what is busen burner

本生燈（Bunsen burner）是科學實驗室常用的高溫加熱工具之一。

該工具以羅伯特·威廉·本生的名字命名，而實際上是由他的助手 Peter Desdega 在1855年改良法拉第原先的一項設計而成。

本生燈可安全地燃燒氣體燃料，火焰不會倒流進氣體供應管內。燃料方面通常會使用煤氣或石油氣，由本生燈下方的導管與空氣混合後導入，比例為空氣:煤氣=3:1，火焰溫度最高可達1500℃，空氣量較少時，混合氣體會產生小碳粒，若空氣過量，火焰會產生回火，在燈管內燃燒。

梅克爾燈和菲希爾燈是依本生燈改良而來的加熱器。

把實驗室的窗戶打開，保持空氣流通。
把本生燈膠喉與煤氣管接上，並放在防火板上。
先把燈腳的空氣調節器關閉，並點燃火柴在出氣口上。
啟動煤氣掣，把燈點燃，這時火焰為橙色。
打開空氣調節器讓新鮮空氣進入，火焰轉為藍色及溫度變高。
在使用完畢後，先把氣孔關上，再關掉煤氣掣。
把本生燈從煤氣管拔出。

A Bunsen burner is a common piece of laboratory equipment used for heating, sterilization, and combustion.

History
A common misconception is that the Bunsen burner was invented by German chemist Robert Wilhelm Bunsen. Although it is named after him, it is actually an improvement made in 1855 by his laboratory assistant, Peter Desaga, on an earlier design by Michael Faraday. The improvement is called a Tirrill Burner. The main differences between these burners is the gas control valve on a Tirrill Burner and the improved structure of the Tirrill Burner. Most Bunsen burners are in fact Tirrill Burners.


Operation
The device safely burns a continuous stream of a flammable gas such as natural gas (which is principally methane) or a liquified petroleum gas such as propane, butane, or a mixture of both. At the time of its invention, the Bunsen burner would have mostly burnt coal gas.

The burner has a weighted base with a connector for a gas line (hose barb) and a vertical tube (barrel) rising from it. The hose barb is connected to a gas nozzle on the lab bench with rubber tubing. Most lab benches are equipped with multiple gas nozzles connected to a central gas source, as well as vacuum, nitrogen, and steam nozzles. The gas then flows up through the base through a small hole at the bottom of the barrel and is directed upward. There are open slots in the side of the tube bottom to admit air into the stream via the Venturi effect, and the gas burns at the top of the tube once ignited by a flame or spark. The most common methods of lighting the burner are using a match or a spark lighter.

The amount of air (or rather oxygen) mixed with the gas stream affects the completeness of the combustion reaction in the flame. Less air yields an incomplete and thus cooler reaction, while a gas stream well mixed with air provides oxygen in an equimolar amount and thus a complete and hotter reaction. The air flow can be controlled by opening or closing the slot openings at the base of the barrel, similar in function to a car's carburetor.


Different flame types of Bunsen Burner depending on flow through the throat holes (holes on the side of Íthe bunsen burner -- not to be confused with the needle valve for gas flow adjustment). 1. air baffle closed (Safety flame) 2. air baffle half open 3. air baffle nearly fully open 4. air baffle fully open (Roaring Flame)If the collar at the bottom of the tube is adjusted so more air can mix with the gas before combustion, the flame will burn hotter, appearing blue as a result. If the holes are closed, the gas will only mix with ambient air at the point of combustion, that is, only after it has exited the tube at the top. This reduced mixing produces an incomplete reaction, producing a cooler but brighter yellow flame which is often called the "safety flame". The yellow flame is luminous due to small soot particles in the flame which are heated to incandescence. When the burner is regulated to produce a hot, blue flame it can be nearly invisible against some backgrounds. Increasing the amount of fuel gas flow through the tube by opening the needle valve will of course increase the size of the flame. However, unless the airflow is adjusted as well, the flame temperature will decrease because an increased amount of gas is now mixed with the same amount of air, starving the flame of oxygen.