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.Hot blast also allowed higher furnace temperatures, which increased the capacity of furnaces.
As first developed, it worked by alternately storing heat from the furnace flue gas in a firebrick-lined vessel with multiple chambers, then blowing combustion air through the hot chamber. This is known as regenerative heating. Hot blast was invented and patented for iron furnaces by James Beaumont Neilson in 1828 at Wilsontown Ironworks [ citation needed ] in Scotland, but was later applied in other contexts, including late bloomeries. Later the carbon monoxide in the flue gas was burned to provide additional heat.
James Beaumont Neilson, previously foreman at Glasgow gas works, invented the system of preheating the blast for a furnace. He found that by increasing the temperature of the incoming air to 300 degrees Fahrenheit, he could reduce the fuel consumption from 8.06 tons of coal to 5.16 tons of coal per ton of produced iron with further reductions at even higher temperatures.He, with partners including Charles Macintosh, patented this in 1828. Initially the heating vessel was made of wrought iron plates, but these oxidized, and he substituted a cast iron vessel.
On the basis of a January 1828 patent, Thomas Botfield has a historical claim as the inventor of the hot blast method. Neilson is credited as inventor of hot blast, because he won patent litigation.Neilson and his partners engaged in substantial litigation to enforce the patent against infringers. The spread of this technology across Britain was relatively slow. By 1840, 58 ironmasters had taken out licenses, yielding a royalty income of £30,000 per year. By the time the patent expired there were 80 licenses. In 1843, just after it expired, 42 of the 80 furnaces in south Staffordshire were using hot blast, and uptake in south Wales was even slower.
Other advantages of hot blast were that raw coal could be used instead of coke. In Scotland, the relatively poor "black band" ironstone could be profitably smelted.It also increased the daily output of furnaces. In the case of Calder ironworks from 5.6 tons per day in 1828 to 8.2 in 1833, which made Scotland the lowest cost steel producing region in Britain in the 1830s.
Early hot blast stoves were troublesome, as thermal expansion and contraction could cause breakage of pipes. This was somewhat remedied by supporting the pipes on rollers. It was also necessary to devise new methods of connecting the blast pipes to the tuyeres, as leather could not longer be used.
Ultimately this principle was applied even more efficiently in regenerative heat exchangers, such as the Cowper stove (which preheat incoming blast air with waste heat from flue gas; these are used in modern blast furnaces), and in the open hearth furnace (for making steel) by the Siemens-Martin process.
Independently, George Crane and David Thomas, of the Yniscedwyn Works in Wales, conceived of the same idea, and Crane filed for a British patent in 1836. They began producing iron by the new process on February 5, 1837. Crane subsequently bought Gessenhainer's patent and patented additions to it, controlling the use of the process in both Britain and the US. While Crane remained in Wales, Thomas moved to the US on behalf of the Lehigh Coal & Navigation Company and founded the Lehigh Crane Iron Company to utilize the process.
Hot blast allowed the use of anthracite in iron smelting. It also allowed use of lower quality coal because less fuel meant proportionately less sulfur and ash.
At the time the process was invented, good coking coal was only available in sufficient quantities in Great Britain and western Germany,so iron furnaces in the US were using charcoal. This meant that any given iron furnace required vast tracts of forested land for charcoal production, and generally went out of blast when the nearby woods had been felled. Attempts to use anthracite as a fuel had ended in failure, as the coal resisted ignition under cold blast conditions. In 1831, Dr. Frederick W. Gessenhainer filed for a US patent on the use of hot blast and anthracite to smelt iron. He produced a small quantity of anthracite iron by this method at Valley Furnace near Pottsville, Pennsylvania in 1836, but due to breakdowns and his illness and death in 1838, he was not able to develop the process into large-scale production.
Anthracite was displaced by coke in the US after the Civil War. Coke was more porous and able to support the heavier loads in the vastly larger furnaces of the late 19th century. 90 :139:
Coke is a grey, hard, and porous fuel with a high carbon content and few impurities, made by heating coal or oil in the absence of air—a destructive distillation process. It is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges when air pollution is a concern.
Anthracite, also known as hard coal, is a hard, compact variety of coal that has a submetallic luster. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.
Steelmaking is the process of producing steel from iron ore and/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon are removed from the sourced iron, and alloying elements such as manganese, nickel, chromium, carbon and vanadium are added to produce different grades of steel. Limiting dissolved gases such as nitrogen and oxygen and entrained impurities in the steel is also important to ensure the quality of the products cast from the liquid steel.
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 "forced" or supplied above atmospheric pressure.
David Thomas was a native of Wales who was influential in the birth of the Industrial Revolution in the United States.
Anthracite iron or Anthracite 'Pig Iron' is the substance created by the smelting together of anthracite coal and iron ore, that is using Anthracite coal instead of charcoal to smelt iron ores — and was an important historic advance in the late-1830s enabling great acceleration the industrial revolution in Europe and North America.
