2. 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

3. BASIC NEEDS

4. Basic Needs The major conditions for a fire to burn is 1.The presence of Oxygen 2.The presence of fuel 3.The temperature to reach flash point

5. Combustion – A chemical process in which a substance reacts with oxygen to give off heat is called combustion. Basics of Combustion and Flame

7. We now understand that fire be seen with the help of the above Q1. What will you do if you see a uncontrolled fire?

8. 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

9. For Example 1. 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

10. 2. By taking away the fuel 3. By decreasing the temperature below flash point This can be done by poring water over the fire Q. What will you do if the fire is caused by an electric short circuit

11. 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

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

13. Given here are some fuels and its ignition temperature Sl no. FuelTemperature 1Diesel210 degrees 2Petrol246 degrees 3Butane405 degrees 4Paper450 degrees 5Magnesium473 degrees 6Hydrogen536 degrees 7Triethylborane-20 degrees

14. Inflammable substance The Substances which have very low ignition temperature and can easily catch fire with a flame are called inflammable substances Some examples are: Petrol, Alcohol, Liquid Petroleum Gas

15. RAPID COMBUSTION AND SPONTANEOUS COMBUSTION

16. Rapid Combustion and Spontaneous Combustion Rapid Combustion: Gas burns rapidly and produces heat and light. Such combustion is known as rapid combustion.

17. 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

18. Zones of Candle Flame

19. Explosion 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.

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

21. 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.

22. 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).

23. Fuel Calorific Value Cow dung cake6000-8000 Wood17000-22000 Coal25000-33000 Petrol45000 Kerosene45000 Diesel45000 Methane50000 LPG55000 Biogas35000-40000 Hydrogen150000

24. BURNING OF FUELS LEADS TO HARMFUL PRODUCTS

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

26. A bear that lost his home because of ice melting

27. 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.

28. Acid rain