Rapid Detection and Suppression of Mining Equipment Cab Fires

The National Institute for Occupational Safety and Health (NIOSH/PRL) conducted a series of large-scale experiments to evaluate the effectiveness of optical flame detectors, photoelectric smoke detectors, and combined ionization and photoelectric smoke detectors for rapidly detecting mining equipment cab fires. The detector alarm times were then used to trigger the discharge of a fire inerting system inside the cab to suppress cab material fires. This paper discusses the types of fire detectors tested, the experiments that were conducted, and the results that were obtained. Conclusions are that rapid detection of equipment cab fires can be achieved to trigger the discharge of a fire inerting system inside the cab to protect the operator in the cab.     

Development and Evaluation of Fire Barriers to Reduce Fire Hazards on large mining Equipment

The National Institute for Occupational Safety and Health has developed and evaluated various fire barriers for their effectiveness in preventing the spraying of pressurized hydraulic fluids onto simulated turbocharger hot surfaces, and in preventing the ignition of flammable vapors and mists onto barrier outer surfaces. This initial study, however, needs to be followed by a larger investigation that deals with barrier effectiveness in preventing or reducing hydraulic fluid fires within compartments of operating equipment, and barrier physical endurance under hostile environments within compartments. Some of the barriers were also evaluated for their effectiveness in suppressing simulated turbocharger fast-developing fires (initial fires, 32 kW). For the evaluation, modeled engine compartments with simulated turbocharger surfaces of 600°C, initial fires of 32 kW, and a pressurized hydraulic fluid spray system, were used. Also, conceptualized designs of some of the fire barriers, set within the compartments of typical mining equipment, have been reported to provide further guidance toward barrier fabrication and installation. The fire barriers included a parachute silica cloth barrier lined with flexible stainless steel foil; a one-panel insulated stainless steel barrier with a water-spray system; a foldable multi-panel insulated stainless steel barrier; and, an open–close steel strip barrier. Results show that all four fire barriers were effective in preventing the spraying of pressurized hydraulic fluids onto simulated turbocharger hot surfaces. Most of the barriers were also effective in preventing the ignition of flammable vapors and mists onto barrier outer surfaces. Results also show that the parachute barrier and the one-panel barrier with a water-spray system were effective in suppressing simulated turbocharger initial fires of 32 kW.     

Effectiveness of Gas Fired Water Heater Elevation in the Reduction of Ignition of Vapors from Flammable Liquid Spills

Elevating ignition sources to protect against the ignition of vapors from flammable liquid spills has a long history in the national standards and codes. Accident data from the Consumer Product Safety Commission and the National Fire Protection Association identify gas fired water heaters as the major ignition source of flammable liquid vapor accidents in the home. During the past ten years, numerous different laboratories have conducted tests to evaluate the effectiveness of elevating gas fired water heaters to prevent the ignition of flammable liquid vapors. Analysis of the results of 48 tests from three laboratories demonstrate the effectiveness of elevating gas fired water heaters in reducing the ignition of flammable liquid vapors in the home.     

A study of portable water mist fire extinguishers used for extinguishment of multiple fire types

This paper describes both theoretical and experimental studies on the application of a portable water mist extinguisher in suppressing multiple fire types. Two prototype portable water mist fire extinguishers were developed and their feasibility in extinguishing flammable liquid, cooking oil and wood crib fires, and for use in fires associated with an energized target was investigated. The interaction between water mist and the fire plume was studied by analyzing the instantaneous process of fire extinction, and fire and fuel temperature profiles. Both theoretical analysis and experimental results showed that the extinguishing mechanisms and process as well as water mist characteristics required (such as water flux density, droplet size and spray coverage) change with the types of fires encountered. The portable water mist extinguisher with appropriate mist characteristics was able to extinguish multiple fire types.     

电缆燃烧典型火源模拟方法综述

针对电缆火灾问题,综述了国内外电缆火灾模拟试验及电缆燃烧测试中使用的火源模拟方法,并对比探讨了多种火源模拟方法的点火时间、火源温度、火源面积、火源功率、可扩展性、可移动性以及可持续使用性等方面的差异:燃气喷灯法和辐射加热法(锥形量热计)所需点火时间短;电加热法火源温度高,操作简便易移动;燃油点火法的点火面积大,可扩展性...     

