• Title/Summary/Keyword: Flame and impact

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A Status of floor impact sound insulation by the floor structure (바닥구조에 따른 바닥충격음 차단성능 현황)

  • 이성호;정갑철;정진연;양관섭
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.513-517
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    • 2004
  • This study aims to evaluate factors of floor structure influencing to the floor impact sound. For this reasons, we measured the vibration of floor and the floor impact sound in moment flame structure. The main results from this study are that slab area and thickness are critical factors of the floor impact sound and aspect ratio slab is not verified in flor impact sound.

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Monitoring of Brominated Flame Retardants (BFRs) for the management of Their Contamination in Environments (브롬화 난연제의 환경오염도 관리 방안)

  • Kim, Yong-Bum;Lee, Sang-Hoon;Chung, Yong
    • Journal of Environmental Impact Assessment
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    • v.14 no.2
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    • pp.83-96
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    • 2005
  • Brominated flame retardants have the market share of 40%, comparing others because of their low cost and highly effective retardation against the flame. However, their toxic effects in human and properties of the accumulation in the environments have been issued among the international organization such as EU, OECD and etc. It, therefore, was surveyed the classification, toxic effects, and the usage of Brominated flame retardants, the trends for their managements in the world and Korea, and their contaminated levels in Korean Peninsula. In addition, the management directions for them were proposed. Penta, octa, and deca-BDE among brominated retardants will seem to be prohibited by the regulation as a flame retardants for plastics in Europe because of their toxic effects. Although Penta and Octa BDEs was used marginally in Korea, deca-BDE was 27% of brominated flame retardants (49,050 ton) which had been used in 2002. However, risk assessment for brominated retardants might not launched in Korea, yet. These reports demonstrate that toxic brominated retardants such as PBDEs will be assessed for their usage and the level of contamination in the environment in the area of the point sources like the industrial areas, incinerators and etc. However, the law to regulate the hazardous chemicals seems not to be dictated the monitoring of their contamination in the environment. We, therefore, suggest how to evaluate and to monitor the toxic contaminants with EIA (Environmental Impact Assessment) and LCA (Life Cycle Assessment) system. Further, to establish the management system of BFRs (such as the monitering of contamination levels in environments, life cycle assessment, and risk assessment for the toxic chemicals), It can be recommended the law to deal with the method analyzing chemicals will be established, which contains QA/QC (Quality Assurance and Quality Control) to evaluate the analytic capability of the companies to prepare EIS (Environment Impact Statement) or other institutes for analyzing chemicals.

A Study on the Effect of Various Brominated Flame Retardants and the Compatibilities Between Polymer and Flame Retardants in PC/ABS Blend System (PC/ABS 블랜드의 난연화 및 상용성에 관한 연구)

  • 이영순;전종한
    • Journal of the Korean Society of Safety
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    • v.5 no.3
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    • pp.63-68
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    • 1990
  • The effects of various brominated flame retardants were investigated in PC/ABS blend system. The compatibilities between polymers and flame retardants were expected with the solubility parameter using group contribution theory. Tetrabromobisphenol A carbonate oligomer, among the flame retardants in this experiment, has been shown good miscibility for PC and ABS, respectively. But polydibromophenylene oxide and octabromodiphenyl oxide has immiscibility. The flame retardant PC/ABS blends containning tetrabromobisphenol A carbonate oligomer have been exhibited higher mechanical properties, tensile strengths and notch Izod impact strengths, at varlous content of flame retardants, than containning other flame retardants. It could be seen that the trends of mechanical properties for the flame retardant PC/ABS blends have a good concidence with the expectation of compatibility.

