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Risk Analysis and Control
Published in Benedito Cardella, Safety at Work and Emergency Control, 2018
Consequence analysis evaluates the aggressive agent action field, calculating the aggressive capacity at each point. The study requires mathematical models, and the difficulties to obtain high fidelity results are not few. Analyzing consequences, one must choose the appropriate level of the hazardous event. Fire and explosion are the hazardous events of interest when a flammable liquid leakage occurs. Fires can be pool fire, jet fire, flash fire, and fireball. An explosion may be a deflagration or detonation. Thermal radiation causes an incidence rate, measured in kcal/h·m2, which reduces as the distance from the fire increases. Explosions produce pressure waves whose intensity reduces as the distance from the center increases. If the leaked product is toxic, one must know how it behaves after leaking, as to the direction and concentration at each location. Concentration reduces as the distance from the releasing point increases.
Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
One of the most important physical characteristics of a flammable liquid is its flash point. Flash point is the minimum temperature to which a liquid must be heated to produce enough vapor to allow a vapor flash to occur (if an ignition source is present). Remember that it is the vapor that burns, not the liquid. Flash point is a measurement of the liquid temperature. Therefore, even if the ambient temperature is not at the flash point temperature of the liquid, the liquid may have been heated to its flash point by some external heat source. For example, the radiant heat from the sun, heat from a fire or heat from a chemical process may heat the liquid to its flash point. If an ignition source is present, fire can occur and probably will.
Terms and Definitions
Published in Rick Houghton, William Bennett, Emergency Characterization of Unknown Materials, 2020
Rick Houghton, William Bennett
Flash point is the lowest temperature of a flammable liquid that can form an ignitable mixture with air. According to the National Fire Protection Association (NFPA), flash point is “the minimum temperature at which a liquid or a solid emits vapor sufficient to form an ignitable mixture with air near the surface of the liquid or the solid.” NIOSH defines flash point as “the temperature at which the liquid phase gives off enough vapor to flash when exposed to an external ignition source.” The vapor pressure of the flammable liquid determines the output of flammable vapor. The vapor pressure is determined by the liquid temperature.
Experimental Research on the Effectiveness of Different Types of Foam of Extinguishing Methanol / Diesel Pool Fires
Published in Combustion Science and Technology, 2022
Zhaoqian Li, Hongqing Zhu, Jinlong Zhao, Yilong Zhang, Lintao Hu
There is an urgent need for a cleaner and more efficient disposal and treatment of the rapidly growing fires in fuel storage tanks, in particular, given the raised public concern about liquid firefighting technology. Usually, foam extinguishing agents are used to combat a variety of flammable liquid fires (Scheffey, Danvin, and Leonard 1995). Foam extinguishing pool fires involved complex heat and mass transferring processes. Various factors affect the effectiveness of foam extinguishing, such as the foam expansion, gas–liquid ratio, effectual fire extinguishing ingredients, the type of liquid fuel, external environmental conditions, etc. Meanwhile, most of the main features of foam fire extinguishing focus on the isolation of liquid-phase combustibles and gas-phase combustion aids, the cooling effect of water in the foam, and the dilution of oxygen concentration in the combustion zone by water vapor generated by heat (Lattimer and Trelles 2007; Ranjbar and Shahraki 2013; Sontake and Wagh 2014; Wang et al. 2021; Zhao and Liu 2016).