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Inerting (gas)
In fire and explosion prevention engineering, inerting refers to the introduction of an inert (non-combustible) gas into a closed system (e.g. a container or a process vessel) to make a flammable atmosphere oxygen deficient and non-ignitable.NFPA 69. Standard on Explosion Prevention Systems. National Fire Protection Association.NFPA 77. Recommended Practice on Static Electricity. National Fire Protection Association. Inerting relies on the principle that a combustible (or flammable) gas is able to undergo combustion (explode) only if mixed with air in the right proportions. The flammability limits of the gas define those proportions, i.e. the ignitable range. In combustion engineering terms, the admission of inert gas can be said to dilute the oxygen below the limiting oxygen concentration. Inerting differs from purging. Purging, by definition, ensures that an ignitable mixture ''never forms''. Inerting makes an ignitable mixture safe by introduction of an inert gas. Certain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inert Gas
An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to as the inert gases. Inert gases are used generally to avoid unwanted chemical reactions degrading a sample. These undesirable chemical reactions are often oxidation and hydrolysis reactions with the oxygen and moisture in air. The term ''inert gas'' is context-dependent because several of the noble gases can be made to react under certain conditions. Purified argon gas is the most commonly used inert gas due to its high natural abundance (78.3% N2, 1% Ar in air) and low relative cost. Unlike noble gases, an inert gas is not necessarily elemental and is often a compound gas. Like the noble gases, the tendency for non-reactivity is due to the valence, the outermost electron shell, being complete in all the inert gases. This is a tendency, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flammability Limits
Mixtures of dispersed combustible materials (such as gaseous or vaporised fuels, and some dusts) and oxygen in the air will burn only if the fuel concentration lies within well-defined lower and upper bounds determined experimentally, referred to as flammability limits or explosive limits. Combustion can range in violence from deflagration through detonation. Limits vary with temperature and pressure, but are normally expressed in terms of volume percentage at 25 °C and atmospheric pressure. These limits are relevant both in producing and optimising explosion or combustion, as in an engine, or to preventing it, as in uncontrolled explosions of build-ups of combustible gas or dust. Attaining the best combustible or explosive mixture of a fuel and air (the stoichiometric proportion) is important in internal combustion engines such as gasoline or diesel engines. The standard reference work is still that elaborated by Michael George Zabetakis, a fire safety engineering special ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limiting Oxygen Concentration
The limiting oxygen concentration (LOC), also known as the minimum oxygen concentration (MOC), is defined as the limiting concentration of oxygen below which combustion is not possible, independent of the concentration of fuel. It is expressed in units of volume percent of oxygen. The LOC varies with pressure and temperature. It is also dependent on the type of inert (non-flammable) gas. Limiting oxygen concentration for solid materials The effect of increasing the concentration of inert gas can be understood by viewing the inert as thermal ballast that quenches the flame temperature to a level below which the flame cannot exist. Carbon dioxide is therefore more effective than nitrogen due to its higher molar heat capacity.Drysdale:92 The concept has important practical use in fire safety engineering. For instance, to safely fill a new container or a pressure vessel with flammable gasses, the atmosphere of normal air (containing 20.9 volume percent of oxygen) in the vess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purging (gas)
In fire and explosion prevention engineering, purging refers to the introduction of an inert (i.e. non-combustible) purge gas into a closed system (e.g. a container or a process vessel) to prevent the formation of an ignitable atmosphere. Purging relies on the principle that a combustible (or flammable) gas is able to undergo combustion (explode) only if mixed with air in the right proportions. The flammability limits of the gas define those proportions, i.e. the ignitable range. Purge into service Assume a closed system (e.g. a container or process vessel), initially containing air, which shall be prepared for safe introduction of a flammable gas, for instance as part of a start-up procedure. The system can be flushed with an inert gas to reduce the concentration of oxygen so that when the flammable gas is admitted, an ignitable mixture cannot form. In NFPA 56,NFPA 56. Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping Systems. Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1954 Bitburg Explosion (jet Fuel Storage Tank)
The devastating Bitburg tank explosion took place on 23 September 1954 at the then NATO air base near the city Bitburg, in the municipality of Niederstedem, Germany. The explosion took place in an underground storage tank containing JP-4, a military jet fuel blend. The toll was 34 dead, 2 injured, 3 missing. The explosion was caused by the deliberate activation of a novel carbon dioxide fire extinguishment system during an acceptance test as part of final commissioning. The JP-4 blend has since largely been abandoned due to safety concerns because of its low flash point. The accident In 1954 at the US Air Force fuel depot near Bitburg, various acceptance tests were being made on a newly constructed underground fuel storage tank. The tank was fitted with a novel carbon dioxide fire extinguishing system, the first of its kind in Germany. The US Army was not responsible for design, construction and operation of storage facilities at the time, but the fuel involved was the property o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crude Oil
