Stages of fire

Chemical measurements can be performed during developing stages of fire using direct reading measurements and sampling techniques like sorbent tubes. 

Moreover, differentiation of the 38 segments of an SP-chip brought about by the temperature and membrane thickness gradient has proved to provide high quality gas discrimination power. An analysis of the signal patterns obtained for some gases present in the early stages of fires is shown in Fig. 3.30. Prior to the... 

Tanaka, T. and Yamada, S., Reduced scale experiments for convective heat transfer in the early stage of fires, Int. J. Eng. Performanced-Based Fire Codes, 1999, 1(3), 196-203. 

To detect the incipient stage of fire, ionization-chamber-type sensors are used that analyze the composition of the atmosphere by measurement of its conductance. The ionization rises as the invisible combustion gas concentration rises. 

Expandable interlayers provide an alternative way for rapid delivery. Migration, even if promoted by an incompatible interlayer, is sometimes not rapid enough to deliver active substances to the surface therefore, a new adaptive concept has been developed recently [53,54], A material utilizing this mechanism contains a phosphorylated polyol (PPOL) interlayer of relatively low decomposition temperature intercalated between layers of nanoparticle. At the early stage of fire action the gaseous degradation products of the interlayer separate the nanolayers and drive them to the surface in the most rapid way. 

Recently, two significant developments have raised the profile of fire toxicity. The first is the development of the steady-state tube furnace (SSTF) (ISO TS 19700 2006), which has been shown to replicate the toxic product yields corresponding to the individual stages of fires. The second is the acceptance of performance-based fire design as an alternative to prescriptive fire regulations, so that architects can specify the components within a building based on a safe escape time, within which toxic and irritant gas concentrations must not approach a lethal level (ISO 13571 2007). 

Ammonium Nitrate Not flammable Not flammable Not flammable Not flammable Use flooding amount of water in early stages of fire. When large quantities are involved in massive fires, control efforts should be confined to protecting from explosion Not pertinent May explode in Ares Not pertinent No ... 

The rate of heat release during the Initial stages of fire exposure is considerably less, however, for treated wood than for untreated wood. Brenden (56), using the FPL rate of heat release method, obtained a maximum heat release rate of 611 Btu per square foot per minute for untreated 3/4-lnch Douglas-flr plywood, with an average release rate of 308 Btu per square foot per minute for the first 10 minutes. Fire-retardant-treated Douglas-fir plywood, with 3.6 pounds per cubic foot dry chemical and a reported flame spread of 25 to 28, had a maximum heat release rate of 132 Btu per square foot per minute at 42 minutes and an average rate of 16 Btu per square foot per minute for the first 10 minutes. 

Figure 1 Stages of fire growth and development. Many fire tests apply to ignition and preflash-over period only.

The ASTM E 603 is a guide written to assist in conducting full-scale compartment fire tests dealing with any or all stages of fire in a compartment. Whether it is a single- or multi-room test, observations can be made from ignition to flashover or beyond full-room involvement. Examples of the full-scale room fire tests are ... 

Blue Enamel. An area in dry-process vitreous enamelware where the coating is too thin and the ware appears blue. Blueing. The production of blue engineering bricks, quarries or roofing tiles by controlled reduction during the later stages of firing this alters the normal state of oxidation of the iron compounds in the material and results in a characteristic blue colour. 

Building Legislation Standards are concerned mainly with safety to life and therefore consider the early stage of fire and how it affects the means of escape, but also aim to prevent eventual spread to other buildings. 

Fire department Trained personnel Advanced stages of fire All portions of each story or section within 30 ft of nozzle with 100 ft of hose 6 in above 100 ft (275 ft maximum unless pressure regulated) 250 gal/min each additional (2500 gal/ min maximum) 30-min duration 65 psi at top outlet with 500 gal/min flow... 

In addition, the masonry wall is subjected to the boundary conditions that determine the stage of fire. The net heat flow into the fire exposed side is expressed as follows ... 

Figure 4. Finite element modeling results showing the stress gradient generated across the cross-section in rocket motor nozzles during the early stages of firing (red signifies tensile stress) [Pluscauskis, 2008]...

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