• Journal of the Korean Society of Safety
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• v.13 no.4
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• pp.155-161
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• 1998

Recently, there are widely needs of small scale electrostatic precipitator(ESP) in machine shop and other factories. Since the space of such factories is limited, the improvement of collection efficiency is predominant subject. In this study, we examine the influence of distribution of wind velocity and oil mist concentration inside the ESP in order to improve the performance of the ESP. The distribution of wind velocity and mist concentration is measured respectively in a cross-sectional plane of the ESP. The former is controlled by using a louver which is placed in front of an ionizer and the latter is controlled by lengthening the pipe of entrance of the ESP in order to have plenty of time that mist is dispersed evenly. It is shown that the uniformity of distribution of wind velocity and mist concentration inside the ESP can be getting by adopting a louver with proper shape and lengthening the pipe of entrance and is also contributed to collection efficiency considerably.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.128.2-128
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• 2001

Since pulse energization can improve the performance of Electrostatic Precipitator(ESP) for high resistivity dusts, high voltage micro-pulse generators, 70kV 140usec duration pulses for instance, are commonly developed by LC resonance for most pulse powered ESPs. Consisting of discharge electrodes and collecting electrodes, ESP has its own capacitance like a capacitor. ESP's capacitance affects the LC resonance phenomenon with resonance inductor and capacitor of micro-pulse power supply, engineers should acquire the value of their ESP to design for proper power supply design. In this study, we describe the ESP's capacitance measuring device which has the same topology with our new developed micro-pulse power supply. In this microcontroller based capacitance measuring equipment, ESP's capacitance can be calculated easily through ...

• Particle and aerosol research
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• v.15 no.2
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• pp.57-65
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• 2019

Recently, there has been much research on the effect of fine dust on human body with increasing interest in the fine dust. Thermal power plant, which is considered as one of the main sources of fine dust, is reported to be responsible for 14% of the total amount of domestic fine dust in the Republic of Korea. Therefore, dust collecting devices in the thermal power plant need to be improved. In this study, the electrostatic precipitator (ESP) was considered to substitute for a mist eliminator used in flue gas desulfurization facility. By considering real situation in the flue gas desulfurization facility, the collection efficiency of the ESP was evaluated by using the sprayed limestone slurry particles. The collection efficiency of the ESP was higher than that of the mist eliminator, showing the possibility of replacing the mist eliminator with the ESP in flue gas desulfurization facility.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1435-1440
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• 2003

Although Dielectric Barrier Discharge (DBD) in air has been applied to a wider range of aftertreatment processes for HAPs(Hazardous Air Pollutants), due to its high electron density and energy, its potential use as precharging dust particles is not well known. In this work, we measured size distributions of bimodal aerosol particles and estimated collection efficiency of the particles by electrostatic precipitator(ESP) using DBD as particle charger. To examine the particle collection with DBD charger, nano size particles of NaCl($20{\sim}100$ nm) and DOS($50{\sim}800$ nm) were generated by tube furnace and atomizer, respectively. For experimental conditions of 60 Hz, 11 kV, and 60 lpm, the particle collection efficiency for the hybrid system comprising DBD charger and ESP was over 85 %, based on the number of particles captured.

• Journal of ILASS-Korea
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• v.16 no.2
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• pp.69-75
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• 2011

This article presents computational fluid dynamics (CFD) simulations of sub-micron particle movements and flow characteristics in laboratory-scale electrostatic precipitator (ESP) without corona discharge, and for simulation, it uses the commercial CFD program (CFD-ACE) including electrostatic theory and Lagrangian-based equation for sub-micron particle movement. For validation of CFD results, a simple cylindrical type of ESP is simulated and numerical prediction shows fairly good agreement with the analytical solution. In particular, the present study investigates the effect of particle diameter, inlet flow rate, and applied electric potential on particle collection efficiency and compares the numerical prediction with the experimental data, showing good agreement. It is found that the particle collection efficiency decreases with increasing inlet flow rate because the particle detention time becomes shorter, whereas it decreases with the increase in sub-micron particle diameter and with the decrease of applied electric voltage resulting from smaller terminal electrostatic velocity.

