere affordably and effectively. This article focuses on solid aerosols, specifically particulate matter, and the design of a low-cost solution for their decrease in the atmosphere. The mass concentration of particulate matter with the proposed optimized electrostatic precipitator was measured and compared with measurement without its implementation. Based on the results, it can be concluded that the designed ESP type could catch approximately 71% of solid particles. However, the real ability to capture particulate matter could be expected to be approximately 50–60% due to possible clogging, irregular cleaning and maintenance under normal conditions. Further, the article deals with the application of the village model with this type of electrostatic precipitator in households. Based on this model, the production of particulate matter would be reduced from 12.24 t/year to 6.12 t/year considering 50% separation efficiency and to 5.25 t/year considering 60% separation efficiency by the application to all heat sources for burning solid fuels for all emission classes. However, the reduction in particulate matter would be lower in real conditions. [ABSTRACT FROM AUTHOR]

An analysis of the operation of EHAH electrostatic precipitators designed for cleaning gases and aspiration air from dust has been carried out. An upgrade of the electrostatic precipitator, which allows eliminating vortex generation, reducing the likelihood of particles slipping (due to their high velocity), improving the collection of purified gas, and reducing stagnant zones in the confuser, has been proposed. A rationally chosen value of the inclination angle of the plates ensures a decrease in the likelihood of a lifting effect, in which particles can slip into the upper electrode-free space. A local decrease in velocity in the outlet gas duct was established to be within 7%. [ABSTRACT FROM AUTHOR]

Electrostatic precipitators (ESPs) may enable high particle collection efficiency with minimal pressure drop in HVAC systems. However, studies of pathogen collection and inactivation in ESPs at medium to higher flow rates are limited. Here, a single-stage, wire-plate ESP operated at flow rates of 51 and 85 m 3 h -1 was used to study the removal of virus-laden aerosol particles for three different airborne viruses: (1) bovine coronavirus (BCoV), (2) influenza A virus (IAV), and (3) porcine reproductive and respiratory virus (PRRSV). Size-resolved measurements of collection efficiency were obtained using Andersen cascade impactors (ACI) sampling upstream and downstream of the ESP. All measurements were analyzed based on three distinctive but complementary methods: (1) fluorimetry to assess physical collection, (2) RT-qPCR to assess viral RNA concentrations and (3) virus titration to assess virus viability. In general, log reductions by virus titration were highest followed by those from RT-qPCR, and last fluorimetry, suggesting that a portion of virus may be potentially inactivated in flight in the ESP. An effective migration (deposition) velocity ranging from 3.10 to 10.05 cm s -1 was also determined using the spatially resolved measurements of virus collection on the ESP plates.

The corona onset voltage is an important operating parameter in the electrostatic precipitation of nanoparticulate, however, its experimental determination depends on the accuracy of the measuring equipment. In this study, a theoretical approach based on the Townsend law was developed to determine the onset voltages and to further investigate the characteristics of an electrostatic precipitator (ESP). The experiments to obtain preliminary data were performed at low air velocities (1.03–4.08 cm/s), varying the number of discharge electrodes from 1 to 4. The theoretical onset voltages agreed with the experimental data and increased with the addition of wires. The ESP could achieve 99% particle charging despite the shielding effect observed in some configurations. [ABSTRACT FROM AUTHOR]

The electrostatic precipitator (ESP) is widely used in the purification of oil mist particles in the industrial workshops. Different from the solid particles, the deposition of oil mist particles in the ESP can reach a steady state and form a saturated oil film on the electrode plate. Based on the deposition experiment data, this paper has established the oil film flow model in ESP coupled with the corona discharge, the gas flow and the oil mist particle deposition model. The characteristics of oil mist particles deposition and the oil film flow were studied. The results show that the oil film is thin in the electrode plate where the current density is high. The oil film is thick at the inlet of ESP and the corresponding collection plate in the middle of the adjacent electrode wires. The peak value appears at the corresponding plate in the middle of the first two electrode wires, which is more than 50 µm. The average oil film thickness is about 9 µm in the current study. As the inlet velocity increases or the applied voltage decreases, the oil film distribution becomes more uniform, and the oil holding capacity of the electrode plate increases. [ABSTRACT FROM AUTHOR]

