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The paper presents a simplified engineering model for the prediction of the rate of heat absorption by heat-up and evaporation of water droplets interacting with fire-induced smoke. The algorithm can be easily implemented in the framework of one-zone or two-zone fire models. The general methodology is based on a decoupled time scale analysis for the heating, evaporation and motion of a single droplet. Such analysis allows to determine the heat absorbed by a droplet during its residence time in the smoke layer. Under the assumption of a monodisperse spray, the injected number of droplets per second is calculated and used to estimate the rate of heat absorption (i.e., cooling) by a full spray. The assessment of the model, for single droplet as well as full spray calculations, has been carried out against results obtained with the Fire Dynamics Simulator (FDS 6.7.0). The results show that the model predicts the rate of heat absorption within 15% for droplet diameters between 0.4 mm and 0.8 mm and a surrounding gas temperature below 150°C. Larger deviations are observed under other conditions. The application of the model to a well-confined and mechanically-ventilated compartment fire (a scenario of relevance to nuclear installations and passive houses) allowed to provide a good estimate of the cooling rate of the water spray system and the subsequent average gas temperature and pressure profile within the room.

A study of firefighter exposure was undertaken as part of a larger smoke exposure study. Teams of Chicago Fire Department firefighters were issued equipment for monitoring exposure conditions during structural fire suppression activity (knockdown and overhaul) and search and rescue operations. Potential inhalation exposure was characterized by outfitting firefighters with direct-reading gas meters and personal cascade impactors. The gas meters used electrochemical sensors to detect six gases of interest: carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), ammonia (NH3), nitrogen dioxide (NO2) and hydrogen cyanide (HCN). The personal cascade impactors were four stage units with 9.8 μm, 3.5 μm, 0.93 μm and 0.52 μm particle size cut points. Size-segregated particles collected on the impactor plates were analyzed for smoke particle weight distribution and for inorganic element content by inductively coupled plasma-mass spectroscopy (ICP-MS). Gloves and hoods were issued to teams of firefighters as part of their standard turnout ensemble and collected at regular intervals for chemical evaluation of accumulated combustion residue. Sections of the hoods and gloves were analyzed for inorganic element content by ICP-MS, mercury by cold vapor atomic absorption spectroscopy (CVAAS), and polynuclear aromatic hydrocarbons (PAHs) and other organic compounds by gas chromatography-mass spectroscopy (GC–MS). Findings indicated that firefighters are exposed to:

This paper is the first in a series of four that collectively provide a substantial body of knowledge on the egress capabilities of disabled people who frequent public-assembly buildings. Here, the results are given of an analysis of survey data estimating the numbers and types of disabled people who are mobile beyond their own homes, the degree of assistance they require, the percentage of the total mobile population they constitute, and the extent to which they are involved in sports and leisure pursuits. This information can be used to derive working estimates of the prevalence and nature of disability among building populations when characterizing building occupancies, a prerequisite to fire engineering.

The original version of this article unfortunately contained an error in Table 1 and text under Sect. 3.3.

Photoelectric smoke detectors, commonly used in aircraft cargo compartments, have high false alarm rates, which may result in huge economic losses and threaten flight safety. Dust aerosols are conventionally considered the main reason for this. Distinguishing dust aerosols from fire smoke by considering the difference between their scattering characteristics using a relatively simple combination of optical elements is crucial for reducing the false alarm rate. According to the relevant provisions for fire smoke and dust specified in the aerospace standard (AS 8036A) of the Society of Automotive Engineers (SAE) and considering the common cargo types, we studied the scattering characteristics of three types of aerosols, including six non-flaming fire smokes, four flaming fire smokes, and two dust aerosols, through numerical calculation and experimental methods. The results showed that these aerosols have different light scattering characteristics for forward and backward scattering due to particle size, morphology, etc. Considering these differences, we distinguished fire smoke from dust aerosols and reduced the false alarm rate in photoelectric smoke detectors in aircraft cargo compartments using an optimised optical structure design with dual wavelengths of 405 and 850 nm and dual scattering angles of 45° and 135°.