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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 i ... [...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 is 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 (). 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 atmosphere. Etymology The process of calcination der ... [...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, such as limestone to lime for cement) and to transform many other materials. 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. In Greek the word ''καίειν, kaiein'', means 'to burn'. Pronunciation The word 'kiln' was originally pronounced 'kil' with the 'n' silent, as is referenced in ''Webster's Dictionary of 1828'' and in ''English Words as Spoken and Written for Upper Grades'' by James A. Bowe ... [...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 * ''Ignition! An Informal History of Liquid Rocket Propellants'', a book by John Drury Clark 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' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants 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. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: * Electron-transfer – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. 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 oxidati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength and low raw material cost, steel is one of the most commonly manufactured materials in the world. Steel is used in structures (as concrete Rebar, reinforcing rods), in Bridge, bridges, infrastructure, Tool, tools, Ship, ships, Train, trains, Car, cars, Bicycle, bicycles, Machine, machines, Home appliance, electrical appliances, furniture, and Weapon, weapons. Iron is always the main element in steel, but other elements are used to produce various grades of steel demonstrating altered material, mechanical, and microstructural properties. Stainless steels, for example, typically contain 18% chromium and exhibit improved corrosion and Redox, oxidation resistance versus its carbon steel counterpart. Under atmospheric pressures, steels generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
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. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil-fuel source of carbon, such as carbon monoxide from incomplete combustion of coke—or, in earlier times, of charcoal. The oxygen in the ore binds to carbon at high temperatures, as the chemical potential energy of the bonds in carbon dioxide () is lower than that of the bonds in the ore. Sulfide ores such as those commonly used to obtain copper, zinc or lead, are roasted before smelting in order to convert the sulfides to oxides, which are more readily reduced to the metal. Roasting heats the ore in the presence of oxygen from air, oxidizing the ore and libe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