In blade-to-plane electrostatic precipitators at variable temperatures, the electric field and the current density distributions of the negative DC corona were experimentally analyzed, and the corona discharge was used as the source of ionization. In this research, an experimental cell was designed and built to adjust the temperature from 20 to 46°C within the cell. The current density-voltage characteristic and the radial distance distribution of the current density of an electrostatic blade-to-plane precipitator were measured over a temperature interval. Based on the Tassicker and Townsend models, the electric field and the onset voltage were determined. With the rise in temperature, the corona current obtained at the collector plate has been observed to increase, but the onset voltage decreased. The applied voltage and temperature greatly affected the corona current density characteristics and the electrical field. If an exponent of 4.6 to 5 for a negative corona discharge is taken, the DC density distribution is satisfied, then the current density distribution follows the well-known Warburg theorem. [ABSTRACT FROM AUTHOR]

Engineering education is an important part of preparing quality graduates for the challenges of the Covid-19 and post-pandemic conditions, and electronics engineering education is no exception. Blended learning-based projects as an alternative to innovative learning at this time. This study aims to explore and explain the application of blended learning-based projects in electronics engineering education courses. The research method used is a project-based product design and development carried out by blended learning. We conduct our project activities in higher education special students from Electronic Engineering Education that take part in the learning of this project. Students who participate are only limited to small groups to avoid the impact of the Covid-19 pandemic, in 1 small group consisting of 3-5 people and there is 1 group leader who manages the work, while other members are supportive and help complete joint projects. The results of this study show the ability of students to work by implementing project-based learning in producing products, namely Exhaust Fan products based on Electrostatic Precipitator (ESP) as a form of a mini prototype that can be used for small household scale industries. The ability of students to work on product manufacturing by applying the principles of project-based learning in the category already has the ability to, skilled and thoroughly working on the project that was planned until it succeeded in becoming a product prototype which was carried out in a project-based blended learning. [ABSTRACT FROM AUTHOR]

A unique electrostatic precipitator combined with an ionic fan is proposed for air purification in a lunar module, and its feasibility was investigated. Dust contaminating the air in the habitat module is circulated by the ionic wind generated by the ionic fan, which comprises coaxial cylinder electrodes. A positive direct current (DC) voltage exceeding the corona discharge onset voltage is applied to the inner electrode, where the sharpened edge faces the outer cylinder electrode. The migration of charged molecules generated by the corona discharge forms an air stream, and simultaneously, dust particles are charged. Charged particles are introduced into the electrostatic precipitator, which comprises parallel-plate electrodes. A high DC voltage less than the onset voltage of the spark discharge is applied to the electrodes, and the introduced charged dust particles are trapped in the collection electrodes owing to the Coulomb force. It appears that dust is effectively cleaned by a compact system. An ozone filter is installed to decompose the ozone synthesized in the corona discharge field. Because the proposed system affords simplicity, a small configuration without mechanical moving components, lightweight, low power consumption, and silence, it is suitable for use in the lunar habitat module and pressurized rover. The proposed air-purification system would contribute to reduce the load on the mechanical filtration system. [ABSTRACT FROM AUTHOR]

The study of electrostatic precipitators (ESP) is of great importance in powder technology. Different physical and chemical processes occur during its operation. The objective of this investigation is to analyze and observe electrical phenomena using mathematical models such as Poisson's equation and the charge conservation equation. To carry out the simulation two flat plates and seven corona wires are geometrically arranged based on an ESP prototype. The general form of partial differential equations mentioned along with the boundary conditions was written in software and associated with the different parts of the geometry. For example, the electric field onset is calculated by Peak's law and set as one of the boundary conditions for the corona wires. Defining the space charge density distribution is an essential part because the next processes inside of ESP depend on this parameter. A specific method that splits the space charge density is used to solve these PDEs. Besides, a review of the concepts of the particle charging process, particle kinetics, and particle collection is introduced. The results obtained from the simulation such as the electric potential, electric field, and space charge density, agree with those proposed in some investigations. [ABSTRACT FROM AUTHOR]

Residential biomass combustion has been pointed out as one of the largest sources of atmospheric pollutants. Rising awareness of the environmental effects of residential biomass combustion emissions boosted the development of different emission reduction devices that are currently available on the market for small-scale appliances. However, detailed studies on the efficiency of these devices in different combustion systems available in Southern European countries are lacking. In this study, two pollution control devices (catalytic converter and electrostatic precipitator) were tested in two different combustion systems (batch mode operated woodstove and automatically fed pellet stove) in order to assess the emission reduction potential of the devices. Pine firewood was used to fuel the woodstove. One commercial brand of pellets and an agricultural fuel (olive pit) were taken for the experiments in the pellet stove. While the efficiency of the electrostatic precipitator in reducing PM10 was only recorded for woodstove emissions (29%), the effect of the catalyst in decreasing gaseous emissions was only visible when applied to the pellet stove flue gas. For wood pellet combustion, reductions of CO and TOC emissions were in the range of 60–62% and 74–77%, respectively. For olive pit combustion, a lower decrease of 59–60% and 64% in CO and TOC emissions, respectively, was recorded. [ABSTRACT FROM AUTHOR]

