• Title/Summary/Keyword: Soot particle

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Analysis of Soot Formation Characteristics in Diffusion Flames with Soot Particle Temperature Measurement (매연입자 온도 측정에의한 확산화염의 매연생성 특성 해석)

  • Lee, Won-Nam;Chung, Young-Hyun
    • 한국연소학회:학술대회논문집
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    • 1999.10a
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    • pp.241-249
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    • 1999
  • Soot particle temperatures in co-flow diffusion flames have been measured using a two-color pyrometry at the pressure of 0.2 MPa(2 atm). The measured soot particle temperatures along with the integrated soot volume fractions are analyzed to understand soot formation characteristics. At 0.2 MPa, the addition of small amount of air into ethylene do not change the soot particle temperature in soot formation regions. This result showed that the increase of soot formation with addition of air is mostly due to the chemical effect of the added air, such as the increased role of C3 chemistry during the early stage of soot inception process. The addition of sufficient air into ethylene, however, changes soot particle temperatures and the understanding of soot formation characteristics becomes complicated. Measured soot particle temperatures also showed that there is no significant temperature effect for the synergistic effect of ethylene/propane mixture on soot formation.

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A Study on the Soot Particle Measurement in Co-Flow Diffusion Flame Using a Laser Diagnostics and a Thermocouple (레이저 및 열전대를 이용한 동축류 확산화염에서의 매연입자 측정에 관한 연구)

  • Han, Yong-Taek;Lee, Ki-Hyng;Lee, Won-Nam
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.7
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    • pp.863-870
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    • 2004
  • The temperature and soot particle measurement technique in a laminar diffusion flame has been studied to investigate the characteristics of soot particle with temperature using a co-flow burner. The temperature distribution in the flame were measured by rapid insertion of a R-type thermocouple and the soot particles by LEM/LIS techniques. In these measurement, soot volume fraction, number density and soot diameters were analyzed experimentally. As a results, the spacial distributions of particle volume fraction, soot diameter, and number density are mapped throughout the flame using the Rayleigh theory for the scattering of light by particles. A laser extinction method was used to measure the soot volume fraction and laser induced scattering method was used to measure the soot particle diameter and number density. Also, we measured temperature without the effect of soot particles attached to the thermocouple junction, which is close to the nozzle. In this result, we found that upstream zone has a unstable flowing in co-flow diffusion flame and the y-axis temperature of flame has a uniform temperature distribution in the most soot volume fraction zone.

A Study on the Soot Particle Measurement in Co-flow Diffusion Flame Using a Laser Diagnostics and a Thermocouple (레이저 및 열전대를 이용한 동축류 확산화염에서의 매연입자 측정에 관한 연구)

  • Han, Yong-Taek;Lee, Ki-Hyung;Lee, Won-Nam
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1267-1273
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    • 2004
  • The temperature and soot particle measurement technique in a laminar diffusion flame have been studied to investigate the characteristics of soot particle with temperature using a co-flow burner. The temperature distributions in the flame were measured by rapid insertion of a R-type thermocouple and the soot particles were detected were detected by LEM/LIS techniques. In these measurement, soot volume fraction, number density and soot diameters were analyzed experimentally. As a results, the spacial distributions of particle volume fraction, soot diameter, and number density are mapped throughout the flame using the Rayleigh theory for the scattering of light by absorbing particles. A laser extinction method was used to measure the soot volume fraction and Laser induced scattering method was used to measure the soot particle diameter and number density. Also, we measured temperature without the effect of soot particles attached to the thermocouple junction, which is close to the nozzle. In this result, we found that upstream zone has a unstable flowing in co-flow diffusion flame and the y-axis temperature of flame has a uniform temperature distribution in the most soot volume fraction zone.

