Types Of Electrostatic Precipitators Research Articles

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.

Decreasing Solid Aerosols from Small Heat Sources Using the Optimized Electrostatic Precipitator

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.

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.

Optimization of pipe-and-spike discharge electrode shape for improving electrostatic precipitator collection efficiency

Numerical analysis was conducted to investigate the effect of wire length, spacing between wires, and wire bending angle, which are geometric parameters of a pipe-and-spike discharge electrode, on collection efficiency. Discharge electrode shape was optimized using the Near Orthogonal Array method. When the distance between collecting plates and the number of discharge electrode wires were fixed, a longer wire length and greater distance between the wires increased the collection efficiency, which was the highest when the bending angle of the wire was 160°. Numerical results were validated through experiments. Collection efficiency of the electrostatic precipitator was increased by about 15% by the optimized discharge electrode, and power consumption and ozone generation showed little difference after optimization. Based on the results of this study, the optimization of the shape of various discharge electrodes is expected to effectively improve the collection efficiency of various types of electrostatic precipitators.

The Guarantee Strategy for Reliable Operation of the Precipitation withMobile Electrode Electrostatic Technology

Research in view of the conventional electrostatic precipitator for ultra fine dust, dust ratio resistance and high viscosity difficult removal, secondary problems such as dust, and domestic environmental protection professional factory introduction, digestion and innovation, a new type of electrostatic precipitator, based on the technology of moving electrode has the following characteristics: low operating cost, the filter processing efficiency, equipment, the advantages of the small resistance, but the moving parts, in order to promote its reliability, the research for mobile motor technology principle and innovative design, this paper discusses the moving electrode duster guarantee reliable operation strategy, in order to offer reference to related staff.

Correlation of design parameters with performance for electrostatic precipitator. Part II. Design of experiment based on 3D FEM simulation

The performance of electrostatic precipitators (ESP) depends on their geometrical and operational parameters. The first part of a two-paper series developed and validated a three-dimensional model describing corona discharge, turbulent flow, and particle charging and tracking in the ESP. Based on the model developed in Part I, this paper correlates the design parameters with ESP performance by applying the design of experiment (DOE) approach. Through a full factorial two-level DOE, both individual and interactive effects of design parameters on ESP performance are studied. Five design parameters are investigated, including wire radius, collecting plate length, plate–plate spacing, applied voltage, and particle diameter. The strength of these effects is quantified with sensitivity factors, based on which the parameters and their interactions are ranked. The ranking changes with the extent of its variation from the nominal value. This analysis can be extended to other design factors and different types of ESPs.

Analysis of the operating parameters of a vortex electrostatic precipitator

A vortex electrostatic precipitator (VEP) forms a vortex flow field within a precipitator by means of the vertical staggered layout of the double-vortex collecting plate facing the direction of the gas flow. The ion concentrations within the precipitator can be significantly increased. Correspondingly, the charging and coagulation rates of fine particles and particle migration velocity are significantly improved within the VEP. Since it can effectively collect fine particles and reduce precipitator size, VEPs represent a new type of electrostatic precipitator with great application potential. In this work the change curve of the external voltage, gas velocity, row spacing and effective collecting area influencing the precipitation efficiency were acquired through a single-factor experiment. Using an orthogonal regression design, attempts were made to analyze the major operating parameters influencing the collecting efficiency of fine particles, establish a multiple linear regression model and analyze the weights of factors and then acquire quantitative rules relating experimental indicators and factors. The regression model was optimized by MATLAB programming, and we then obtained the optimal factor combination which can enhance the efficiency of fine particle collection. The final optimized result is that: when gas velocity is 3.4 m s−1, the external voltage is 18 kV, row spacing is 100 mm and the effective collecting area is 1.13 m2, the rate of fine particle collection is 89.8867%. After determining and analyzing the state of the internal flow field within the VEP by particle image velocimetry (PIV), the results show that, for a particular gas velocity, a vortex zone and laminar zone are distinctly formed within the VEP, which increases the ion transport ratio as well as the charging, coagulation and collection rates of fine particles within the precipitator, thus making further improvements in the efficiency of fine particle collection.

ACTIVE ELECTRODE SHAPE EFFECT ON THE CORONA DISCHARGE IN AN ELECTROSTATIC PRECIPITATOR\

An experimental study of the wires-two plates is presented in this paper. The principal running of these types of electrostatic precipitators is based on the corona discharge on which depend their performances. The factors affecting corona formation on wire - to- plate gaps are investigated experimentally.There are many factors affecting such corona formation. The investigated factors were the interspace between the two wires, gap length between the wire and the plate, ambient temperature, relative humidity, polarity or frequency of the applied voltage, and electrode material. In order to study and explain such phenomena, simultaneous measurements of both the applied voltage and the corona current were introduced. Several design parameters have been taken into consideration especially the numbers of active electrodes and their diameter. Current-voltage curves are particularly analyzed. Experimental results show that discharge current is strongly affected by the active electrode diameters.