A reverberatory furnace is a metallurgical or process furnace that isolates the material being processed from contact with the fuel, but not from contact with combustion gases. The term reverberation is used here in a generic sense of rebounding or reflecting, not in the acoustic sense of echoing.
James Beaumont Neilson was a Scottish inventor whose hot-blast process greatly increased the efficiency of smelting iron.
Abraham Darby, in his later life called Abraham Darby the Elder, now sometimes known for convenience as Abraham Darby I, was the first and best known of several men of that name. Born into an English Quaker family that played an important role in the Industrial Revolution, Darby developed a method of producing pig iron in a blast furnace fuelled by coke rather than charcoal. This was a major step forward in the production of iron as a raw material for the Industrial Revolution.
An air preheater is any device designed to heat air before another process (for example, combustion in a boiler With the primary objective of increasing the thermal efficiency of the process. They may be used alone or to replace a recuperative heat system or to replace a steam coil.
Puddling is a step in the manufacture of high-grade iron in a crucible or furnace. It was invented in Great Britain during the Industrial Revolution. The molten pig iron was stirred in a reverberatory furnace, in an oxidizing environment, resulting in wrought iron. It was one of the most important processes of making the first appreciable volumes of valuable and useful bar iron without the use of charcoal. Eventually, the furnace would be used to make small quantities of specialty steels.
The Lehigh Crane Iron Company was a major ironmaking firm in the Lehigh Valley from its founding in 1839 until its sale in 1899. It was founded under the patronage of Josiah White and Erskine Hazard, and financed by their Lehigh Coal & Navigation Company, which hoped to promote the then-novel technique of smelting iron ore with anthracite coal. This was an important cost and energy savings technique, since either an expensive charcoaling nor coke producing process and transport costs was totally eliminated so produced a great acceleration in the underpinnings of the American industrial revolution.
Seend Ironstone Quarry and Road Cutting is a 3 acres (1.2 ha) Geological Site of Special Scientific Interest at Seend in Wiltshire, England, notified in 1965. The site contains facies of Lower Greensand containing specimens of fauna not found elsewhere.
Ferrous metallurgy, the metallurgy of iron and its alloys, began in prehistory. The earliest surviving iron artifacts, from the 4th millennium BC in Egypt, were made from meteoritic iron-nickel. It is not known when or where the smelting of iron from ores began, but by the end of the 2nd millennium BC iron was being produced from iron ores from at least Greece to India, and in Sub-Saharan Africa. The use of wrought iron was known by the 1st millennium BC, and its spread defined the Iron Age. During the medieval period, smiths in Europe found a way of producing wrought iron from cast iron using finery forges. All these processes required charcoal as fuel.
Cold blast, in ironmaking, refers to a furnace where air is not preheated before being blown into the furnace. This represents the earliest stage in the development of ironmaking. Until the 1820s, the use of cold air was thought to be preferable to hot air for the production of high-quality iron; this effect was due to the reduced moisture in cool winter air.
Charcoal iron is the substance created by the smelting of iron ore with charcoal.
Neilson v Harford (1841) 151 ER 1266 is a 19th-century English patent law decision that several United States Supreme Court patent law opinions rely upon as authority. The question, as Baron Alderson posed it, was “[W]here is the difference between claiming a principle, which is to be carried into effect any way you will, and claiming a mere principle?” The answer, as the opinions of the various courts that have considered the matter develop, is nowhere.
There are two types of coal found in Pennsylvania: anthracite and bituminous. Anthracite coal is a natural mineral with a high carbon and energy content that gives off light and heat when burned, making it useful as a fuel. It was possibly first used in Pennsylvania as a fuel in 1769, but its real history begins with a documented discovery near Summit Hill and the founding of the Lehigh Coal Mine Company in 1792 to sporadically send expeditions to the wilderness atop Pisgah Ridge to mine the deposits, mostly with notable lack of great success, over the next 22 years. The owners of this company were absentee management—reliant on teams of workers sent under a foreman to fell timber to build so called 'Arks', then mine coal around nine miles from the right bank Lehigh, then trek with mule loads to fill the boats for the trip down the rapid strewn Lehigh River, and then more than 60 miles (97 km) to Philadelphia docks on the unimproved often log choked Delaware River.
The US iron and steel industry has paralleled the industry in other countries in technological developments. In the 1800s, the US switched from charcoal to coke in ore smelting, adopted the Bessemer process, and saw the rise of very large integrated steel mills. In the 20th century, the US industry successively adopted the open hearth furnace, then the basic oxygen steelmaking process. Since the American industry peaked in the 1940s and 1950s, the US industry has shifted to small mini-mills and specialty mills, using iron and steel scrap as feedstock, rather than iron ore.
Metallurgical coal or coking coal is a grade of coal that can be used to produce good-quality coke. Coke is an essential fuel and reactant in the blast furnace process for primary steelmaking. The demand for metallurgical coal is highly coupled to the demand for steel. Primary steelmaking companies often have a division that produces coal for coking, to ensure a stable and low-cost supply.
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