In the current paper, the dust transfer system in production line 4 of the Tehran cement factory has been simulated using computational fluid dynamics and a method has been presented to improve the system's performance by changing the geometry. In this line to separate the particles from the gas, three electrostatic precipitators have been utilized in a parallel format. The shape of this line was modeled using Gambit software, and the distribution plates that are positioned at the beginning of electrostatic precipitators have been under consideration; then, grid generation was carried out for the created model. The model was transferred into Fluent software and solved numerically as a two-phase flow using the discrete phase model. Velocity values were obtained at different points of this system, and the trajectory of particles was drawn. The obtained results demonstrate a remarkable reduction in the velocity value before one of the electrostatic precipitators due to the horizontal duct; the considerable proportion of particles deposited on the walls of this duct. To improve this issue, a method has been proposed. In the modified case, the geometry of the horizontal duct was changed and the model was run again and the velocity and particles deposition values were compared with the current case. The results showed an increase in the velocity and a decrease in the sedimentation rate by 79.3 and 42.9%, respectively. [ABSTRACT FROM AUTHOR]

Considerable loss of life, economic slowdown, and public health risk associated with the transmission of airborne respiratory pathogens was underscored by the recent COVID-19 pandemic. Airborne transmission of zoonotic diseases such as the highly pathogenic avian influenza (HPAI) and porcine reproductive and respiratory syndrome virus (PRRSV) has caused major disruptions to domestic and global food security. Current ambient air pathogen monitoring systems involves the collection of air samples from indoor settings suspected of viral contamination, followed by subsequent processing of capture samples to determine the presence and species of airborne viral matter. Nucleic acid amplification techniques are considered the gold standard for pathogen diagnostics. Currently, the necessary extraction and purification of viral RNA from air collector systems prior to sample analysis is both time consuming and performed manually. A monitoring system with separate air sampling and biochemical detection procedures is prone to delay the response to emergent viral threats. In this paper, we present a pathogen monitoring system that overcomes these limitations related to extraction and purification of viral samples and lays the groundwork for a real-time monitor for airborne viral pathogens. We demonstrate a high flow electrostatic precipitator system, that uses small collection wells as counter electrodes for pathogen collection. Integrated reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) is used for detection of captured viral matter within wells. On-chip heating of collection wells is enabled by integrated planar heaters and small volumes of reagent (30 μ L) directly to the collection wells. We present the design of such a system and show experimental results that demonstrate the use of this device for detection of aerosolized SARS-CoV-2 virus like particles (VLPs), a model pathogen for SARV-CoV-2. • A system for collection and real-time detection of airborne viral pathogens. • Integrates airborne viral capture with isothermal nucleic acid amplification. • Electrostatic capture of airborne viruses into a custom well-plate. • No need for viral extraction from collection surface (one-pot detection). • Experimental verification of real-time detection using aerosolized engineered viral model. [ABSTRACT FROM AUTHOR]

The electrostatic precipitator (ESP) utilizes corona discharge to effectively separate particles from polluted air. The arrangement of electrode is a crucial role in achieving higher efficiency. Needle discharge electrodes can generate concentrated corona discharge at lower applied voltages. In this study, a staggered needle-plate electrode configuration was presented to expand the domain for particle charging, and thereby improve collection efficiency. A three-dimensional model was established to describe the multi-physics phenomenon in the ESP. The ion charge distribution, electric field, and particle collection efficiency were investigated under various conditions. The staggered model showed an average ion charge density that was 20% higher than that of the aligned arrangement. Particles introduced via staggered model acquired higher charge and showed improved collection efficiency across inflow velocities of 0.5 to 1.5 m/s and particle diameters of 0.1 to 50 μm. In the staggered model, particles predominantly escaped near the sidewall of the ESP. [Display omitted] • A 3-D CFD method was used to simulate Corona discharge and particle charging. • The effects of electrode configuration on particle transport and deposition characteristics were analyzed. • The staggered configuration provided more pervasive dispersion of ion charge. • Particle collection processes were investigated under various conditions. [ABSTRACT FROM AUTHOR]