• Journal of Environmental Science International
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• v.7 no.4
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• pp.505-510
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• 1998

This study has been carried out to investigate Electrostatic Precipitator's(ESP) performance enhancement and removal efficiency of fine particle according to (NH4)2SO4injection rate. The following conclusions are derived from the these test results : 1) For plant condition cases, according to the variation of concentration agent [(NH4)2SO4]-10ppm, when inlet dust loading was 2g/m2. And when Inlet dust loading was 3g/m", that was increased to 98 19% 99.16% 99.23%, 99.58%, 2) It Is seen from thins experiments that the increasing 30ppm concentration of (NH4)2SO4 increase the collection efficiency and fine particle omission control.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.251-259
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• 2000

The ionic wind formed in a nonuniform electric field has been recognized to have a significant effect on particle collection in an electrostatic precipitator(ESP). Under normal operating conditions the effect of ionic wind is not pronounced. However, as the flow velocity becomes smaller, the ionic wind becomes pronounced and induces secondary flow, which has a significant influence on the flow field and the particle collecting efficiency. In this paper, experiments for investigating the effect of secondary flow on collection efficiencies were carried out by changing the flow velocities in 0.2-0.7m/s and the applied voltages in 9-11kV/cm. The particle size distributions and concentrations are measured by DMA and CNC. To analyze the experimental results, numerical analysis of electric filed in ESP was carried out. It shows that particle collection is influenced by two independent dimensionless numbers, $Re_{ehd}\;and\;Re_{flow}$ not by $N_{ehd}$ alone. When $Re_{flow}$, decreases for constant $Re_{ehd}$, the secondary flow prohibits the particle collection. But when $Re_{ehd}$ increases for constant $Re_{flow}$, it enhances the particle collection by driving the particles into the collection region.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.7
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• pp.572-578
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• 2001

This study conducts a laboratory measurement on a cylindrical electrostatic precipitator(ESP) with a 30mm-diameter cylinder. Several kinds of test aerosols are generated with an atomizer and a diffusion dryer. The effects of applied voltage, flow state, gas velocity, and gas temperature on the electrical characteristics of the precipitator and onset of corona are experimentally investigated. The corona onset voltage is decreased, as diameter of discharge electrode wire becomes small or temperature of the precipitator increases. As the fluid velocity or particle load in the precipitator increases, the corona current is decreased.

• Particle and aerosol research
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• v.9 no.2
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• pp.79-87
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• 2013

In this study, the characteristics of turbulent flow and collection efficiency for an one-stage electrostatic precipitator(ESP) with slit type collecting electrode for urban railway underground tunnels were obtained using computational fluid dynamics(CFD) commercial code FLUENT 6.3 and lab-scale experiments. The electrostatic precipitator was operated under high gas velocity(3~12m/s). Five different designs of collecting electrode, flat plate-type and a slit-type of 3mm, 5mm, 7mm and 10mm slit width and four various gas velocity(3, 6, 9, and 12m/s) were used and applied. A standard k-${\varepsilon}$ model in CFD commercial code FLUENT 6.3 was used for flow simulation. The flow simulation results showed that the turbulent intensity of flat plate-type was higher than slit-type under all gas velocity conditions and also the turbulent intensity of flat plate-type was increased continuously, but in case of slit-type was maintained at constant range. And, the turbulent intensity was decreased according to increasing of slit width. The experimental results showed that the collection efficiency of slit-type was higher than flat plate-type under all gas velocity conditions. And, over 6m/s gas velocity condition, the collection efficiency of 5mm and 7mm was highest, when compared to 3mm and 10mm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.7
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• pp.83-91
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• 2011

Even if smoke, fumes, mist or dust particles are removed by electrostatic precipitators (ESPs), the occurrence of ozone, which is harmful to human body, has to be severely restricted in the indoor environments of hospitals, offices, and workshops. Therefore, the two-stage ESP generating positive corona at the ionizer is typically used because it creates less ozone than the two-stage ESP generating negative corona at the ionizer. In order to predict the collection performance and the optimal design of the two-stage ESP applied to positive high-voltage, particle concentration is experimentally investigated in this paper. In addition, particle motion within the collector section is also numerically analyzed. The positive corona discharge current of the ionizer is found to be affected by the applied voltage in the collector section but less so by the particle concentration. Particle concentration shows a minimum near the high voltage electrode of the collector section. The minimum value of the collection efficiency is almost proportional to gas velocity. When the collector length decreases, the minimum value of the collection efficiency increases. Charged particles entering the collector region are linearly deflected towards the grounded plate by an electric field. From the above experimental and numerical results, two empirical equations on the concentration ratio and the collection efficiency are derived, and are in good agreement with the experimental data.