• Title/Summary/Keyword: Heat Release Rate ($HRR_{mean}$)

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Combustion Characteristics and Thermal Properties for Wood Flour-High Density Polyethylene Composites (목분-고밀도폴리에틸렌 복합체의 연소성 및 열적특성)

  • Shin, Baeg-Woo;Chung, Kook-Sam
    • Fire Science and Engineering
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    • v.26 no.1
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    • pp.89-95
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    • 2012
  • In this study, we were manufactured wood flour-HDPE composites by modular co-rotating twin screw extruder with L/D ratio of 42. We was measured cone calorimeter test and thermogravimetric analysis (TGA) to find the combustion characteristics and thermal properties for wood flour-HDPE composites. We then evaluated the effect of three additive-type flame retardants on fire resistance performance. The cone calorimeter test showed that the heat release rate (HRR) of untreated composites was the highest Peak HRR ($446.6kW/m^2$) as well as Mean HRR ($185.5kW/m^2$). From the TGA, it was shown that composites added flame retardants began early thermal decomposition and improved thermal stability.

Combustion Properties of Major Wood Species Planted in Indonesia (인도네시아 주요 조림수종의 연소특성)

  • Park, Se-Hwi;Jang, Jae-Hyuk;Hidayat, Wahyu;Qi, Yue;Febrianto, Fauzi;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.6
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    • pp.768-776
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    • 2015
  • This study was performed to understand combustion properties four major Indonesian wood species such as Albizia, Gmelina, Mangium and Mindi were investigated by cone-calorimeter for better utilization of theses wood species. Heat release rate (HRR), total heat release (TSR), specific mass loss rate (SMLR), effective heat of combustion (EHC), time to ignition (TTI), flame time (FT), specific extinction area (SEA), smoke production rate (SPR) and CO compound production rate were measured. HRR, THR and FT were proportional to the density of woods. Albizia showed the highest HRR, while Mindi had the lowest HRR. For SPR, Albizia showed the highest value due to its higher SEA. On the other hand, Mindi had the lowest SPR due to a lower SEA value. The highest smoke emission was for Albizia at the beginning of combustion. After 300 seconds, smoke emission of Gmleina and Mangium was increased greatly. Mangium and Mindi showed the highest total carbon dioxide emission. Expecially, Gmelina released the highest carbon monoxide during the combustion period and presented three times higher $CO/CO_2$ ratio than those of other species due to incomplete combustion.

Combustion Chracteristics of the Pinus rigida and Castanea savita Dried at Room Temperature (실온에서 건조된 리기다 소나무와 밤나무의 연소특성)

  • Chung, Yeong-Jin;Jin, Eui
    • Fire Science and Engineering
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    • v.24 no.3
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    • pp.86-92
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    • 2010
  • One of the limitation of wood as building materials is its flammability. The purpose of this paper is to examine the combustion properties of the Pinus rigida and Castanea savita which are grown in Korea and meet the desirable characteristics for use of construction materials. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO and $CO_2$ production and smoke obscuration. The $HRR_{mean}$ of the Castanea savita and Pinus rigida at $50\;kW/m^2$ of radiant heat flux was $70.4\;kW/m^2$ and $68.5\;kW/m^2$. Furthermore, the THR of Castanea sativata was 120.8 MJ/kg and it was higher than the THR of Pinus rigida ($81.9\;MJ/m^$). These results are depend on the bulk density of tested wood species. The Castanea savita has high $CO_{mean}$ yield and high CO/$CO_2$ yield compared with that of Pinus rigida.

