combustion and flame

SCEINCE

PRESENTATIONBY – RAGHAV BINDAL

ombustion

Flame&

COMBUSTIONCombustion  or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can produce light in the form of either glowing or a flame. Fuels of interest often include organic compounds (especially hydrocarbons) in the gas, liquid or solid phase.In a complete combustion reaction, a compound reacts with an oxidizing element, such as oxygen or fluorine, and the products are compounds of each element in the fuel with the oxidizing element.

TYPES OF COMBUSTION

Rapid

Spontaneous

Explosion

RAPID COMBUSTION

Rapid combustion is a form of combustion, otherwise known as a fire, in which large

amounts of heat and light energy are released, which often results in a flame. This is used in a form of machinery such as internal combustion engines and in thermobaric weapons. Such a combustion is frequently called an explosion,

though for an internal combustion engine this is inaccurate. An internal combustion engine

nominally operates on a controlled rapid burn. When the fuel-air mixture in an internal

combustion engine explodes, that is known as detonation. Combustion need not involve

oxygen; e.g., hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat

and light characteristic of combustion.

SPONTANEOUS COMBUSTION

Spontaneous combustion is a type of combustion which occurs by self heating (increase in temperature due to exothermic internal reactions), followed by thermal runaway (self heating which rapidly 

accelerates to high temperatures) and finally, ignition.

EXPLOSION

An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with

the generation of high temperatures and the release

of gases. Supersonic explosions created by high explosives are

known as detonations and travel via supersonic shock

waves. Subsonic explosions are created by low explosives through a slower burning process known

as deflagration.

Fire extinguisherA fire extinguisher, flame extinguisher, or simply an extinguisher, is an active fire protection device used to extinguish or control small fires, often in emergency situations. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i.e., no escape route, smoke, explosion hazard, etc.), or otherwise requires the expertise of a fire department. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire.

TYPES OF FIRE EXTINGUISHER

Dry powder

Soda – acid

Foam

DRY POWDER FIRE EXTINGUISHERIt contains sand

and Baking

soda .When this Mixture is

thrown over Fire, baking

soda decomposes to release carbon Dioxide which

extinguishes the fire.

FOAM FIRE EXTINGUISHER A fire fighting

foam is simply a stable mass of small air-filled bubbles, which have a lower density than oil, gasoline or water. Foam is made up of three ingredients - water, foam concentrate and air.

SODA – ACID FIRE EXTINGUISHERSodium

bicarbonate (baking soda) is a substance found in all living things, regulating pH balance. Made from sodium carbonate (soda ash), soda ash is mined from trona ore.

LABELLED FIRE EXTINGUISHER

FLAMEA flame is the visible, gaseous part of a fire. It is caused by a highly exothermic reaction taking place in a thin zone.  Some flames, such as the flame of a burning candle, are hot enough to have ionized gaseous components and can be considered plasma. This subject is, however, hotly debate

ZONES OF CANDLE FLAME

Non - combustion

Incomplete combustion

Complete combustion

Blue zone

BLUE ZONE

BLUE ZONE

There is a surplus of oxygen and the flame burns clean and blue.  Temperature is around 800°C.  In a candle the heat from this zone melts nearby wax to allow for wicking.

NON COMBUSTION

DARK ZONE Pyrolysis (cracking) of the fuel begins due to the shortage of oxygen creating minute carbon particles.  The temperature is about 1,000°C.

COMPLETE COMBUSTION

NON-LUMINOUS

 There is oxygen surplus in this non-luminous zone and carbon particles burn faster and more completely at the boundary between Zone 4 and Zone 5.  The temperature is around 1,400°C.  If a draft lowers the temperAature below 1,000°C, soot particles cease burning and end up on your pot or in your lungs.

INCOMPLETE COMBUSTION

 This area is bright yellow.  There is still insufficient oxygen for complete burning so pyrolysis continues and larger carbon particles are produced. The temperature is around 1,200°C.

Luminous zone

Fuels are any materials that store potential energy in forms that can be practicably released and used as heat energy. The concept originally applied solely to those materials storing energy in the form of chemical energy that could be released through combustion,[1] but the concept has since been also applied to other sources of heat energy such as nuclear energy (via nuclear fission or nuclear fusion), as well as releases of chemical energy released through non-combustion oxidation (such as in cellular biology or in fuel cells).

TYPES OF FUELS

Liquid fuel

Solid fuel

Gaseous fuel

LIQUID FUEL

Liquid fuels are combustible or energy-generating molecules that can be harnessed to create mechanical energy, usually producing kinetic energy; they also must take the shape of their container. It is the fumes of liquid fuels that are flammable instead of the FLUID.

SOLID FUELSolid fuel refers to various types of solid material that are used as fuel to produce energy and provide heating, usually released through combustion. Solid fuels include wood (see wood fuel), charcoal, peat, coal, Hexamine fuel tablets, and pellets made from wood (see wood pellets), corn, wheat, rye and other grains. Solid-fuel rocket technology also uses solid fuel (see solid propellants).

GASEOUS FUEL

GASEOUSFU

EL

Fuel gas is any one of a number of fuels that under ordinary conditions are gaseous. Many fuel gases are composed of hydrocarbons (such as methane or propane), hydrogen, carbon monoxide, or mixtures thereof.