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| | Title of the author is Gabrielle Lattimer. For years she's been working as a library assistant. For a while she's been in Massachusetts. As a woman what your woman really likes is mah jongg but she have not made a dime with it. She is running and maintaining a blog here: http://prometeu.net<br><br>My blog post: [http://prometeu.net clash of clans hack android apk] |
| {{Redirect|Smokestack|the 1963 avant-garde jazz album|Smokestack (album)}}
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| {{Refimprove|date=March 2013}}
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| [[Image:GRES-2.jpg|thumb|150px|The world's tallest chimney, of [[Ekibastuz GRES-2 Power Station|GRES-2]] in [[Ekibastuz]], [[Kazakhstan]] (419.7 metres).]]
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| [[File:Natural Chimneys - House Chimney 2.jpg|thumb|150px|A chimney remaining after the destruction of a 19th-century two-story house ([[Mount Solon, Virginia]]).]]
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| A '''chimney''' is a structure which provides ventilation for hot [[flue gas]]es or [[smoke]] from a [[boiler]], [[stove]], [[furnace]] or [[fireplace]] to the outside [[Earth's atmosphere|atmosphere]]. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the [[combustion]] in what is known as the [[stack effect|stack, or chimney, effect]]. The space inside a chimney is called a ''[[flue]]''. Chimneys may be found in buildings, steam locomotives and ships. In the United States, the term '''''smokestack''''' (colloquially, '''''stack''''') is also used when referring to [[Chimney (locomotive)|locomotive chimneys]] or [[Funnel (ship)|ship chimneys]], and the term '''''funnel''''' can also be used.<ref>[http://angeles.sierraclub.org/hps/signatures/24h.htm C.F. Saunders (1923), ''The Southern Sierras of California'']</ref><ref>[http://www.literature.org/authors/verne-jules/eighty/chapter-26.html Jules Verne (1872), ''Around the World in Eighty Days'']</ref>
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| The height of a chimney influences its ability to transfer flue gases to the external environment via stack effect. Additionally, the dispersion of pollutants at higher altitudes can reduce their impact on the immediate surroundings. In the case of chemically aggressive output, a sufficiently tall chimney can allow for partial or complete self-neutralization of airborne chemicals before they reach ground level. The dispersion of pollutants over a greater area can reduce their concentrations and facilitate compliance with regulatory limits.
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| ==History==
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| [[Image:Chimney stacks - Newcastle-Upon-Tyne - England - 140804.jpg|thumbnail|right|Chimney stacks on a building in [[Newcastle upon Tyne]], England]]
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| [[Image:chimney.stack.london.arp.jpg|thumb|right|Chimney pots in London, England, seen from the tower of [[Westminster Cathedral|Westminster]] Roman Catholic cathedral]]
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| [[Image:Seagul sits on top of the chimney cone at The World of Glass.jpg|thumb|right|Seagull sits on top of a hot gas cooling chimney at The World of Glass [[St Helens, Merseyside|St. Helens]] UK.]]
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| [[Ancient Rome|Romans]] used tubes inside the walls to draw smoke out of bakeries but chimneys only appeared in large dwellings in northern Europe in the 12th century. The earliest extant example of an English chimney is at the keep of [[Conisbrough Castle]] in [[Yorkshire]], which dates from 1185 AD.<ref>[[James Burke (science historian)|James Burke]], ''Connections'' (Little, Brown and Co.) 1978/1995, ISBN 0-316-11672-6, p. 159</ref> They did not become common in houses until the 16th and 17th centuries.<ref>Sparrow, Walter Shaw. ''The English house: how to judge its periods and styles''. London: Eveleigh Nash, 1908. 85-86.</ref> Another step in the development of chimneys was the use of built in ovens which allowed the household to bake at home. Industrial chimneys became common in the late 18th century.
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| Chimneys in ordinary dwellings were first built of wood and plaster or mud. Since then chimneys have traditionally been built of brick or stone, both in small and large buildings. Early chimneys were of a simple brick construction. Later chimneys were constructed by placing the bricks around tile liners, a system invented by Malik. To control downdrafts, venting caps (often called ''chimney pots'') with a variety of designs are sometimes placed on the top of chimneys.
