Uses of needle valve in Bunsen burner?
The needle valve is used to control the amount of gas flowing to the burner. The air valve controls the amount of air.
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Answer . You should check if the gas works and that the air hole is closed then you light it .You will need to use a match to light it.If it doesn't light the rubber tubin…g might be blocked or the gas does not work.
CH4 is the gas used in a Bunsen burner.
you use them for heating things (added) mainly used fot heating solutions for chemistry
When the University of Heidelberg hired Robert Bunsen in 1852, the authorities promised to build him a new laboratory building. Heidelberg had just begun to install coal-gas …street lighting, so the new laboratory building was also supplied with illuminating gas. Illumination was one thing; a source of heat for chemical operations something quite different. Previous laboratory lamps left much to be desired regarding economy and simplicity, as well as the quality of the flame; for a burner lamp, it was desirable to maximize the temperature and minimize the luminosity. While his building was still under construction late in 1854, Bunsen suggested certain design principles to the university's talented mechanic, Peter Desaga, and asked him to construct a prototype. The Bunsen/Desaga design succeeded in generating a hot, sootless, non-luminous flame by mixing the gas with air in a controlled fashion before combustion. Desaga created slits for air at the bottom of the cylindrical burner, the flame igniting at the top. By the time the building opened early in 1855, Desaga had made fifty of the burners for Bunsen's students. Bunsen published a description two years later, and many of his colleagues soon adopted the design.. The device in use today safely burns a continuous stream of a flammable gas such as natural gas (which is principally methane) or a liquefied petroleum gas such as propane, butane, or a mixture of both.. 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. 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.. 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 which is often called the "safety flame"or "luminous flame". The yellow flame is luminous due to small soot particles in the flame which are heated to incandescence. The yellow flame is considered "dirty" because it leaves a layer of carbon on whatever it is heating. 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. The blue flame in a Bunsen burner is hotter than the red flame.. Many lab accidents are related to burn injuries or exposed flames, and as a result new students are trained carefully in the use of a Bunsen burner. In general, the user should make sure that hair and clothing are secure, and unlikely to fall into the flame. In addition, flammable chemicals should be kept away from the Bunsen burner, and someone should remain by the burner at all times to supervise it. The flexible rubber hose connecting the Bunsen burner to the gas nozzle on the lab bench should also be secure, with no evidnce of leaking, and people should be cautious about touching things which have been exposed to the often considerable heat of a Bunsen burner, especially glass objects.
The use of the Bunsen burner in a laboratory varies. It is mainlyused for causing combustion, heating items, and sterilizing items.
to burn liquids and solids
See the link below.
setting things on fire
The needle valve or flow valve controls the flow of gas into the Bunsen Burner.
Matches or lighter
Usually natural gas, which is primarily Methane (CH4)
the bunsun burner is used for heatin it just has other uses also
It is used to heat / burn objects.
The Bunsen burner is an instrument, with flame, used for heating in laboratories. .
"Turning on" generally refers to opening the gas supply valve. The valves in most laboratories are quarter-turn ball valves with hand levers resembling those on water faucets.… That being the case, the valve handle would be used. If you are using "turning on" to mean lighting the burner, there are many options. The burner could be lit by nearly any ignition source with an open flame such as matches, candles, burning wood splints, cigarette lighter, barbecue pit lighter, etc. The most popular tool, though, is the striker. The striker has a cup to collect the gas and improve ignition.