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Superheaters
A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming. There are three types of superheaters: radiant, convection, and separately fired. A superheater can vary in size from a few tens of feet to several hundred feet (a few metres to some hundred metres). Types * A radiant superheater is placed directly in radiant zone of the combustion chamber near the water wall so as to absorb heat by radiation. * A convection superheater is located in the convective zone of the furnace usually ahead of economizer (in the path of the hot flue gases). These are also called primary superheaters. * A separately fired superheater is a superheater that is placed outside the main boiler, which has its own separate combustion system. This superheater design incorporates additional burners in the area of superheater pipe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superheater
A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming. There are three types of superheaters: radiant, convection, and separately fired. A superheater can vary in size from a few tens of feet to several hundred feet (a few metres to some hundred metres). Types * A radiant superheater is placed directly in radiant zone of the combustion chamber near the water wall so as to absorb heat by radiation. * A convection superheater is located in the convective zone of the furnace usually ahead of economizer (in the path of the hot flue gases). These are also called primary superheaters. * A separately fired superheater is a superheater that is placed outside the main boiler, which has its own separate combustion system. This superheater design incorporates additional burners in the area of superheater pipes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prussian S 4
The Prussian S 4's were German superheated express steam locomotives with the Prussian state railways, later grouped as DRG Class 13.5 in the Deutsche Reichsbahn. They were an evolutionary development of the Prussian S 3. The first locomotive was built in 1898 by Vulcan, Stettin as a modified S 3. She was the first superheated locomotive in the world.Rauter and Scheingraber (1991), pp. 84-90. She was initially designated as ''Hannover 74'' and towards the end as the S 4 ''Cassel 401''. Two further trials locomotives appeared in 1899 and 1900 as ''Hannover 86'' and ''Berlin 74'' also classed as S 3's. They were later reclassified as S 4's ''Hannover 401'' and ''Posen 401''. Not until the teething troubles had been resolved was the S 4 put into series production in 1902 in Borsig, from 1906 also in Henschel and Humboldt. Unlike the prototypes the production engines were developed independently of the S 3, and 104 examples were built in the years to 1909 when procurement was halted in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, central heating, boiler-based power generation, cooking, and sanitation. Heat sources In a fossil fuel power plant using a steam cycle for power generation, the primary heat source will be combustion of coal, oil, or natural gas. In some cases byproduct fuel such as the carbon monoxide rich offgasses of a coke battery can be burned to heat a boiler; biofuels such as bagasse, where economically available, can also be used. In a nuclear power plant, boilers called steam generators are heated by the heat produced by nuclear fission. Where a large volume of hot gas is available from some process, a heat recovery steam generator or recovery boiler can use the heat to produce steam, with little or no extra fuel consumed; such a configuration is common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snifting Valve
A snifting valve (sometimes snifter valve) is an automatic anti-vacuum valve used in a steam locomotive when coasting. The word ''Snift'' imitates the sound made by the valve. Overview When the driver shuts off the steam to the cylinders of a steam locomotive while it is in motion, the moving pistons could create a partial vacuum in the cylinders. This would give rise to two problems. Firstly, the pumping action would absorb energy and prevent the engine from coasting freely. Secondly, when the exhaust valve opened, soot and cinders from the smokebox could be sucked down the exhaust pipe and into the valve chest or cylinder, causing damage. (The exhaust is open to the smokebox because in normal running the exhaust steam is sent through the blastpipe to draw the fire and eject the combustion products from the chimney.) These problems are avoided by using snifting valves to allow air to be drawn into the cylinder. On railways which did not use snifting valves, drivers were instr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturated Steam
Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Steam that is saturated or superheated is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as water vapor condenses. Water increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines, which are a sub-group of steam engines. Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80% of the world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure, it can create a steam explosion. Ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D Slide Valve
