Combustion & Flame

  • View
    62

  • Download
    3

Embed Size (px)

DESCRIPTION

Combustion & Flame. By Vishnu M Nair. Index. Basic needs How to extinguish Fire The Ignition temperature Inflammable combustion Rapid & Spontaneous Combustion Zones Of Candle Flame Explosion Fuel Fuel Efficiency Global Warming Acid Rain. Basic Needs. - PowerPoint PPT Presentation

Text of Combustion & Flame

Slide 1

Combustion & FlameBy Vishnu M Nair Index Basic needs How to extinguish Fire The Ignition temperature Inflammable combustion Rapid & Spontaneous Combustion Zones Of Candle Flame Explosion Fuel Fuel Efficiency Global Warming Acid Rain

Basic NeedsBasic Needs The major conditions for a fire to burn isThe presence of OxygenThe presence of fuelThe temperature to reach flash point

Combustion A chemical process in which a substance reacts with oxygen to give off heat is called combustion.

Basics of Combustion and Flame

We now understand that fire be seen with the help of the above

Q1. What will you do if you see a uncontrolled fire?How to extinguish fire? The answer to that question is so simple. Fire can only burn with presence of oxygen and fuel and if temperature is above flash point.So to extinguish fire remove away any of these For Example By denying the access of oxygen Example: If fire is on a human body we should cover him tightly with a blanket like that on the picture below

2. By taking away the fuel 3. By decreasing the temperature below flash pointThis can be done by poring water over the fireQ. What will you do if the fire is caused by an electric short circuit In such a case DO NOT TRY TO EXTINGUISH IT WITH WATER. As water may come in contact with electric shock which could lead to serious injuries or even DEATH

The Ignition Temperature The lowest temperature at which a substance catches fire is called its Ignition TemperatureIt is essential for a substance to reach its ignition temperature to burn

12Given here are some fuels and its ignition temperature Sl no. FuelTemperature1Diesel210 degrees2Petrol246 degrees3Butane405 degrees4Paper450 degrees5Magnesium473 degrees6Hydrogen536 degrees7Triethylborane-20 degreesInflammable substance The Substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substancesSome examples are: Petrol, Alcohol, Liquid Petroleum GasRapid Combustion and Spontaneous Combustion Rapid Combustion and Spontaneous Combustion Rapid Combustion: Gas burns rapidly and produces heat and light. Such combustion is known as rapid combustion.Rapid Combustion and Spontaneous Combustion Spontaneous Combustion: The type of combustion in which a material suddenly bursts into flames, without the application of any apparent cause is called Spontaneous Combustion

Zones of Candle FlameExplosion When a cracker is ignited, a sudden reaction takes place with the evolution of heat, light and sound. A large amount of gas formed in the reaction is liberated. Such a reaction is called explosion.

Fuel The substance that undergoes combustion is said to be combustible or FUEL

Know more on fuels A Good Fuel A good fuel is:- Readily Available Cheap Burns easily in air And does not leave any undesirable substance behind.Fuel Efficiency The amount of heat produced on complete combustion of 1 kg fuel is called its calorific value. The calorific value is expressed in a unit called kilojoules per kg (kj/kg).FuelCalorific ValueCow dung cake6000-8000Wood17000-22000Coal25000-33000Petrol45000Kerosene45000

Diesel45000

Methane50000LPG55000Biogas35000-40000Hydrogen150000Burning of fuels leads to harmful productsGlobal Warming

Combustion of most fuels releases carbon dioxide in environment. Increased carbon dioxide in air is believed to cause global warming

A bear that lost his home because of ice melting

Acid Rain Burning of coal and diesels releases sulphur dioxide gas. Oxides of sulphur and nitrogen dissolve in rain water and forms acids. Such a rain is called acid rain.Acid rain

THE END

Done ByVishnuHope you liked it ?For More Slide showsLog on towww.slideshare.wordpress.com