The assessment of airborne viruses in air is a critical step in the design of appropriate prevention and control measures. Hence, herein, we developed a novel wet-type electrostatic air sampler using a viral dissolution buffer containing a radical scavenging agent, and verified the concentration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the air of hospital rooms inhabiting coronavirus disease 2019 (COVID-19) patients and public areas. RNA damage caused by corona discharge was negligible when Buffer AVL was used as the collecting electrode. The viral RNA concentration in the air of the room varied by patient: 3.9 × 103 copy/m3 on the 10th day after onset in a mild case and 1.3 × 103 copy/m3 on the 18th day in a severe case. Viral RNA levels were 7.8 × 102 and 1.9 × 102 copy/m3 in the air of the office and food court, respectively, where people removed their masks when eating and talking, but it remained undetected in the station corridor where all the people were wearing masks. The assessment of airborne SARS-CoV-2 RNA using the proposed sampler can serve as a basis for the safe discontinuation of COVID-19 isolation precautions to identify exposure hotspots and alert individuals at increased infection risks.

To reduce corrosion, cost, and weight, we developed a nonmetallic, two-stage electrostatic precipitator (ESP) using electrodes fabricated from carbon ink and polyethylene terephthalate (a plastic), rather than expensive corrosion-resistant metals. Five collection modules were manufactured; we varied the materials used to fabricate the high-voltage and ground electrodes. The plate-type electrodes of the collection module were made of stainless steel, carbon-coated plastic (CPC), or plastic-coated carbon (PCP). Particle removal performance was investigated by the voltages of the precharger and collection modules, the particle diameter, the airflow rate, and the particle collection area. The particles were an oil mist. The electrode material had little effect on particle removal performance. The experimental performances of two-stage ESPs featuring plastic and carbon plate electrodes met the theoretical efficiencies predicted by the Deutsch equation and Cochet charging theory. Although fluttering developed when the flow velocity exceeded 2 m/s over CPC electrodes, the use of PCP electrodes (the rigidity of which was reinforced by the plastic coatings) eliminated fluttering. Moreover, in an extremely humid condition where the water vapor continuously condensed into water droplets, the polyethylene terephthalate film of the PCP electrode ensured stable operation without spark regardless of humidity or water droplets on the surface. In summary, plastic electrodes were light and economical, while affording high removal efficiencies similar to the removal efficiencies of metals. Moreover, the PCP electrode plastic coating protected the carbon ink from abrasion and corrosion. [ABSTRACT FROM AUTHOR]

Combustion of biomass-based solid fuels is becoming increasingly popular, especially in small heat sources. A major problem in the combustion of biomass is the increased production of emissions and especially the solid component of PM particles. Currently, the most used solution to this problem is the application of electrostatic chimney separators, which innovations are discussed in our article. Two models of electrostatic precipitators were constructed in this work. The aim of this work was to compare the use of a standard single-pipe chimney electrostatic precipitator with a newer four-pipe variant. Eight measurements were performed on both devices with and without the use of an electrostatic precipitator, on the basis of which the separation efficiency was evaluated for both variants. The results of the measurements showed the initial value of the average PM production in the one-pipe variant decreased from 1012 to 416 mg. m − 3 when using the separator, while in the use of the four-pipe variant it decreased from the starting value 342 to only 152 mg. m − 3 . These results show that the improvement of the classic single-pipe separator by increasing the number of tubes significantly reduced the production of PM emissions and increased the separation efficiency from 66 to 85%. [ABSTRACT FROM AUTHOR]

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The article is focused on capturing process-related dust at industrial enterprises (in chemical, metallurgical and energy industries). An electrocyclone can be recommended for the purification of gases emitted into the atmosphere from particulates, such as sodium percarbonate (efficiency 97.5%–99.9%), iron-vanadium concentrate (98.0% - 99.9%), fly ash (99.0%–99.9%). However, the fumes from copper-smelting furnaces cannot be purified with high efficiency (less than 50–60%) because of their properties. Using electrocyclone will reduce the amount of aerosol emissions, and in some cases, let the emission reach the values set by standards.

