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Fire Triangle
The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most fires. The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). A fire naturally occurs when the elements are present and combined in the right mixture. A fire can be prevented or extinguished by removing any one of the elements in the fire triangle. For example, covering a fire with a fire blanket blocks oxygen and can extinguish a fire. In large fires where firefighters are called in, decreasing the amount of oxygen is not usually an option because there is no effective way to make that happen in an extended area. Fire tetrahedron The fire tetrahedron represents the addition of the chemical chain reaction to the three already present in the fire triangle. Combustion is a chemical reaction that feeds a fire more heat and allows it to continue. Once a fire has started, the resulting exothermic chain re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactivity (chemistry), reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. It exhibits a metallic luster (mineralogy), luster. It corrosion, corrodes quickly in air to a dull silvery gray, then black tarnish. It does not occur freely in nature, but occurs mainly as pegmatite, pegmatitic minerals, which were once the main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines. Lithium metal is isolated electrolysis, electrolytically from a mixture of lithium chloride and potassium chloride. The Atomic nucleus, nucleus of the lithiu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Extinguisher
A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i.e., no escape route, smoke, explosion hazard, etc.), or otherwise requires the equipment, personnel, resources or expertise of a fire brigade. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an #Types of extinguishing agents, agent that can be discharged to extinguish a fire. Fire extinguishers manufactured with non-cylindrical pressure vessels also exist, but are less common. There are two main types of fire extinguishers: stored-pressure and cartridge-operated. In stored-pressure units, the expellant is stored in the same chamber as the firefighting agent itself. Depending on the agent used, different propellants are used. With dry chemical extingu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Controlled Burn
A controlled burn or prescribed burn (Rx burn) is the practice of intentionally setting a fire to change the assemblage of vegetation and decaying material in a landscape. The purpose could be for forest management, ecological restoration, land clearing or wildfire fuel management. Controlled burns may also be referred to as hazard reduction burning'', ''backfire'', ''swailing or a burn-off. Controlled burns are conducted during the cooler months to reduce fuel buildup and decrease the likelihood of more dangerous, hotter fires. Controlled burning stimulates the germination of some trees and reveals soil mineral layers which increases seedling vitality. In grasslands, controlled burns shift the species assemblage to primarily native grassland species. Some seeds, such as those of lodgepole pine, sequoia and many chaparral shrubs are pyriscent, meaning heat from fire causes the cone or woody husk to open and disperse seeds. Fire is a natural part of both forest and grass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildfire
A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire (Bushfires in Australia, in Australia), desert fire, grass fire, hill fire, Peat#Peat fires, peat fire, prairie fire, vegetation fire, or veld fire. Some natural forest ecosystems Fire ecology, depend on wildfire. Modern forest management often engages in prescribed burns to mitigate fire risk and promote natural forest cycles. However, controlled burns can turn into wildfires by mistake. Wildfires can be classified by cause of ignition, physical properties, combustible material present, and the effect of weather on the fire. Wildfire severity results from a combination of factors such as available fuels, physical setting, and weather. Climatic cycles with wet periods that create substantial fuels, followed by drought and heat, of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ember
An ember, also called a hot coal, is a hot lump of smouldering solid fuel, typically glowing, composed of greatly heated wood, coal, or other carbon-based material. Embers (hot coals) can exist within, remain after, or sometimes precede, a fire. Embers are, in some cases, as hot as the fire which created them. They radiate a substantial amount of heat long after the fire has been extinguished, and if not taken care of properly can rekindle a fire that is thought to be completely extinguished and can pose a fire hazard. In order to avoid the danger of accidentally spreading a fire, many campers pour water on the embers or cover them in dirt. Alternatively, embers can be used to relight a fire after it has gone out without the need to rebuild the fire – in a conventional fireplace, a fire can easily be relit up to 12 hours after it goes out, provided that there is enough space for air to circulate between the embers and the introduced fuel. They are often used for cookin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorine Trifluoride
