• Title/Summary/Keyword: Ethylene flame

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Effects of Oxidant Addition to Fuel on Soot Formation of Laminar Diffusion Flames (동축류 확산화염의 매연생성에 미치는 연료에 첨가된 산화제의 영향)

  • Lee, Won-Nam
    • Journal of the Korean Society of Combustion
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    • v.3 no.1
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    • pp.11-19
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    • 1998
  • The influence of oxidant addition on soot formation is investigated experimentally with ethylene, propane and mixture fuel co-flow diffusion flames. Oxidant addition into fuel shows the increase of integrated soot volume fractions for ethylene, ethylene/ethane and ethylene/methane mixture flames. However, the increase of integrated soot volume fraction with oxidant addition was not significant for propane and ethylene/propane mixture flames. This discrepancy is explained with $C_2\;and\;C_3$ chemistry at the early stage of soot formation process. The oxidant addition increases the concentration of $C_3H_3$ in the soot formation region, and therefore, enhances soot formation process. A new soot formation rate model that includes both dilution effect and chemical effect of oxygen is suggested to interpret the increase of integrated soot volume fractions with oxidant addition into ethylene. Also, the role of adiabatic flame temperature for the chemical effect of oxygen addition into fuel was reviewed. The influence of oxidant or diluent addition into fuel on soot formation process are the fuel dilution effect, the adiabatic flame temperature altering effect and/or the chemical effect of oxygen. Their relative importance could change with fuel structure and adiabatic flame temperature.

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Study on the Oil Resistance, Morphological and Dynamic Mechanical Properties, Flame Retardance of Ethylene Vinyl Acetate Copolymer and Ethylene Propylene Rubber Compounds

  • Sung, Il Kyung;Lee, Won Ki;Park, Chan Young
    • Elastomers and Composites
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    • v.52 no.1
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    • pp.27-34
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    • 2017
  • In this experiment, blends of ethylene vinyl acetate rubber (EVM) with a vinyl acetate (VA) content greater than 40 wt% and ethylene propylene rubber (EPM) were prepared by mechanical mixing; a number of parameters of the blends, including oil resistance, morphological and dynamic mechanical properties and flame retardancy, were subsequently measured. In the $100^{\circ}C$ oil resistance test, both the ammonium polyphosphate/dipentaerythritol/expandable graphite (APP/DPER/EG) and aluminum hydroxide (ATH) flame retardant systems showed an increase in volume change with increasing EPM content. For the ATH system, the dispersion shape was coarse and aggregation was observed. The results of a dynamic mechanical test showed slightly higher E' and E'' for the APP/DPER/EG flame retardant system when compared to the single ATH system. For both the APP/DPER/EG and ATH systems, the limited oxygen index (LOI) tests performed at increasing content of EPM showed a LOI value higher than 30, indicating excellent flame resistance.

A Study on Effect of n-heptane Mixing on PAH and Soot Formation in Counterflow Ethylene Diffusion Flames (대향류 에틸렌 확산화염내 PAH 및 매연의 생성에 미치는 n-헵탄 혼합의 영향에 관한 연구)

  • Choi, Jae-Hyuk;Han, Won-Hui
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.1
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    • pp.55-60
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    • 2012
  • In order to investigate the effect of n-heptane mixing on PAH and soot formation, small amount of n-heptane has been mixed in counterflow ethylene diffusion flame. Laser-induced incandescene and laser-induced fluorescene techniques were employed to measure soot volume fraction and polycyclic aromatic hydrocarbon(PAH) concentration, respectively. Results showed that the mixing of n-heptane in ethylene diffusion flame produces more PAHs and soot than those of pure ethylene flame. However, signals of LIF for 20% n-heptane mixture flame were lower than that of pure ethylene flame. It can be considered that the enhancement of PAH and soot formation by the n-heptane mixing of ethylene can be explained by methyl($CH_3$) radical in the low temperature region. And it can be found that reaction rate of H radical for 10% n-heptane plays a crucial role for benzene formation.