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LASER-INDUCED SOOT VAPORIZATION CHARACTERISTICS IN THE LAMINAE DIFFUSION FLAMES

  • Park, J.K.;Lee, S.Y.;Santor, R.
    • International Journal of Automotive Technology
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    • v.3 no.3
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    • pp.95-99
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    • 2002
  • The characteristics of soot vaporization induced by a high-energy Pulsed laser were studied in an ethylene-air laminar flame. A system consisting of two pulsed lasers was used for the experiments. The pulse from the first laser was used to vaporize the soot particles, and the delayed pulse from the second laser was used to measure the residual soot volume fraction. Laser-induced soot vaporization was characterized according to the initial particle size distribution. The results indicated that soot particles could not be completely vaporized simply by introducing a high intensity laser pulse. Residual soot volume fractions present after vaporization appeared to be insensitive to the initial soot particle size distribution. Since the soot vaporization effect is more pronounced in the region of high soot concentrations, this laser-induced soot vaporization technique may be a very useful tool for measuring major species in highly sooting flame.

Electrical characteristics of soot particles in a LPG diffusion flame and particle size change by electric fields (LPG 확산화염내 매연입자의 전기적 특성 및 전기장에 의한 입자 크기 변화)

  • Park, Jong-In;Ji, Jun-Ho;Hwang, Jeong-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1326-1338
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    • 1997
  • Electrical characteristics of soot particles in a LPG diffusion flame were studied for the control of soot particle coagulation. When a DC voltage was applied between two electrodes installed parallel to gas flow, ionic wind effect caused soot deposition on the cathode, implying that most of the soot particles were positively charged. Soot deposit on the cathode linearly increased and was saturated with respect to the strength of the applied voltage. The possibility of applying an AC voltage to enhance the particle coagulation was then investigated and the efficiency of the size control was checked with transmission electron microscope photographs. For the amplitude of 2 kV AC field, primary (spherical) soot particle size decreased from 30 ~ 40 nm to around 20 nm when the frequency of the applied AC voltage was 60 Hz and higher. Collisions between the soot particles in such a selected AC condition could lead to the formation of much bigger agglomerates of roughly 1-5 .mu.m in size.

Characterization of Soot Particles Generated in Non-sooting and Sooting Normal Diffusion Flames (Sooting 및 Non-Sooting 정상 확산 화염에서 생성되는 매연 입자의 특성에 대한 연구)

  • Choi, In-Chul;Lee, Jae-Bok;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.7
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    • pp.984-993
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    • 2000
  • Characteristics of carbon soot particles generated in diffusion flames were studied. Non-sooting and sooting normal diffusion flames using propane or ethylene as fuel were selected. In the flames, soot volume fraction was measured by a thermocouple, and primary particle diameter and cluster size were analyzed by TEM photographs. The characteristics of soot particles depended on flame(non-sooting or sooting) and fuel(propane or ethylene) type. Unlike the sooting diffusion flames, particle growth and oxidation processes were clearly observed in the non-sooting diffusion flames. In the sooting diffusion flames, soot particle size was slightly changed at the flame tip.

Study of Incipient Soot Particles with Measuring Methodologies (입자 측정방법을 통한 초기 수트입자 연구)

  • Lee Eui Ju
    • Journal of the Korean Society of Visualization
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    • v.2 no.1
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    • pp.12-17
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    • 2004
  • The physical characteristics of soot near the soot inception point were investigated with various measurements. In-situ measurements of particle size and volume fraction were introduced based on time resolved laser-induced incandescence (TIRE-LII) and laser-induced ion mobility (LIIM). The one has more convenience and accuracy than conventional LII technique and the other works best for particle sizes of a few nanometers at high concentrations in a uniform concentration field. A complementary ex-situ measurement of particle size is nano differential mobility analyzer (Nano-DMA), which recently developed for measuring particle sizes between 2nm and 100nm and provides high-resolution size information for early soot. Particles will be also collected on transmission electron microscope (TEM) grids using rapid thermophoretic sampling and analyzed for morphology. These measurements will allow fresh and original insight into the characterizing soot inception process. The measured physical properties of incipient soot will clarify the controlling growth mechanism combined with chemical ones, and the dominant mechanism for soot modeling can be deduced from the information.

