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Detonators
A detonator is a device used to make an explosive or explosive device explode. Detonators come in a variety of types, depending on how they are initiated (chemically, mechanically, or electrically) and details of their inner working, which often involve several stages. Types of detonators include non-electric and electric. Non-electric detonators are typically stab or pyrotechnic while electric are typically "hot wire" (low voltage), exploding bridge wire (high voltage) or explosive foil (very high voltage). The original electric detonators invented in 1875 independently by Julius Smith and Perry Gardiner used mercury fulminate as the primary explosive. Around the turn of the century performance was enhanced in the Smith-Gardiner blasting cap by the addition of 10-20% potassium chlorate. This compound was superseded by others: lead azide, lead styphnate, some aluminium, or other materials such as DDNP ( diazo dinitro phenol) to reduce the amount of lead emitted into the atmosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead Azide
Lead(II) azide is an inorganic compound. More so than other azides, it is explosive. It is used in detonators to initiate secondary explosives. In a commercially usable form, it is a white to buff powder. Preparation and handling Lead(II) azide is prepared by the reaction of sodium azide and lead(II) nitrate in aqueous solution. Lead(II) acetate can also be used. Thickeners such as dextrin or polyvinyl alcohol are often added to the solution to stabilize the precipitated product. In fact, it is normally shipped in a dextrinated solution that lowers its sensitivity. Production history Lead azide in its pure form was first prepared by Theodor Curtius in 1891. Due to sensitivity and stability concerns, the dextrinated form of lead azide (MIL-L-3055) was developed in the 1920s and 1930s with large scale production by DuPont Co beginning in 1932. Detonator development during World War II resulted in the need for a form of lead azide with a more brisant output. RD-1333 lead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diazodinitrophenol
Diazodinitrophenol (DDNP) was the first diazo compound produced; it was subsequently used to make dyes and explosives. It forms yellow crystals in pure form; however, the color of impure forms may vary from dark yellow to green to dark brown. It is soluble in acetic acid, acetone, concentrated hydrochloric acid, like most non-polar solvents and is slightly soluble in water. A solution of cold sodium hydroxide may be used to destroy it. DDNP may be desensitized by immersing it in water, as it does not react in water at normal temperature. It is less sensitive to impact but more powerful than mercury fulminate and almost as powerful as lead azide. The sensitivity of DDNP to friction is much less than that of mercury fulminate and lead azide. DDNP is used with other materials to form priming mixtures, particularly where a high sensitivity to flame or heat is desired. DDNP is often used as an initiating explosive in propellant primer devices and is a substitute for lead styphnat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive Train
A triggering sequence, also called an explosive train or a firing train, is a sequence of events that culminates in the detonation of explosives. For safety reasons, most widely used high explosives are difficult to detonate. A primary explosive of higher sensitivity is used to trigger a uniform and predictable detonation of the main body of the explosive. Although the primary explosive itself is generally a more sensitive and expensive compound, it is only used in small quantities and in relatively safely packaged forms. By design there are low explosives and high explosives made such that the low explosives are highly sensitive (i.e. their Figure of Insensitivity is low) and high explosives are comparatively insensitive. This not only affords inherent safety to the usage of explosives during handling and transport, but also necessitates an explosive triggering sequence or explosive train. The explosive triggering sequence or the explosive train essentially consists of an 'initiat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diazo Dinitro Phenol
Diazodinitrophenol (DDNP) was the first diazo compound produced; it was subsequently used to make dyes and explosives. It forms yellow crystals in pure form; however, the color of impure forms may vary from dark yellow to green to dark brown. It is soluble in acetic acid, acetone, concentrated hydrochloric acid, like most non-polar solvents and is slightly soluble in water. A solution of cold sodium hydroxide may be used to destroy it. DDNP may be desensitized by immersing it in water, as it does not react in water at normal temperature. It is less sensitive to impact but more powerful than mercury fulminate and almost as powerful as lead azide. The sensitivity of DDNP to friction is much less than that of mercury fulminate and lead azide. DDNP is used with other materials to form priming mixtures, particularly where a high sensitivity to flame or heat is desired. DDNP is often used as an initiating explosive in propellant primer devices and is a substitute for lead styphnat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leyden Jar
A Leyden jar (or Leiden jar, or archaically, Kleistian jar) is an electrical component that stores a high-voltage electric charge (from an external source) between electrical conductors on the inside and outside of a glass jar. It typically comprises a glass jar with metal foil cemented to the inside and the outside surfaces, and a metal terminal projecting vertically through the jar lid to make contact with the inner foil. It was the original form of the capacitor (also called a ''condenser''). Its invention was a discovery made independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden), Netherlands, in 1745–1746. The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electrostatics. It was the first means of accumulating and preserving electric charge in large quantities that could be discharged at the experi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Fuse
The safety fuse is a type of fuse (explosive), fuse invented and patented by English inventor William Bickford (1774–1834), William Bickford in 1831. Originally it consisted of a "tube" of gunpowder surrounded by a waterproofed varnished jute "rope." It replaced earlier and less reliable methods of igniting gunpowder blasting charges which had caused many injuries and deaths in the mining industry. The safety fuse burns at a rate of typically about 30 seconds per foot (1 second per cm). History Documented evidence suggests that the earliest fuse (explosive), fuses were first used by the Chinese between the 10th and 12th centuries. After the Chinese had invented gunpowder, they began adapting its explosive properties for use in military technology. By 1044 they were using gunpowder in simple grenades, bombs, and flamethrowers. Gunpowder did not reach Europe until the early 13th century, carried over from China by Middle Eastern traders and merchants along the old Silk Road. For ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be: * chemical energy, such as nitroglycerin or grain dust * pressurized gas, such as a gas cylinder, aerosol can, or boiling liquid expanding vapor explosion * nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperial Chemical Industries
Imperial Chemical Industries (ICI) was a British Chemical industry, chemical company. It was, for much of its history, the largest manufacturer in Britain. Its headquarters were at Millbank in London. ICI was listed on the London Stock Exchange and was a constituent of the FT 30 and later the FTSE 100 Index, FTSE 100 indices. ICI was formed in 1926 as a result of the merger of four of Britain's leading chemical companies. From the onset, it was involved in the production of various chemicals, explosives, fertilisers, insecticides, dyestuffs, non-ferrous metals, and paints; the firm soon become involved in plastics and a variety of speciality products, including food ingredients, polymers, electronic materials, fragrances and flavourings. During the Second World War, ICI's subsidiary Nobel Enterprises, ICI Nobel produced munitions for Britain's war effort; the wider company was also involved with Britain's nuclear weapons programme codenamed Tube Alloys. Throughout the 1940s and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rack And Pinion
rack and pinion is a type of linear actuator that comprises a circular gear (the '' pinion'') engaging a linear gear (the ''rack''). Together, they convert between rotational motion and linear motion: rotating the pinion causes the rack to be driven in a line. Conversely, moving the rack linearly will cause the pinion to rotate. The rack and pinion mechanism is used in rack railways, where the pinion mounted on a locomotive or a railroad car engages a rack usually placed between the rails, and helps to move the train up a steep gradient. It is also used in arbor presses and drill presses, where the pinion is connected to a lever and displaces a vertical rack (the ram). In pipelines and other industrial piping systems, a rack displaced by a linear actuator turns a pinion to open or close a valve. Stairlifts, lock gates, electric gates, and the mechanical steering mechanism of cars are other notable applications. The term "rack and pinion" may be used also when the rac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
