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Multiple Hearth Furnace
A sketch of a Herreshoff multiple-hearth furnace, 400x400px A multiple hearth furnace also known as a vertical calciner, is used for continuous preparation and calcining of materials. Working The multiple hearth furnaces consist of several circular hearths or kilns superimposed on each other. Material is fed from the top and is moved by the action of rotating "rabble arms", and the revolving mechanical rabbles attached to the arms move over the surface of each hearth to continuously shift the ore. The arms are attached to a rotating central shaft that passes through the center of the roaster. As the material is moved, the ore that is charged at the top hearth gradually moves downward as it passes through windows in the floor of each hearth or through alternate passages around the shaft and the periphery until it finally emerges at the bottom. Gas The oxidizing gases flow upward, i.e., counter-current to the descending charge. In a well-insulated roaster, external heating is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herreshoff Multiple-hearth Furnace (scheme)
Herreshoff may refer to: * Herreshoff (surname), a German surname * Herreshoff (automobile), any of three models of automobile built by the U.S. manufacturer Herreshoff Motor Company, 1909–14 * ''Herreshoff Bull's Eye'' * Herreshoff Castle, an unusual residence in Marblehead, Massachusetts * Herreshoff family * Herreshoff Marine Museum * USS Herreshoff No. 306 (SP-1841), USS ''Herreshoff'' No. 306 (SP-1841) * USS Herreshoff No. 308 (SP-2232), USS ''Herreshoff'' No. 308 (SP-2232) * USS Herreshoff No. 309 (SP-1218), USS ''Herreshoff'' No. 309 (SP-1218) * USS Herreshoff No. 321 (SP-2235), USS ''Herreshoff'' No. 321 (SP-2235) * USS Herreshoff No. 322 (SP-2373), USS ''Herreshoff'' No. 322 (SP-2373) * USS Herreshoff No. 323 (SP-2840), USS ''Herreshoff'' No. 323 (SP-2840) * Herreshoff 31, ''Herreshoff'' 31 * Herreshoff 12½, ''Herreshoff'' 12½ {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcining
Calcination refers to thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), generally for the purpose of removing impurities or volatile substances and/or to incur thermal decomposition. The root of the word calcination refers to its most prominent use, which is to remove carbon from limestone (calcium carbonate) through combustion to yield calcium oxide (quicklime). This calcination reaction is CaCO3(s) → CaO(s) + CO2(g). Calcium oxide is a crucial ingredient in modern cement, and is also used as a chemical flux in smelting. Industrial calcination generally emits carbon dioxide (), making it a major contributor to climate change. A calciner is a steel cylinder that rotates inside a heated furnace and performs indirect high-temperature processing (550–1150 °C, or 1000–2100 °F) within a controlled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilns
A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Kilns have been used for millennia to turn objects made from clay into pottery, tiles and bricks. Various industries use rotary kilns for pyroprocessing—to calcinate ores, to calcinate limestone to lime for cement, and to transform many other materials. Pronunciation and etymology According to the Oxford English Dictionary, kiln was derived from the words cyline, cylene, cyln(e) in Old English, in turn derived from Latin ''culina'' ("kitchen"). In Middle English the word is attested as kulne, kyllne, kilne, kiln, kylle, kyll, kil, kill, keele, kiele. For over 600 years, the final "n" in kiln was silent. It wasn't until the late 20th century where the "n" began to be pronounced. This is due to a phenomenon known as spelling pronunciation, where the pronunciation of a word is surmised from its spelling an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignition
Ignition may refer to: Science and technology * Firelighting, the human act of creating a fire for warmth, cooking and other uses * Combustion, an exothermic chemical reaction between a fuel and an oxidant * Fusion ignition, the point at which a nuclear fusion reaction becomes self-sustaining * Ignition SCADA, software by Inductive Automation Arts and entertainment * ''Ignition'' (video game), a top-down racing game for PC published in 1997 * ''Ignition'' (2001 film), directed by Yves Simoneau * Ignition Entertainment, a computer video games company founded in 2002 * '' Ignition! An Informal History of Liquid Rocket Propellants'', (1972) by John Drury Clark Music Albums and EPs * ''Ignition'' (B1A4 album), 2012 * ''Ignition'' (Darude album), 2001 * ''Ignition'' (John Waite album), 1982 * ''Ignition'' (Mark Boals album), 1998 * ''Ignition'' (Nicky Romero album), 2014 * ''Ignition'' (The Offspring album), 1992 * ''Ignition'' (The Music Machine album) * ''Ignition!'', album ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of carbon, other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind. The reducing agent is commonly a fossil fuel source of carbon, such as coke—or, in earlier times, charcoal. The oxygen in the ore binds to carbon at high temperatures due to the lower potential energy of the bonds in carbon dioxide (). Smelting most prominently takes place in a blast furnace to produce pig iron, which is converted into steel. The carbon source acts as a chemical reactant to remove oxygen from the ore, yielding the purified metal element as a product. The carbon source is oxidized in two stages. First, the carbon (C) combusts with oxygen (O2) in the air to produce carbon monoxide (CO). Second, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