A Study on Composites of Ethylene-Vinyl Acetate Copolymer and Ethylene-Propylene-Diene Rubber with Aluminum Hydroxide as a Fire Retardant

  • Lee, Yu Jun;Lee, Su Bin;Jung, Jae Young;Lee, Dam Hee;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.51 no.2
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    • pp.93-98
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    • 2016
  • The composites of EVA/EPDM including aluminum trioxide (ATH) as a fire retardant were manufactured for the purpose of improving low temperature property and flame resistance in the rubbery materials. The ratio of EVA to EPDM didn't affect the flame resistance of the rubber composites. The addition of ATH resulted in increase of the flame resistance. In the evaluation of the cold resistance, the increasing EPDM content showed enhancement of cold resistance in the composites due to increasing low Tg EPDM. It was found out that tensile strengths of the composites showed a maximum value at 100 phr of ATH by reinforcing effect, but a minimum value at 200 phr of ATH owing to slippage between the flame retardant by the external stress. In the measurement of solvent resistance in tetrahydrofuran, the increasing ATH content yielded enhancement of solvent resistance by reducing swelling of the composite, and increasing EPDM content also resulted from increase of the solvent resistance by reduction of polarizability as well as increase of crosslink in the composites.

Experimental Study on Turbulent Ethylene Diffusion Flame (에틸렌 난류확산 화염에 관한 실험적 연구)

  • Yang, G.S.;Kim, Y.M.
    • Journal of the Korean Society of Combustion
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    • v.4 no.2
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    • pp.23-33
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    • 1999
  • A turbulent non-premixed ethylene flame, which was set up in a vertical wind tunnel, was examined to understand the effect of turbulent mixing on formations of soot and gaseous species in the flames. Temperature and velocity profiles were measured using uncoated thermocouples and LDV system. Gaseous samples were withdrawn by using a water cooled stainless iso-kinetic gas sampling probe. The samples for inorganic compounds and light hydrocarbons were collected with sampling bottles and were analyzed by a gas chromatography. The samples for aromatic hydrocarbons were collected on a sorbent tube and were analyzed on a GC/MS system. Some of main results were followed. CO and $CO_2$ were measured relatively in early part of flame and the concentration of CO was greater than that of $CO_2$ all over the early flame region due to the scavenging of the oxidizing species OH by soot particles. Aromatic hydrocarbons were measured at x/D=122 along the radial direction and main important species were benzene, xylene, toluene, styrene, indene, naphthalene. The peak points of these compounds occurred at r/D=0.8 apart from the center of flame, around in which the concentration of $C_2H_2$ decayed relatively rapidly from the maximum value.

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Temperature Distribution in Ethylene Diffusion Flames Based on Measurement Techniques;Comparison of Thermocouple and Tow-Color Pyrometry (측정방법에 따른 에틸렌 확산화염의 온도분포;열전대 및 이색법 측정 결과 비교)

  • Lee, Won-Nam;Na, Yong-Dae;Lee, Bum-Ky;Park, Seong-Nam
    • 한국연소학회:학술대회논문집
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    • 2000.12a
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    • pp.175-182
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    • 2000
  • Flame temperatures were measured and compared using a rapid insertion technique and a two-color pyrometry with Abel inversion process in co-flow ethylene diffusion flames. The measured line-of-sight temperature showed very limited usefulness in understanding the detailed soot formation/oxidation process in a co-flow diffusion flame. The flame temperatures could be measured with reasonable accuracy for the soot laden regions in ethylene diffusion flames using two-color pyrometry with an Abel inversion technique. Two-color-pyrometry with Abel inversion was demonstrated as a useful temperature measurement technique for co-flow diffusion flames, expecially under pressure conditions, where a thermocouple is not applicable. The soot volume fraction could be also obtained using tow-color pyrometry with Abel inversion, which provides important information for understanding the soot formation/oxidation mechanism in diffusion flames.

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Study on Soot Primary Particle Size Measurement in Ethylene Diffusion Flame by Time-Resolved Laser-Induced Incandescence (시분해 레이저 유도 백열법을 이용한 에틸렌 확산 화염에서의 매연 일차입자크기 측정에 관한 연구)