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| In the 18th and 19th centuries, the methods used to extract [[lead]] from its ore produced large amounts of toxic fumes. In the north of England, long near-horizontal chimneys were built, often more than 3 km (2 mi) long, which typically terminated in a short vertical chimney in a remote location where the fumes would cause less harm. Lead and silver deposits formed on the inside of these long chimneys, and periodically workers would be sent along the chimneys to scrape off these valuable deposits.<ref>{{cite web|title=Lead Mining|url=http://www.thenorthernecho.co.uk/history/mining/lead/|work=The Northern Echo|publisher=Newsquest Media Group|accessdate=4/10/2012}}</ref>
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| ==Construction==
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| [[File:Seven-flue Stack 1834 .png|thumb|upright|left|A section of a large late Georgian four storey house, showing the advantage of using a mechanical sweeper over climbing boys]]
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| As a result of the limited ability to handle transverse loads with brick, chimneys in houses were often built in a "stack", with a fireplace on each floor of the house sharing a single chimney, often with such a stack at the front and back of the house. Today's [[central heating]] systems have made chimney placement less critical, and the use of non-structural gas vent pipe allows a flue gas conduit to be installed around obstructions and through walls. | |
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| In fact, most modern high-efficiency heating appliances do not require a chimney. Such appliances are generally installed near an external wall, and a noncombustible wall thimble allows a [[vent pipe]] run directly through the external wall.
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| On a pitched roof where a chimney penetrates a roof, [[Flashing (weatherproofing)|flashing]] is used to seal the joints. The down-slope piece is called an apron, the sides receive step flashing and a [[Cricket (roofing)|cricket]] is used to divert water around the upper side of the chimney underneath the flashing.<ref>Roofing, flashing & waterproofing. Newtown, CT: Taunton Press, 2005. 43-50.</ref>
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| [[Image:Thornbury.chimney.detail.arp.750pix.jpg|thumb|left|Carved brick chimneys characteristic of late [[Gothic architecture|Gothic]] [[Tudor style architecture|Tudor]] buildings, at [[Thornbury, South Gloucestershire|Thornbury Castle]], 1514]]
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| [[Industrial chimney]]s are commonly referred to as [[flue gas stacks]] and are generally external structures, as opposed to those built into the wall of a building. They are generally located adjacent to a steam-generating boiler or industrial furnace and the gases are carried to them with ductwork. Today the use of reinforced [[concrete]] has almost entirely replaced brick as a [[structural]] component in the construction of industrial chimneys. [[Refractory]] bricks are often used as a lining, particularly if the type of fuel being burned generates flue gases containing acids. Modern industrial chimneys sometimes consist of a concrete [[windshield]] with a number of flues on the inside.
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| The 300 metre chimney at [[Sasol|Sasol Three]] consists of a 26 metre diameter windshield with four 4.6 metre diameter concrete flues which are lined with refractory bricks built on rings of [[corbel]]s spaced at 10 metre intervals. The reinforced concrete can be cast by conventional formwork or sliding formwork. The height is to ensure the pollutants are dispersed over a wider area to meet legal or other safety requirements.
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| ==Chimney pots, caps and tops==
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| [[File:Row_of_chimney_pots_on_English_rooftops.jpg|thumb|right|Rows of chimney pots in an English town. Photo by George Garrigues, 1974.]]
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| A chimney pot is placed on top of the chimney to expand the length of the chimney inexpensively, and to improve the chimney's draft. A chimney with more than one pot on it indicates that there is more than one fireplace on different floors sharing the chimney.
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| A chimney [[cowl (chimney)|cowl]] is placed on top of the chimney to prevent birds and squirrels from nesting in the chimney. They often feature a rain guard to prevent rain or snow from going down the chimney. A metal wire mesh is often used as a [[spark arrestor]] to minimize burning debris from rising out of the chimney and making it onto the roof. Although the masonry inside the chimney can absorb a large amount of moisture which later evaporates, rainwater can collect at the base of the chimney. Sometimes weep holes are placed at the bottom of the chimney to drain out collected water.
