• 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.

• 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.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.267-268
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• 2012

Soot formation and oxidation characteristics of air-diluted propane diffusion flames have been experimentally investigated under the elevated pressure conditions. PAH concentrations showed more pressure sensitive behavior comparing to soot volume fractions. The flame/soot temperatures in soot oxidation region were obtained using the MOLLIP technique. Under the complete soot oxidation environment, the flame/soot temperature is increased with pressure. The increased temperature could accelerate the soot oxidation process and then exothermic oxidation reaction, in turn, could further raise the flame/soot temperature, which would result in the enhancement of soot oxidation process.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.55-58
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• 2013

A new soot particle generation system has been developed and tested. The soot generation system consists of two sections, a fuel supply and a soot production. In the fuel supply module, either liquid fuel precisely controlled by a syringe pump is mixed with preheated carrier gas and rapidly evaporated or gaseous fuel controlled by a MFC is diluted with dilution gas. The soot production module contains a heater that can raise the gas/fuel temperature up to $1400^{\circ}C$. The physical and chemical properties of produced soot particles depend on the type and concentration of fuel, the residence time, and temperature in the soot production section. The soot generation system will be utilized to produce well-defined soot particles for soot studies such as the evaluation of experimental sampling and analysis processes for the quantitative assessment of PM and BC from ships and the adverse health effects on pulmonary and cardiovascular systems of human body.

• 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.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.437-442
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• 2009

In this work, thermal shock and simultaneous removal reaction for NOx, soot over Pt catalysts using $TiO_2$, $Al_2O_3$ as support were studied. The catalytic reaction test for NOx and soot were also performed independently and simultaneously, as a result, it showed different NOx removal efficiency and soot oxidation rate according to support and phase, and the onset temperature of soot oxidation has correlation to NOx removal efficiency for the catalyst. The onset temperature of soot oxidation shifted to lower temperature by generated $NO_2$ at the simultaneous reaction for NOx and soot. Also Pt/$TiO_2$ catalyst is more affected than Pt/$Al_2O_3$ on NOx removal efficiency caused by thermal shock while Pt sintering effect induced to reduce the performance on soot oxidation rate for all catalysts.

• 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.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.114-120
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• 2020

In this study, we analyzed the structural characteristics of soot, which is one of the anticipated regulatory substances of the IMO, and used a novel classification method to distinguish between exhaust soot and engine soot in marine engines. As an extension of a recent study on exhaust soot recycling, annealing was performed at 2,000 ℃ on engine soot to determine whether it could be recycled. Soot samples before and after annealing were analyzed using HR-TEM and Raman spectroscopy. The HR-TEM results showed that exhaust soot and engine soot had similar nanostructures; the exhaust soot has a spherical primary particle with a chain-like structure, whereas engine soot particles have amorphous structures. The Raman spectroscopy showed a D-peak and a G-peak for both exhaust soot and engine soot. However, the G/D ratio indicated that the value of exhaust soot was relatively higher than that of engine soot, which implies that the exhaust soot has a more graphitized structure. The analysis of annealed engine soot confirmed that graphitization proceeded without any problems, similar to the exhaust soot. This confirmed that both exhaust soot and engine soot generated by marine diesel engines could be recycled as graphite materials.

• 한국연소학회:학술대회논문집
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• 1997.06a
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• pp.1-11
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• 1997

The soot and OH radical distributions have been experimentally studied in ethylene and propane laminar diffusion flames. The integrated soot volume fraction was measured along the centerline of a flame using a laser light extinction method. Planar laser light scattering and PLIF techniques are employed for the soot and OH radical distribution measurements utilizing Nd:YAG laser and OPO, FDO system. The concentration of OH radical is rapidly decreased at the edge of sooting region, which implies the importance of OH radical species on the soot oxidation process. For ethylene flames, the addition of air in fuel moves the OH radical distribution towards the center line of a flame at the soot oxidation region, while the concentration of OH radical remains relatively high at the soot formation region. The interaction between soot particles and OH radicals becomes more active with fuel-air at the soot oxidation region. For propane flames, however, any indication of the increased interaction between soot particles and OH radicals with fuel-air was not noticed.