Electrostatic precipitators are devices that remove charged particles from an air stream. We present the design and characterization of an electrostatic precipitator that is intended to be incorporated into aerosol sampling equipment. Hardware and software components of the design are open, all components can be directly purchased from vendors, and the device can be assembled with standard tools. Generic components are used to allow the repurposing of parts for other uses. The computer-controlled high-voltage power supply box associated with the project can be used for other common high-voltage applications in Aerosol Science and Technology, such as data acquisition and control systems for scanning mobility particle sizers. Computational fluid dynamics simulations are used to quantify the 3D flow field. The transfer function associated with the partial transmission is characterized through modeling and experiments. The observed transfer function is unique but deviates from the ideal transfer function due to the distortion of the flow near the inlet and the outlet of the device. Singly charged particles up to 624 nm and 253 nm can be completely removed for 0.5 L min−1 and 1 L min−1, respectively. We anticipate that our device will increase the accessibility of the technique to a broader audience.

It is about how much fine dust can be efficiently removed with respect to the electric dust collector used in factories and large facilities. The results of evaluating the fine dust removal efficiency are as follows. At 10,000 V, Efficiency method I showed 68.1 %, and Efficiency method Ⅱ was 58.6 %, which was lower than that of Efficiency method I. At 5,000 V, Efficiency method I showed 57.6%, and Efficiency method II showed 51.6%, which was lower than Efficiency method I. At 2,500 V, Efficiency method I showed 50.3%, and Efficiency method II showed 24.4%, which was lower than Efficiency method I. In case of Efficiency method I, it is the efficiency calculated by using the dust concentration before and after passing through the filter. Efficiency method Ⅱ calculated Efficiency method Ⅱ to measure the efficiency a little more accurately in the environment where the air after the filter and the polluted air are mixed. Efficiency method II showed lower efficiency than Efficiency method I. As a result of the electrostatic precipitator test, the dust collecting performance was highest at 10,000 V, followed by 5,000 V and 2,500 V in that order. [ABSTRACT FROM AUTHOR]

Electrostatic precipitators (ESPs) are widely used to control air pollution. However, their applications in portable air cleaners are limited owing to ozone generation during the discharging process. In this article, we developed a compact two-stage ESP that combines corona discharging and particle collection modules. The former generates an extremely small amount of ozone using dielectric film coating, whereas the latter has a large specific surface area. A polypropylene (PP) film is coated as a dielectric material on the ground electrode of the discharging module. The corona current is reduced by the PP film, which in turn reduces the ozone generation. The efficiency of atmospheric particle collection and ozone generation were evaluated by varying the flow rates and applied voltages of the four-channel discharging and roll-type collection modules. Additionally, the specific surface area of 707 m2/m3 of the roll-type collection module minimized the size of the device by increasing its integrity. The proposed ESP with PP coating exhibited the tendency of a conventional ESP that follows the Deutsch equation. All particles of size over 1 μm were removed from the atmosphere by the proposed device at a flow rate of 194.4 L/min, which is more than three times that of human breathing. Furthermore, our experimental device removed more than 50% of the ultrafine particles of size 0.3 μm without ozone generation. Therefore, the proposed device can be potentially used in portable or wearable air-cleaning devices to aid individual healthcare. [ABSTRACT FROM AUTHOR]

Dipterocarpus alatus Roxb, sometimes called the 'diesel tree', because its resin has been reported to run small engines directly, has not been studied as a source of bio-oil from pyrolysis, although considerable waste is generated from furniture making. Here, we compared it with rubber tree waste, using cassava rhizomes (already extensively studied as a bio-oil source) as a reference. Our free-fall pyrolysis system used a conventional cooled condenser, as well as an electrostatic precipator, to capture bio-oil. Total bio-oil yields were: D alatus, 62% w/w of input biomass, cassava 61%, rubber wood and leaves, 59%. The electrostatic precipitator was responsible for ~20% of the total bio-oil yield: adding the precipitator increased overall yield significantly. HHV values wre highest for rubber wood (21–22 MJ/kg), but only slightly lower for D alatus and cassava (19–20 MJ/kg). Small differences in the properties of the bio-oil from both condensers confirmed that different fractions of the oils were collected in the two condensers. Overall, D alatus showed good potential as a high yielding source of bio-mass for pyrolysis. [ABSTRACT FROM AUTHOR]