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The Function of Halogen Additive in $CH_4/O_2/N_2$ Flames ($CH_4/O_2/N_2$ 화염에서 할로겐 첨가제의 역할)

  • Lee, Ki-Yong;Shin, Sung-Su
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.209-214
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    • 2003
  • Numerical simulations are performed at atmospheric pressure in order to understand the effect of additives on flame speed, flame temperature, the radical concentration, the NOx formation in freely propagating $CH_4/O_2/N_2$ flames. The additives used are carbon dioxide and hydrogen chloride which have a combination of physical and chemical behavior on hydrocarbon flame. In the flame established with the same mole of methane and additive, $CO_2$ addition significantly contributes toward the reduction of flame speed and flame temperature by the physical effect, whereas addition of HCl mainly does by the chemical effect. The impact of HCl addition on the decrease of the radical concentration is about 1.6-1.8 times as large as $CO_2$ addition. Hydrogen chloride addition is higher on the reduction of EINO than $CO_2$ addition because of the chemical effect of HCl.

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Effect of Heating Rate on the Behavior of the Flame Front in the Pulverized-Coal Flame (미분탄화염에서 가열률이 화염선단의 거동에 미치는 영향)

  • Cho, Han Chang;Park, Jung Kyu;Shin, Hyun Dong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.5
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    • pp.687-694
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    • 1999
  • An experimental study was carried out in two laboratory-scale reactors to investigate the effect of heating rate on the behavior of flame front in a pulverized coal flame. Each. reactors had different heating mechanisms. For reactor A losing large heat through transparent quartz wall. pulverized coal particles were ignited by secondary air of 1050K. Flame front could be visualized through the transparent wall. Reactor B was insulated with castable refractory to minimize the heat loss through the reactor wall and accompanied with secondary air of 573K. Flame front was estimated from the gas temperature and species concentration measured using R-type thermocouple(Pt-Pt/Rh 13%) and gas chromatograph at various coal-air ratios and swirl intensities. The flame front position was closely related with the magnitude of heating rate. The heating rate for lifted flame was of the order of $10^4$ to $10^5K/s$ and for coal Ignition at least over $10^4K/s$. The heating mechanism had little impact on the extinction limits. The weak swirl number of 0.68 forced the flame front to move toward the upstream by the rapid mixing of coal and air. The primary/secondary momentum ratio was an inappropriate variable to distinct the liftoff of flame.

Flame Retardancy and Mechanical Property of Recycled Polyolefinic Plastic Composites with Hybrid fillers (폴리올레핀계 폐플라스틱/복합filler 성형체의 난연성 및 기계적 물성 연구)

  • 강영구;송종혁
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.56-63
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    • 2003
  • Flame retardancy and mechanical properties of recycled polyolefinic plastics/inorganic filler composite systems were investigated by using several inorganic flame retardants such as magnesium hydroxide and slag powder generated electro arc furnace Compatibilizer user each maleic anhydride functionalized polyethylene (PE-g-MAH) and polypropylene(PP-g-MAH) or used mixture of these. The effect of polymeric compatibilizers on the properties of composites was studied by tensile and impact test, differential scanning calorimetry, in the changed fracture mechanism. The improved adhesion was particularly reflected in the mechanical properties. The flame retardancy of composites was examined by measuring limiting oxygen index(LOI, ASTM D2863), smoke density(ASTM D2843) and vertical burning test(UL94). Regarding the flame retardant effect, the EAF slag powder is behaving as synergists as they are only active in the presence of magnesium hydroxide.

Evaluation of mechanical properties and non-flammability of Nylon6 using melamine-based halogen-free flame retardant (Melamine계 난연제를 이용한 Nylon6의 난연성 및 물리적 특성 평가)

  • Kim Dong-Hak;Ryu Kwan-Suk;Son Young-Gon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.743-748
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    • 2006
  • We investigated the flame retardancy and the mechanical properties of Nylon6 by using melamine-based halogen-free flame retardants(melamine cyanurate:MC-100 and melamine phosphate:MP-100). We chose the UL-94 method for flame retardancy and measured the tensile strength, flexural strength, flexural modulus by using UTM and impact strength by using Izod impact tester. We also tested the effect of nano-clay on flammability and mechanical properties. We obtained the V0 grade when the concentration of flame retardant was over 5 wt%. The tensile strength and flexural strength decreased and flexural modulus increased with the concentration of both flame retardant systems. The results showed that MC-100 system was better than MPP-100 system. Because of poor dispersion, we did not obtain the synergistic effect of nano-clay.

