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A Bunsen burner is a type of gas burner that produces a safe, smokeless, hot, non-luminous flame that can be used for various scientific experiments.
The flame is created by the gas and oxygen being mixed in a controlled environment, which allows precise regulation of the size and heat of the burner.
The Bunsen burner consists of a flat base with a vertically extending straight tube, called a barrel or chimney. Natural gas (mainly methane) or a liquefied petroleum gas such as propane or butane is supplied at the bottom of the chimney, it is connected to a gas valve using a rubber tube.
The burner is named after Robert Bunsen, a German scientist who designed it in 1857 with his laboratory assistant, Peter Desaga.
◉ The basic function of a Bunsen burner in the laboratory is heating, sterilization and combustion.
◉ barrel or chimney : It is a metal tube about 5 inches long that rests on the base of the burner. It has two diametrically opposed holes near the bottom end which form the air vent. The barrel can be screwed to the base. The gas from the nozzle mixes with the air from the vent and burns at its upper end
◉ Air holes : Air holes allow air to enter the burner to make a mixture of air and gas or other liquid fuel with air.
◉ The air regulator (Collar ) : IIt is a short metallic cylindrical sleeve with two holes diametrically opposed to each other. Present around the ventilation holes, the main function of the collar is to control the amount of air entering the barrel.
Bunsen burner parts
Bunsen burners are normally fitted with a barbed fitting at the base of the chimney to allow a rubber tube to feed gas from a gas nozzle on the laboratory bench.
The adjustable valve (collar) at the bottom dictates the amount of oxygen that enters the mix. With a closed valve, very little oxygen enters and a smoky yellow "low temperature" flame is produced. With the valve fully open, a hot, nearly colorless, roaring flame results.
There are two main fuel sources for a Bunsen burner : natural gas (mostly methane) and liquefied petroleum gas (propane, butane, or a mixture of the two). Be sure to select the correct burner for the fuel source you will be using: it is dangerous to use a burner for one type of fuel with the other fuel.
◉ There are several types of Bunsen burners to choose from depending on your gas source and experimental conditions :
◉ Safety Flame : This flame is yellow, easy to see in a well-lit room, and helps others remember that your Bunsen burner is on. Reaches temperatures of approximately 300 degrees, not used to heat materials for experiment.
Explanation : When the vent of a Bunsen burner is closed , the air needed for the combustion reaction comes only from the area near the top of the burner, incomplete combustion, resulting in a bright yellow flame resembling a candle.
◉ Medium blue flame : This particular flame on a burner can reach 500 degrees. Can be difficult to see in a bright room and is created when the air gap is partially open.
◉ Roaring blue flame : (It's the only flame that makes noise) This is the hottest flame, it can reach temperatures of 1400 degrees, with the hottest part of the flame just at the tip of the white cone in the middle of the blue flame.
Explanation : Increasing airflow to the burner produces more complete combustion and a hotter flame. The gas-air mixture is then ignited above the barrel. The result is a noisy, bluish-colored three-cone flame. This blue flame provides the highest possible burner temperature.
Types of flames