• 제목/요약/키워드: DOS 입자

검색결과 11건 처리시간 0.031초

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

  • 유경훈;여국현;손승우;황광호;정진원;김윤신
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 춘계학술대회
    • /
    • pp.1795-1800
    • /
    • 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.

  • PDF

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

  • 여국현;유경훈;손승우;김윤신
    • 설비공학논문집
    • /
    • 제18권9호
    • /
    • pp.745-752
    • /
    • 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.

입자 퇴적이 승용차용 정전 필터의 미세 입자 포집 특성에 미치는 영향 (Effect of Particle Loading on the Collection Performance of an Electret Cabin Air Filter for Submicron Particles)

  • 지준호;강석훈;황정호;배귀남
    • 대한기계학회논문집B
    • /
    • 제26권8호
    • /
    • pp.1102-1114
    • /
    • 2002
  • An electret filter is composed of permanently charged electret fibers and is widely used in applications requiring high collection efficiency and low-pressure drop. In this work, the collection efficiency of the filter media used in manufacturing cabin air filters was investigated by using poly-disperse particles when submicron particles were loaded. Long-term experiments were conducted by applying two different charging states, which were spray electrification and charge equilibrium by bipolar ionization. In order to investigate the effect of particle loading in filter media, NaCl particles were generated from 0.1% and 1% solutions by an atomizer. Liquid DOS particles were used to evaluate the effect of liquid particles on the collection efficiency of an electret filter. The results show significant effect of charge amount and size distribution of loading particles on the collection performance of a filter media in submicron region. Smaller particles loaded in electret fibers cause a more rapid degradation in collection efficiency and have lower minimum efficiency with time. The pressure drop of a filter media do rarely increase when the collection efficiency decreases to the minimum value. For the larger particles charged by spray electrification, which have charge amounts more than that of Boltzmann equilibrium charge distribution, the pressure drop of a filter media slowly increases in comparison with that of equilibrium charged particles. For DOS particles it is shown that the charging level of an electret filter severely decreases and the collection efficiency is below 10% in some particle size range.

배리어 유전체 방전을 이용한 전기 집진부에서의 나노 입자 집진 효율 (Collection Efficiency of Nano Particles by Electrostatic Precipitator using Dielectric Barrier Discharge)

  • 강석훈;지준호;변정훈;황정호
    • 대한기계학회논문집B
    • /
    • 제27권11호
    • /
    • pp.1542-1547
    • /
    • 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 an electrostatic precipitator (ESP) using DBD as particle charger. To examine the particle collection with DBD charger, nano size particles of NaCl(20∼100nm) and DOS (50∼500nm) were generated by a tube furnace and an atomizer, respectively. For experimental conditions of 60㎐, 11㎸ and 60 lpm, the particle collection efficiency for the hybrid system was over 85%, based on the number of particles captured.

배리어 유전체 방전을 이용한 전기 집진부에서의 나노 입자 집진 효율 (Collection Efficiency of Nano Particles by Electrostatic Precipitator using Dielectric Barrier Discharge)

  • 강석훈;변정훈;지준호;황정호
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 춘계학술대회
    • /
    • pp.1435-1440
    • /
    • 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.

  • PDF

AC 전기장내 하전 액체 입자의 응집에 관한 실험적 연구 (Experimental Study on Electrical Agglomeration of Liquid Particles in an Alternating Electric Field)

  • 지준호;황정호;배귀남;김용진
    • 대한기계학회논문집B
    • /
    • 제25권3호
    • /
    • pp.442-450
    • /
    • 2001
  • Experiments were carried out on agglomeration of bipolarly charged particles in an alternating current electric field. Laboratory-scale setup was built and experiments were conducted at atmospheric condition. DOS(Di-octyl Sebacate) particles with 100% purity were generated by an atomizer. The particles were branched into two, each of which passed through a wire-to-plate type charging section where a positive or a negative DC high voltage was applied and was charged positively or negatively. These bipolarly charged particles together passed through an agglomeration section where an $\pm$20kV AC power was applied between two plates. The resident time in the agglomeration section was adjusted as l sec. Particle sampling was made by a cascade impactor (MOUDI). The effect of agglomeration system on the reduction ratio of particles below l ㎛ was 42∼45%. Effect of AC frequency on the particle size distribution was found insignificant.