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Experimental Study on the Effect of a Metal Storage Cask and Openings on Flame Temperature in a Compartment Fire

  • Bang, Kyoung-Sik
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.3
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    • pp.395-405
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    • 2020
  • Compartment fire tests were performed using kerosene and Jet A-1 as fire sources to evaluate the relationship between flame temperature and opening size. The tests were performed for a fire caused by the release of kerosene owing to vehicle impact, and for a fire caused by the release of Jet-A-1 owing to airplane collision. The compartment fire tests were performed using a 1/3-scale model of a metal storage cask when the flame temperature was deemed to be the highest. We found the combustion time of Jet-A-1 to be shorter than that of kerosene, and consequently, the flame temperature of Jet-A-1 was measured to be higher than that of kerosene. When the opening was installed on the compartment roof, even though the area of the opening was small, the ventilation factor was large, resulting in a high flame temperature and long combustion. Therefore, the position of the opening is a crucial factor that affects the flame temperature. When the metal storage cask was stored in the compartment, the flame temperature decreased proportionally with the energy that the metal storage cask received from the flame.

Research on Flame Retardant Plywood with Different Flame Retardants

  • LIU, Yang;XU, Jun-xian;WEN, Ming-yu;PARK, Hee-Jun;ZHU, Jia-zhi;LIU, Yu-nan
    • Journal of the Korean Wood Science and Technology
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    • v.49 no.6
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    • pp.667-678
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    • 2021
  • The flame retardancy of plywood should be improved as much as possible while minimizing the impact on the bonding strength of plywood. Six commercial flame retardants and three laboratory synthesized phosphorous nitrogen flame retardants were selected. E0, E1 and E2 grade commercial formaldehyde resins (UF) were applied in this study to evaluate the effect of different flame retardants on the curing time of resin, bonding strength, flame retardant performance, and formaldehyde emission of plywood. The results show that the effect of the addition of different flame retardants on the bonding strength of plywood gradually decreased with the increase of the formaldehyde molar ratio of the resin. The effect of flame retardants on the curing time of UF gradually decreased as the mole ratio of formaldehyde increasing, while the amount of formaldehyde emission varied according to the content of formaldehyde in the flame retardant. Compared with plywood without flame retardant, flame retardant of plywood added with phosphorous nitrogen flame retardant was improved.

Effect of Flame Spray Distance on Particle Behavior and Morphological Characteristics of $Ni_{20}Cr$ Coated Layers (화염용사 거리에 따른 입자의 거동 및 $Ni_{20}Cr$ 코팅층 특성 연구)

  • Lee, Jae Bin;Shin, Dong Hwan;Lee, Seong Hyuk
    • Journal of ILASS-Korea
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    • v.17 no.3
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    • pp.128-133
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    • 2012
  • The present study aims to examine the influence of flame spray distance on the thermal behavior of micro-metal particles and the morphological characteristics of $Ni_{20}Cr$ layers coated on the preheated SCM415 substrates by using the conventional flame spray system. Commercially available nickel-based $Ni_{20}Cr$ particles with a mean diameter of $45{\mu}m$ were used. In addition, CFD simulations using a commercial code (FLUENT ver. 6.3.26) were conducted to estimate temperature and velocity distributions of the continuous and discrete phases before impact on the substrate. From FE-SEM images of coated layers on the substrates, it was observed that as the spray distance decreased, the metal particle morphology showed splash-like patterns and such a short stretch shape, resulting from higher particle momentums and the impact of partially melted particles. Moreover, it was found that the spray distance should be considered as one of important parameters in controlling the porosity and the adhesion strength.