Litton Charles D, Perera Inoka E, Harteis Samuel P, Teacoach Kara A, DeRosa Maria I, Thomas Richard A, Smith Alex C
National Institute for Occupational Safety and Health, Pittsburgh Mining Research Division, 626 Cochrans Mill Road, PO Box 18070, Pittsburgh, PA 15236, USA.
Fuel (Lond). 2018 Apr 15;218:306-315. doi: 10.1016/j.fuel.2017.12.106.
When combustible materials ignite and burn, the potential for fire growth and flame spread represents an obvious hazard, but during these processes of ignition and flaming, other life hazards present themselves and should be included to ensure an effective overall analysis of the relevant fire hazards. In particular, the gases and smoke produced both during the smoldering stages of fires leading to ignition and during the advanced flaming stages of a developing fire serve to contaminate the surrounding atmosphere, potentially producing elevated levels of toxicity and high levels of smoke obscuration that render the environment untenable. In underground mines, these hazards may be exacerbated by the existing forced ventilation that can carry the gases and smoke to locations far-removed from the fire location. Clearly, materials that require high temperatures (above 1400 K) and that exhibit low mass loss during thermal decomposition, or that require high heat fluxes or heat transfer rates to ignite represent less of a hazard than materials that decompose at low temperatures or ignite at low levels of heat flux. In order to define and quantify some possible parameters that can be used to assess these hazards, small-scale laboratory experiments were conducted in a number of configurations to measure: 1) the toxic gases and smoke produced both during non-flaming and flaming combustion; 2) mass loss rates as a function of temperature to determine ease of thermal decomposition; and 3) mass loss rates and times to ignition as a function of incident heat flux. This paper describes the experiments that were conducted, their results, and the development of a set of parameters that could possibly be used to assess the overall fire hazard of combustible materials using small scale laboratory experiments.
当可燃材料着火燃烧时，火灾蔓延和火焰扩散的可能性显然构成一种危险，但在着火和燃烧过程中，还存在其他危及生命的因素，应将其纳入考虑，以确保对相关火灾危险进行有效的全面分析。特别是，在导致着火的火灾阴燃阶段以及发展中火灾的剧烈燃烧阶段产生的气体和烟雾会污染周围大气，可能导致毒性升高和浓烟弥漫，使环境变得不适宜生存。在地下矿井中，现有的强制通风可能会将这些气体和烟雾带到远离火源的地方，从而加剧这些危险。显然，与在低温下分解或在低热通量下着火的材料相比，需要高温（高于1400 K）且在热分解过程中质量损失较小、或需要高热通量或热传递速率才能着火的材料所构成的危险较小。为了定义和量化一些可用于评估这些危险的参数，进行了多种配置的小规模实验室实验，以测量：1）无焰燃烧和有焰燃烧过程中产生的有毒气体和烟雾；2）作为温度函数的质量损失率，以确定热分解的难易程度；3）作为入射热通量函数的质量损失率和着火时间。本文描述了所进行的实验、实验结果，以及开发一组可能用于通过小规模实验室实验评估可燃材料整体火灾危险的参数。