In this paper, three types of wire-plate electrostatic precipitators with expanded-shrunk spoilers (ESP-ESSs) were proposed. The influences of different geometric characteristics and arrangements of the expanded-shrunk spoilers (ESSs) on the electric field intensity, airflow field, particle trajectory, and collection efficiency were investigated by experiment and numerical simulation. The ESP-ESSs was compared with ESP with parallel plates (ESP-PP). The numerical results were relatively in agreement with the experimental data. The maximum error was 6.5%. The results showed that with the increase of the ESS height, the electric field intensity increased. The ESSs could generate low-velocity vortices contributing to extend the retention time of particles, which was conducive to particle collection. In general, the collection efficiency of the ESP-ESS was superior to the ESP-PP, but there was no advantage for fine particles at high inlet gas velocity and low applied voltage. [Display omitted] • The performances of three different ESP-ESSs were investigated. • The ESP-ESSs were systematically compared with ESP-PP. • The effects of ESSs on performances were studied. • The mechanism of the ESS enhancement was analyzed [ABSTRACT FROM AUTHOR]

The efficiency of electrostatic precipitators at thermal power plants can be enhanced by increasing their active volume by increasing the height of the electrode systems to 15 – 18 m. However, when increasing height, deviations in the flatness of the surface of the collecting electrode are enlarged up to 22.5 mm, leading to an increase in emissions up to 3 times or more. Experiments were carried out to establish the causes of deviations in the electrodes of domestic electrostatic precipitators to include the technology of profiling the collecting electrode elements, the method of assembling the elements together in height, the symmetry of the element cross-section relative to the center of gravity, as well as the method of fastening between the elements and the shaking beam. Based on an analysis of factors affecting the flatness of collecting electrodes, as well as bench and industrial testing, a collecting electrode having minimal surface deviations from the plane was developed. As a result of the industrial application of the collecting electrode created using an innovative manufacturing technology, including profiling of the collecting electrode elements and assembling them into the electrode, the efficiency of the electrostatic precipitator was increased. [ABSTRACT FROM AUTHOR]

The electrohydrodynamic (EHD) flow induced by a corona discharge has an important influence on the movement and collection of fine particles in an electrostatic precipitator. In this paper, three-dimensional particle image velocimetry (3D-PIV) is used to investigate the impact of different primary flow velocities and applied voltage on diffusion and transport of the spiked tubular electrode corona discharge EHD flow in a wide type electrostatic precipitator. In order to measure the flow characteristics of different positions of a spiked tubular electrode, the PIV measurements are carried out in several cross-sectional planes along the ESP duct. From 2D flow streamlines, in plane 1 (where the tip of the spike is oriented in the direction of primary flow), the velocity of the counter-clockwise vortex caused by the EHD flow near the plate decreases as the primary flow velocity increases. However, in plane 3 (where the tip direction is opposite to the primary flow), two vortices rotate adversely, and the flow velocity of the clockwise vortex near the plate increases as the primary flow velocity increases. Flow velocity increasing near the plate makes the particles deposited on the plate more easily to be re-entrained. It can be found in the three-dimensional analysis of the flow field that there are mainly “ascending vortex” and downward tip jet in the three observation planes. There is a discrepancy (in terms of distribution region and the magnitude of velocity) between the three-dimensional characteristics of these vortices and tip jets in the different cross-sectional planes.

High concentration particulate matter (PM) has been a serious environmental problem in China and other developing countries. Electrostatic-based purification technology is a method to remove airborne particles, and can reduce the energy consumption of ventilation fans in buildings because of its low pressure drop. In this study, we developed a new pin-to-plate corona discharger with particle-free external air protection to prevent particles polluting the surface of discharge pins. By using an optical microscope, we observed a certain number of particles deposited on the non-protected (exposed pins) and few particles deposited on the protected pins after they operating for 3 weeks. We experimentally studied the long-term performances of the exposed and protected pins in single-pass PM removal efficiency and ozone production. The results showed that the protected pins produce less ozone and have higher breakdown voltage than the exposed pins. Experimental results indicated that the improved pin-to-plate corona discharger has better long-term performance and is safer than the exposed one. The results of the research can give an understanding of how to improve electrostatic-based purification technologies toward stable discharging for high removal efficiency of particles.

