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Bellows

A bellows is a device for delivering pressurized air in a controlled quantity to a controlled location. Basically, a bellows is a deformable container which has an outlet nozzle. When the volume of the bellows is decreased, the air escapes through the outlet. A bellows typically also has a separate inlet and valves or flaps for ensuring that air enters only through the inlet and exits only through the outlet.

Metallurgy

Several metallurgical processes, such as iron smelting and welding, require so much heat that they could only be developed after the invention of the bellows. The bellows are used to deliver additional air to the fuel, raising the rate of combustion and therefore the heat output.

Various kinds of bellows are used in metallurgy:

• Box bellows were and are traditionally used in Asia. (1)
• Pot bellows were used in ancient Egypt. (2)
• Accordion bellows, with the characteristic pleated sides, have been used in Europe for many centuries. (3)
• Piston bellows were developed in the middle of the 18th century. (4)

The ancient Chinese engineer Du Shi once applied water-power (waterwheel) to operate bellows of a blast furnace forging cast iron. The ancient Greeks, ancient Romans, and other civilizations used bellows in bloomery furnaces producing wrought iron.

In modern industry, reciprocating bellows are usually replaced with motorized blowers.

Musical instruments

In musical instruments, the bellows is often employed as a substitute or regulator for air pressure provided by the human lungs.

The following instruments use bellows:

• Reed organ
• Bagpipe
• Harmonium
• Portative

Cuckoo clocks also use bellows.

References

1. http://www.anvilfire.com/FAQs/archives/g072002d.htm .
2. http://www.archaeogate.org/egittologia/article/182/8/mersa-gawasis-red-sea-egypt-unoisiao-and-bu-2003-2004-f.html .
3. [ref. needed]
4. http://www.davistownmuseum.org/TDMtoolGlossary.htm

See also

• sylphon for uses of metal bellows in experimental physics and engineering.

External links

• http://www.wwmag.net/blacksmith.htm for bellows used in primitive blacksmithing.
• http://www.1911encyclopedia.org/Bellows for a general discussion of bellows in metal work.

Contents

• Metallurgy
• Musical instruments
• References
• See also
• External links