• Clean Technology
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• v.3 no.1
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• pp.96-105
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• 1997

The objectives of this study were to investigate $SO_2$ removal efficiency of anthracite - bituminous coal blend combustion in a fludized bed coal combustor with Ca/S, anthracite ratio, bed temperature, and waste paper sludge particle size. The experimental results were presented as follow ; the effect of the desulfurization by the particle size of waste paper sludge was a great and $SO_2$ removal efficiency was heigest in paper sludge dia $1016{\mu}m$. And the difference of $SO_2$ removal efficiency according to air velocity was not too large. As Ca/S mole ratio incresed, $SO_2$ removal efficiency incresed rapidly up to Ca/S mole ratio 3 while the desulfurization rates did not increse too largely in the range of more than the level. The bed temperature had a great deal of effect on the desulfurization rate. So the $SO_2$ removal efficiency was a graet using waste paper sludge that the properbility of paper sludge as sorbent was conformed.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.1
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• pp.16-24
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• 2005

Mathematical model was developed to verify a sequential particle removal taking place in a granular media gravity filter. Consequential multi-layer filtration cycle model was applied to verify the fraction of filter effluent particles that are filter influent particles that were never removed as well as the fraction of filter effluent particles that were detached after deposition were performed through laboratory experiments. Three sizes of marker particles were injected ahead of the filter column as a pulse in the presence of four sizes of polystyrene particles that were used as a primary source of particles in the raw suspension to investigate particle attachment alone in contrast to net removal from attachment and detachment. Microscopic counting of filter effluent particles was assumed to reflect attachment. Experimental results indicated that particle detachment is significant beginning from the early phase of filtration. For each size of fluorescent microspheres at one filter depth, fluorescent microsphere removal increased with filter runtime to a maximum due to ripening. The detached fraction of effluent particles increased with particle size and filter depth. The presence of detached particles and the increasing fraction of detached particles in deeper bed were confirmed.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2005.11a
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• pp.494-496
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• 2005

• Journal of the Korean Society of Safety
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• v.14 no.1
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• pp.78-85
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• 1999

The removal characteristics of H$_2$S from IGCC process over the natural manganese ore(NMO) containing several metal oxides($MnO_x$ : 51.85%, $FeO_y$ : 3.86%, CaO : 0.11%) were carried out in a batch type fluidized bed reactor(I.D.=40mm, height=0.8m). The $H_2S$ breakthrough curves were obtained as a function of temperature, initial gas velocity, initial gas concentration, and aspect ratio. The effect of particle size ratio and particle mixing fraction on $H_2S$ removal were investigated with binary system of different particle size. From this study, the adsorption capacity of $H_2S$ increased with temperature but decreased with excess gas velocity. The breakthrough time for $H_2S$ is reduced as the gas velocity is increased which leaded to gas by-passing and gas-solid contacting in a fluidized bed reactor. The results of the binary particle system with different size in batch experimental could predict to improve the behavior of continuous process of $H_2S$ removal efficiency. The natural manganese ore could be considered as potential sorbent in $H_2S$ removal.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.719-726
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• 2009

One of the alternative runoff management measures is on-site runoff mitigation, such as rainwater retention tank and infiltration facilities especially the latter that is possible to manage simultaneously runoff quality and quantity as a perspective of water-cycle. This study was conducted to develop a particle separator, inclined-pipe settling system, that could improve particle removal efficiency of road runoff as a pre-treatment device of stormwater infiltration. Solid particles larger than $100{\mu}m$ are separated by simple sedimentation; however, the significant amount of pollutants with a diameter less than $100{\mu}m$ remain in suspension. Without any treatment in that case of the runoff into infiltrate, groundwater would be deteriorated and also infiltration rate would be decreased by clogging. Therefore, we suggest optimal design parameters (inclined angle, pipe length, and surface loading rate) of inclined-pipe settling system which can be designed to effectively remove particles diameter smaller then $70{\mu}m$. Thus, the results showed TSS removal efficiency more than 80% with a particle diameter between $20{\mu}m$ and $70{\mu}m$, 100% above particle diameter $70{\mu}m$ for the inflow rate $0.018 m^3/m^2{\cdot}hr$ with pipe inclined at angle $15^{\circ}$.

