• Title/Summary/Keyword: heat spreading

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An Experimental Study on Fire Spreading External Wall of Buildings Using Dry Construction Method (건식공법을 이용한 건축물의 외벽 화재 확산의 실험적 연구)

  • Park, Jung-Woo;Cho, Nam-Wook
    • Fire Science and Engineering
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    • v.32 no.4
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    • pp.75-85
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    • 2018
  • The Grenpell tower fire in England in June of 2016 is a representative example of damage caused by a vertical fire spreading through external insulation. Organic insulation materials, which are widely used in external insulation, have the disadvantage that they have good insulation performance but are vulnerable to fire. Aluminum composite panels are used as exterior wall finishing materials, and plastics used in aluminum are regarded as the cause of vertical fire spread. Due to the steel frame used to secure the aluminum composite panel to the outer wall, a cavity is formed between the outer wall and outer wall finish. When a fire occurs on the outer wall, the flammable outer wall as well as the flame generated from the heat-insulating material spreads vertically through the cavity, resulting in damage to people and property. In Korea, material unit performance tests are carried out by the Ministry of Land, Infrastructure and Transport notice 2015 - 744. However, in the UK, the BS 8414 test is used to measure the vertical fire spreading time on the outer wall in real scale fire tests. In this study, the risk of external wall fire was evaluated in an actual fire by conducting a real scale wall fire test (BS 8414), which was carried out in Europe, using aluminum composite panels of semi-noncombustible materials suitable for current domestic standards. The purpose of this study was to confirm the limitations of material unit evaluation of finishing materials and to confirm the necessity of introducing a system to prevent the spread of outer wall fire through an actual scale fire test.

A Literature study on the external therapy of contact dermatitis. (接觸性皮膚炎의 外治法에 關한 文獻的 考察)

  • Jeon, Jae-hong;Kim, Hyun-a;Kang, Yun-ho;Ho
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.11 no.1
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    • pp.197-218
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    • 1998
  • In this study, I invastigate about oriental medical drug, dosage form and directions in external therapy of contact dermatitis. and after study on relationship oriental medical drug, dosage form and directions with cause, symptom and differentiation of symptom and sign. The results are as follows; 1. Most frequently used oriental medical drug is until qing(淸) dynasty Eriocheir sinensis H. Milne-Edwards(蟹), Salix babylonica L.(柳葉), Natrii sulfas(芒硝), Allium macrostemon Bge.(해), Nelumbo nucifera Gaertn.(荷葉), nowadays in Korea and China Phellodendron amurense Rupr.(黃柏), Gypsum(石膏), Rheum palmatum L.(大黃), Baphicacanthus cusia Bremek(靑黛), Talcum(滑石). 2. In the frequency of dosage form, until qing(淸) dynasty powder 1case, liquor 49cases, liquer and solid mixture 58cases, nowadays Korea and China powder 16cases, liquor 96cases, liquer and solid mixture 59cases. 3. Most frequently used directions of dosage is thinly attaching method(薄貼法), attaching method(敷貼法), furnigating and cleansing method(熏洗法), cleansing method(洗傷法), wet dressing method(濕敷法), spreading powder method(撲粉法), plaster method(途차法), rubbing skin method(摩擦法) 4. In the external therapy of contact dermatitis, oriental medical drug's usage is based on stage of contact dermatitis In acute stage, most frequently used drug is heat and damp remove drug(淸熱燥濕藥), nature of drug(藥性) is bitter taste and cold charactor(苦寒), In chronic stage, most frequently used drug is nourishing the blood drug(養血藥), promoting blood circulation drug(活血藥). 5. The dosage form of drug is based on symptom. In acute stage, when papules and vesicles, or erosion and exudation is the main symptom of skin, liquor or powder is used, when erosion and crust is the main symptom of skin, plaster is used. In chronic stage, plaster is used. 6. In the directions of dosage is based on dosage form of drug and symptom. In acute stage, when papules and vesicles is the main symptom of skin, fumigating and cleansing method, cleansing method, plaster method is used, when erosion, vesicles and exudation the main symptom of skill, cleansing method, wet dressing method, spreading powder method, attaching method, spreading powder method is used, when crust is the main symptom of skin, plaster method is used. In chronic stage, plaster method, rubbing skin method is used.

