detonators. This consists of an aluminum cap, inside which is a quantity of explosive.
electric detonators. Activated, as its name indicates, by means of electricity. Are most commonly used today. It consists of three parts placed inside a metal cap aluminum or copper (which is used in coal mines). These three parts are: the electrical, the retarder and the explosive. The electrical part, placed at the top is formed by the igniter or match and the connecting wires are of different colors depending on the type of detonator. Retarding part exists only in the detonators of time, delay or microrretardo, not have the instant. Is placed in the intermediate zone between the igniter and the explosive. It is a metal cap filled with a paste explosive precision retarding burning at a rate calculated. The explosive part is housed in the bottom of the cap and is composed of two charges, lower elementary and one called charge higher than base-load is high. When an electric current passes through the connecting wires, through the strength of the match, causes it to warm up to the ignition temperature of the dough retarder (or explosive if it is instantaneous) that when finished burning cargo explodes primary explodes and blows up the base load.
Detonators instant. There are delays and the explosion of the primary load is instantaneous. A thread is white and the other depends on the sensitivity. Detonators
delay of 500 milliseconds. These detonators explode with streams of media in half a second. The wire colors are blue and other color depends on the sensitivity. Fuses
microrretardo 20 milliseconds. Used for special work with a sequence of 20 to 20 milliseconds. The color of the wires is the same as above. Mecha
slow. It is a flexible cord containing powder and which transmits the heat to a steady speed up the detonator.
detonating cord. It is a flexible cord in which there is PETN. Used to transmit the detonation of explosives initiated by the detonator.
Ohmmeter. Apparatus for measuring the blasting circuit resistance. The analog is and digital .
exploder . are the devices that generate electrical power required to activate the detonator.
ARTICLES OF INTEREST
New meteor to detect explosives
A group of U.S. and Danish researchers have developed a new method to detect explosives based on the physical properties of vapors emanating from these substances.
This technology is already being tested in prototitpos, is described in the latest issue of the journal Review of Scientific Instruments, published by the American Institute of Physics.
"Certain kinds of explosives have unique thermal characteristics that help identify explosive vapors in the presence of other vapors," says Thomas Thundat, a researcher at the National Oak Ridge Laboratory and the University of Tennessee, who led the research with researchers from the Technical University Denmark.
In their study, the scientists show that its technology is capable of explosives trace detection, and even distinguish between harmless chemicals or explosive so as to differentiate between explosives such as TNT, PETN or RDX.
Thundat and his team have been working for years in the development of sensors for explosives. Conmvencionales sensors use ion mobility spectrometers, which ionize small amounts of chemicals and measure how fast they move through an electric field. But while these tools are fast and responsive, very expensive and bulky, which has led to development of other cheaper and portable systems to detect explosives.
In line with other research for micromechanical sensors desarroillar standard Thundat and his team have managed to get a prototype that detect explosives in a selective and highly sensitive means of sensors that measure the "thermal signature" of chemical vapors
pyrotechnics within the reach of children
No pyrotechnic product is harmless, and less for children, "said Abner Hurtado, director of the Fire Department in El Salvador.
23 years experience as a firefighter support that claim. "For most small to be seen, always, always a risk, and the head of children is one that must be alert to avoid accidents, "says Hurtado.
The stars, volcanoes, primers and milpitas are, for some parents, the products are less harmful to their children during the holiday season and year-end. "Big mistake," said Hurtado. The injury may cause these products on the skin of a child ranging from first-degree burn (which is the redness of the skin) via second-degree burns (which causes blisters on the skin) to an amputation.
"We have had cases in previous years have been very severe burns on the face of the kids because the stars are very close to the face, or come to see why not turn the volcanoes, and suddenly the flame of fire ... Adults must stay alert, "says the director of Fire.
burns will depend on the amount of time the dermis (skin) of the child is exposed to contact with fire or light.
risks
insignificant These fireworks have already led to some claims, not only in dry brush, but also in homes in dropping a spark of fire in flammable fabric products curtains, paper or wooden furniture.
The pompano and five sizes of mortars are some of the fireworks produced by explosion, and are, according to Hurtado, the leading cause of amputation of fingers in the little ones.
"It's not the same thing that a mortar explode in the hand of an adult in a child's hand: the skin is more sensitive and the havoc that will occur are enormous," said the director of Fire. But the official
the product more dangerous fireworks is the whistle. "There have been reports that a singer burns the eyes of children," he says.
THE FIREWORKS HISTORY
The first reports on the use of mixtures pirical match the use of black powder, attributing its invention to the Chinese. The birthplace of fireworks is generally recognized as China, with the first explosive mixture found there and called "black powder" during the Sung Dynasty (960-1279). It is said that a cook in ancient China found that a mixture of sulfur, saltpeter, and charcoal was highly flammable and would explode if it was included in a small space. The first application of this technology was for entertainment. The Chinese are still the largest producers and concerning fireworks. Once the recipe for black powder was perfected, they found they could easily be used as rocket fuel, rockets and made hand-carved wood with the dimensions to be placed and the mouth of a dragon, in the sixth century. Such as rocket powered arrows out of the mouth of the dragon, and were used against the invaders from Mongolia in 1279. The principle of operation of these rockets is still used today in fireworks.