The slide valve is a rectilinear valve used to control the admission of steam into and emission of exhaust from the cylinder of a steam engine. Use In the 19th century, most steam locomotives used slide valves to control the flow of steam into and out of the cylinders. In the 20th century, slide valves were gradually superseded by piston valves, particularly in engines using superheated steam. There were two reasons for this: * With piston valves, the steam passages can be made shorter. This reduces resistance to the flow of steam and improves efficiency. * It is difficult to lubricate slide valves adequately in the presence of superheated steam. Murdoch's D slide valve The D slide valve, or more specifically Long D slide valve, is a form of slide valve, invented by William Murdoch and patented in 1799. It is named after the hollow central D-sectioned piston. This valve worked by "connecting the upper and lower valves so as to be worked by one rod or spindle, and in makin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Pump
An air pump is a pump for pushing air. Examples include a bicycle pump, pumps that are used to aerate an aquarium or a pond via an airstone; a gas compressor used to power a pneumatic tool, air horn or pipe organ; a bellows used to encourage a fire; a vacuum cleaner and a vacuum pump. All air pumps contain a part that moves (vane, piston, impeller, diaphragm etc.) which drives the flow of air. When the air gets moved, an area of low pressure gets created which fills up with more air. Pumps and compressors use very similar mechanisms, and basically perform the same action, but in different fluid regimes. At some point there is a crossover point in terminology, but here are some stereotypes: • Compressors operate on compressible fluids, typically gases. Pumps operate on fluids, typically liquids, approximated as in-compressible. • Compressors are intended to develop a very high pressure rise against a closed system; pumps are designed to develop relatively little pressure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston Valve (steam Engine)
Piston valves are one form of valve used to control the flow of steam within a steam engine or locomotive. They control the admission of steam into the cylinders and its subsequent exhausting, enabling a locomotive to move under its own power. The valve consists of two piston heads on a common spindle moving inside a steam chest, which is essentially a mini-cylinder located either above or below the main cylinders of the locomotive. Overview In the 19th century, steam locomotives used slide valves to control the flow of steam into and out of the cylinders. In the 20th century, slide valves were gradually superseded by piston valves, particularly in engines using superheated steam. There were two reasons for this: * It is difficult to lubricate slide valves adequately in the presence of superheated steam * With piston valves, the steam passages can be made shorter. This, particularly following the work of André Chapelon, reduces resistance to the flow of steam and improves eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poppet Valves
A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usually a disk shape on the end of a shaft known as a valve stem. The working end of this plug, the valve face, is typically ground at a 45° bevel to seal against a corresponding valve seat ground into the rim of the chamber being sealed. The shaft travels through a valve guide to maintain its alignment. A pressure differential on either side of the valve can assist or impair its performance. In exhaust applications higher pressure against the valve helps to seal it, and in intake applications lower pressure helps open it. The poppet valve was invented in 1833 by American E.A.G. Young of the Newcastle and Frenchtown Railroad. Young had patented his idea, but the Patent Office fire of 1836 destroyed all records of it. Etymology The word po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Schmidt (engineer)
Wilhelm Schmidt, known as Hot Steam Schmidt (German: ''Heißdampf-Schmidt'') (1858–1924) was a German engineer and inventor who achieved the breakthrough in the development of superheated steam technology for steam engines. Wilhelm Schmidt was born in Wegeleben in the Prussian Province of Saxony on 18 February 1858. Education At school Wilhelm Schmidt had difficulties with reading, writing and arithmetic, a case of dyslexia. For example, he was unable to recite the alphabet without hesitation all his life. Nor could he memorise poetry or prose. He developed a passion for drawing, however, and for machines. Career Schmidt began his professional career as a machine fitter. He studied at the technical high school in Dresden under Gustav Zeuner. Superheated steam In 1883 he took a post as a civil engineer in Kassel, where he developed superheated steam technology to the point where it could be practically used. In 1908 he transferred his home and the base of his firm to Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lubrication
Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubricated systems are designed so that the applied load is partially or completely carried by hydrodynamic or hydrostatic pressure, which reduces solid body interactions (and consequently friction and wear). Depending on the degree of surface separation, different lubrication regimes can be distinguished. Adequate lubrication allows smooth, continuous operation of machine elements, reduces the rate of wear, and prevents excessive stresses or seizures at bearings. When lubrication breaks down, components can rub destructively against each other, causing heat, local welding, destructive damage and failure. Lubrication mechanisms Fluid-lubricated systems As the load increases on the contacting surfaces, distinct situations can be observed wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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