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Fabrication and Electrical Insulation Property of Thick Film Glass Ceramic Layers on Aluminum Plate for Insulated Metal Substrate (알루미늄 판상에 글라스 세라믹 후막이 코팅된 절연금속기판의 제조 및 절연특성)

  • Lee, Seong Hwan;Kim, Hyo Tae
    • Journal of the Microelectronics and Packaging Society
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    • v.24 no.4
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    • pp.39-46
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    • 2017
  • This paper presents the fabrication of ceramic insulation layer on metallic heat spreading substrate, i.e. an insulated metal substrate, for planar type heater. Aluminum alloy substrate is preferred as a heat spreading panel due to its high thermal conductivity, machinability and the light weight for the planar type heater which is used at the thermal treatment process of semiconductor device and display component manufacturing. An insulating layer made of ceramic dielectric film that is stable at high temperature has to be coated on the metallic substrate to form a heating element circuit. Two technical issues are raised at the forming of ceramic insulation layer on the metallic substrate; one is delamination and crack between metal and ceramic interface due to their large differences in thermal expansion coefficient, and the other is electrical breakdown due to intrinsic weakness in dielectric or structural defects. In this work, to overcome those problem, selected metal oxide buffer layers were introduced between metal and ceramic layer for mechanical matching, enhancing the adhesion strength, and multi-coating method was applied to improve the film quality and the dielectric breakdown property.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2015 (설비공학회 분야의 최근 연구 동향 : 2015년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.6
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    • pp.256-268
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    • 2016
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2015. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering were carried out in the areas of flow, heat and mass transfer, cooling and heating, and air-conditioning, the renewable energy system and the flow inside building rooms. Research issues dealing with air-conditioning machines and fire and exhausting smoke were reduced. CFD seems to be spreading to more research areas. (2) Research works on heat transfer area were carried out in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the economic analysis of GHG emission, micro channel heat exchanger, effect of rib angle on thermal performance, the airside performance of fin-and-tube heat exchangers, theoretical analysis of a rotary heat exchanger, heat exchanger in a cryogenic environment, the performance of a cross-flow-type, indirect evaporative cooler made of paper/plastic film. In the area of pool boiling and condensing, the bubble jet loop heat pipe was studied. In the area of industrial heat exchangers, researches were performed on fin-tube heat exchanger, KSTAR PFC and vacuum vessel at baking phase, the performance of small-sized dehumidification rotor, design of gas-injection port of an asymmetric scroll compressor, effect of slot discharge-angle change on exhaust efficiency of range hood system with air curtain. (3) In the field of refrigeration, various studies were carried in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, a cold-climate heat pump system, $CO_2$ cascade systems, ejector cycles and a PCM-based continuous heating system were investigated. In the alternative refrigeration/energy system category, a polymer adsorption heat pump, an alcohol absorption heat pump and a desiccant-based hybrid refrigeration system were investigated. In the system control category, turbo-refrigerator capacity controls and an absorption chiller fault diagnostics were investigated. (4) In building mechanical system research fields, eighteen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the user and location awareness technology applied dimming lighting control system, the lighting performance evaluation for light-shelves, the improvement evaluation of air quality through analysis of ventilation efficiency and the evaluation of airtightness of sliding and LS window systems. The subjects of building energy were worked on the energy saving estimation of existing buildings, the developing model to predict heating energy usage in domestic city area and the performance evaluation of cooling applied with economizer control. The studies were also performed related to the experimental measurement of weight variation and thermal conductivity in polyurethane foam, the development of flame spread prevention system for sandwich panels, the utilization of heat from waste-incineration facility in large-scale horticultural facilities.

A Study on the Damaged Pattern of Dryvit by External Flame (외부화염에 의한 드라이비트의 소손패턴 연구)

  • Park, Young Ju;Hong, Yi Pyo;Lee, Hae Pyeong
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.40-47
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    • 2015
  • In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length ${\times}$ 50 cm height ${\times}$ 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in $218^{\circ}C{\sim}995^{\circ}C$ at 30 seconds and $501^{\circ}C{\sim}1078^{\circ}C$ at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of $501^{\circ}C$ was shown at 300 seconds and marble inner wall showed the following lowest temperature of $900^{\circ}C$. Temperature rising over $1000^{\circ}C$ was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

Study on the Thermal Radiation Performance of the Multi-functional Structure Made of the Carbon Fiber Composite Material (탄소섬유 복합재를 이용한 위성용 다기능 구조체의 방열성능 분석)

  • Kim, Taig-Young;Hyun, Bum-Seok;Seo, Young-Bae;Jang, Tae-Seong;Seo, Hyun-Suk;Lee, Jang-Joon;Kim, Won-Seock;Rhee, Ju-Hun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.2
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    • pp.157-164
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    • 2012
  • The design strategy of the multi-functional structure is that the electrical components and the circuits are directly put on their supporting structural panel in which the radiation shields and the thermal control functions are integrated. Applying the multi-functional structure reduces the total mass and size of the space system and makes it possible to lower launch cost. In present study the performance of thermal radiation for six types of multi-functional structure are investigated by the numerical method. The effect of the rib configuration on heat transfer for the multi-functional-structure is not important alone but is meaningful considering with the structural stiffness, difficulty of manufacturing and mass increase. In heat spreading point of view, the thickness of the outer conductive layer is important rather than the rib configuration and the trade-off study with the mass and thickness is required for optimum design.