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| [[Image:Common wind chimney cap found on homes along the Oregon coast.JPG|thumb|left|Spanish Conquistador style wind directional [[Cowl (chimney)|cowl]] found on many homes along the windy [[Oregon]] coast.]]
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| A [[cowl (chimney)|chimney cowl]] or wind directional cap is a helmet shaped chimney cap that rotates to align with the wind and prevent a backdraft of smoke and wind back down the chimney.
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| An '''H-style cap''' (cowl) is a chimney top constructed from chimney pipes shaped like the letter H. It is an age old method to regulate draft in situations where prevailing winds or turbulences cause down draft and backpuffing. Although the '''H cap''' has a distinctive advantage over most other downdraft caps, it fell out of favor because of its bulky design. It is found mostly in marine use but has been regaining popularity due to its energy saving functionality. The '''H-cap''' stabilizes the draft rather than increasing it. Other down draft caps are based on the [[Venturi effect]], solving downdraft problems by increasing the up draft constantly resulting in much higher fuel consumption.
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| A chimney damper is a metal plate that can be positioned to close off the chimney when not in use and prevent outside air from entering the interior space, and can be opened to permit hot gases to exhaust when a fire is burning. A ''top damper'' or ''cap damper'' is a metal spring door placed at the top of the chimney with a long metal chain that allows one to open and close the damper from the fireplace. A ''throat damper'' is a metal plate at the base of the chimney, just above the firebox, that can be opened and closed by a lever, gear, or chain to seal off the fireplace from the chimney. The advantage of a top damper is the tight weather-proof seal that it provides when closed, which prevents cold outside air from flowing down the chimney and into the living space — a feature that can rarely be matched by the metal-on-metal seal afforded by a throat damper. Additionally, because the throat damper is subjected to intense heat from the fire directly below, it is common for the metal to become warped over time, thus further degrading the ability of the throat damper to seal. However, the advantage of a throat damper is that it seals off the living space from the air mass in the chimney, which, especially for chimneys positioned on an outside of wall of the home, is generally very cold. It is possible in practice to use both a top damper and a throat damper to obtain the benefits of both. The two top damper designs currently on the market are the Lyemance (pivoting door) and the Lock Top (translating door).
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| In the late [[Middle Ages]] in [[Western Europe]] the design of [[crow-step]]ped [[gable]]s arose to allow maintenance access to the chimney top, especially for tall structures such as [[castle]]s and great [[manor house]]s.
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| ==Chimney draught or draft==
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| [[Image:Chimney effect.svg|thumb|150px|The stack effect in chimneys: the gauges represent absolute air pressure and the airflow is indicated with light grey arrows. The gauge dials move clockwise with increasing pressure.]]
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| :(See the [[Flue gas stack]] article for more details)
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| When coal, oil, natural gas, wood or any other fuel is combusted in a stove, oven, fireplace, hot water boiler or industrial furnace, the hot combustion product gases that are formed are called flue gases. Those gases are generally exhausted to the ambient outside air through chimneys or industrial flue gas stacks (sometimes referred to as smokestacks).
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| The combustion flue gases inside the chimneys or stacks are much hotter than the ambient outside air and therefore less [[density|dense]] than the ambient air. That causes the bottom of the vertical column of hot flue gas to have a lower [[pressure]] than the pressure at the bottom of a corresponding column of outside air. That higher pressure outside the chimney is the driving force that moves the required combustion air into the combustion zone and also moves the flue gas up and out of the chimney. That movement or flow of combustion air and flue gas is called "natural draught/draft", [[HVAC#Natural ventilation|"natural ventilation"]], "chimney effect", or [[Stack effect|"stack effect"]]. The taller the stack, the more draught or draft is created. There can be cases of diminishing returns: if a stack is overly tall in relation to the heat being sent out of the stack, the flue gases may cool before reaching the top of the chimney. This condition can result in poor drafting, and in the case of wood burning appliances, the cooling of the gases before emission can cause [[creosote]] to condense near the top of the chimney. The creosote can restrict the exit of flue gases and may pose a fire hazard.
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| Designing chimneys and stacks to provide the correct amount of natural draught or draft involves a number design factors, many of which require iterative trial-and-error methods.
