A tuyere or tuyère (; ) is a tube,

nozzle A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe. A nozzle is often a pipe or tube of varying cross sectional area, a ...

or pipe through which air is blown into a furnace or hearth.W. K. V. Gale, The iron and Steel industry: a dictionary of terms (David and Charles, Newton Abbot 1972), 216–217. Air or

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...

is injected into a hearth under pressure from bellows or a blowing engine or other devices. This causes the fire to be hotter in front of the blast than it would otherwise have been, enabling metals to be smelted or melted or made hot enough to be worked in a forge, though these are blown only with air. This applies to any process where a blast is delivered under pressure to make a fire hotter. The term (like many technical terms relating to ironmaking) was introduced to England from

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

with the new technology of the blast furnace and finery forge in around 1500, and was sometimes anglicised as tue-iron or tue iron. Following the introduction of

hot blast Hot blast refers to the preheating of air blown into a blast furnace or other metallurgical process. As this considerably reduced the fuel consumed, hot blast was one of the most important technologies developed during the Industrial Revolution ...

, tuyeres are often water-cooled.

Examples

* A bloomery normally had one tuyere. * Early blast furnaces also had one tuyere, but were fed from bellows perhaps 12 feet (3.7m) long operated by a waterwheel. During the

Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...

, the blast began to be provided using

steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...

s, initially Watt engines working blowing cylinders. Improvements in foundry practice enabled gas-tight

cast iron Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impu ...

pipes to be produced, enabling one engine to deliver blast to several sides of a furnace, through multiple tuyeres. * A finery forge contained finery and chafery hearths, usually one of the latter and one to three of the former. Each hearth was equipped with its own set of bellows, blowing into it through a tuyere. * The blacksmith's hearth at their forge has a tuyere, often blown by foot-operated bellows. * Tuyeres were also used in smelting

lead Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate ...

and

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish ...

in smeltmills. * Modern blast furnaces may have up to 42 tuyeres, through which the

is injected in the furnace. They are usually made from copper and cooled with a water jacket to withstand the extreme temperatures.

References

{{wiktionary Steelmaking Industrial furnaces