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Nano-Soot Particle Formation in Inverse Diffusion Flames (인버스 확산화염에서의 나노 수트 입자 생성)

  • Lee, Eui-Ju;Shin, Hyun-Joon;Oh, Kwang-Chul;Shin, Hyun-Dong
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.19-26
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    • 2003
  • Experimental measurements of flame structure and soot characteristics were performed for ethene inverse diffusion flames (IDF). IDF has been considered as the excellent flow field to study the incipient soot because soot particle do not experience the oxidation process. In this study, LIF image clarified the reaction zone of IDF with OH signal and PAH distribution. laser light scattering technique also identified the being of soot particle. To address the degree of soot maturing, C/H ratio and morphology of soot sample were investigated. From these measurements, the effect of flow residence time and temperature on soot inception could be suggested, and more details on soot characteristic in the IDF was determined according to fuel dilution and flame condition. The fuel dilution results in a decrease of temperature and enhancement of residence time, but the critical dilution mole fraction is existed for temperature not to effect on soot growth. Also, the soot inception evolved on the specific temperature and its morphology are independent of the fuel dilution ratio of fuel.

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Preliminary Study on the Cloud Condensation Nuclei (CCN) Activation of Soot Particles by a Laboratory-scale Model Experiments

  • Ma, Chang-Jin;Kim, Ki-Hyun
    • Asian Journal of Atmospheric Environment
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    • v.8 no.4
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    • pp.175-183
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    • 2014
  • To visually and chemically verify the rainout of soot particles, a model experiment was carried out with the cylindrical chamber (0.2 m (D) and 4 m (H)) installing a cloud drop generator, a hydrotherometer, a particle counter, a drop collector, a diffusing drier, and an artificial soot particle distributer. The processes of the model experiment were as follows; generating artificial cloud droplets (major drop size : $12-14{\mu}m$) until supersaturation reach at 0.52%-nebulizing of soot particles (JIS Z 8901) with an average size of $0.5{\mu}m$-counting cloud condensation nuclei (CCN) particles and droplets by OPC and the fixation method (Ma et al., 2011; Carter and Hasegawa, 1975), respectively - collecting of individual cloud drops - observation of individual cloud drops by SEM - chemical identifying of residual particle in each individual droplet by SEM-EDX. After 10 minutes of the completion of soot particle inject, the number concentrations of PM of all sizes (> $0.3{\mu}m$) dramatically decreased. The time required to return to the initial conditions, i.e., the time needed to CCN activation for the fed soot particles was about 40 minutes for the PM sized from $0.3-2.0{\mu}m$. The EDX spectra of residual particles left at the center of individual droplet after evaporation suggest that the soot particles seeded into our experimental chamber obviously acted as CCN. The coexistence of soot and mineral particle in single droplet was probably due to the coalescence of droplets (i.e., two droplets embodying different particles (in here, soot and background mineral particles) were coalesced) or the particle capture by a droplet in our CCN chamber.

The Characteristics of Exhausted Soot Particles from a Common-Rail Direct Injection Diesel Engine by TIRE-LII (커먼레일 직접분사식 디젤엔진에서 시분해 레이저 유도 백열법을 이용한 매연입자의 배출 특성)

  • Kim, Gyu-Bo;Han, Hwi-Young;Chang, Young-June;Jeon, Chung-Hwan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.5
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    • pp.78-85
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    • 2007
  • Recently, diesel vehicles have been increased and their emission standards have been getting strict. The emission of diesel vehicles contains numerous dangerous compounds, especially particulate matters cause a serious environmental pollutant and affect to human health seriously. Thousands of studies have already reported that particulate matters are associated with respiratory and cardiovascular diseases, and death. Due to these, it is necessary to measure the soot concentration and soot particle size in laboratory flames or practical engines to recognize the soot formation, and develop the control strategies for soot emission. In this study, the characteristics of exhausted soot particle size and volume fraction from 2.0L CRDI diesel engine have been investigated as varying engine speed and load. Laser induced incandescence has been used to measure soot concentration. Time-resolved laser induced incandescence has been used to determine soot particle size in the engine. The soot volume fraction is increased as increasing engine load but soot volume fraction is decreased as increasing engine speed. The primary particle size is distributed about $35nm{\sim}60nm$ at each experimental conditions.