  • Kim Gyu-Bo;Cho Seung-Wan;Lee Jong-Ho;Jeong Dong-Soo;Chang Young-June;Jeon Chung-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.10 s.253
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    • pp.973-981
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    • 2006
  • Recently there is an increasing interest in particulate matter emission because of new emission regulations, health awareness and environmental problems. It requires to improve particulate measurement techniques as well as to reduce soot emissions from combustion systems. As mentioned above, it is demanded that reduction techniques together with measurement techniques of exhausted particulate matters in combustion systems such as vehicles. However, measurement techniques of particulate matters should be prior to reduction techniques of that because it is able to know an increase and a decrease of exhausted particulate matters when measured particulate matters. Therefore, in this study, we report the measurement of soot primary-particle size using time-resolved laser induced incandescence (TIRE-LII) technique in laminar ethylene diffusion flame. As an optical method, laser induced incandescence is one of well known methods to get information for spatial and temporal soot volume fraction and soot primary particle size. Furthermore, TIRE-LII is able to measure soot primary particle size that is decided to solve the decay ate of signal S $(t_1)$ and S $(t_2)$ at two detection time. In laminar ethylene diffusion flame, visual flame height is 40 mm from burner tip and measurement points are height of 15, 20, 27.5, 30 mm above burner tip along radial direction. As increasing the height of the flame from burne. tip, primary particle size was increased to HAB(Height Above Burner tip)=20mm, and then decreased from HAB=27.5 mm to 30 mm. This results show the growth and oxidation processes for soot particles formed by combustion.

Effect of Fuel Mixing on PAH and Soot Formation in Counterflow Diffusion Flames (다양한 연료의 혼합에 따른 대향류 확산화염에서의 PAH 및 매연생성 특성)

  • Yoon, S.S.;Lee, S.M.;Chung, S.H.
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.137-142
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    • 2003
  • In order to investigate the effect of fuel mixing on PAH and soot formation, four species of methane, ethane, propane and propene have been mixed in counterlfow ethylene diffusion flame. Laser-induced incandescene and laser-induced fluorescene techniques were employed to measure soot volume fraction and polycyclic aromatic hydrocarbon (PAH) concentration, respectively. Results showed that the mixing of ethane (or propane) in ethylene diffusion flame produces more PAHs and soot than those of propene, even though the propene diffusion flame produces more PAHs and soot than that of propane and ethane. Considering that propene directly dehydrogenates to propargyl radical, this behavior implied that the enhancement of PAH and soot formation by the fuel mixing of ethylene and ethane (or propane) cannot be explained by propargyl radical directly dehydrogenated from ethane (or propane).

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Study on Properties with Different Plasticizers in the Preparation of Polymer Compounds for Cable Sheath

  • Li, Xiang Xu;Lee, Sang Bong;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.54 no.1
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    • pp.35-39
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    • 2019
  • Four different polymer compounds were prepared from four kinds of plasticizers, viz. di-2-ethylhexyl azelate (DOZ), di-2-ethylhexyl adipate (DOA), di-2-ethylhexyl sebacate (DOS), and di-2-butyl sebacate (DBS), for making cable sheaths for ships. Ethylene-vinyl acetate and ethylene-propylene-diene-copolymer as matrix polymers and ethylene-vinyl acetate grafted maleic anhydride as a coupling agent were compounded with a flame retardant, crosslinking agent, filler, and other additives, besides the plasticizer to obtain the polymer compounds. The polymer containing DOZ showed the highest MH and ${\Delta}T$ in the rheology test, while that containing DBS was found to have the lowest tensile strength and highest elongation because of low ${\Delta}T$. The four polymers showed similar values (31.7-31.9) for flame resistance, while the polymer containing DOZ showed the highest value for cold resistance.

Numerical Analysis for the Detailed Structure and the Soot Formation Mechanism in Counterflow Ethylene-Air Nonpremixed Flame (대향류 에틸렌/공기 비예혼합 화염의 구조 및 Soot 생성 메커니즘 해석)

  • 임효준;김후중;김용모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.5
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    • pp.40-54
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    • 1999
  • The flame structure and soot formation in the counterflow Ethylene-Air nonpremixed flame are numerically analyzed. The present soot reaction mechanism involves nucleation, surface growth, particle coagulation, and oxidation steps. The gas phase chemistry and the soot nucleation, surface growth reactions are coupled by assuming that the nucleation and soot mass growth has the certain relationship with the concentration of benzene and acetylene. In terms of the centerline velocity and the soot volume fraction, the predicted results are compared with the experimental data. The detailed discussion has been made for the sensitivity of model constants and the deficiencies of the present model. Numerical results indicated that the acetylene addition to the soot surface plays the dominant role in the soot mass growth for the counterflow nonpremixed flame.

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