Fire Triangle Science Essay

wake Triangle Science Essay chemical science of flakUnit 36 Forensic elan Investigation2/3/2015Windows UserContentsFire TetrahedronPage 2 master(a) Sources of fervor..Page 3Secondary Sources of Ignition..Page 4Methods of ExtinctionPage 5 passionateness Transfer..Page 6Different Types of Fire..Page78BibliographyPage 9Reference ListPage 10Fire TetrahedronHere is a diagram of the discharge tetrahedron.This diagram shows the three elements that have to be award in order for a incinerate to occur. Combustion only occurs when in flammable vapors atomic number 18 mixed with oxygen and atomic number 18 ignited by a spark or flame.FuelA fuel is whatsoever substance that toilette undergo combustion such as wood, plastics, rubber, fabric, gas, homework oil, nail vanish remoer, butane, natural gases and pro movee. This is needed to fuel the perk up.Organic fuels channel one C hydrogen and oxygen in varying ratios in some cases, nitrogen ordain be present such as wood, plastic s, gasoline, alcohol and natural gases.Inorganic fuels contain no carbon and include combustible surfaces such as magnesium or sodium. group OOxygen is need for a nurture to begin because when oxygen in the air combines with flammable vapours given off by fuels they reach a form of genus Oestrus at a molecular level.HeatHeat is produced in a prove when oxygen and flammable vapours from the fuels combine, once this happens a source of ignition is the needed to cause it to combust.Primary Sources of IgnitionIgnition is the act or process of initiating combustion. (dictionary.reference.com, 2012).A elemental source of ignition is when you expose a flammable object to an blustering flame and causes fire directly.Here atomic number 18 a number of primary sources of ignitionCooking AppliancesSpace- heating planting AppliancesElectric Wiring, Connections or TerminationsOther Electrical Appliances e.g. wash drawing machines, bed warmers and televisions.CigargonttesMatchesGas Light ersBlow-LampsBlow TorchesWelding torchesBonfiresCandlesSecondary Sources of IgnitionA subaltern source of ignition is where a flammable object is heated up until its burning point. During a family unit fire the primary source will be ignited which will whence(prenominal) cause a secondary source to ignite which will ignite the furniture. According to the Journal of Fire Sciences An important aspect of many secondary sources is that they frequently occur in areas where they use burn downnot easily be controlled or restricted.Examples of secondary sources of ignition areWaste paper basketsSoft toys piece of furnitureCurtains/blindsNewspapersCarpetMethods of ExtinctionA fire place be bear away if any of three components in the fire triangle that cause a fire (heat, oxygen and fuel) are removed. removal of HeatTo remove heat from a fire or cool a fire, water is most commonly used. Water has corking heat absorbing properties. The water is able to extinguish a fire as it is able t o absorb more heat than the fire is generating.Removal of OxygenA fire can be extinguish by removing or limiting its oxygen offer. To do this it is known as blanketing or smothering. You do not need to remove all of the oxygen supply to extinguish a fire, a reduction of oxygen below 6% is sufficient enough to extinguish a fire. Examples are snuffing out a lit candle, placing a lid on a chip pan fire and closing doors and windows if there is a fire in a room it may burn itself out.Removal of FuelAccording to Chubb.co.uk, 2014A fire will go out if deprived of its fuel supply. A fire caused by a gas leak can be extinguished by turning off the gas. If pallets are stacked in the open, rather than against a warehouse wall, they will steadytually burn out, going the warehouse and its contents out of danger.Heat TransferHeat can be transferred from place to place by conduction, convection and radiation. Dark matt surfaces are better at absorbing heat life force than light hopeful surfa ces. Heat energy can be lost from homes in many disparate ways and there are ways of reducing these heat losses. (bbc.co.uk, 2014)ConductionHeat energy can move through a substances by conduction, metals are very good conductors heat, whereas non-metals and gases are poor conductors of heat. The poor conductors are called insulators. The heat energy is conducted from the hot nullify to the cool end of an object.The electrons in a piece of metal can leave their atoms and are free to move around in the metal as free electrons. The parts of the metal that have left foot atoms become charged metal ions, the ions are packed closely unneurotic and vibrate continually. The hotter the metal the more kinetic energy the vibrations gain, this energy is then transferred from the hotter parts of the metal to the cooler parts by the free electrons. As these electrons move around in the metal