Types of Explosives

Explosives can be divided into two primary groups, high explosives and low explosives, based upon the speed with which the chemical transformation takes place, usually expressed in feet per second. Low explosives change physical state from a 

Dry-bulk truck transporting Class 1.5 blasting agent on the highway. 

Explosive 1.3 Fire, Minor Blast, Minor Projection Hazards 

Explosive 1.4 Device with Minor Explosion Hazard 

Explosives 1.4-1.6 Compressed Gases 2.1-2.2 Flammable Liquids 3 Flammable Solids 4.1-4.2 Oxidizers 5.1-5.2 

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This type of explosion is important in engines where detonation can vary from an incipient stage, often referred to as pinking, to a more severe condition known as knocking. ... 

Ammonia from coal gasification has been used for fertilizer production at Sasol since the beginning of operations in 1955. In 1964 a dedicated coal-based ammonia synthesis plant was brought on stream. This plant has now been deactivated, and is being replaced with a new faciUty with three times the production capacity. Nitric acid is produced by oxidation and is converted with additional ammonia into ammonium nitrate fertilizers. The products are marketed either as a Hquid or in a soHd form known as Limestone Ammonium Nitrate. Also, two types of explosives are produced from ammonium nitrate. The first is a mixture of fuel oil and porous ammonium nitrate granules. The second type is produced by emulsifying small droplets of ammonium nitrate solution in oil. 

The types of explosives that have been used include both high (4500—7600 m/s) and low to medium (1500—4500 m/s) velocity matetials (24,26). 

Fig. 8. Microhardness profile across interfaces of two types of explosion clads that show widely divergent response resulting from the inherent cold-work hardening characteristics where Q represents the 3.2-mm type 304L stainless/28.6-mm, A 516-70 control (before cladding) ( ) = clad + flat ...

Volume of vessel (free volume V) Shape of vessel (area and aspect ratio) Type of dust cloud distribution (ISO method/pneumatic-loading method) Dust explosihility characteristics Maximum explosion overpressure P ax Maximum explosion constant K ax Minimum ignition temperature MIT Type of explosion suppressant and its suppression efficiency Type of HRD suppressors number and free volume of HRD suppressors and the outlet diameter and valve opening time Suppressant charge and propelling agent pressure Fittings elbow and/or stub pipe and type of nozzle Type of explosion detector(s) dynamic or threshold pressure, UV or IR radiation, effective system activation overpressure Hardware deployment location of HRD suppressor(s) on vessel... 

This type of explosive behaviour is not to be confused with explosions such as drat of gunpowder, where the explosion is caused by the extremely rapid expansion of the gases which are liberated by chemical reaction widr a large release of heat. 

Column 1 Type of explosive Column 2 Maximum net explosive content in tonnes in any group of adjacent containers or wagons Column 3 Minimum separation distance in metres between groups of containers or wagons... 

Historically, this phenomenon was referred to as unconfined vapor cloud explosion, but, in general, the term unconfined is a misnomer. It is more accurate to call this type of explosion simply a vapor cloud explosion. ... 

Table 6.10 presents some damage effects. It may give the impression that damage is related only to a blast wave s peak overpressure, but this is not the case. For certain types of structures, impulse and dynamic pressure (wind force), rather than overpressure, determine the extent of damage. Table 6.10 was prepared for blast waves of nuclear explosions, and generally provides conservative predictions for other types of explosions. More information on the damage caused by blast waves can be found in Appendix B. 

Confined combustion explosions (gaseous or liquid) usually occur when a flammable vapor leaks into an enclosure and mixes witJi air to form a flarmnable mix-ture, whereupon this mix+ure contacts an ignition source tliat was present before the leak occurred. This type of explosion ctm tUso occur in storage taitks or sliips where tlie vapor space above tlie stored flanunable liquid (fuel) is in tlie cxplosivity range. In tliis case, an ignition source accidentally introduced will cause an explosion. 

Section 7.4 presented tlwee major types of explosion. Tliis section more closely examines plant-related explosions, focusing on causes, results, and damage potentials. The means for explosion protection and prevention arc the subject of a subsequent chapter. 

The three basic types of explosions to be concerned about in the chemical and petrochemical environment are combustion explosions (deflagrations), detonation explosions, and BLE 7Es or boiling-liquid expanding vapor explosions [38]. 

This particular type of explosion is less known and understood, but nevertheless is an important type for damage consideration. This is a type of pressure release explosion and there are several descriptions. 

Reference [40] presents a rather thorough review of the history and theoretical analysis of these types of explosions. 

Torpex, Sensitivity to S.A. Fire. Results of Comparative Trials with Various Types of Explosives Attacked by 20mm Projectiles , BritOrdnBoardProc 31986 (August 1945) 43) W.P. 

The open-top floating roof tank design eliminates the potential for BLEVE. Further, the material being handled has no potential for chemical reactions or for condensed-phase explosions. Thus, these types of explosions can also be eliminated from consideration. 

This type of explosion results from the release of a considerable quantity of flammable gas, or vapour, into the atmosphere, and its subsequent ignition. Such an explosion can cause extensive damage, such as occurred at Flixborough, HMSO (1975). Unconfined vapour explosions are discussed by Munday (1976) and Gugan (1979). 

The most complete set of statistics is that published in the United States of America, which showed a total consumption of industrial explosives in 1977 of 1 680 000 tonnes. Details of the types of explosives consumed and the industries using the products are given in Tables 1.2 and 1.3 respectively. 

Nitrocellulose is usually handled wet and containing approximately 30% of water. Under these conditions it can be considered as a nonexplosive material when the nitrogen content does not exceed 12-6%. More highly nitrated cellulose is known as guncotton and is explosive even when moderately wet. When dry, nitrocellulose of all types is an extremely sensitive and dangerous explosive. Dry nitrocellulose is required for use in certain types of explosives and is then prepared by slow drying of the wet material in a current of warm air. 

A type of explosive, not based on nitroglycerine or on TNT, which achieved popularity for a time and is still used in some countries, is the liquid oxygen explosive or LOX. This is made on the site of the blasting operations by immersing in liquid oxygen a pre-formed cartridge of absorbent charcoal. Charcoal saturated with a suitable proportion of... 

It will, therefore, be seen that the best and safest practice is to use in each situation in the coal mine an explosive which is best adapted for the operation in hand. The use of unnecessarily weak explosives, even though apparently safer in some tests, is often a disadvantage and can be dangerous. These considerations have led to the development of a series of types of explosives suited for particular purposes in coal mines and subjected to tests relevant to their individual uses. Thus, in Britain there are now five classes of permitted explosives. In Germany there are three classes. In the U.S.A. geological conditions are different and the hazards are less than in Europe, and it has been possible to work throughout with the strongest types of permissible explosives. 

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