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In a laboratory under normal gravity conditions and with a closed air inlet, a Bunsen burner burns with yellow flame (also called a safety flame) with a peak temperature of about 2,000 K (3,100 °F). The yellow arises from incandescence of very fine soot particles that are produced in the flame.
Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. [1] [a] Flames, the most visible portion of the fire, are produced in the combustion reaction when the fuel reaches its ignition point.
In other words, a combustible material ignites with some effort and a flammable material catches fire immediately on exposure to flame. The degree of flammability in air depends largely upon the volatility of the material – this is related to its composition-specific vapour pressure, which is temperature dependent
The constant volume adiabatic flame temperature is the temperature that results from a complete combustion process that occurs without any work, heat transfer or changes in kinetic or potential energy. Its temperature is higher than in the constant pressure process because no energy is utilized to change the volume of the system (i.e., generate ...
The fire triangle or combustion triangle is a simple model for understanding the necessary ingredients for most fires. [1] The triangle illustrates the three elements a fire needs to ignite: heat, fuel, and an oxidizing agent (usually oxygen). [2] A fire naturally occurs when the elements are present and combined in the right mixture. [3]
The autoignition temperature or self-ignition temperature, often called spontaneous ignition temperature or minimum ignition temperature (or shortly ignition temperature) and formerly also known as kindling point, of a substance is the lowest temperature at which it spontaneously ignites in a normal atmosphere without an external source of ignition, such as a flame or spark. [1]
This temperature slightly depends on the fuel to oxygen ratio and strongly depends on gas pressure – there is a threshold below which cool flame is not formed. A specific example is 50% n- butane –50% oxygen (by volume) which has a cool flame temperature (CFT) of about 300 °C (572 °F) at 165 mmHg (22.0 kPa).
Flashover normally occurs at 500 °C (932 °F) or 590 °C (1,100 °F) for ordinary combustibles and an incident heat flux at floor level of 20 kilowatts per square metre (2.5 hp/sq ft). [ jargon ] An example of flashover is the ignition of a piece of furniture in a domestic room.