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These Bunsen burners are an inexpensive option with an adjustable air supply port. They can be used with either liquid propane or natural gas.
An inexpensive Bunsen burner with adjustable air ports. Only the air supply ports can be adjusted. A flame retainer is furnished only on Catalog No. AP8344. Accepts burner tubing with an inside diameter of 5/16" (Catalog No. AP8285). Maximum temperature of flame can reach 1560 ºC.
Bunsen Burner Background
Bunsen burners were developed by Robert Bunsen and Peter Desaga in 1855. Bunsen needed a reliable burner for his new laboratory at the University of Heidelberg and designed a burner that mixed air with the gas before combustion. Most of the gas burners and lights available in the 1800s mixed the gas and air at the combustion site.
The Bunsen burner uses the combustion of methane (also called natural gas) and oxygen according to Equation 1 to produce heat. If enough oxygen is available, roughly two moles of oxygen for each mole of methane, then complete combustion will occur, and maximum heat (flame) will be produced. If the amount of oxygen is deficient, then incomplete combustion (Equation 2) will occur, and carbon (also called soot) and carbon monoxide will also be formed. Less heat is produced during incomplete combustion. Mixing air with the gas before combustion ensures that enough oxygen will be available and complete combustion will occur.
CH4 + 2O2 → CO2 + 2H2O + heat Equation 1
CH4 + O2 → C + 2H2O + heat Equation 2a
CH4 + 3⁄2O2 → CO + 2H2O + heat Equation 2b
The modern Bunsen burner has changed very little from Robert Bunsen’s original design. It consists of a base, a gas inlet, the gas jet, the air control vent with a collar for adjusting the air flow, the barrel, and the mouth of the tube.
Procedure for Lighting a Bunsen Burner
Safety Rules for Using Bunsen Burners and Heating Substances
Using a Bunsen Burner
When the air vent of a Bunsen burner is closed, air for the combustion reaction is only coming from the area near the top of the burner. As a result, incomplete combustion occurs, and elemental carbon is produced. The temperature of the flame is lower, and it is a bright yellow, candle-like flame. The yellow flame is called a luminous flame and is very similar to a candle or gaslight flame. It is also a quiet flame that is greatly affected by air currents, much like a candle. The flame is also called a yellow safety flame because it is a cooler flame and makes the burner easier to light.
Increasing the air flow to the burner produces more complete combustion and a hotter flame. The air is increased by opening up the air vent (turning the metal collar). The air is drawn into the barrel of the burner by the gas coming out of the gas jet. 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 temperature from the burner. The temperature varies greatly across the three major regions of the flame. The hottest part of the flame is just above the inner blue cone.
Sometimes when the air flow is being adjusted, the flame may “blow out.” If this happens, simply turn off the gas and close the air vent. Wait 30 seconds for the burner to slightly cool and then follow the proper procedures for lighting the Bunsen burner. If the flame continually “blows out,” try turning the gas pressure down a little.
The flame can also be adjusted by adjusting the gas flow. Major adjustments in gas flow are made by turning the handle on the natural gas valve. The height and intensity of the Bunson burner flame depend on both the gas flow and the amount of air available for combustion. If either of these two gases is too high, the flame will continually “blow out.” If this happens, turn off the gas and close the air vents, allow the burner to cool for 30 seconds, and relight the burner with less gas and air pressure.
A Tirrill burner is similar to a Bunsen burner but it has a brass needle valve below the gas jet to regulate the gas supply. Minor gas adjustments can be made by turning this valve. A Meker burner is a high temperature burner that has a much larger burner mouth. The Meker burner mouth has a screen that forms many short, small, uniform blue flame cones. These multiple flame cones reach temperatures closer to 1750 °C.