4. COMBUSTION AND FLAME

4. COMBUSTION AND FLAME

  • 4

    Combustion And Flame

    This section discusses combustion, the types of fuels, conditions for combustion, and fire control techniques.

  • 4.1

    What Is Combustion?

    Combustion is a chemical process where a substance reacts with oxygen, producing heat and light.

  • 4.2

    How Do We Control Fire?

    This section explains the essential requirements for fire, methods to control it, and the types of fire extinguishers used.

  • 4.3

    Types Of Combustion

    This section discusses different types of combustion, including rapid combustion, spontaneous combustion, and explosions, along with their characteristics.

  • 4.4

    Flame

    This section delves into the phenomenon of flame produced during combustion, exploring its characteristics and structure.

  • 4.5

    Structure Of A Flame

    The structure of a flame is composed of different zones, including the dark zone, luminous zone, and non-luminous zone, each exhibiting distinct characteristics.

  • 4.6

    What Is A Fuel?

    Fuels are materials that release energy through combustion, and a good fuel is inexpensive, burns easily, and produces considerable heat without leaving harmful residues.

  • 4.7

    Fuel Efficiency

    Fuel efficiency refers to the amount of heat energy produced from fuels and compares their calorific values.

  • 4.7.1

    Burning Of Fuels Leads To Harmful Products

    The combustion of fuels, such as wood and gasoline, results in various harmful emissions that impact the environment.

  • 4.8

    Keywords

    This section explores the concept of combustion, the requirements for fire, and the types and impacts of fuels.

  • 4.9

    What You Have Learnt

    This section discusses the processes and importance of combustion, types of fuels, and the necessary conditions for combustion to occur.

  • 4.10

    Exercises

    This section provides exercises related to combustion and flame, aiming to reinforce understanding of key concepts through practical application.

  • 4.11

    Extended Learning — Activities And Projects

    This section encourages practical exploration and deeper understanding of combustion and fuels through engaging activities and projects.

    • Key Summary

    Combustion involves the chemical reaction of a substance with oxygen, resulting in heat and light. Various fuels such as wood, coal, and LPG are used for different purposes, impacting both energy efficiency and environmental safety. The chapter also covers the conditions for combustion, types of flames produced, and methods for controlling fire, emphasizing safety measures and environmental considerations related to fuel consumption.

    Key Takeaways

    • Substances that burn in air are called combustible.
    • Oxygen (in air) is essential for combustion.
    • During combustion, heat and light are released.
    • The ignition temperature is the lowest temperature at which a combustible substance ignites.
    • Inflammable substances have low ignition temperatures.
    • Fire can be controlled by removing fuel, air, or heat.
    • Water is commonly used to extinguish fires, but not suitable for electrical or oil-related fires.
    • Different types of combustion include rapid combustion, spontaneous combustion, and explosions.
    • Flames have different zones: dark zone, luminous zone, and non-luminous zone.
    • An ideal fuel is inexpensive, readily available, highly combustible, and environmentally friendly.

    Key Concepts

    • Combustion: A chemical process in which a substance reacts with oxygen, producing heat and light.
    • Fuel: Materials that can burn to produce energy; commonly categorized as solid, liquid, or gas.
    • Ignition Temperature: The lowest temperature at which a combustible material catches fire.
    • Calorific Value: The amount of heat energy produced on complete combustion of 1 kg of a fuel, expressed in kilojoules per kilogram (kJ/kg).
    • Inflammable Substances: Materials with a low ignition temperature that can easily catch fire.
    • Acid Rain: Rain that has been made acidic by pollutants like sulfur oxides and nitrogen oxides.
    • Global Warming: The increase in Earth's average surface temperature due to rising levels of greenhouse gases.