Until the nineteenth century, fireworks lacked a key aesthetic feature today: the color. Then the fireworks began using a combination of potassium chlorate and various metallic salts to make brilliant colors. The salts of these metals produce the different colors: strontium burns red copper makes blue, barium glows green; and sodium, yellow. Magnesium, aluminum, and titanium were found to emit sparkling white or flash.
Although China invented fireworks, Europe surpassed the technical development in the fourteenth century, which coincides with the time that the gun was invented. Shot and gunpowder for military use were made by skilled tradesmen, later called "firemakers" (manufacturers of fire), who also did the fireworks for celebrations of the peace or victory. During the Renaissance, Europe emerged two schools of thought fireworks, one in Italy and the other in Nuremberg (Germany). The Italian school of pyrotechnics emphasized elaborate fireworks, and the scientific breakthrough of the German school was. Both schools added significantly to the further development of pyrotechnics, and by the mid seventeenth century fireworks were used for entertainment on a scale unprecedented in Europe, being popular even public gardens. In the nineteenth century fireworks became popular in the United States. Several injuries associated with fireworks, especially in children, because their use was made without restriction. Consequently, in many U.S. states and parts of Canada the sale of fireworks now is restricted by law.
Since its inception the main element of the devices was a tube light, fireproof, terminated on one end and filled with a mixture similar to black powder. Regardless of these tubes hanging or mounted on mobile or fixed frames, were obtained as today the most diverse efectos.El progress on fireworks has been to the new formulas introduced, fuel blends greater lighting effect, more rapid combustion and study of the safety standards, aimed at reducing or eliminating any possibility of an accident.
The first applications of the mixtures were always parties pirical more later used as a means of war, until they were displaced by artillería.En the two world wars have been used intensively pyrotechnic mixtures either as a means of marking the day and night, in mixtures smoke for concealment of areas of land, with tracer bullets streak of light (air defense artillery), etc. .. Currently, the use of mixtures pirical or pyrotechnic devices, has been extended to agricultural protection (anti-hail rockets), to combat pests, as a propellant ( engine starter cartridges), welding aids, signage (flares), etc. ..
basic loads of fireworks pyrotechnic mixtures that burn rapidly and its composition should contain enough oxygen for combustión.La raw material used in fireworks is black powder, finely divided, or magazine, which can be added in different proportions substances in order to modify some of its properties, particularly its speed combustión.Para more easily realize the effects of such aggregates in the pyrotechnic field, we will briefly review the chemical process of the combustion means combustión.Se chemical combination of oxygen with other substances, with development of heat and light, forming what is called a burn oxidación.Las substances, ie those that under certain conditions tend to combine with oxygen, called fuel, oxygen is an oxidizer, ie the factor influencing the air combustión.El consists of a mixture of oxygen and nitrogen (basically), of which the oxygen in the same work even at ordinary temperature for some metals, oxidizing. For example, iron, resulting in the formation of oxides, in which case the reaction is very slow, ie, involves a lot of time to take place, it is called combustion lenta.Combustiones faster we get when we burn a wooden match, the acrid smell it feels is due to sulfur dioxide formed by the action of atmospheric oxygen on the azufre.Cuando burn coal, according to the amount of air available, form various gases: carbon dioxide (if the air is insufficient) and maleic carbon (if the air is in the proper proportions or in excess). To burn the substance must be at a certain temperature, this temperature varies depending on the substance fuel (combustion temperature). There are substances that replacement air can provide oxygen needed for combustion of the mixtures, these oxidizing substances called oxidants such as nitrates, chlorates, bichromate, etc. .. The combustion of these mixtures is naturally faster than those in which it operates air oxygen, as oxygen is released in close contact.
varying the proportions of oxidant (or oxidizing) and fuel mixtures, adjustable burn rate the same, or producing a change in the constitution of the pyrotechnic mixture. The most obvious example is given by the black powder through numerous formulas, obtained by varying the proportions of its three components: carbon and sulfur (fuel) and sodium or potassium nitrate (oxidising). If the composition is invariable leaves the amount of nitrate and sulfur, and gradually increased the proportion of coal, you get a powder a bit slower in their rate of combustion.
Another quality in mixtures pirical study is the variety of colors that can occur when burned. In practice, the compositions are designated with the name of color that give the quemarse.Se used for this purpose, some powdered metals or salts of those metals which decompose at the temperature of combustion of the mixtures, communicated to the combustion gas coloración.La a special feature of light intensity depends on the temperature of the flame. It may happen that some substances are volatile at temperatures just high, in this case required the composition or mixture shall be such as to decompose develop a temperature sufficient to cause the vapors llama.En give color to the composition of mixtures of colored lights, usually add a small amount to achieve white light, because the components of that on to develop a significant amount of hot gas and thereby facilitating the decomposition of dyes, salts are less volatile.