The analysis of recent studies and publications on the use of equipment for cleaning of sinter gases is carried out; these are battery multicyclones and electrocyclones, bag filters, electrostatic precipitators. It is established that when using such devices for cleaning of sinter gases, there are significant problems and shortcomings associated with the treatment of a large number of highly dusty gases. These are low efficiency due to the accumulation of dust in the equipment elements, the large size of the filters, rapid wear of the elements of the used devices, high aerodynamic resistance, increased operating costs, etc. Based on the analysis of shortcomings of existing equipment, the authors of the article performed computer simulation of the movement of dusty gas flows through a dust deposition and established the dependence of the speed, direction of gas flow, size of dust and the efficiency of the inertial device, depending on its resistance. The VAV-250-AFK inertial deposition apparatus for preliminary gas purification was developed and tested on sinter machine No. 12 of the sinter plant of PJSC "Dnieper metallurgical plant". According to the results of measurements conducted by the environmental service of the plant, the dust content of gases at the outlet of the apparatus is 0.92 g/nm3 when the incoming dust is 3 g/nm3. Cleaning efficiency was about 70 %. A design and technical solution is proposed for replacing battery cyclones with the device of thin gas purification "VAV-400/50D", that will allow us to achieve European standards on dust emission in the atmosphere up to 40–50 mg/nm3. A technical solution to reduce gas dust during the implementation of our developments for various conditions of equipment location is possible. Three options are proposed for the modernization of existing treatment equipment in order to increase its efficiency. When introducing the proposed technical solutions, it is possible to obtain a steady reduction in the content of dust and harmful gases in the outgoing sintering gases to established standards and to solve the dust problem of industrial cities with a working sintering industry, which are the main sources of dust and harmful gas emissions from the metallurgical enterprise.

The electrical characteristics and electrohydrodynamic (EHD) flows in a wire-plate electrostatic precipitator with six shaped discharge electrodes are analyzed by employing the commercial software ANSYS FLUENT with the aid of User Defined Function (UDF). The results show that the corona position of the discharge electrode plays important roles in generating space charge distribution. When the inlet velocity is relatively low, the vortexes induced by the secondary flow exist not only in the downstream of the discharge electrode, but also in the vicinity of the collecting plate. The vortex near the collecting surface in the Knife-shaped system produces the highest recirculation velocity and turbulence intensity, and covers the widest region among the six configurations. For the high inlet velocity, the local recirculation and high turbulence by the secondary flow near the collecting plate in the all six channels disappear but still remain in the downstream of the discharge electrodes, and the airflow in the central region of the six channels would be accelerated. The highest vortex strength and turbulence intensity and the strongest speed-up effect occur in the center of the channel with the Knife-shaped discharge electrode compared with the cases of the other five systems.

Environmental pollution caused by human activities, the harmful mixture of gases (CO, CO2, NO2, SO2, PM), resulting from industrial production processes and vehicular traffic is a global environmental health problem in urban and rural areas; it affects vulnerable groups, children and older adults, affecting respiratory, cardiovascular and cancerous diseases. In Ecuador, in the city of Cuenca, among the main sources of contamination is the vehicle fleet in high-traffic areas and avenues; in addition to the industrial zone, that coexists with the city within the urban area in the northwest zone, which generates contamination to properties located around these strips. This paper presents the development of a purifying element based on the “evolutionary development” model. It begins by analyzing and studying concepts of lattices, ionization, and air purification, among others; subsequently, existing air purification systems are investigated in detail and a prototype of an ionizing lattice is generated, whose function is to filter polluted air when installed as an aesthetic part in buildings. Finally, the purification performance of gases and particles typical of the electrostatic precipitator (ESP) was tested by means of air quality stations. By means of a type of correlational applied research, the similarity between external and internal gases and particulate matter was verified, obtaining, as a result, the effective reduction of the same; decreasing by 4.15% of CO2, 30% of CO and 57% of particulate matter. With this analysis, it is concluded that the prototype of the ionization air purifying lattice can be efficient with some of the gases against particulate pollution in domestic interiors, positively influencing the health of the inhabitants of a building.

Emissions of marine traffic can be lowered by switching to less polluting fuels or by investing in exhaust aftertreatment. Electrostatic precipitation is a widely used method for particle removal but it is not currently used in combination with marine engines. This study presents the particle filtration characteristics of an emission reduction system designed for marine applications and consisting of a scrubber and a Wet Electrostatic Precipitator (WESP) in series. Partial flow of exhaust from a 1.6 MW marine engine, operated with light and heavy fuel oil, was led to the system. Particle concentrations were measured before the system, after the scrubber and after the WESP. Particle removal characteristics were determined for different engine loads. The scrubber alone removed 15–55% of non-volatile particle number, 30–40% of particle mass and 30–40% of black carbon mass depending on engine load, when HFO fuel was used. By studying particle size distributions, scrubber was found also to generate particles seen as an additional mode in 20–40 nm size range. The system combining the scrubber and WESP removed over 98.5% of particles in number, mass and black carbon metrics when HFO fuel was used. With MDO fuel, 96.5% of PN and 99% of black carbon were removed.