they collide with ions as they go. (Bbc.co.uk, 2014)ConvectionThe particles in liquids and gases are a ble to move around more freely, as they are not packed together like solids. Convection occurs when particles in liquids and gases with a business deal of heat energy move and head the places of particles with less heat energy, this is how heat energy is transferred using convection.RadiationAll objects give out and take in thermal radiation which is in addition known as infrared frequency radiation. The hotter an objects gets the more infrared radiation it emits.Infrared radiations is a type of electromagnetic radiation that involves waves instead of particles unlike convection and conduction. Due to this radiation can even work through the vacuum of space. This is why we are able to expression heat of the sun even though it is 150 million km away from the earth.Different Types of FireHouse FiresHouse fires are fires that get together out within the home and there are many different causes for them such asCareless fastballLit candlesElectrically appliances acquire left onA rsonCooking equipmentHeating equipmentChildren playing with fire insideInadequate wiringFlammable liquidsChristmas tree decorationsA house fire could spread by either conduction, convection or radiation depending on which one of the above started the fire. If the fire is a small fire within the house a fire blanket or water can be used to extinguish it. If you have access to fire extinguishers a water extinguisher is good for burning paper, wood or barmy furnishings, a foam extinguisher is good for an arson fire, as throttle or other fuels would probably have been used. Then a carbon dioxide extinguisher is good for putting out fires caused by electrical appliances. If the fire has spread through most of the house and is a lot bigger, then the fire brigade would put the fire out with water. Wet chemic extinguishers were designed to extinguish fires in the kitchen involving burning oil and deep risque fryers. House fires can be prevent by being elaborate when using appliances, flammable liquids, candles and decorations, they could also be prevented by getting your electrics get a line every year or so.WildfiresWildfires are fires that break out in the wilderness, the causes of them includeArsonLightningUnattended campfiresBurning of debrisCarelessly discarding of cigarettesA wildfire would generally spread by convection, as they would be in strain with an open flame which could be one of the following. A wildfire could be extinguish by a helicopter or plane throwing water over the fire from above or by the fire brigade with water, They could also be put out with leaf dragers, as this will blow the fire in the direction that it has already been meaning it has nothing else to take into custody fire too. Wildfires can be prevent by using fire breaks, people to comply with laws and regulations and never leave a fire unattended. gas pedal Fires accelerator pedal is a dangerous substance and it is a highly flammable liquid. The petrol gives off a vapour wh ich can easily be set on fire if it is not handled safely. The causes of a petrol fire areArsonPetrol LeakCar Crash luminousness at Petrol Station e.g. using a mobile phone, smoking.Petrol fires are able to spread using conduction and convection, to extinguish these types of fires a foam extinguisher, CO2 extinguisher or a powder extinguisher is best being used. As these extinguisher will place a layer of powder or foam over the fire starved it of oxygen. These can be prevent by people not smoking or using their mobile phone at a petrol station and people comply with laws and regulations.Bibliographyhttps//answers.yahoo.com/question/index?qid=20110106060151AAjbfWohttp//www.chubb.co.uk/utcfs/Templates/Pages/Template-66/0,,pageId=14542siteId=403,00.htmlJournal of Fire Science Standard Flaming Ignition Sources for Upholstered Composties, Furniture and Bed prevarication Tests.http//www.readersdigest.ca/home-garden/cleaning/top-10-causes-house-firesQMoRMblOIpwYaxGA.97http//www.hse.gov .uk/fireandexplosion/petroleum.htmhttp//www.fireservice.co.uk/safety/extinguishersReference ListChubb (2014) Methods of Fire Extinction. Available at http//www.chubb.co.uk/utcfs/Templates/Pages/Template-66/0,,pageId=14542siteId=403,00.html(Accessed on 11th February 2015)Dictionary.com (2012) Ignition. Available at http//dictionary.reference.com/browse/ignition(Accessed on 10th February 2015)GCSE Bitesize (2014) Heat Transfer and efficiency. Available at http//www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/energy/heatrev2.shtml(Accessed on 11th Febrauary 2014)K.T. Paul S.D Christian. (1987) Standard Flaming Ignition Sources for Upholstered Composties, Furniture and Bed Assembly Tests. Journal of Fire Sciences, 178 (5), pp 179(Accessed on 11th February 2015)Chemistry of FirePage 1