The most commonly used pyrotechnic burning and explosion. The blast, with few exceptions, should be avoided and putrefaction has no value in putrefaction pirotecnia.La is a slow process and is usually caused by fungi and bacteria, aided by moisture and calor.La explosion was caused by a violent reaction of the chemical elements and is generally initiated by application of heat. The heat required is achieved by heat, friction or combustion espontánea.La decomposition or detonation is instantaneous reaction. This phenomenon is used in blasting with dynamite (among others), where you want to get as much energy possible.The chemical reactions occur only under certain conditions. For example, if one part oxygen and two parts of hydrogen are mixed in a container at the normal temperature nothing happens, but if it blows up a spark into the mixture produces a violent explosion, obtaining product agua.Este principle applies to virtually all pyrotechnic mixtures and should be sought optimal conditions in which the reaction should occur.
Applications:
pyrotechnics used by all of us in a very common but is an element that if not used properly, can be extremely dangerous even fatal. The firework device consists of explosives that give rise to colored flames and sparks to be burning. These devices are commonly referred to as fireworks, they are used in exhibitions and all sorts of festivities.
Since the invention of gunpowder by the Chinese, the technique was brought to Europe by Marco Polo, making the fireworks take a very strong in Italy, expanding gradually throughout Europe and in Muslim culture, that because its occupation of the peninsula, they established the foundation and tradition sprinkled with profit in the whole area of \u200b\u200bsouthern Spain, from Madrid to Valencia, causing them to take a bit of an increasing interest in pyrotechnics.
types of pyrotechnics:
The sophistication of pyrotechnics and their derivatives are its size and power, which is why these pyrotechnics are regulated by the Explosives Regulations, it determines the restrictions and legislation for use, manufacture and trade.
Thus, as local authorities have the authority to authorize or permit the shooting and the use of pyrotechnics and fireworks.
are on the market range of products that are able to create different results, which are commonly known as rocket, fireworks and explosions that occur are the purpose of them, among them are models, like trucks or firecrackers, rockets or flying pyrotechnic shells or bombs, fireworks, firecrackers, and masclets holes, there are the pigeons and doves, flares and witches and other types of pyrotechnics.
Technical data on the pyrotechnics.
specific data exist on each of the fireworks: the cascade of rain has a duration of 3 minutes, its length is 5 meters and height is 5 meters to 20 meters. Colorful pumps have a 8.5 caliber radius of 3 meters, the colors are varied (blue, red, green, silver and yellow), its duration is 1 minute dropping about 20 bombs and a height of 60 meters. 7.5 caliber explosive bombs pose a range of 20 meters, an effect of noise, a height of 60 meters and his 20 bombs last 1 minute.
We must also take into account the danger that may be the uncontrolled use of this product. prevention campaign fireworks: From The Security Secretariat reported on the preventive measures for the use of pyrotechnics that the community should have occasion to approach the holidays this year.
In this sense, it was reported that operations were conducted joint prevention and control between the Fire Department of the provincial police and the municipal capital, in the field of capital to purposes of finding the appropriate enabling local market products authorized by the National Registry of Weapons (RENAR).
however, are advised to take precautions when purchasing fireworks, avoid illegal sales positions, checks that are products of good quality and approved by RENAR, respecting the indications for use of products, not to sell fireworks to under 16 years, without detonating fireworks in bottles, cans or containers or confined areas; not carry fireworks in pockets or hold lit firecracker in his hand.
also informed that the task of controlling bodies with responsibility and prudence of those you sell and buy fireworks, they will help in the holidays are celebrated in their homes, happily and with better health. Sources
failures Valencia. Declared International Festival of Tourist Interest, famous throughout the world, the people were born and were rejected at first, by the bourgeoisie and the clergy.
has its origins in the habit of artisans in the winter dusk lit chandeliers hanging in the "estai", "parot" or "pelmodo", similar to a long candlestick with many branches, to get good weather, spring , burned it and carpenters, who for throughout the year had been working in their shops, took advantage of the arrival of good weather to clean your carpentry drawing boards, shingles, beams and other stacking the street and set fire to them, over time, neighbors began piling up furniture and other old items that no longer served at home.
This became a popular festival and what were initially furniture gradually came to be represented by "ninots" society in which they lived, what provoked the displeasure of the bourgeoisie and the clergy (usually ironic on them.) Is a quote about the failures dedicated to San Vicente (the fire spring) in 1596 were paid Peter Torralba 74 pounds, a salary and six money by "les Graeber (grills) which burned" les fan failures on the feast of St. Vincent Ferrer glories. "