Chlorine trifluoride is an interhalogen compound with the formula . It is a colorless, poisonous, corrosive, and extremely reactive gas that condenses to a pale-greenish yellow liquid, the form in which it is most often sold (pressurized at room temperature). It is notable for its extreme oxidation properties. The compound is primarily of interest in plasmaless cleaning and etching operations in the semiconductor industry, in nuclear reactor fuel processing, historically as a component in rocket fuels, and various other industrial operations owing to its corrosive nature. Preparation, structure, and properties It was first reported in 1930 by Ruff and Krug who prepared it by fluorination of chlorine; this also produced chlorine monofluoride (ClF) and the mixture was separated by distillation. : Several hundred tons are produced annually. The molecular geometry of is approximately T-shaped, with one short bond (1.598 Å) and two long bonds (1.698 Å). This structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Perchlorate
Ammonium perchlorate ("AP") is an inorganic compound with the formula . It is a colorless or white solid that is soluble in water. It is a powerful oxidizer. Combined with a fuel, it can be used as a rocket propellant called ammonium perchlorate composite propellant. Its instability has involved it in accidents such as the PEPCON disaster. Production Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid. This process is the main outlet for the industrial production of perchloric acid. The salt also can be produced by salt metathesis reaction of ammonium salts with sodium perchlorate. This process exploits the relatively low solubility of NH4ClO4, which is about 10% of that for sodium perchlorate.Helmut Vogt, Jan Balej, John E. Bennett, Peter Wintzer, Saeed Akbar Sheikh, Patrizio Gallone "Chlorine Oxides and Chlorine Oxygen Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH. AP crystallises as colorless rhombohedra. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perchlorate
A perchlorate is a chemical compound containing the perchlorate ion, , the conjugate base of perchloric acid (ionic perchlorate). As counterions, there can be metal cations, quaternary ammonium cations or other ions, for example, nitronium cation (). The term ''perchlorate'' can also describe perchlorate esters or covalent perchlorates. These are organic compounds that are alkyl or aryl esters of perchloric acid. They are characterized by a covalent bond between an oxygen atom of the ClO4 moiety and an organyl group. In most ionic perchlorates, the cation is non-coordinating. The majority of ionic perchlorates are commercially produced salts commonly used as oxidizers for pyrotechnic devices and for their ability to control static electricity in food packaging. Additionally, they have been used in rocket propellants, fertilizers, and as bleaching agents in the paper and textile industries. Perchlorate contamination of food and water endangers human health, primarily af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bellows
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtight cavity which can be expanded and contracted by operating the handles, and fitted with a valve allowing air to fill the cavity when expanded, and with a tube through which the air is forced out in a stream when the cavity is compressed. It has many applications, in particular blowing on a fire to supply it with air. The term "bellows" is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight (but not airtight) bag allowing the distance between the lens and film of a folding photographic camera to be varied is called a bellows. Etymology "Bellows" is only used in plural. The Old English name for "bellows" was , 'blast-bag', 'blowing-ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion
An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated by a slower expansion that would normally not be forceful, but is not allowed to expand, so that when whatever is containing the expansion is broken by the pressure that builds as the matter inside tries to expand, the matter expands forcefully. An example of this is a Volcano, volcanic eruption created by the expansion of magma in a magma chamber as it rises to the surface. Supersonic explosions created by high explosives are known as detonations and travel through shock waves. wikt:subsonic, Subsonic explosions are created by low explosives through a slower combustion process known as deflagration. Causes For an explosion to occur, there must be a rapid, forceful expansion of matter. There are numerous ways this can happen, both natura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Classes
Fire classification is a system of categorizing fires with regard to the type(s) of combustion, combustible material(s) involved, and the form(s) of suitable extinguishing agent(s). Classes are often assigned letter designations, which can differ somewhat between territories. Standards * International Organization for Standardization, International (ISO): ISO3941 Classification of fires * Australia: AS/NZS 1850 * Europe: DIN EN2 Classification of fires * United States: NFPA 10 Chapter 5.2.1-5.2.5 Materials and hazards Flammable solids: Class A (US/EU/AU) Fires involving ordinary flammable solids fall under Class A. This includes wood, paper, fabric, rubber, and some types of plastics. Such fires may be extinguished by water, wet chemical suppression, or dry chemical powder. Flammable liquids: Class B (US/EU/AU) Fires involving flammable liquids or liquefiable solids fall under Class B. Examples may include gasoline, petrol/gasoline, petroleum, oil, paint, some waxes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
