• Title/Summary/Keyword: Fire Protection Rate

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A Study on the Textile for Protective Clothing of Fire Fighters (한국 소방대원 방수피복의 소재특성에 관한 비교 연구)

  • 정정숙;이연순
    • Journal of the Korean Home Economics Association
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    • v.40 no.5
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    • pp.15-24
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    • 2002
  • The following research conclusions were made, relative to the experiments of the textiles of fire fighters Protective Clothing. 1. When the body protection efficiency such as the thickness, the strength and heat resistance are considered, Nomex(N) is tuned out the best outer shelf, Gore-tex(KG) the best moisture barrier, and Wool-felt(WC) the best thermal barrier. 2. In the hygienic and sanitary efficiency also, N is turned out the best outer shelf, KG the best moisture barrier, and WC the best thermal barrier in its degree of water resistance, water vapour permeability, and air permeability. 3. In the washing and maintenance efficiency, too. N is turned out the best outer shell, KG the best moisture barrier, and WC the best thermal barrier, being considered the material's rate of contraction, the changing rate of frame resistance, water resistance, and water vapour permeability. 4. When considered the frame resistance against the reflection tape and reflection efficiency, O is the best material for it marks the highest score in the frame resistance and reflective effect.

Strength Characteristics of Passive Fire Protection Material Applied Structural Members on Fire Load (수동화재보호 재료가 적용된 구조부재의 화재하중에 대한 강도 특성)

  • Jo, Sang Chan;Yu, Seung Su;Seo, Jung Kwan
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.1
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    • pp.29-38
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    • 2022
  • In offshore installations, fires cause the structure to lose its rigidity and it leads to structural integrity and stability problems. The Passive Fire Protection (PFP) system slows the transfer rate of fire heat and helps prevent the collapse of structures and fatality. Especially, intumescent epoxy coating is widely used in the offshore industry, and not only is the material cost expensive, but it also takes a lot of time and cost for construction. Several studies have been conducted on the efficient application and optimal design of the PFP system. However, the mechanical properties and the strength of the PFP material have not been considered. In addition, researches on the correlation between the thickness of PFP and the structural behavior were insufficient. Therefore, this study aims to analyze the thermal and mechanical effects of the PFP on the structure when it is applied to the structural member. In particular, it is intended to resolve the change in strength characteristics of the structural members as the thickness of the PFP increases.

Analysis of Abnormal Signals for Induction Motor according to Operating Status of Fire Pumps (소방펌프의 운전상태에 따른 유도전동기의 이상 신호 분석)

  • Ku, Bonhyu;Kim, Doo-Hyun;Kim, Sung-Chul
    • Journal of the Korean Society of Safety
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    • v.37 no.4
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    • pp.20-27
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    • 2022
  • This article aims to develop an algorithm that detects fire pump defects by analyzing the current signals of an induction motor, which are triggered by changes in the flow rate and pressure of multistage volute pumps that are used for fire services. The operational status of the pumps was categorized into three: first, normal operation; second, a defect that is caused by a change in the current value; and third, a defect occasioned by a change in current, pressure, and flow rate. When a fire pump was in normal operation, the motor's operating current was measured between 5.06 A and 6.9 A, the flow rate was estimated at 0-0.27 m3/min, and the pressure ranged from 0 to 0.47 MPa. In the event that a defect was caused by an abnormal current value in the motor, it was attributed to the pump's adherence. Furthermore, if there was no source of water, the defect was considered to have been induced by phase-loss operation, no-load operation, or run-stop operation, with the current value of each scenario being measured at > 52.8 A, < 4.13 A, > 45.15 A, and < 3.8 A, respectively, placing its overall range between 0 and 50 A. The sources of defects were detected based on an analysis of the flow rate, pressure, and current, which represent the following causes: air inflow into the casing, inadequate suction of water, and reverse-phase operation, respectively. Each cause entailed the following values: when air seeped into the casing, the pressure was measured at 0.24 MPa irrespective of changes in the flow rate; when there was inadequate suction of water, the pressure was recorded between 0 and 0.05 MPa despite changes in the flow rate; and when the power line's reverse-phase loss was the cause of the defect, the pressure was measured at 0.33 MPa for a flow rate of 0 L/min, and a higher flow rate decreased the pressure to nearly 0 MPa. The results of this study will enable engineers to develop a pump defect detection algorithm that is based on an analysis of current, and this algorithm will facilitate the execution of a program that will control a fire pump defect detection system.

A Study on the Development of a Head for Prevent the Fire Spread of Exterior (외장재 연소확대방지용 헤드 개발에 관한 연구)

  • Min, Se-Hong;Kim, Mi-Suk;Jang, Young-Jin;Sa, Jae-Chun;Bae, Yeon-Jun;Lee, Jae-Moon
    • Fire Science and Engineering
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    • v.26 no.1
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    • pp.113-119
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    • 2012
  • In this research, in order to prevent spread of vertical flame from building exterior fire, A head was developed. The performance standards of Head development complied with NFPA 80A 7.7.4.3 (Recommended Practice for Protection of Buildings Exterior Fire Exposures) and the standards are applied to the discharge pressure was 0.05 MPa and the discharge flow rate was 60 l/min. The head was developed about applied to 0.05 MPa and 65 l/min through the process of the experiment of five times, it is processed from drencher head and used in domestic intended use and structure are quite different. An appropriate distances between the head and the head proved as the experimental results to within 3 m~5 m and it selectively applied to the design is being considered depending on the fire hazard strength.