一起橡胶厂胶粉车间火灾事故的调查

对一起橡胶厂胶粉车间火灾事故进行调查,通过火灾现场勘查、调查走访、物证鉴定,认定了起火时间、起火部位及起火点,分析了此起火灾事故的起火原因,报告了车间消防安全管理的现状。为有效预防此类企业火灾事故的发生,提出了一些防范此类火灾发生的措施和建议。     

烧结砖脱硫塔及厂房火灾认识和分析

烧结砖企业要避免脱硫塔系统内防腐层、喷淋层、喷嘴和除雾器、PP材料和管道、玻璃钢屋面瓦等材料发生火灾,应加强辨识热烟气介质着火源的特殊性,防止烟气介质温度超过玻璃钢制品的工作温度限制,防止高温烟气介质成为着火源,与玻璃钢挥发可燃性气体、空气相互作用达到燃烧条件.     

The strategies of fire prevention on residential fire in Taipei

Records from Taipei City Fire Department show that age and gender of the victims, housing type, the location of the fire, source of ignition, hour range and residential fire deaths are all related to how and why residential fires occurred in Taipei City. With aids of the prevention strategy on residential fire which includes safety precaution, arson prevention and reinforcement of rescue training and the employment of fire rescue decision-making system, we are able to build hierarchy of prevention strategy to reduce the probability of residential fires and injury and deaths.     

Extinction of gas and liquid pool fires with water sprays

Extinction in open space of flames from pool fires by downwardly directed water sprays has been investigated on two linear scales, one three times larger than the other. Circular pool fires were employed as fire sources, mostly in the form of gas discharge (methane) from a horizontal sand surface but also, to a limited extent, in the form of heptane pools. The results are presented in normalized plots based on scaling theory verified in a previous study. Extinction data from the methane fires are insensitive to the initial spray angle of the nozzle discharge. The data are consistent with an engineering relation showing extinction water flow rate approximately proportional to an effective nozzle diameter, and to the 0.4-power of both nozzle height and freeburn heat release rate. This result has been interpreted to indicate that spray-induced dilution of the flammable gas is a major factor in extinguishing fires from gaseous discharge. Extinction data of liquid pool fires from this study (n-heptane) and previous investigations (gasoline, JP-5) are consistent with the methane data, except for somewhat higher water rates at extinction.     

Monitoring Multiple Aspects of Fire Signatures for Discriminating Fire Detection

Numerous researchers are exploring multisensor detection as the principal means of discriminating between fire and nuisance sources. Multisensor detectors can monitor multiple aspects of a wide variety of signatures produced by flaming fires, non-flaming fires, and nuisance sources. This paper describes one program of small- and large-scale experiments that has been conducted using a prototype advanced fire detector with multiple gas sensors. An elementary analysis is applied to demonstrate that spacing guidance can be rationally developed for multiple gas sensors to detect fires of a particular threshold fire size, i.e., heat release rate. Discriminating between flaming fires, non-flaming fires, and nuisance sources could be achieved using either a threshold concentration or CO₂ rate-of-rise to identify flaming fires and a CO or CO₂ rate-of-rise for non-flaming fires. Time to detection was also compared to commercial smoke detectors, and the reductions in time were noted.     

锂电池粉尘惰化装置微量连续送粉优化研究

针对锂电池粉尘惰化装置总是出现物料结拱而无法保证锂电池生产的安全问题,对惰化装置进行优化研究。分析惰化装置系统主要结构及工作原理,建立输送系统料仓仓压数学模型,研究料仓仓压对惰性粉输送卸料率的影响,以此为基础结合搜索优化思想确定出料口尺寸范围;对气动破拱辅助送粉装置进行仿真分析,结合破拱机理优化气动破拱装置。结果表明：根据计算与实验分析结果,料仓仓压越大,惰性粉输送越困难,原惰化装置单次惰性粉添加量最大3.6 kg,而改进出料口尺寸为89 mm左右时可达20 kg;新型双倾斜喷嘴破拱结构相比于单喷嘴破拱效果提升30.9%;优化后的惰化装置未出现送粉中断问题,单次惰性粉添加量可达25 kg,每小时送粉量在0.16～0.37 kg波动。     

水喷雾系统抑制电动汽车火灾有效性实验研究

为解决现有消防手段难以有效扑灭电动汽车火灾的问题,设计了水喷雾隔热阻火系统和拖车式车载水喷雾灭火降温系统.对模拟电动汽车火灾进行灭火有效性全尺度实验.结果表明,在现有工况条件下,水喷雾隔热阻火系统能有效抑制车辆底盘的射流火焰,可防止火灾向相邻车辆蔓延,但受安装位置限制,该系统对驾驶舱内部火焰的抑制和降温效果较差,灭火后...     