Experimental Study of the Blowoff Flame Phenomena Due to Changes of Balcony Length (발코니 길이변화에 의한 화염분출성상의 실험적 고찰)

  • Kim, Hoe-Cheon;Sohn, Jang-Yeul;Park, Hyung-Ju
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.3
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    • pp.235-244
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    • 2007
  • In the case of the fire outburst within a partitioned space, it can disappear inside it through smoldering process if the fire cannot obtain sufficient imflammability. On the contrary, if it obtains it, the fire is not restricted within the room, spreading to the higher levels beyond outside windows and the compartment room. The method to prevent the fire spread through windows is considered to build a balcony or equip with sprinkler facilities. This case study is to identify which effects and controlibility a balcony brings about on the spread of fire through a full scale model experiment. In order to understand the effects of fire spread on the upper levels of the room on fire by changing the length of balcony, the temperature was measured, radiant heat was investigated, and products of combustion were analyzed. The result showed that when fire occured, longer length of the balcony, which linked to the outside wall of the apartments, led to the blocking of the fire spread, lower level of radiant heat, and significantly less transfer of toxic gases, and the driving force of the outburst of flame was identified as the attractive force due to the turbulence of uncombusted gases, which exist on the upper level of the outbursting flame.

A Study on the Performance Criteria of Smoke Control System for Underground Spaces Through Numerical Analysis (수치해석을 통한 지하공간의 제연설비 성능기준 검토)

  • Ahn, Chan-Sol;Chae, Han-Sic;Kim, Hyeung-Youl
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.356-362
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    • 2008
  • This study is intended to evaluate the characteristics of smoke spreading and the appropriateness of evacuation time extended by operation of smoke control system during fire within the underground space of the building structured in compliance with the smoke control system performance criteria from the local fire safety standard in Korea. As a preceding review of this study, the combustibles was categorized and identified their heat release rates. For validate the estimated values, modeling a single underground shop was carried out. And a numerical analysis both in case of smoke control system in operation and the system not in operation was carried out of underground space. From the viewpoint of securing the evacuation time, the results were compared in an attempt to assess the appropriateness of the fire safety criteria.

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The Air/water Interface Characteristics of Maleate Copolymer LB Films (말레에이트계 공중합체 I-l3막의 공기/물에서의 계면 특성)

  • 신훈규;권영수;이범종;장정수;배진호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.220-223
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    • 1995
  • Stable polyion-complexed polymeric monolayrers were prepared by spreading perfluoroalkyl monomaleatd copolymers. C$_2$F$\_$8/MA-VE$_2$ and C$_2$F$\_$8/Mv-VE$_3$ on aqueous poly(allylamine) subphase. The monolayer properties have been studied by the surface pressure-area($\pi$-A) isotherms. The C$_2$F$\_$8/MA-VE$_3$containing longer oligoethyleneglycol pendant showed more expaned monolayer phase than the C$_2$F$\_$8/MA-VE$_2$ The polyion-complexed monolayers were transferable on various substrates, and the resulting Langmuir-Blodgett(LB) films were characterized b ET-IR spectroscopy and scanning electron microscopy(SEM) Two-dimensional crosslinking to from a polymer network was achieved by amide formation through heat treatment under vacuum with concurrent removel of perfluoroalkyl tails. SEM observation of this film ona porous membrane filter showed that the four layer film was sufficiently stable to cover the filter pore size of 0.1$\mu\textrm{m}$. The C$_2$F$\_$8/MA-VE$_3$revealed better covering capability than the C$_2$F$\_$8/MA-VE$_2$Immersion of this film in water or in benzend did not cause any change in its appearance and in FT-IR spectra.

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THE EFFECT OF HYDROLYZED ALKYLKETENE DIMER ON SIZING DEVELOPMENT

  • Seo, Won-Sung;Shin, Jong-Ho;Cho, Nam-Seok
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.11b
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    • pp.50-55
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    • 1999
  • Sizing development of AKD-sized paper by beta-ketoester formation has been debated until recent years because of absence of its obvious and direct spectroscopic evidence. In this study, reaction between AKD and cellulose was investigated to disclose the possibility of beta-ketoester formation between two components under no catalyzed neutral condition. In absence of water, AKD reacted with cellulose to form beta-ketoester linkage under no catalyzed neutral condition, while, in presence of water, most of AKD was hydrolyzed to a dialkyl ketone or beta-ketoacid. Therefore, the main mechanism of AKD sizing would not be the formation of beta-ketoester between AKD and cellulose in the papermaking process. It could be suggested that the sizing development of AKD-sized paper is obtained by next two mechanisms: 1) formation of a thin-layer of AKD on the fiber surface through melting and spreading of AKD emulsion particles by heat, and 2) the formation of ketone by the hydrolysis of AKD during drying and storage of AKD-sized papers.