A Suggestion for Effectiveness Secure of Fire Servant's Three Shift Working System (소방공무원 3교대 근무 실효성 확보를 위한 제언)

  • Song, Yong-Sun
    • Fire Science and Engineering
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    • v.28 no.2
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    • pp.98-104
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    • 2014
  • The fire servant's three shift working system tried out from 2009, and the performance rate of the fire servant's three shift working system is currently 98%. The Domestic study on fire servant's three shift working system is very elementary and puerile level, and its study is almost zero. Accordingly, this study aimed to sort through problems and prior task of the three shift working system implementation, and to suggestion for effectiveness secure of Fire servant's three shift working system.

Numerical study on fire resistance of cyclically-damaged steel-concrete composite beam-to-column joints

  • Ye, Zhongnan;Heidarpour, Amin;Jiang, Shouchao;Li, Yingchao;Li, Guoqiang
    • Steel and Composite Structures
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    • v.43 no.5
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    • pp.673-688
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    • 2022
  • Post-earthquake fire is a major threat since most structures are designed allowing some damage during strong earthquakes, which will expose a more vulnerable structure to post-earthquake fire compared to an intact structure. A series of experimental research on steel-concrete composite beam-to-column joints subjected to fire after cyclic loading has been carried out and a clear reduction of fire resistance due to the partial damage caused by cyclic loading was observed. In this paper, by using ABAQUS a robust finite element model is developed for exploring the performance of steel-concrete composite joints in post-earthquake fire scenarios. After validation of these models with the previously conducted experimental results, a comprehensive numerical analysis is performed, allowing influential parameters affecting the post-earthquake fire behavior of the steel-concrete composite joints to be identified. Specifically, the level of pre-damage induced by cyclic loading is regraded to deteriorate mechanical and thermal properties of concrete, material properties of steel, and thickness of the fire protection layer. It is found that the ultimate temperature of the joint is affected by the load ratio while fire-resistant duration is relevant to the heating rate, both of which change due to the damage induced by the cyclic loading.

Study on the Pressure Loss of Hoses in a Fire Hose Reel Hydrant (호스릴옥내소화전 호스에 대한 압력손실에 관한 연구)

  • Whang, Young-Kwon;Lee, Seung-Chul
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.63-67
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    • 2019
  • In this study, the pressure loss of a fire hose reel hydrant was examined and the effects of each factor on the pressure loss were analyzed. First, in the pressure loss experiment according to the length of the reel hose, the pressure loss increased with increasing length of the reel hose; it was approximately 38.86% based on a 25 m hose. Second, the pressure loss of the reel hose per unit length was estimated to be $.13{\sim}.15kgf/cm^2$. Third, in the pressure loss experiment according to the change in the flow rate, the result was similar to the relation, flow rate - pressure loss (${\Delta}P{\sim}Q^2$), in the piping flow. These results provide basic data on the evaluation of fire pump pressure and the performance-based fire-protecting design of fire hose reel hydrants used in buildings.

The Influence of Pressure, Temperature, and Addition of CO2 on the Explosion Risk of Propylene used in Industrial Processes

  • Choi, Yu-Jung;Choi, Jae-Wook
    • Korean Chemical Engineering Research
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    • v.58 no.4
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    • pp.610-617
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    • 2020
  • In process installations, chemicals operate at high temperature and high pressure. Propylene is used as a basic raw material for manufacturing synthetic materials in the petrochemical industry; However, it is a flammable substance and explosive in the gaseous state. Thus, caution is needed when handling propylene. To prevent explosions, an inert gas, carbon dioxide, was used and the changes in the extent of explosion due to changes in pressure and oxygen concentration at 25 ℃, 100 ℃, and 200 ℃ were measured. At constant temperature, the increase in explosive pressure and the rates of the explosive pressure were observed to rise as the pressure was augmented. Moreover, as the oxygen concentration decreased, the maximum explosive pressure decreased. At 25 ℃ and oxygen concentration of 21%, as the pressure increased from 1.0 barg to 2.5 bar, the gas deflagration index (Kg) increased significantly from 4.71 barg·m/s to 18.83 barg·m/s.

Applied Time-Temperature Curve for Safety Evaluation in the Road Tunnel by Fire (도로터널내 화재에 따른 터널구조체의 안정성 평가를 위한 시간-온도곡선의 적용)

  • Won, Jong-Pil;Choi, Min-Jung;Jang, Chang-Il;Lee, Sang-Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.551-555
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    • 2009
  • This study is performed to apply a standard to evaluate fire protection assessment for tunnel structures when a fire breaks out in the road tunnel. Recently, a number of road tunnels have been rapidly increased and fire risk also multiplyed according to extend tunnel length, due to natural features and environmentally-friendly road construction in Korea. But we have not yet been prescribed appropriate time-temperature curve for tunnel fire. Therefore, we presented fire design model and investigated time-temperature curve proposed by a foreign country considering traffic, a kinds of vehicles which are a basis of heat rate. At the end, Hydrocarbon modified curve applied as design fire model by using numerical analysis and presented design fire model and examined the effects of tunnel structures.

A Study on Smoke Movement in Room Fires with Various Pool Fire Location

  • Jeong, Jin-Yong;Ryou, Hong-Sun
    • Journal of Mechanical Science and Technology
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    • v.16 no.11
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    • pp.1485-1496
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    • 2002
  • In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.