A CRITICAL REVIEW OF MODELS USED IN NUMERICAL SIMULATION OF ELECTROSTATIC PRECIPITATORS

The electrostatic precipitators (ESP) have been drawing more and more attention due to their high efficiency and low costs. Numerical simulation is a powerful, economical and flexible tool to design ESP for industry applications. This review summarizes the available numerical models to simulate different physical processes in ESP, including ionized electric field, air flow, particle charging and motion. It has been confirmed that the available models could provide acceptable results and the computing requirements are affordable in industry applications. The coupling between different physical processes can also be considered in simulation. However, there are still some problems not solved, such as selection of a suitable turbulence model in EHD simulation and the coupling criteria. The future study should focus on these issues. This review also includes new types of ESP developed in recent years, such as dielectric barrier discharge (DBD) ESP and corona assisted fibrous filter. These new types of ESP have had high efficiency and low energy consumption. Even though nearly all new ESP types can be modeled using the available numerical models, the most challenging issue is the DBD simulation.

304 バリア放電によるディーゼル排ガス中の微小粒子の除去(大気環境保全・改善技術(1))

Diesel particulate matter exhausted from marine diesel engine during the combustion process cause a various human health and environment impacts. Many methods were applied to control mass concentration of particulate matter from diesel exhaust gas.Many studies of electrostatic precipitator (ESP) were reported to collect 10w resistive particles generated from diesel engine. This research has been developed an after treatment system for removal of particulate matter (PM) emissions from a diesel engine. The system is composed of electrostatic precipitator (ESP) and a high-frequency dielectric barrier discharge (DBD) reactor. A single stage type of ESP was used in this research. The objective is to investigate experimentally DBD reactor's performance on removal of diesel particulate. In the DBD reactor, the air is activated by discharge and produces ozone, oxygen radical and nitrogen radical, resulting the diesel particulates are oxidized under low temperature condition

Improving designs of precipitating electrodes for ug and ega types of electrostatic precipitators

A case has been made for use of Eko MK 4 × 160 precipitating element, whose merit is that it ensures deviations of dimensions from rectilinearity and planarity of not more than 3 mm × 18 m in EGA, EGBM, EGB, and EGAV types of apparatuses as well as in updated versions of DGPN, DGP, PGD, UG, and EG types of electrostatic precipitators (electric filters). Use of Eko MK 4 × 160 precipitating element will help meet current requirements of dust ejections from electrostatic precipitators.

Electric air cleaner composed of nonthermal plasma reactor and electrostatic precipitator

Recent concerns of environmental protection encourage the use of a compact indoor air cleaner and various types of electrostatic precipitators (ESPs) have been manufactured. Although a wide range of airborne particles can be collected effectively with an ordinary ESP using a positive DC corona, it is difficult to remove gaseous compounds such as tobacco smoke which induces submicron particles and an offensive odor. In the present paper, the authors investigated the collection of submicron particles and the decomposition of acetaldehyde (CH/sub 3/CHO) using a commercial ESP and a nonthermal plasma reactor because the offensive odor of tobacco smoke is mainly caused by acetaldehyde molecules. For an ESP, the authors evaluated the particle-size dependent collection efficiency using a monodispersed aerosol because little investigations have been conducted in this area. As for acetaldehyde decomposition, more than 90% of decomposition efficiency was obtained with the use of the nonthermal plasma under dry air. However, the decomposition efficiency was deteriorated under humidified conditions. The higher collection efficiency was achieved for a particle size of 0.6 /spl mu/m than that of 0.3 /spl mu/m although the overall over collection efficiency exceeded more than 99%. The combination of ESP and nonthermal plasma technologies leads to the breakthrough of the conventional indoor electronic air cleaner technology.

Numerical modeling of wire-plate electrostatic precipitator for control of submicron and ultra fine particles

The objective of this work is to develop computer code for the prediction of electrostatic collection (precipitation) of submicron and ultrafine particles from industrial flue gases. Despite the fact that several types of electrostatic precipitators (ESP) are commercially available and widely used, the physical foundations of the interaction between submicron to ultrafine particles with electrical parameters and their coupling to the fine transport processes are not well understood at present. The state of the art calls for the development of a unified approach combining the features of theoretical modelling of the electrostatic precipitation process and the phenomenologically introduced parameters. This will lead to a reliable prediction of the collection performance over a wide range of particle sizes. This will also allow the assessment of the technological performance of a particular collection system prior to the actual installation. Experimental validation was conducted at the well equipped flue gas cleaning test facility.

Preparation of ultrafine superconductive BiCaSrCuO particles by metalorganic chemical vapor deposition

Uniformly-distributed ultrafine superconductive particles with the composition of Bi 2CaSr 2CU 2O x have been prepared by the metalorganic chemical vapor deposition (MOCVD) method. A new type of electrostatic precipitator was developed for continuous collection of ultrafine particles. The particles produced were spherical and the crystalline phases of the particles were found to be greatly dependent on the decomposition temperature and the reaction time. The particles with the 80 K superconducting phase were only formed at around 800°C and a reaction time longer than about 14 s, and the average diameter of the particles was 0.05–0.06 μm.

Application of the electrostatic precipitator to the measurement of radioactive aerosols

A continuous air monitor and a portable dust sampler are described both using a new type of electrostatic precipitator. In the continuous air monitor the dust is collected on a moving aluminium tape which then passes the radiation detectors. The precipitator is operated at very low efficiency, giving a high sensitivity which is nearly independent of air flow rate. The effective drift velocity of the particles towards the collection surface is more than ten times that in the Cottrell-type precipitator.

Power supplies for electrostatic precipitation

Industry has found a multitude of diverse applications for electrostatic precipitation. This article describes the functions of the various types of electrostatic precipitators in use today and points out their common characteristics, and in particular the similarities of their electric power requirements.