Fire extinction mechanism

The counterflow configuration has been extensively utilized to provide benchmark experimental data for the study of stretched flame phenomena and the modeling of turbulent flames through the concept of laminar flamelets. Global flame properties of a fuel/oxidizer mixture obtained using this configuration, such as laminar flame speed and extinction stretch rate, have also been widely used as target responses for the development, validation, and optimization of a detailed reaction mechanism. In particular, extinction stretch rate represents a kinetics-affected phenomenon and characterizes the interaction between a characteristic flame time and a characteristic flow time. Furthermore, the study of extinction phenomena is of fundamental and practical importance in the field of combustion, and is closely related to the areas of safety, fire suppression, and control of combustion processes. 

Fires may be started by one or several of die following so-called "common fire hazards matches and cigarets, rubbish (spontaneous ignition), locomotive sparks, mechanical spartks, friction, open-flame devices, heating appliances, electric wiring and equipment, static electricity and lightning. The primary object of fire prevention and extinction is to avoid loss of life and personal... 

Using this concept, it has been shown by cone calorimetry that over a 3 min combustion period, 3 and 6 mm thick laminated structures, made with different fire-retardant skin and unfilled core combinations can give similar resistance to ignition and comparable HRR and smoke extinction area (SEA) results to fully fire-retardant compositions (Table 7.4). Mechanical properties, in particular impact strength, were also found to be greatly enhanced by this approach, since less fire-retardant filler is present in the material. Whereas this approach has been demonstrated to be effective with hydrated fillers, it is applicable to all fire-retardant types. 

Resistant to temperatures and chemical agents, including water, overheated vapor, solutions of alkali, mineral acids and salts, microorganisms and radiation. Decomposes in aliphatic hydrocarbons, has high mechanical and dielectric strength, stiffness, dimensional stability, resistance to sparking, self-extinction when removed from fire. 

---