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 was 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.
It consists of several parts, each of which plays an important role in the functioning of the burner. The main parts of a Bunsen burner include :
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.
The choice of fuel source for a Bunsen burner depends on the specific application, availability of fuel sources, and safety considerations :
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
The type of flame produced can be controlled by adjusting the air intake using the needle valve.
◉ There are several types of Bunsen burners to choose from depending on your gas source and experimental conditions :
The type of flame produced can be controlled by adjusting the air intake using the needle valve. It is important to choose the appropriate flame for the specific laboratory application to ensure accurate and safe results.
◉ Safety Flame : The smallest and least hot flame, easy to see in a well-lit room, and helps others remember that your burner is on. Reaches temperatures of approximately 300 degrees, not used to heat materials for experiment.
Explanation : When the vent 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.
◉ Yellow flame : Produced when there is not enough air mixing with the gas, causing incomplete combustion. This flame is not commonly used in laboratory work as it can contaminate samples with soot.
◉ 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 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 flame provides the highest possible burner temperature.
Types of flames