Radiation fire spread

For aii buiidings that are buiit within 1 m of the boundary to the property, fiame spread is the main mechanism. Beyond this distance, the mechanism for fire spread is assumed to be radiation. Fire spread from buiiding to buiiding by radiation is dependent upon the ... 

The fire spreads easily by, e.g., running liquid fire, a pool fire, a fire ball, heat radiation or thermal lift (convection). 

Storage vessels are usually located on tank farms. The space around a tank and the distances to other equipment depend on the materials stored, their potential hazardousness and the possibility of the unexpected changes in storage conditions. Fluid storages should be in a safe location away from process and public areas. It is also important to prevent fire spreading between tanks by keeping the level of heat radiation in an acceptable level (Mecklenburgh, 1985). 

Thermal radiation or fire spread resulting from a spill fire hazard involving flammables or combustibles. 

Fire, fire spread, fireballs, radiation Explosion, secondary explosion, domino effects Noise, smoke, toxic fumes, exposure effects Collapse, falling objects, fragmentation... 

In the context of fire CFD, it is sometimes appropriate to distinguish between flame and fire spread simulations. Flame spread simulation usually means the ability to predict the fire growth starting from a small initial fire or ignition point, where all the three subprocesses are important but the second subprocess dominates the heat transfer. Fire spread, in turn, means the ignition of solid surfaces in the presence of a relatively large initial fire dominating the heat transfer by radiation. In practice,... 

Figure 7.19 Fire spread by radiation from heater to com-bustibie materiai...

Figure 7.20 Fire spread by radiation from one buiiding to another...

This section provides detailed guidance relating to the fire resistance of external walls, space separation between buildings to minimise the risk of fire spread through radiation and discusses the requirements of roof coverings. 

The risk of fire spread by radiation is affected by a number of factors relating to space separation between buildings, the construction of the external walls and the combustibility of roof coverings. 

Evidence of 1 fire spread When examining a fire scene it is often not clear how the fire has spread, particularly if there are a variety of materials involved. Reference to the mechanisms of fire spread will help the consideration of conduction, convection, radiation and direct burning as methods of how the fire as spread. This will also help to confirm the location of the seat of the fire. 

The Ohio State University (OSU) calorimeter (12) differs from the Cone calorimeter ia that it is a tme adiabatic instmment which measures heat released dufing burning of polymers by measurement of the temperature of the exhaust gases. This test has been adopted by the Federal Aeronautics Administration (FAA) to test total and peak heat release of materials used ia the iateriors of commercial aircraft. The other principal heat release test ia use is the Factory Mutual flammabiHty apparatus (13,14). Unlike the Cone or OSU calorimeters this test allows the measurement of flame spread as weU as heat release and smoke. A unique feature is that it uses oxygen concentrations higher than ambient to simulate back radiation from the flames of a large-scale fire. 

Tlie growfii and spread of fires occurs fiuough heat transfer or tlie migration of burning materials. There are fiuee main modes of heat transfer conduction, convection, and radiation. 

Equation (8.6) demonstrates that as the face weight, pd, decreases the spread rate increases. Moreover, if a material undergoing spread is heated far away from the flame, such as would happen from smoke radiation in a room fire, Ts will increase over time. As Ts - Tig, an asymptotic infinite speed is suggested. This cannot physically happen. Instead, the surface temperature will reach a pyrolysis temperature sufficient to cause fuel vapor at the lower flammable concentration. Then the speed of the visible flame along the surface will equal the premixed speed. This speed in the gas phase starts at about 0.5 m/s... 

In normal atmospheric conditions, fire usually is initialed by a combustible material coming in contact with a heat source. The spread of fire occurs due to direct flame impingement or the transfer of heat to the surrounding combustible materials. Heat transfer occurs by three principal mechanisms - conduction, convection, and radiation. Conduction is the movement of heat through a stationary medium, such as solids, liquids or gases. Steel is a good conductor of heat as is aluminum, therefore they can pass the heat of a fire if left unprotected. 

Good heat radiating qualities are an asset to an incendiary agent, that is, the spread of luminosity for good distances greatly increases the probability of fire raising. 

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