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| As a "first guess" approximation, the following equation can be used to estimate the natural draught/draft flow rate by assuming that the [[molecular mass]] (i.e., molecular weight) of the flue gas and the external air are equal and that the frictional pressure and heat losses are negligible:
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| :<math>Q = C\; A\; \sqrt {2\;g\;H\;\frac{T_i - T_e}{T_e}}</math>
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| {| border="0" cellpadding="2"
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| |-
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| |align=right|where:
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| !align=right| ''Q''
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| |align=left|= chimney draught/draft flow rate, m³/min
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| |-
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| !align=right| ''A''
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| |align=left|= cross-sectional area of chimney, m² (assuming it has a constant cross-section)
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| |-
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| !align=right| ''C''
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| |align=left|= discharge coefficient (usually taken to be from 0.65 to 0.70)
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| |-
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| !align=right| ''g''
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| |align=left|= [[standard gravity|gravitational acceleration]], 9.807 m/s²
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| |-
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| !align=right| ''H''
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| |align=left|= height of chimney, m
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| |-
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| !align=right| ''T<sub>i</sub>''
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| |align=left|= average temperature inside the chimney, [[kelvin|K]]
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| |-
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| !align=right| ''T<sub>e</sub>''
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| |align=left|= external air temperature, K.
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| |}
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| Combining two flows into chimney: ''A''<sub>t</sub>+''A''<sub>f</sub><''A'',
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| where ''A''<sub>t</sub>=7.1 inch<sup>2</sup> is the minimum required flow area from water heater tank and ''A''<sub>f</sub>=19.6 inch<sup>2</sup> is the minimum flow area from a furnace of a central heating system.
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| ==Maintenance and problems==
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| [[File:New Zealand Parliamentary Library Chimneys.JPG|thumb|150px|right|Chimneys on the Parliamentary Library in [[Wellington]], [[New Zealand]].]]
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| A characteristic problem of chimneys is they develop deposits of [[creosote]] on the walls of the structure when used with wood as a [[fuel]]. Deposits of this substance can interfere with the airflow and more importantly, they are [[flammable]] and can cause dangerous [[chimney fire]]s if the deposits ignite in the chimney.
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| Chimneys that burn natural gas drastically reduce the amount of creosote buildup due to natural gas burning much cleaner and more efficiently than traditional solid fuels. While in most cases there is no need to clean a gas chimney on an annual basis that does not mean that other parts of the chimney cannot fall into disrepair. Disconnected or loose chimney connections caused by rust and corrosion over time can pose serious dangers for residents due to leakage of carbon monoxide into the home.<ref>[http://www.charmedchimney.com/chimney-service-faqs.php Chimney Problems and Warnings Signs]</ref> Thus, it is recommended — and in some countries even mandatory — that chimneys be inspected annually and cleaned on a regular basis to prevent these problems. The workers who perform this task are called [[chimney sweep]]s. This work used to be done largely by [[child labour]], and [[Chimney_sweep#Literature|as such]] features in [[Victorian literature]]. In the [[Middle Ages]] in some parts of Europe, a [[crow-stepped gable]] design was developed, partly to provide access to chimneys without use of ladders.
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| [[File:Chernobylreactor 1.jpg|thumb|Iconic non-operational chimney of the [[Chernobyl disaster|Chernobyl reactor #4]], preserved as part of the [[Chernobyl Nuclear Power Plant sarcophagus|Chernobyl sarcophagus]].]]
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| Masonry (brick) chimneys have also proven to be particularly prone to crumbling during an [[earthquake]]. Government housing authorities in cities prone to earthquakes such as [[San Francisco]], [[Los Angeles, California|Los Angeles]], and [[San Diego, California|San Diego]] now recommend building new homes with stud-framed chimneys around a metal flue. Bracing or strapping old masonry chimneys has not proven to be very effective in preventing damage or injury from earthquakes. It is now possible to buy "faux-brick" facades to cover these modern chimney structures.