• Particle and aerosol research
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• v.16 no.1
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• pp.1-8
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• 2020

Nano-pulse plasma technology has great potential as the process simplicity, high efficiency and low energy consumption for SO₂ removal. The research on the gas-to-particle conversion is required to achieve higher efficiency of SO₂ gas removal. Thus, we studied the effect of the relative humidity, NH₃ concentration and applied voltage of the nano-pulse plasma system in the gas to particle conversion of SO₂. The particles from the conversions were increased from 10 to 100 nm in diameter as relative humidity, NH₃ concentration, applied voltage increases. With these results, nano-pulse plasma system can be used to more efficient removal of SO₂ gas by controlling above parameters.

• Korean Chemical Engineering Research
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• v.57 no.4
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• pp.461-468
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• 2019

Demand for improving dust removal efficiency in coal power plants and the dust removal requirement to the level of capturing fine particulate matter and ultrafine particles have been increasing. While bag filter and electrostatic precipitator (ESP) are typically used for dust removal in the processes operating at atmospheric pressure, metal filters or ceramic filters are employed for dust which is produced at high temperature/pressure system as in coal gasification. For dust removal at the high temperature/pressure conditions, two metal filters of five compressed/sintered layers were manufactured and applied to analyze the dust removal characteristics. Manufactured metal filters exhibited more than 99% dust removal efficiency on coal gasification fine particulates in mass basis. To evaluate the fine particulate removal efficiency of less than $2.5{\mu}m$, JIS standard fine sample was used and confirmed the removal efficiencies of 97% and 70~82% on the fine particulates of $1{\sim}2.5{\mu}m$ size range. For the size range of less than $1{\mu}m$, dust removal efficiency of manufactured metal filters significantly degraded with smaller particle size. Improving methods are proposed to overcome the limitations in applying to fine dust of less than $1{\mu}m$.

• Particle and aerosol research
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• v.6 no.4
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• pp.173-183
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• 2010

The high temperature pleated filter bags which were used during this study were made of pleated nonwoven fabric of heat and acid resistant polysulfonate fibers which can withstand the heat up to $300^{\circ}C$ and have a filtration area which is 3 to 5 times larger than the conventional round filter bags. Cartridge module packed with 3 kind of the sulfur impregnated activated-carbon based sorbents were inserted in the inner of the pleated filter bag. This type of pleated filter bag was designed to remove not only the particulate matter but also the gaseous elemental mercury. The electrostatic precipitator part can enhance the particulate removal efficiency and reduce the pressure drop of the pleated filter bag by agglomerated particles to form a more porous dust layer on the surface of the pleated bag which is increased the filter bag cleaning efficiency. In addition, the most of particles are separated from the flue gas stream through the cyclone and the electrostatic precipitator part which were installed at the lower part and main body part of the convergence particulate collector, respectively. Thus reduce particulate loading of the high temperature pleated filter bags were applied in this study to analyze the removal characteristics of particulate matter and gaseous elemental mercury.

• Particle and aerosol research
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• v.16 no.4
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• pp.119-130
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• 2020

In this study, we developed a separated two-stage electrostatic precipitator applicable in a subway air conditioning system. We studied the characteristics of collection efficiency of 0.3 ㎛ particle and ozone generation at different charger sizes and gaps of collector plates. Also, we compared the performance of the two-stage ESP to the MERV 10 filter with the removal efficiency of 10% used in actual subway air conditioning system. The maximum collection efficiency of 0.3 ㎛ particle was 93% at A charger (600 mm×250 mm×600 mm) and 84% at B charger (330 mm×280 mm×330 mm). Especially, with voltages applied to chargers with collection efficiency of about 80% or more, the ozone concentration of two different chargers was 5 ppb to 35 ppb. Finally, the filter quality of the collector developed in this study was 400 times higher than that of the MERV 10 filter. Therefore, it was concluded that the two-stage ESP could be a promising PM removal device suitable for subway air conditioning system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.10
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• pp.792-800
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• 2002

A grease filter is used to remove grease generated from a cooking appliance in a kitchen. This numerical study has been conducted to investigate the particle collection characteristics of a grease filter having nominal flowrate of $100m^3$/h. The flow field and particle trajectories in the grease filter with a flow chamber were simulated by using the commercial code of STAR-CD. The air velocity and pressure distributions were discussed in detail. The pressure drop of a grease filter rapidly increases with increasing the air flowrate. The numerical values of the pressure drop are slightly lower than the experimental values when the air flowrates are 50, 75, and 100㎥/h. The particle collection efficiency of a grease filter increases with increasing the particle diameter, the particle density, and the air flowrate, which means that the inertial impaction is a dominant particle removal mechanism in a grease filter. The cut-off diameter of the tested grease filter representing 50-% collection efficiency is about 11.6$\mu$m for water droplets at $100m^3$/h.