A tuyere or tuyère (; ) is a

tube Tube or tubes may refer to: * ''Tube'' (2003 film), a 2003 Korean film * "Tubes" (Peter Dale), performer on the Soccer AM television show * Tube (band), a Japanese rock band * Tube & Berger, the alias of dance/electronica producers Arndt Rör ...

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 (material), pipe. A nozzle is often a pipe or tube of varying cross ...

pipe Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circular ...

allowing the blowing of

air An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

into a furnace or

hearth A hearth () is the place in a home where a fire is or was traditionally kept for home heating and for cooking, usually constituted by a horizontal hearthstone and often enclosed to varying degrees by any combination of reredos (a low, partial ...

.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 a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

is injected into a hearth under pressure from

bellows A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtig ...

or a

blowing engine A blowing engine is a large stationary steam engine or internal combustion engine directly coupled to air pumping cylinders. They deliver a very large quantity of air at a pressure lower than an air compressor, but greater than a centrifugal f ...

or other devices. This causes the fire to become hotter in front of the blast than it would otherwise have been, enabling metals to be

smelted Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron, copper, silver, tin, lead and zinc. Sm ...

or melted or made hot enough to be worked in a

forge A forge is a type of hearth used for heating metals, or the workplace (smithy) where such a hearth is located. The forge is used by the smith to heat a piece of metal to a temperature at which it becomes easier to shape by forging, or to the ...

, though these are blown only with air. This applies to any process where a blast is delivered under pressure to make a fire hotter. Archeologists have discovered tuyeres dating from the

Iron Age The Iron Age () is the final epoch of the three historical Metal Ages, after the Chalcolithic and Bronze Age. It has also been considered as the final age of the three-age division starting with prehistory (before recorded history) and progre ...

; one example dates from between 770 BCE and 515 BCE. Following the introduction of

hot blast Hot blast is the preheated air blown into a blast furnace or other metallurgical process. This technology, which considerably reduces the fuel consumed, was one of the most important technologies developed during the Industrial Revolution. Hot b ...

, tuyeres are often water-cooled. Around the year 1500 new ironmaking techniques, including the

blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being supplied above atmospheric pressure. In a ...

and

finery forge A finery forge is a forge used to produce wrought iron from pig iron by decarburization in a process called "fining" which involved liquifying cast iron in a fining hearth and decarburization, removing carbon from the molten cast iron through Redo ...

, were introduced into England from France, along with the French technical terms relating to the new technology. "Tuyere" () is one of these French words, sometimes Anglicised as tue-iron or tue iron.

Examples

* A

bloomery A bloomery is a type of metallurgical furnace once used widely for smelting iron from its iron oxides, oxides. The bloomery was the earliest form of smelter capable of smelting iron. Bloomeries produce a porous mass of iron and slag called ...

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, sometimes divided into the First Industrial Revolution and Second Industrial Revolution, was a transitional period of the global economy toward more widespread, efficient and stable manufacturing processes, succee ...

, the blast began to be provided using

steam engine A steam engine is a heat engine that performs Work (physics), 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 (locomotive), cyl ...

s, initially

Watt engine The Watt steam engine design was an invention of James Watt that became synonymous with steam engines during the Industrial Revolution, and it was many years before significantly new designs began to replace the basic Watt design. The first s ...

s 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 of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its car ...

pipes to be produced, enabling one engine to deliver blast to several sides of a furnace, through multiple tuyeres. * A

contained finery and

chafery A chafery is a variety of hearth used in ironmaking for reheating a bloom of iron, in the course of its being drawn out into a bar of wrought iron. The equivalent term for a bloomery was string hearth, except in 17th century Cumbria, where the ...

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 A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from #Other metals, other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such ...

'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; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

and

copper Copper is a chemical element; it has symbol Cu (from Latin ) 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-orang ...

smeltmill Smeltmills were water-powered water mill, mills used to smelting, smelt lead or other metals. The older method of smelting lead on wind-blown bole hills began to be superseded by artificially-blown smelters. The first such furnace was built by Bu ...

s. * As of 2009 the world's largest blast furnace in Caofeidan, China operated by Shougang Jing Tang United Iron and Steel Ltd had 42 tuyeres, through which the

is injected in the furnace. They are usually made from copper and cooled with a

water jacket A water jacket is a water-filled casing surrounding a device, typically a metal sheath having intake and outlet vents to allow water to be pumped through and circulated. The flow of water to an external heating or cooling device allows precise ...

to withstand the extreme temperatures.

References

{{wiktionary Steelmaking Industrial furnaces