On the way to reducing emissions released into the atmosphere, there is an obstacle in the form of the emissions of solid pollutants produced by households, namely the burning of solid fuels in small heat sources. In this article, the authors deal with the development of a low-cost electrostatic precipitator, which would be able to significantly reduce the production of particulate matter. This is a tubular precipitator concept, which is enhanced by dividing the precipitation space into four chambers, each of which has an ionization electrode. With the investigated structural arrangement, it is possible to increase the size of the collection area without affecting the external dimensions of the separator. The essence of this article was to focus on the design of an ionization electrode, which, in addition to the function of a negative electrode, would also fulfill the function of a structural element of the proposed geometry. The work contains a technical design for the shape of the ionization electrode, which was subsequently examined using ANSYS Fluent software. The conditions under which a corona discharge will occur on the electrodes and how particulate matter is captured in the separation device were investigated with the help of simulations of the electric field intensity. According to the achieved simulation results, calculations were made for the theoretical efficiency of particle collection, which reached a value of approximately 78%.

In this paper, a wire-plate electrostatic precipitator with expanded-contracted plates（ESP-ECP） was proposed. A numerical method was adopted to investigate the influences of different arrangements of ECP on the electric field intensity, airflow field, particle trajectory and collection efficiency under different voltages, inlet gas velocities and particle sizes. Furthermore, it was compared with the traditional ESP with parallel plates（ESP-PP）. The results indicated that the ECP expands the surface area of the collecting electrode, and effectively enhances the electric field intensity near the collecting electrode. With the increase of the ECP height, the electric field intensity and influence range increase. The low-velocity vortices generated by the ECP help to prolong the retention time of particles, which is conducive to particle removal. In general, the collection efficiency of the ESP-ECP is superior to the ESP-PP. [ABSTRACT FROM AUTHOR]

The analysis of industrial operation of EGAV1-22-15-7-4 precipitators, designed for cleaning non-aggressive non-explosive process gases and aspiration air from dust, has been carried out. The non-uniform distribution of flows at the inlet to the working area of the precipitator, which leads to a decrease in the dust collection efficiency, an increase in energy consumption and frequent cleaning of the precipitation electrodes, has been revealed. In the course of the research, the authors of this article have proposed design modifications to improve gas distribution in electrostatic precipitators. [ABSTRACT FROM AUTHOR]

Viral respiratory tract infections are a leading cause of morbidity and mortality worldwide. Unfortunately, the transmission routes and shedding kinetics of respiratory viruses remain poorly understood. Air sampling techniques to quantify infectious viruses in the air are indispensable to improve intervention strategies to control and prevent spreading of respiratory viruses. Here, the collection of infectious virus with the six‐stage Andersen cascade impactor was optimized with semi‐solid gelatin as collection surface. Subsequently, the collection efficiency of the cascade impactor, the SKC BioSampler, and an in‐house developed electrostatic precipitator was compared. In an in vitro set‐up, influenza A virus, human metapneumovirus, parainfluenza virus type 3, and respiratory syncytial virus were nebulized and the amount of collected infectious virus and viral RNA was quantified with each air sampler. Whereas only low amounts of virus were collected using the electrostatic precipitator, high amounts were collected with the BioSampler and cascade impactor. The BioSampler allowed straight‐forward sampling in liquid medium, whereas the more laborious cascade impactor allowed size fractionation of virus‐containing particles. Depending on the research question, either the BioSampler or the cascade impactor can be applied in laboratory and field settings, such as hospitals to gain more insight into the transmission routes of respiratory viruses. [ABSTRACT FROM AUTHOR]

The results of studies evaluating the efficiency of fog dispersion by collecting water droplets contained in the fog using the grid electrostatic precipitator are considered. The precipitator includes a corona discharge generation system that provides electric charging of fog droplets and a grounded gauze structure free for airflow. When air flows through the cells of the grounded conductive gauze, electrically charged drops are deposited on its surfaces and are separated from the wind stream. The airflow purified from drops is directed to the protected area and forces fog out of it. Data of the presented studies are based on the experiments conducted in the large aerosol chamber of the Institute of Experimental Meteorology (Taifun Research and Production Association). High efficiency of the investigated method is shown, it may be recommended for practical work to improve visibility in fog in a controlled area. [ABSTRACT FROM AUTHOR]