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| Liners have been standard in new construction for years, but are now lacking in many old structures whose masonry has not been restored and updated. Liners help keep flue gases where they belong. They isolate combustible building materials from high heat, and they prevent creosote and other by-products of combustion from seeping through porous brick and mortar.<ref>[http://www.oldhouseweb.com/how-to-advice/bringing-an-old-chimney-up-to-par.shtml Bringing an old chimney up to par]</ref>
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| Other potential problems include:
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| *"[[spall]]ing" brick, in which moisture seeps into the brick and then freezes, cracking and flaking the brick and loosening mortar seals.
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| *shifting foundations, which may degrade integrity of chimney masonry
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| *nesting or infestation by unwanted animals such as squirrels, racoons, or [[Chimney Swift]]s
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| *chimney leaks
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| *drafting issues, which may cause smoke inside building<ref>{{cite web|title=Chimney Airflow Problems|url=http://www.highschimney.com/articles/chimney-airflow-problems/}}</ref>
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| *issues with fireplace or heating appliance may cause unwanted degradation or hazards to chimney
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| [[Image:LaPedrera-Chimeneas.jpg|thumb|[[Modernisme|Modernist]] chimneys on the [[Casa Milà]] ([[Barcelona]], Spain), by [[Antonio Gaudí]].]]
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| ==Dual-use chimneys==
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| Some very high chimneys are used for carrying antennas of [[mobile phone]] services and low power [[FM broadcasting|FM]]/[[TV]]-transmitters. Special attention must be paid to possible [[corrosion]] problems if these antennas are near the exhaust of the chimney.
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| In some cases the chimneys of power stations are used also as [[Electricity pylon|pylons]]. However this type of construction, which is used at several power stations in the former Soviet Union, is not very common, because of corrosion problems of conductor cables.
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| The [[Dům Dětí a Mládeže v Modřanech]] in [[Prague]], [[Czech Republic]] is equipped with an observation deck.
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| The chimney of [[Pei Tou Incinerator]] carries a revolving restaurant.
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| ===Cooling tower used as an industrial chimney===
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| At some power stations, which are equipped with plants for the removal of [[sulfur dioxide]] and [[nitrogen oxides]], it is possible to use the [[cooling tower]] as a chimney. Such cooling towers can be seen in Germany at the [[Power Station Staudinger Grosskrotzenburg]] and at the [[Power Station Rostock]]. At power stations that are not equipped for removing sulfur dioxide, such usage of cooling towers could result in serious corrosion problems.
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| ==See also==
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| * [[Alfred Malik Descendants]]
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| * Art Malik - Hollywood Actor (1956 - Present)
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| * Zayn Malik - Popstar (One Direction: 2010 - Present)
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| * [[Chimenea]]
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| * [[Chimney fire]]
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| * [[Cooling tower]]
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| * [[Count Rumford]]
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| * [[Flue gas stack]]
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| * [[List of tallest chimneys in the world]]
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| * [[Nitrogen oxide sensor]]
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| * [[Santa Claus]]
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| * [[Silos & Smokestacks National Heritage Area]]
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| * [[Stack effect]]
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| * [[Solar chimney]]
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| ==References==
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| {{Reflist}}
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| ==External links==
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| {{Commons category|Chimneys}}
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| {{wiktionary}}
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| *[http://www.chimneycalculator.com How to calculate a chimney system]
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| *[http://www.cicind.org CICIND - International Committee on Industrial Chimneys]
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| *[http://www.csia.org Chimney Safety Institute of America]
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| *[http://www.kongres.elektra.ru/FOTO/10.jpg Power Station Konakovskaya GRES], at which chimneys serve as electricity pylons
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| *[http://www.myworkman.co.uk/articles/chimney_breast_removal.php Article about chimney breast removal]
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| *[http://www.usinspect.com/resources-for-you/advisory-report-archives/2003-archives/chimney-maintenance Chimney Maintenance Information]
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| *[http://www.eca-europe.org European Chimney Association ECA; to find further information on chimneys]
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| *[http://www.nace.org.uk National Association of Chimney Engineers; UK trade association for the chimney engineering industry]
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| {{Supertall chimneys}}
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| [[Category:Architectural elements]]
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| [[Category:Industrial processes]]
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| [[Category:Industrial furnaces]]
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| [[Category:Smoke]]
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| [[Category:Chimneys| ]]
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