Investigation of a heat stress-related death of a fire fighter

The National Institute for Occupational Safety and Health (NIOSH) Division of Surveillance, Hazard Evaluations and Field Studies (DSHEFS) conducts investigations of health hazards in the workplace under the NIOSH Health Hazard Evaluation (HHE) program. In September 1990, the International Association of Fire Fighters (IAFF) requested that NIOSH assess the health and safety practices used by fire personnel during a brush fire on September 6, 1990, in Sedgwick County, Kansas. A 25-year-old fire fighter died of heat stroke at the scene.The NIOSH site visit to Sedgwick County, Kansas included a tour of the fire scene, personal interviews with 25 fire fighters and support personnel, and a review of incident reports, incident command procedures and other documents. NIOSH investigators concluded that a preventable series of events preceded the fire fighter's death. Recommendations were made for incident command and safety procedures, as well as medical monitoring, rehabilitation of fire fighters at fire scenes, and rehydration schedules.     

易燃液体使用场所的火灾危险性半定量评价

从近年来我国工业场所火灾情况的实际出发,以使用易燃液体的工作场所为评价对象,以事件树分析为基础,建立了半定量的火灾风险评价模型.从易燃液体泄漏的可能性、泄露液体被引燃的可能性和人员受到伤害的可能性三方面对火灾风险进行了分析,并建立了易燃液体火灾人员伤害风险评价指标体系,介绍了风险计算方法及影响因素的重要度分析.     

Spread and burning behavior of continuous spill fires

Spill fire experiments with continuous discharge on a fireproof glass sheet were conducted to improve the understanding of spill fire spread and burning. Ethanol was used as the fuel and the discharge rate was varied from 2.8 mL/s to 7.6 mL/s. Three ignition conditions were used in the experiments; no ignition, instantaneous ignition and delayed ignition. The spread rate, regression rate, penetrated thermal radiation and the temperature of the bottom glass were analyzed. The experiments clearly show the entire spread process for spill fires. Further, the regression rate of spill fires at the quasi-steady burning was lower than that of pool fires and the ratio of the spill fires’ regression rate to the pool fires’ regression rate was found to be approximately 0.89. With respect to the radiative penetration and the heat conduction between the fuel layer and the glass, a regression rate expression for spill fires was developed based on some modifications on existing expressions for pool fires. In addition, a complete phenomenological model for spill fires was developed by combining the characteristics of spread and burning. The model was verified by the experimental data and found to predict the spread process for spill fires with reasonable accuracy.     

基于建筑火灾安全的逃生互动影响分析

建筑火灾是破坏性的复杂动态过程。建筑火灾有其普遍的特征规律,也因其作用的对象和时间的不同而体现出不同的效果。建筑火灾发展受到建筑特征、相关人员干预、环境条件变化等众多因素的影响而呈现出复杂的变化趋势。建筑火灾的动态过程可以理解为火势蔓延与建筑内外的主动、被动防御系统及人员作用相互影响的互动过程。本文在对建筑火灾特性分析的基础上,应用微剂量作用计量方法(Fractional Effective Dose,FED)分别分析可用安全疏散时间(Available Safety Egress Time,ASET)内的高温伤害、毒气侵袭、浓烟影响和结构坍塌对建筑火灾逃生安全的影响。基于建筑火灾安全分析和建筑消防系统互动作用分析,研究在火灾风险威胁和消防系统保护双重作用下逃生者的环境互动影响与逃生行为决策关系。     

非开放空间内灭火的技术难点及新技术的展望

分析了非开放空间内火灾的特点和传统的水灭火系统的弱点,对气体灭火系统的优点作了比较,并论述了氮气灭火的性能和安全性,介绍了氮气分离膜的性能及应用氮气分离膜产生富氮空气用于防火和灭火的可能性.     

一种低压中速离心式水雾喷头的开发和实验研究

根据对喷头结构参数的理论计算，设计了一种低压中速离心式水雾喷头，并与目前常见的低压高速水雾喷头进行了灭火实验效果比较，结果表明新设计的水雾喷头能更好抑制和扑灭A类火、B类火及AB类混合火，并节省用水量。     

浅议我国建筑保温火灾及其预防

建筑保温火灾既能造成生命财产损失,也给建筑节能工程带来冲击。因有机保温建材既有优良的保温隔热性能,又有易燃的火灾危险性,故应扬长避短,认真执行安全第一的生产方针;加强监管;及时修改建筑防火规范,才能在安全的基础上实现建筑节能减排。     

高层建筑消防隐患分析与防火监督策略研究

文章通过文献资料法进行分析,得出相应的结论:高层建筑火灾具有可燃物多、蔓延速度快、人员疏散困难等特点,存在消防设计与施工不规范、消防安全管理意识薄弱、消防安全检查工作落实不到位等消防隐患,需要围绕消防设计与施工管理、消防安全教育、消防安全检查制度、消防远程监管系统等方面工作,做好高层建筑防火监督工作。