서브마이크론 입자 측정용 저압 임팩터의 설계 및 성능평가 (Design and Performance Evaluation of a Low Pressure Impactor for Sampling Submicron Aerosols)

  • 지준호;조명훈;배귀남;황정호
    • 대한기계학회논문집B
    • /
    • 제28권3호
    • /
    • pp.349-358
    • /
    • 2004
  • A low pressure impactor is an impaction device to separate airborne particles into aerodynamic size classes at low pressure condition. We designed a two-stage low-pressure impactor to classify submicron sized environmental aerosols. Performance evaluation was carried out for stages 1 and 2 by using an electrical method. Monodisperse liquid dioctyl sebacate (DOS) particles were generated using evaporation-condensation process followed by electrostatic classification using a DMA (differential mobility analyzer). The test particles were in the range of 0.08∼0.8$\mu\textrm{m}$. For the evaluation of the impactor we used two electrometers; one was connected to the impaction plate of the impactor and the other was to the Faraday cage used as a backup filter. The effect of polydispersity of test aerosols on the performance was investigated. The results showed that the experimental 50-% cutoff diameters at each impactor's operation pressure were 0.53 and 0.187$\mu\textrm{m}$ for stages 1 and stage 2, respectively. The effects of operation pressure on the cutoff diameter and the steepness of collection efficiency curves were also investigated.

실시간 미세입자 측정을 위한 다이오드형 코로나 하전기의 설계 및 성능평가 (Design and Performance Evaluation of a Diode Type Corona Charger for Real-Time Measurement of the Submicron Aerosol)

  • 조명훈;지준호;박동호;배귀남;황정호
    • 대한기계학회논문집B
    • /
    • 제28권9호
    • /
    • pp.1066-1074
    • /
    • 2004
  • With a diode corona charger, which is a component of ELPI(Electrical Low Pressure Impactor), aerosol particles are charged to make electrical detection possible before they are collected by the impactor. We designed and evaluated two cylindrical corona chargers, each of which had a central corona needle electrode. For the performance evaluation of each corona charger the polydisperse dioctyl sebacate(DOS) particles, with diameters of 0.1∼0.8 $\mu$m and NaCl particles, smaller than 0.1$\mu$m, were used. The particles were then led through an electrostatic classifier (TSI model 3081) to classify monodisperse aerosol with minimal size deviation. After evaluating the wall loss of the particles in the corona charger, we measured the product of penetration and number of charges, Pㆍn, to evaluate the corona charger efficiency at high positive voltages of 4, 5, 6 kV.

나노 환경입자 측정용 전기적 임팩터의 설계 및 성능평가 (Design and Performance Evaluation of Electrical Impactor for Nano Environmental Aerosols)

  • 지준호;조명훈;배귀남;황정호
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 춘계학술대회
    • /
    • pp.1417-1422
    • /
    • 2003
  • An electrical cascade impactor is a multistage impaction device to separate airborne particles into aerodynamic size classes using electrical method. We designed a real-time three-stage electrical low-pressure impactor, which is proper to nanometer sized environmental aerosols. Performance evaluation was carried out for stage 1 and 2. The monodisperse liquid dioctyl sebacate (DOS) particles were generated using condensation-evaporation followed by electrostatic classification using DMA (differential mobility analizer) for particles with diameters in the range of $0.04{\sim}0.8{\mu}m$. The evaluation of the electrical impactor is based on the use of two electrometers, one connected to the impaction plate of the impactor, and the other to the faraday cage as backup filter. The results showed that the experimental 50% cutoff diameters in the operation pressure were 0.53 and $0.12{\mu}m$ for stage 1 and stage 2. The effect of operation pressure on the cutoff diameter and the steepness of collection effcieicy curves is investigated.

  • PDF

노즐 막힘이 미세 오리피스형 다단 임팩터의 입자 채취 성능에 미치는 영향 (Effect of Particle Clogging in Orifices on the Particle Collection Efficiency of a Micro-Orifice Impactor)

  • 지준호;배귀남;황정호
    • 대한기계학회논문집B
    • /
    • 제27권2호
    • /
    • pp.197-205
    • /
    • 2003
  • A cascade impactor is a multistage impaction device used to separate airborne particles into aerodynamic size classes. A micro-orifice impactor uses micro-orifice nozzles to extend the cut sizes of the lower stages to as small as 0.05 ${\mu}{\textrm}{m}$ in diameter without resorting to low pressures or creating excessive pressure drops across the impactor stages. In this work, the phenomenon of particle clogging in micro-orifice nozzles was experimentally investigated for a commercial micro-orifice uniform deposit impactor (MOUDI). It was observed, using an optical microscope, that the micro-orifice nozzles of the final stages were partially clogged due to particle deposition during the aerosol sampling. Therefore the pressure drops across the nozzles were higher than the nominal values given by the manufacturer. To examine the effect of particle clogging in micro-orifice nozzles, the particle collection efficiency of the MOUDI was evaluated using an electrical method for fine particles with diameters in the range of 0.1-0.6 ${\mu}{\textrm}{m}$. The monodisperse liquid dioctyl sebacate (DOS) particles were used as test aerosols. A faraday cage was employed to measure the low-level current of the charged particles upstream and downstream of each stage. It was found that the collection efficiency curves shifted to correspond to smaller orifice sizes, and the 50-% cutoff sizes were much smaller than those given by the manufacturer for the three stages with nozzles less than 400 ${\mu}{\textrm}{m}$ in diameter.