• Title/Summary/Keyword: Wet Scrubber

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Removal Characteristics of Gaseous Contaminants by a Wet Scrubber with Different Packing Materials (충진제의 종류에 따른 습식 스크러버의 가스상 물질 제거특성)

  • Han, Bang-Woo;Kim, Hak-Joon;Kim, Yong-Jin;Han, Kyeong-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.6
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    • pp.744-751
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    • 2007
  • Wet scrubber is widely used to remove toxic gaseous contaminants in various industries such as semi-conductor industry, display manufacturing industry and so on. In this study, to optimize a packed bed scrubber as one of typical wet scrubber size while keeping its performance, four different packing materials were investigated at different air flow rates, liquid-gas ratios and pH values. Ammonia, hydrochloric acid and hydrofluoric acid were used as test gases to characterize the scrubber performance. Gas removal efficiency increased as the packing size decreased, which resulted in the increase of specific surface area. The increase of air flow rate led to the decrease of gas removal efficiency, while the increase of liquid-gas ratio led to the increase of gas removal efficiency. For the case of $NH_3$ gas, lower pH, and for the cases of HCl and HF, higher pH contributed to higher gas removal efficiency. Gas removal efficiency of a wet scrubber increased in the order of HCl < $NH_3$ < HF according to its water solubility.

Performance evaluation of nitrate removal in high TDS wet scrubber wastewater by ion exchange resin with dissolved air flotation (DAF) process

  • Kim, Bongchul;Yeo, Inseol;Park, Chan-gyu
    • Membrane and Water Treatment
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    • v.13 no.1
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    • pp.1-6
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    • 2022
  • The regulations of the International Maritime Organization (IMO) have been steadily strengthened in ship emissions. Accordingly, there is a growing need for development of related technologies for the removal of contaminants that may occur during the treatment of SOx and NOx using a wet scrubber. However, this system also leads to wastewater production when the exhaust gas is scrubbed. In this research, we evaluated the performance of an ion selective resin process in accordance with scrubber wastewater discharge regulations, specifically nitrate discharge, by the IMO. Accelerated real and synthetic wastewater of wet scrubbers, contained high amounts of TDS with high nitrate, is used as feed water in lab scale systems. Furthermore, a pilot scale dissolved air flotation (DAF) using microbubble generator with ion exchange resin process was combined and developed in order to apply for the treatment of wet scrubber wastewater. The results of the present study revealed that operating conditions, such as resin property, bed volume (BV), and inlet wastewater flow rate, significantly affect the removal performance. Finally, through a pilot test, DAF with ion exchange resin process showed a noticeable improvement of the nitrate removal rate compared to the single DAF process.

An Experiment on the Particle Collection Characteristics in a Packed Wet Scrubber (충진층식 세정집진기의 집진특성 실험)

  • 유경훈;노희환;최은수;김종균
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.4
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    • pp.305-311
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    • 2003
  • DOP aerosol particles with geometric mean diameter of 0.5-3.0 ${\mu}{\textrm}{m}$, geometric standard deviation of 1.1-1.3 and total number concentration of 1,500-8,000 Particles/㎤ were used to determine collection efficiencies of a packed wet scrubber with respect to particle size. The tested operating variables included air velocity and water injection rate. It was shown from the experimental results that the collection efficiencies increased with increasing water injection rate and decreasing air velocity. Meanwhile, as for the particle size variation, all of the collection efficiency curves increased rapidly between 0.57-1.41${\mu}{\textrm}{m}$ for the range of water injection rate above 30 L/min. It was also seen that the collection efficiency of a packed wet scrubber is mainly governed by the mechanism of inertial impaction.

An Experiment on Particle Collection Characteristics of a Duct-type Wet Scrubber (덕트형 세정집진기의 입자포집 특성실험)

  • Yoo, Kyung-Hoon;Yeo, Kuk-Hyun;Son, Seung-Woo;Hwang, Kwang-Ho;Jung, Jin-Won;Kim, Yoon-Shin
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1795-1800
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    • 2004
  • DOS and NaCl aerosol particles with geometric mean diameter of $0.1{\sim}3.0{\mu}m$ geometric standard deviation of $1.1{\sim}1.8$ and total number concentration of $450{\sim}400$ $particles/cm^3$ were used to determine collection efficiencies of a duct-type wet scrubber with respect to particle size. The tested operating variables included air velocity and water injection rate. It was shown from the experimental results that the collection efficiencies increased with increasing water injection rate and decreasing air velocity. It was also seen that the collection efficiency of the Duct-type wet scrubber is mainly governed by the mechanism of inertial impaction.

