Types of Chemical Explosions

Primary by ignition Secondary by detonation Microseconds 1 to 6 Miles/Second 

Pressure and heat waves travel away from the center of the blast equally in all directions. The reaction occurs at supersonic speed or, in other words, faster than the speed of sound, which is 1250 ft/s. Many of the reactions occur between 3300 and 29,900 ft/s, or over 20,300 miles/hr  

Often the terms explosion and detonation are used interchangeably, which is not accurate. An explosion may be a detonation however, an explosion can occur that is not a detonation. In either case, each occurs rapidly, and the difference cannot be distinguished easily by the human senses. The only way you can distinguish a detonation from a deflagration is by hearing the sound of the explosion. In a detonation, the explosion will be visualized, and the shock wave sent off before the explosion is actually heard. In a deflagration, the explosion will be heard almost immediately. The two terms only apply to the speeds of the explosions they do not infer that one is any less dangerous than the other. 

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A thermal explosion is the third type of chemical explosion. In this case, no reaction front is present, and it is therefore called a homogenous explosion. Initially, the material has a uniform temperature distribution. If the temperature in the bulk material is sufficiently high so that the rate of heat generation from the reaction exceeds the heat removal, then self-heating begins. The bulk temperature will increase at an increasing rate, and local hot spots may develop as the thermal runaway proceeds. The runaway reaction can lead to overpressurization and possible explosive rupture of the vessel. 

Detonation is an instantaneous decomposition of the explosive material in which all of the sohd material changes to a gas instantaneously with the release of high heat and pressure shock waves. Detonation is the only type of chemical explosion that wiU produce a true shock wave. A material that detonates is considered a high-yield explosive (see Figure 3.11). Blast pressures can be as much as 700 tons/sq in. 

Forbidden Explosives for Transportation Types of Chemical Explosions Explosive Effects Yield vs. Order... 

The procedure begins with a material factor that is a function only of the type of chemical or chemicals used. This factor is adjusted for general and special process hazards. These adjustments or penalties are based on conditions such as storage above the flash or boiling point, endo- or exothermic reactions, and fired heaters. Credits for various safety systems and procedures are used for estimating the consequences of the hazard, after the fire and explosion index has been determined. 

For onsite analysis, the examination of the vast number of samples necessitates the use of quick, reliable, field portable equipment that can rapidly, quantitatively verify the many chemically different types of ammunition, explosives, and pyrotechnics. The most common suite of analytes to detect is large, consisting of very chemically different compounds and usually occurs at trace levels in complex environmental matrices. This suite encompasses smokeless powders, black powders, and numerous propellant and energetic formulations. Detection should also be sought for common decomposition products of these explosives such as the methylanalines, aminonitrotoluenes, nitrotoluenes, mono- and dinitoroglycerines, and the nitrobenzenes under on-site conditions. 

If the answer to Question 11 is YES, then you should make use of the information in Chapter 4, because a chemical reactivity hazard is present. The essential practices presented in Chapter 4 should be sufficient to manage this type of chemical reactivity hazard, excluding considerations for commercial explosives, which are also self-reactive materials. 

In order to obtain higher values of propellants and explosives, various types of chemicals are admixed, such as plasticizers, stabilizers, and reachon rate modifiers. The major chemicals are fuels and oxidizers. The fuels react with the oxidizers to produce heat and gaseous products. Even when the AHf J values of both the fuel... 

Chemicals are a part of everyday life and can be found all around us. Many common chemicals, when mixed improperly (intentionally or not), can have serious implications for those who come into contact with them or are in their vicinity. This book is designed to give the user the ablility to quickly identify what type of explosive or chemical weapon could possibly be the focus of an investigation and what types of chemicals might be involved. It cannot be used to help manufacture these items. It is merely a tool for law enforcement to use in the war on terrorism and other types of criminal activities. 

Thermochemistry is an important part of explosive chemistry it provides information on the type of chemical reactions, energy changes, mechanisms and kinetics which occur when a material undergoes an explosion. This chapter will carry out theoretical thermochemical calculations on explosive parameters, but it must be noted that the results obtained by such calculations will not always agree with those obtained experimentally, since experimental results will vary according to the conditions employed. 

Some of the reactions described in this chapter constitute what is virtually a separate and distinct type of chemical change, namely one where there is no region of transition between very slow reaction and explosively rapid reaction. Such changes, which must be exothermic, depend upon branching reaction chains which get out of hand when a certain critical concentration is exceeded. 

This version is best used as a short-delay ignitor for explosives or incendiaries. It could be used in mines if its inherent delay is tactically acceptable. (Note This or any other HTH/glycerin delay should not be used if the temperature falls below 50 degrees F. It will misfire. Conversely, extremely hot temperatures—particularly if the delay has been left sitting in the hot sun—shortens the delay. This is common with most types of chemical delay fuze. As a consequence, they should always be tested at the operational temperature.)... 

Thermochemistry is an important part of explosive chemistry it provides information on the type of chemical reactions, energy changes, mechanisms, and kinetics that occur when a material undergoes an explosion [4],... 

Chemical changes, also called chemical reactions, are more complex, and they tend to be harder to reverse than physical changes. There are many different types of chemical changes. Some happen very quickly, such as an explosion, and some happen slowly, such as rusting, but they all result in the production of one or more new substances. Look at the equation for the decomposition of water, shown on page 28, and compare it to the equation for melting water, shown previously. 

The second type of explosion occurs via physical or chemical means, as in the case of a hot-water heater or boiler explosion. The water inside the heater turns to steam when overheated, which results in a pressure inaease inside the container, and the container fails at its weakest point. This is by far the most common type of accidental explosion. 

The physical, chemical and hazardous properties of a number of highly toxic or flammable substances that were in the past or being currently used in the warfare have been discussed in detail in several chapters in this book. Some of these compounds are further discussed under specific chapters, such as. Sulfur Mustards, Nerve Gases, Dioxin and Related Compounds and Napalm. These and many other compounds are in most cases grouped together in this book based on their chemical structures along with their toxic or flammable properties. Presented below is a brief discussion on various types of chemicals weapons developed for military applications. Explosive substances have been omitted from this section. They are discussed separately in this book under topics such as Explosive Characteristics of Chemical Substances, Nitro Explosives, Oxidizers and Organic Peroxides and also under specific title compounds in various chapters. 

Before any of the munitions are delivered to the facility, they will have been previously assessed by the portable isotopic neutron spectroscopy (PINS) technique, x-rayed where appropriate, and the results reviewed by the Munitions Assessment and Review Board (MARB) to properly identify the contents. Data indicating the presence or absence of explosive and fuze components and the type of chemicals will be provided to the PBNSF operator for each item. The munitions will arrive at the facility overpacked individually in airtight containers. The following briefly describes the typical process flow for the categories of RCWM to be processed. 

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