Explosion exothermic chemical reaction

Potential explosion phenomena include vapor cloud explosions (VCEs), confined explosions, condensed-phase explosions, exothermic chemical reactions, boiling liquid expanding vapor explosions (BLEVEs), and pressure-volume (PV) ruptures. Potential fire phenomena include flash fires, pool fires, jet fires, and fireballs. Guidelines for evaluating the characteristics of VCEs, BLEVEs, and flash fires are provided in another CCPS publication (Ref. 5). The basic principles from Reference 5 for evaluating characteristics of these phenomena are briefly summarized in this appendix. In addition, the basic principles for evaluating characteristics of the other explosion and fire phenomena listed above are briefly summarized, and references for detailed evaluation of characteristics are provided. 

In the search for a better approach, investigators realized that the ignition of a combustible material requires the initiation of exothermic chemical reactions such that the rate of heat generation exceeds the rate of energy loss from the ignition reaction zone. Once this condition is achieved, the reaction rates will continue to accelerate because of the exponential dependence of reaction rate on temperature. The basic problem is then one of critical reaction rates which are determined by local reactant concentrations and local temperatures. This approach is essentially an outgrowth of the bulk thermal-explosion theory reported by Fra nk-Kamenetskii (F2). 

Liquid ammonia and the solvent may explode when mixed. (It is possible this was a liquefied gas (physical) explosion, rather than an exothermic chemical reaction.)... 

Compatibility Group G comprises any substance which is an explosive substance because it is designed to produce an effect by heat, light, sound, gas or smoke, or a combination of these as a result of non-detonative, self-sustaining, exothermic chemical reactions, or an article containing such a substance or an article containing both a substance which is explosive because it is capable by chemical reaction in itself of producing gas at such a temperature and pressure. 

Hazards, Prediction of. D.R. Stull has developed methods of linking thermodynamics and kinetics to the prediction of potential and real hazards arising from exothermic chemical reactions (including explosions). We quote extensively from his publications... 

On suitable initiation of a homogeneous liquid explosive, such as liquid nitroglycerine, the pressure, temperature, and density will all increase to form a detonation wave front. This will take place within a time interval of the order of magnitude of 10 12 s. Exothermic chemical reactions for the decomposition of liquid nitroglycerine will take place in the shockwave front. The shockwave will have an approximate thickness of 0.2 mm. Towards the end of the shockwave front the pressure will be about 220 kbar, the temperature will be above 3000 °C and the density of liquid nitroglycerine will be 30% higher than its original value. 

The occurrence of various explosion rates for liquid nitroglyceiine has been explained by Audibert [97] by postulating two successive reaction stages. First a slightly exothermic chemical reaction (4a) would occur ... 

Over the last 10-15 years, interest has grown significantly in the kinetics of combustion and explosion reactions, which are characterized by the presence of some mechanism of acceleration of the reaction. This acceleration, which leads to ignition, may be related either to the accumulation of active products which catalyse the reaction, the chain carriers (autocatalysis, chain explosion), or to an increase in the temperature of the mixture due to heat release in an exothermic chemical reaction (thermal explosion). 

Exothermic chemical reactions Endothermic processes pressure Material handling and transfer Enclosed or indoor process units Access relief pressure Drainage and spill control Toxic materials Sub-atmospheric Operation in or near flammable range Dust explosion... 

Some months after installing a biocide dosing system on the cooling water unit, one of the dosing tanks overpressurized and ruptured. The explosion propelled the dosing liquids about 20 ft. (6m) in the air. The unusually warm temperature of the tank was a clue that some form of exothermic chemical reaction occurred. Samples analyzed of the liquids and... 

In general, an explosion is an exothermic chemical reaction between two components. A well-known example is the reaction between the oxygen content of the atmospheric air and a combustible substance like petrol. As an exception, there are very few substances - such as acetylene - which are thermodynamically unstable and tend to exothermic self-decomposition. An explosion can start only with an ignition source and a volume or mass ratio of the two components in such a manner that the reaction zone is sustained by itself. Typical values of the peak explosion pressure - when starting with components at atmospheric pressure in a constant volume - are 1 MPa (10 bar) and a propagation velocity of the reaction zone up to 102m/ s (as an order of magnitude). 

The explosion was heard 240 km away. An anchor from the ship flew through the air and created a 3 m wide hole in the ground where it landed. Every building in the city was either destroyed or damaged. The catastrophe on the Grandcamp was caused by an exothermic chemical reaction that released a tremendous amount of energy as heat. 

In Sec. 5.3 we considered the thermodynamics of explosions that did not involve chemical reaction. Here, we extend this discussion to explosions with chemical reaction. Since the energy released on an exothermic reaction may be very large, chemical explosions are generally more devastating than purely mechanical explosions. In a... 

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