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An Experiment on Particle Collection and Gas Removal in a 2-Stage Electrostatic Wet Scrubber (2단 정전식 세정집진기의 집진 및 가스제거 특성)

  • Yeo, Kuk-Hyun;Yoo, Kyung-Hoon;Son, Seung-Woo;Kim, Yoon-Shin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.9
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    • pp.745-752
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    • 2006
  • DOS and NaCl aerosol particles were used to determine collection efficiencies of a 2-stage electrostatic wet scrubber with respect to particle size. The DOS and NaCl aerosols have geometric mean diameters of 0.1-3.0 urn, geometric standard deviations of $1.1{\sim}1.8$ and total number concentrations of $450{\sim}2,400\;particles/cm^3$. The tested operating variables for the electrostatic wet scrubber included air velocity and water injection rate. It was shown from the experimental results that particle collection efficiencies increased in the submicron particle size range when different polarities were applied on the water nozzle and corona wire, respectively. This increase in the collection efficiency is attributed to strong electrostatic attraction between the negative water droplets and positive submicron particles. The collection efficiencies also increased when water injection rate was increased or air velocity was decreased. Meanwhile, the pressure drop across the wet scrubber decreased by 90% compared with the existing mechanical wet scrubber. Finally, ammonia gas was used to determine gas removal efficiencies. It was observed that the gas removal efficiencies increased when the air velocity was decreased or the water injection rate was increased.

Collection Efficiency Enhancement of Spray Tower Scrubber by Introducing Electrospray with Two-flow Nozzle (분무탑식 스크러버에서 이류체 정전분무에 의한 집진효율의 향상)

  • Hwang, You-Seong;Kim, Jong-Ho;Kim, Jong-Hyeon
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.3
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    • pp.339-345
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    • 2010
  • There have been a number of efforts to satisfy national emission regulations and reduce the amount of emitted air pollutants. There are several air pollution control devices, however, only wet scrubber is efficiently used to remove particulate matters and gaseous pollutants, even if it has minimum collection efficiency in the particle size range of $0.1{\sim}1{\mu}m$. This study aimed to improve the collection efficiency of a spray tower type scrubber by introducing an electrospray system with two-flow nozzle. We found that the collection efficiency of a spray tower type scrubber was similar to that of a conventional wet scrubber. However, installation of an electrospray system in the scrubber resulted in drastic further improvement of collection efficiency comparing to that of a conventional scrubber, which is 26%, 35.2%, and 45.1% at the liquid to gas ratio of 0.26 $L/m^3$ and 19.9%, 35.1%, and 42.5% at 0.34 $L/m^3$ for the applied voltage of -30 kV, -35 kV, and -40 kV, respectively. Therefore, we found that the introduction of an electrospray system is very effective to improve the collection efficiency of a spray tower type scrubber.

Efficient Management of the pH of the Wet Scrubber Washing Water for Risk Mitigation (리스크 완화를 위한 Wet Scrubber 세정수 pH의 효율적 관리)

  • Joo, Dong-Yeon;Seoe, Jae Min;Kim, Myung-Chul;Baek, Jong-Bae
    • Journal of the Korean Society of Safety
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    • v.35 no.6
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    • pp.85-92
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    • 2020
  • Wet Scrubber reacts the incoming pollutant gas with cleaning water (water + absorbent) to absorb pollutants and release the clean air to the atmosphere. Wet scrubbers and packed tower scrubbers using this principle are widely used in businesses that emit acid gases. In particular, in the etching process using hydrochloric acid (HCl), alkaline washing water (NaOH) having a pH of about 8 to 11 is used to absorb a large amount of acid gas. However, These salts are attached to the injection nozzle (nozzle), filling material (packing), and the demister (Demister), causing air pollution, human damage, and inoperability due to clogging and acid gas discharge. Therefore, In this study, an improvement plan was proposed to manage the washing water with pH 3~4 acidic washing water. The test method takes samples from the Wet Scrubber flue measurement laboratory twice a month for 1 year. Hydrogen chloride (HCl) concentration (ppm) was measured, and nozzle clogging and scale conditions were measured, compared, and analyzed through a differential pressure gauge and a pressure gauge. As a result of the check, it was visually confirmed that the scale was reduced to 50% or less in the spray nozzle, filler, and demister. In addition, the emission limit of hydrogen chloride in accordance with the Enforcement Regulation of the Air Quality Conservation Act [Annex 8] met 3 ppm or less. Therefore, even if the washing water is operated in an acidic pH range of 3 to 4, it is expected to reduce air pollution and human damage due to clogging of internal parts, and it is expected to reduce maintenance costs such as regular cleaning or replacement of parts.

