Explosion probability

At 5 45 A.M., a flash fire resulted. The vapor cloud is assumed to have penetrated houses, which were subsequently destroyed by internal explosions. A violent explosion, probably involving the BLEVE of several storage tanks, occurred 1 minute after the flash fire. It resulted in a fireball and the propulsion of one or two cylindrical tanks. Heat and fragments resulted in additional BLEVEs. 

As described in Section 6.2.1., British Gas performed full-scale tests with LPG BLEVEs similar to those conducted by BASF. The experimenters measured very low overpressures firom the evaporating liquid, followed by a shock that was probably the so-called second shock, and by the pressure wave from the vapor cloud explosion (see Figure 6.6). The pressure wave firom the vapor cloud explosion probably resulted from experimental procedures involving ignition of the release. The liquid was below the superheat limit temperature at time of burst. 

All other dangerous reactions consist of oxidations of bismuth by strong oxidants. Thus, chloric and perchloric acids lead to highly sensitive explosives (probably bismuth chlorate and perchlorate). Fuming nitric acid causes the incandescence of bismuth at ambient temperature whereas a detonation occurs when molten bismuth is mixed with concentrated nitric acid. Rnally, a bismuth/molten ammonium nitrate mixture causes a very violent or even an explosive reaction. 

During dropwise addition of the bromide to the liquid alcohol, the mechanical stirrer stopped, presumably allowing a layer of the dense tribromide to accumulate below the alcohol. Later manual shaking caused an explosion, probably owing to the sudden release of gaseous hydrogen bromide on mixing. 

Reaction of the silane with nitromethane is explosive, probably by intermediacy of fulminic acid (a dehydration product of nitromethane). 

Ethyl 3,4-dihydroxybenzenesulfonate, Oleum Dohmen, E. A. M. F. et al., Chem. Weekbl., 1942, 39, 447-448 Attempted nitration of the sulfonate in 20% oleum led to a violent explosion, probably from decomposition of the nitrate. 

Mixing of propylene oxide and epoxy resin in a waste bottle led to an explosion, probably owing to the polymerisation of the oxide catalysed by the amine accelerator in the resin. 

Dining dehydration of manganese(II) perchlorate [1] or nickel(II) perchlorate [2] with dimethoxypropane, heating above 65°C caused violent explosions, probably involving oxidation by the anion [1] (possibly of the methanol liberated by hydrolysis). Triethyl orthoformate is recommended as a safer dehydrating agent [2] (but methanol would still be liberated). 

Neruda, B. et al., J. Organomet. Chem., 1976, 111, 241-248 In the exothermic reaction with trimethyl phosphite to give r/.v-dimethyl-bis(trimethyl phosphito)platinum, the azide must be added to the phosphite in small portions with stirring. Addition of the phosphite to the solid azide led to a violent explosion, probably involving the transitory by-product methyl azide. 

Addition of charcoal to the gas causes an immediate explosion, probably initiated by the heat of adsorption of the gas on the solid. 

Attempted recrystallisation of the salt from ethanol caused an explosion (probably involving ethyl perchlorate). 

In agreement with Sallack, if the water or green liquor temperature were high, the explosion probability decreased, but he cites one anomalous case a composition which gave an immediate violent surface explosion in cold water produced a terrificany violent deep explosion in hot quenching water. The blast was heard more than 1 mile away (100 g of smelt was used). 

In the first set of experiments, the water vessels had rusted bottoms. Of the 21 tests, 14 produced explosions, but no correlation of explosion probability could be deduced. It was reported that, in all tests, molten aluminum reached the bottom of the vessel. High-speed movies showed that the entire explosion sequence between the first visible disturbance in the system to a full-scale chemical reaction was very rapid (on the order of 600 /Ltsec). Note that the word chemical was used in the quote. Lemmon suggests that chemical reactions play a key role in the explosion phenomenon, particularly for violent incidents. The proof that chemical reactions are important stems from the finding that strong explosions produced light and, also, limited spectrographic data indicated local temperatures in excess of 3000 K. The emphasis on chemical reactions was not stressed in the work of other investigators. 

Higher water temperatures seem to reduce the ease of triggering. This may be due to the simple fact that less water is trapped on the surface. Inorganic salts dissolved in the water act in an opposite manner and increase the explosion probability. The vessel cross section does not appear to be a significant variable. 

Voronkov, M. G. et al., Zh. Obshch. Khim., 1989, 59(5), 1055. (Chem. Abs., 112, 77304) Reaction of the silane with nitromethane is explosive, probably by intermediacy of fulminic acid (a dehydration product of nitromethane). 

Attempted nitration of the sulfonate in 20% oleum led to a violent explosion, probably... 

Halogenated hydrocarbons undergo an insertion reaction in the carbon-halogen bond and, in the case of fluorine, the reaction products are explosive, probably because of the large energy of formation of the Si—F bond. 

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