Combustion Characteristics of Pinus rigida Specimens Treated with Phosphorus-Nitrogen Additives (인-질소 첨가제로 처리된 리기다 소나무 시험편의 연소특성)

  • Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.29 no.6
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    • pp.13-19
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    • 2015
  • This study was performed to test the combustive properties of Pinus rigida specimens treated with phosphorus (P) and nitrogen (N) additives. Each Pinus rigida specimen was painted three times with 15 wt% P-N additive solutions at room temperature. After drying the treated specimens, the combustion properties were examined using a cone calorimeter (ISO 5660-1). The time to ignition (TTI) for the treated specimens was 90 to 148 s except for the specimen treated with PP/$4NH_4^+$, and the time to flameout (TF) was 556 to 633 s, which was longer than that of virgin plate. While the The specimens treated with P-N additives showed 12.5 to 43.4% higher mean heat release rate ($HRR_{mean}$) and 11.8 to 43.1% higher total heat release (THR) than virgin plate. The effective heat of combustion (EHC) was by 2.9 to 17.5% lower than that of virgin plate. It can thus be concluded that the combustion-retardation properties were partially improved compared to those of virgin plate.

A Study on the Heat Hazard Assessment of Building Wood (건축용 목재의 열 유해성 평가에 대한 연구)

  • Woo, Tae-Young;Jin, Eui;Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.32 no.5
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    • pp.6-14
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    • 2018
  • This study was carried out with respect to the heat release rate (HRR) properties of building wood. Heat release characteristics were measured using a cone calorimeter (ISO 5660-1) with four kinds of wood. The time to ignition measured after the combustion in $25kW/m^2$ external heat flux was 35 to 55 s. Time to ignition of both lauan and red pine was marked with the most delayed value in each of 54 s, 55 s. The maximum heat release rate ($HRR_{peak}$) was $156.87{\sim}235.1kW/m^2$, and the risk of early fire was highest in spruce. Total heat release of red pine was obtained in the highest value with $114.2MJ/m^2$. The mean effective heat of combustion of Japanese cedar was 19.1 MJ/kg and the highest among the samples. Fire risk of wood by FPI was orderly increased from lauan ($0.2468s{\cdot}m^2/kW$), red pine ($0.2339s{\cdot}m^2/kW$), spruce ($0.2308s{\cdot}m^2/kW$) to Japanese cedar ($0.2231s{\cdot}m^2/kW$). Fire risk of wood by FGI get increased from lauan ($0.5088kW/m^2{\cdot}s$), red pine ($0.5111kW/m^2{\cdot}s$), Japanese cedar ($2.8522kW/m^2{\cdot}s$) to spruce ($3.0662kW/m^2{\cdot}s$). Therefore, the risk of fire on the heat release characteristics of woods were found that spruce and Japanese cedar showed the high value compared with the other specimens.

Combustion Characteristics of the Quercus variabilis and Zelkova Serrata Dried at Room Temperature (자연 건조된 굴참나무와 느티나무의 연소특성)

  • Chung, Yeong-Jin;Kwon, In-Kyu
    • Journal of Korean Society of Forest Science
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    • v.99 no.1
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    • pp.96-101
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    • 2010
  • One of the restriction of wood as building material is its combustibility. The purpose of this paper is to examine the combustion properties of the quercus variabilis and zelkova serrata which are dried at room temperature and meet the desirable characteristics for use of construction materials. The cone calorimeter (ISO 5660-1) was used to determine the heat release rate (HRR) and fire smoke index, as well as CO production and smoke obscuration. The $HRR_{mean}$ 77.94 kW/$m^2$ of the quercus variabilis at 50 kW/$m^2$ was high in comparison with $HRR_{mean}$ 13.06 kW/$m^2$ for the zelkova serrata. Furthermore, the quercus variabilis has high specific extinction area ($SEA_{mean}$), 41.11 $m^2$/kg compared with $SEA_{mean}$ 9.23 $m^2$/kg of zelkova serrata. Thease results are depend on the density of tested wood species. In addition, the quercus variabilis has high CO production rate compared with that of zelkova serrata. Also, zelkova serrata showed an increase of retardant properties attributed to char formation compared with that of quercus variabilis.

Synergistic Effect of 3A Zeolite on The Flame Retardant Properties of Poplar Plywood Treated with APP

  • Wang, Mingzhi;Ji, Haiping;Li, Li
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.2
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    • pp.258-264
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    • 2015
  • To evaluate the influence of 3A zeolite on the flame retardant properties of poplar plywood. Ammonium polyphosphate (APP) and 3A zeolite were used as flame retardants to prepare plywood samples. The combustion properties, such as heat release rate (HRR), total heat release (THR), mean CO and $CO_2$ yield, smoke production rate (SPR), and total smoke production (TSP), were characterized by a cone calorimeter. A synergistic effect was observed between 3A zeolite and APP on reducing the HRR and mean CO yield. The probable flame retardation mechanism was proposed.