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude oil and petroleum products that consist of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, mostly zooplankton and algae, are buried underneath sedimentary rock and subjected to both prolonged heat and pressure. Petroleum is primarily recovered by oil drilling. Drilling is carried out after studies of structural geology, sedimentary basin analysis, and reservoir characterisation. Recent developments in technologies have also led to exploitation of other Unconventional (oil & gas) reservoir, unconventional reserves such as oil sands and oil shale. Once extracted, oil is refined and separated, most easily by Continuous distillation#Continuous distillation of crude oil, distillation, into innume ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naphtha
Naphtha ( or ) is a flammable liquid hydrocarbon mixture. Mixtures labelled ''naphtha'' have been produced from natural gas condensates, petroleum distillates, and the distillation of coal tar and peat. In different industries and regions ''naphtha'' may also be crude oil or refined products such as kerosene. ''Nephi'' and ''naphthar'' are sometimes used as synonyms. It is also known as Shellite in Australia. Etymology The word ''naphtha'' is from Latin and Ancient Greek (νάφθα), derived from Middle Persian ''naft'' ("wet", "naphtha"), the latter meaning of which was an assimilation from the Akkadian ''napṭu'' (see Semitic relatives such as Arabic ''nafṭ'' petroleum" Syriac ܢܰܦܬܳܐ ''naftā'') and Hebrew נֵפְט ''neft'' (meaning petroleum). In Ancient Greek, it was used to refer to any sort of petroleum or pitch. There is a hypothesis that the word is connected with the name of the Indo-Iranian god Apam Napat, which occurs in Vedic and in Avestic; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gasoline
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. On average, U.S. refineries produce, from a barrel of crude oil, about 19 to 20 gallons of gasoline; 11 to 13 gallons of distillate fuel (most of which is sold as diesel fuel); and 3 to 4 gallons of jet fuel. The product ratio depends on the processing in an oil refinery and the crude oil assay. A barrel of oil is defined as holding 42 US gallons, which is about 159 liters or 35 imperial gallons. The characteristic of a particular gasoline blend to resist igniting too early (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating, which is produced in several grades. Tetraethyl lead and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inert Gas Generator
Inert gas generator (IGG) refers to machinery on board marine product tankers. Inert gas generators consist distinctively of a gas producer and a scrubbing system. Process Diesel is burned using atmospheric air in a combustion chamber and the exhaust gas collected, the resulting exhaust gas contains less than 5% oxygen, thereby creating "inert gas An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to ...", which mainly consist of Nitrogen and partly Carbon Dioxide. The hot, dirty gas is then passed through a scrubbing tower which cleans and cools it using seawater. This gas is then delivered to cargo tanks to prevent explosion of flammable cargo. This generator is sometimes confused with ''flue gas systems'', which draw inert gas from the boiler systems of the ship. Flue gas systems d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purging (gas)
In fire and explosion prevention engineering, purging refers to the introduction of an inert (i.e. non-combustible) purge gas into a closed system (e.g. a container or a process vessel) to prevent the formation of an ignitable atmosphere. Purging relies on the principle that a combustible (or flammable) gas is able to undergo combustion (explode) only if mixed with air in the right proportions. The flammability limits of the gas define those proportions, i.e. the ignitable range. Purge into service Assume a closed system (e.g. a container or process vessel), initially containing air, which shall be prepared for safe introduction of a flammable gas, for instance as part of a start-up procedure. The system can be flushed with an inert gas to reduce the concentration of oxygen so that when the flammable gas is admitted, an ignitable mixture cannot form. In NFPA 56,NFPA 56. Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping Systems. Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATEX
The ATEX directives are two EU directives describing the minimum safety requirements for workplaces and equipment used in explosive atmospheres. The name is an initialization of the French term ''Appareils destinés à être utilisés en ATmosphères EXplosibles'' (French for "Equipment intended for use in explosive atmospheres"). Directives Organizations in the EU must follow Directives to protect employees from explosion risk in areas with an explosive atmosphere. There are two ATEX Directives (one for the manufacturer and one for the user of the equipment): * the ATEX 114 "equipment" Directive 2014/34/EU - Equipment and protective systems intended for use in potentially explosive atmospheres * the ATEX 153 "workplace" Directive 1999/92/EC - Minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres. Note: The ATEX 95 "equipment" Directive 94/9/EC, was withdrawn on 20 April 2016 when it was replaced by ATE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flammability Limits
Mixtures of dispersed combustible materials (such as gaseous or vaporised fuels, and some dusts) and oxygen in the air will burn only if the fuel concentration lies within well-defined lower and upper bounds determined experimentally, referred to as flammability limits or explosive limits. Combustion can range in violence from deflagration through detonation. Limits vary with temperature and pressure, but are normally expressed in terms of volume percentage at 25 °C and atmospheric pressure. These limits are relevant both in producing and optimising explosion or combustion, as in an engine, or to preventing it, as in uncontrolled explosions of build-ups of combustible gas or dust. Attaining the best combustible or explosive mixture of a fuel and air (the stoichiometric proportion) is important in internal combustion engines such as gasoline or diesel engines. The standard reference work is still that elaborated by Michael George Zabetakis, a fire safety engineering special ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