Quantitative Analysis of the Impact of Inlet Duct Spray on Scrubbing Efficiency using Experimental Design (실험계획법을 이용한 입구덕트 스프레이의 습식 세정 효율 변화효과 분석 연구)

  • Lee, Minwoo;Kim, Hyun Ho;Koo, Junemo
    • Journal of ILASS-Korea
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    • v.24 no.1
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    • pp.8-14
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    • 2019
  • The purpose of this study is to develop a packing-free wet scrubber to prolong the maintenance interval compared with the conventional packed bed wet scrubbers with which frequent operation stops are unavoidable to clean the packing materials. The main- and interaction-effects were quantitatively analyzed by regression analysis for the measured ammonia scrubbing data from the experiments prepared by experimental design. The scrubbing efficiency of the newly developed wet scrubber was found to be over 95% under the condition of flue gas flow rate of 90CMM and liquid-to-gas ratio $2l/m^3$ for all considered trials of experimental design. The interaction effect between the inlet duct spray and the filter was found to be important, which controls the droplet growth due to the droplet collisions between the duct- and scrubbing tower-spray. The presented methodology to analyze the impacts of operational and design factors on the scrubber efficiency showed potential for applications to optimize the future flue gas abatement process in semiconductor plants.

The Effect of Spray Flow Rate, Aspect Ratio, and Filling Rate of Wet Scrubber on Smoke Reduction (습식 스크러버의 분무유량, 형상비 및 충진율 변화가 스모크 저감에 미치는 영향)

  • Son, Kwun;Lee, Ju-Yeol;Park, Kweon-Ha
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.3
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    • pp.217-222
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    • 2015
  • There has been increased amount of atmospheric pollutants including NOx and SOx which cause acid rain and photochemical smog as a result of increased use of fossil fuels. In order to reduce the amount of pollutants produced by fossil fuel, wet scrubber system is introduced in this experiment. Wet scrubber system is applied to a diesel engine (3,298 cc) and the amount of smoke is measured before and after the application in terms of aspect ratio, filling rate, and flow rate. The result showed a lot of smoke reduction when wet scrubber system was applied, and also the aspect ratios and water spray flow rate were the important factors to improve smoke reduction.

Development of Marine Emission Control System on NOx and SOx through Seawater Electrolysis

  • Kim Houng-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.1
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    • pp.81-87
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    • 2006
  • In marine air pollution control, SCR (Selective Catalytic Reduction) is reconized as the most effect method to control NOx, but on the other hand. seawater scrubber applying the basic characteristic that is naturally alkaline (pH typically around 8.1) is viewed as an economical SOx removal system at present. Especially, seawater scrubber would not be necessary to follow any of the various land based flue gas desulfurization methods. i.e. wet, dry or alkali scrubbing. However, these methods are not readily adaptable to marine conditions due to the quantifies of consumables required i.e. lime or limestone, the means of operation and the commercial availability. This research is undertaken to develop a new method as the main target of eliminating all exhaust emissions, particularly vessel, because of easy access to seawater and apt to apply a wet scrubber system. First, using the acidic seawater by seawater electrolysis, nitric monoxide(NO) is adequately oxidized to nitric dioxide $(NO_2)$by ClOx-in the acidic seawater, the electrolyzed alkaline seawater by electrolysis which contains mainly NaOH together with alkali metal ions $(i.e\;Na^{+}\;K^{+},\;Mg_{2}\;^{+},\;Ca_{2}\;^{+})$, is used as the absorption medium of NOx, the SOx are absorbed by relatively high solubility compared to other components of exhaust pollutants. The results found that the NOx and SOx removals could be achieved nearly Perfect.