A Study on the Combustion Characteristics of Synthetic Insulation for Building (건축용 합성 단열재의 연소특성에 관한 연구)

  • Kwon, Hyun-Seok;Lee, Si-Young;Kim, Jong-Buk;Yoon, Myoung-Oh
    • Fire Science and Engineering
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    • v.32 no.2
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    • pp.30-37
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    • 2018
  • This study is an analysis of combustion characteristics of synthetic insulation materials such as houses and warehouses. Using combustion cone calorimeter and SEM, the researching has experimented combustion characteristics of four kinds of materials such as flame retardant styrofoam, general styrofoam, urethane and gypsum board. And analyzed. As a result of the test, the ignition time (TTI) for the thermal insulation material was found at 27 s~43 s, and the flame retardant styrofoam was ignited at the lowest TTI at 27 s and disappears at 28 s. In addition, the maximum heat release rate (peak HRR) and average heat release rate (mean HRR) of each material were expressed in the following order: urethane> flame retardant styrofoam> styrofoam> gypsum board. Also, the total smoke release ($m^2/m^2$) was the largest at $30.798m^2/m^2$ in flame-retardant styrofoam. The general CO concentration of styrofoam was 0.275 kg/kg and the emission concentration was 12.807 kg/kg. The residues showed the highest 0.029 g in the gypsum board among the above materials.

Risk of Smoke Occurring in the Combustion of Plastics (플라스틱의 연소 시 발생하는 연기 위험성에 관한 연구)

  • You, Jisun;Chung, Yeong-jin
    • Fire Science and Engineering
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    • v.33 no.1
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    • pp.69-75
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    • 2019
  • In this study, the combustibility of five types of plastic plates, fiber reinforced plastic (FRP), polystyrene (PS), polycarbonate (PC), polypropylene (PP), and polyvinyl chloride (PVC), were tested using a cone calorimeter (ISO 5660). The PVC plate showed a $44.65kW/m^2$ lower peak heat release rate (HRR) and a $30.97kW/m^2$ lower maximum average rate of heat emission than the other four types of plastics, whereas the PS plate showed a $773.44kW/m^2$ higher peak HRR and $399.14kW/m^2$ higher maximum average rate of heat emission. The PC plate and PS plate showed the highest HRR by a maximum of 3.88 times in $CO_{mean}$ yields, while the PS pate and PP plate showed the highest HRR by a maximum 4.88 times in $CO_{2mean}$ yields. In addition, the smoke performance index (SPI) of the PS plate decreased by 74.81%~95.99%; the smoke growth index (SGI) increased to 76%~300%; the smoke intensity (SI) also increased to 917.73% ~ 9607.57%, and the danger of smoke increased. The PS plate was found to have the highest risk of life damage due to smoke on the thermal and smoke sides.

Study on Flame Retardancy and Thermal Resistance Properties of Phenolic Foam and Polyurethane Foam (페놀 폼과 폴리우레탄 폼의 난연 및 내열성 연구)

  • Lee, Ju-Chan;Seo, Jung-Seok;Kim, Sang Bum
    • Journal of the Korean Institute of Gas
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    • v.17 no.1
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    • pp.35-41
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    • 2013
  • In this study, flame retardancy of polyurethane foam and phenolic foam were investigated by addition of phosphorous flame retardants. The thermal degradation behavior of polyurethane foam and phenolic foam in the presence of flame retardants has been studied by thermogravimetric analysis(TGA). Heat release rate(HRR), mean HRR, mass loss rate(MLR), total smoke released(TSR) and limited oxygen index(LOI) were tested by cone calorimeter. From the test results, Phenolic foam showed low HRR, MLR and TSR than polyurethane foam.