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Diagram of a fireplace hand-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 airtight cavity which can be expanded and contracted by operating the handles, and fitted with a valve allowing air to ...
Blast furnaces used in the ISP have a more intense operation than standard lead blast furnaces, with higher air blast rates per m 2 of hearth area and a higher coke consumption. [ 79 ] Zinc production with the ISP is more expensive than with electrolytic zinc plants, so several smelters operating this technology have closed in recent years. [ 80 ]
A tuyere, seen from inside a blast furnace An old tuyere in Nok, Nigeria. A tuyere or tuyère (French pronunciation:; English: / t w iː ˈ j ɛər /) [1] [2] is a tube, nozzle or pipe allowing the blowing of air into a furnace or hearth. [3] Air or oxygen is injected into a hearth under pressure from bellows or a blowing engine or other devices.
Blast furnace gas (BFG) [1] is a by-product of blast furnaces that is generated when the iron ore is reduced with coke to metallic iron. It has a very low heating value , about 3.5 MJ/m 3 (93 BTU /cu.ft), [ 2 ] because it consists of about 51 vol% nitrogen and 22 vol% carbon dioxide , which are not flammable.
The Chinese are thought to have skipped the bloomery process completely, starting with the blast furnace and the finery forge to produce wrought iron; by the fifth century BC, metalworkers in the southern state of Wu had invented the blast furnace and the means to both cast iron and to decarburize the carbon-rich pig iron produced in a blast ...
A metallurgical furnace, often simply referred to as a furnace when the context is known, is an industrial furnace used to heat, melt, or otherwise process metals. Furnaces have been a central piece of equipment throughout the history of metallurgy ; processing metals with heat is even its own engineering specialty known as pyrometallurgy .
For blast furnaces, direct reduction corresponds to the reduction of oxides by the carbon in the coke. However, in practice, direct reduction only plays a significant role in the final stage of iron reduction in a blast furnace, by helping to reduce wustite (FeO) to iron. In this case, the chemical reaction can be trivially described as follows ...
This used a blast furnace to make pig iron, which then had to undergo a further process to make forgeable bar iron. Processes for the second stage include fining in a finery forge. In the 13th century during the High Middle Ages the blast furnace was introduced by China who had been using it since as early as 200 b.c during the Qin dynasty.