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Encyclopedia > Steam engine

Contents

Energy Portal
The term steam engine may also refer to an entire railroad steam locomotive.

A steam engine is an external combustion heat engine that makes use of the heat energy that exists in steam, converting it to mechanical work. Image File history File links Portal. ... One of the last mainline steam locomotives built in the UK: British Railways Standard Class 9F 2-10-0 no. ... An external combustion engine is an engine which burns its fuel to heat a separate working fluid which then in turn performs work. ... A heat engine is a physical or theoretical device that converts thermal energy to mechanical output. ... For other uses, see Steam (disambiguation). ... In physics, mechanical work is the amount of energy transferred by a force. ...


Steam engines were used as the prime mover in pumping stations, locomotives, steam ships, traction engines, steam lorries and other road vehicles. They were essential to the Industrial Revolution and saw widespread commercial use driving machinery in factories and mills, although most have since been superseded by internal combustion engines and electric motors. For the philosophical/theological concept of a prime mover (that is, a self-existent being that is the ultimate cause or mover of all things), see cosmological argument. ... Pumping station Van Sasse in Grave, the Netherlands Pumping station Van Sasse in Grave, the Netherlands Pumping stations are facilities including pumps and equipment for pumping fluids from one place to another. ... Great Western Railway No. ... Paddle steamers - Lucerne-Switzerland Left: original paddlewheel from a paddle steamer on the lake of Lucerne. ... // A traction engine (sometimes called a road locomotive) is a wheeled steam engine used to move heavy loads, plough ground or to provide power at a chosen location. ... A Watt steam engine, the steam engine that propelled the Industrial Revolution in Britain and the world. ... An internal combustion engine is an engine that is powered by the expansion of hot combustion products of fuel directly acting within an engine. ... For other kinds of motors, see motor. ...


Steam turbines, technically a type of steam engine, are still widely used for generating electricity. About 86% of all electric power in the world is generated by use of steam turbines. A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ... For delivered electrical power, see Electrical power industry. ...


A steam engine requires a boiler to heat water into steam. The expansion of steam exerts force upon a piston or turbine blade, whose motion can be harnessed for the work of turning wheels or driving other machinery. One of the advantages of the steam engine is that any heat source can be used to raise steam in the boiler; but the most common is a fire fueled by wood, coal or oil or the heat energy generated in a nuclear reactor. A boiler is a closed vessel in which water or other fluid is heated. ... This article or section is in need of attention from an expert on the subject. ... For other uses, see Wood (disambiguation). ... Coal Example chemical structure of coal Coal (pronounced ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... An oil tanker taking on bunker fuel. ... Core of a small nuclear reactor used for research. ...

 
Steam engine in action (animation). Note that movement of the connecting linkage from the centrifugal governor operating the steam throttle is shown for illustrative purpose only, in practice this link only operates when the engine speeds up or slows down.
Steam engine in action (animation). Note that movement of the connecting linkage from the centrifugal governor operating the steam throttle is shown for illustrative purpose only, in practice this link only operates when the engine speeds up or slows down.
 

Image File history File links Steam_engine_in_action. ... Image File history File links Steam_engine_in_action. ... A centrifugal governor is a specific type of governor that controls the speed of an engine by regulating the amount of fuel admitted, so as to maintain a near constant speed whatever the load or fuel supply conditions. ... In an engine, the throttle is the mechanism by which the engines power is increased or decreased. ...

Invention and development

Aeolipile
Aeolipile

The first recorded steam-powered device, the aeolipile, was described by Hero of Alexandria (Heron) in 1st century Roman Egypt, in his manuscript Spiritalia seu Pneumatica.[1] Steam ejected tangentially from nozzles caused a pivoted ball to rotate; this suggests that the conversion of steam pressure into mechanical movement was known in Roman Egypt in the 1st century, the device was used for some simple work, such as opening temple doors,[2] but saw no other major uses. This was a major technological breakthrough since it represents the first recorded use of the steam engine/steam turbine and the first industrial application of steam power, more then a millennium before the onset of the industrial revolution. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... An illustration of Herons aeolipile An aeolipile is a device consisting of an air-tight chamber (usually a sphere or cylinder) with bent or curved pipes projecting from it, through which steam is expelled perpendicular to the radius of rotation. ... Hero (or Heron) of Alexandria (Greek: Ήρων ο Αλεξανδρεύς) (c. ... The Roman Empire 120, with Aegyptus province highlighted See Egypt Province for the province of the Ottoman Empire. ...


Another practical steam turbine was invented much later by Taqi al-Din,[3] an Arab philosopher, astronomer, and engineer in 16th century Ottoman Egypt, who exposed a method for rotating a spit by means of a jet of steam playing on rotary vanes around the periphery of a wheel. A similar machine is shown by Giovanni Branca, an Italian engineer,[4] in 1629 for turning a cylindrical escapement device that alternately lifted and let fall a pair of pestles working in mortars. The steam flow of these early steam turbines, however, was not concentrated and much of its energy was dissipated in all directions and would have led to a considerable waste of energy and are usually called "mills". A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ... Taqi al-Din Muhammad ibn Maruf al-Shami al-Asadi (Arabic: تقي الدين محمد بن معروف الشامي السعدي) (c. ... For other uses, see Arab (disambiguation). ... Early Muslim philosophy is considered influential in the rise of modern philosophy. ... This is a sub-article of Islamic science and astronomy. ... A significant number of inventions were produced in the Muslim world, many of them with direct implications for Fiqh related issues. ... Egypt was conquered by the Ottoman Empire in 1517. ... It has been suggested that this article or section be merged with rotisserie. ... Giovanni Branca (1571-1645) was an italian engineer and architect from Loretto who, in 1929, designed a steam turbine, which he didnt build. ... A simple escapement. ... A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ...


Commercial development of the steam engine, however, required an economic climate in which the developers of engines could profit by their creations. Classical, and later Medieval and Renaissance civilisations provided no such climate. Even as late as the 17th century, steam engines were created as one-off curiosities. The difficulty in breaking out of this situation is evident judging by the difficulties encountered by the Marquis of Worcester and later by his widow in gaining financial investment into the practical application of his ideas for the exploitation of steam power. In 1663, he published designs for, and installed a steam-powered device for raising water on the wall of the Great Tower at Raglan Castle (the grooves in the wall where the engine was installed were still to be seen in the 19th century). However, no one was prepared to risk money in this revolutionary new concept, and without backers the machine remained undeveloped.[5] (16th century - 17th century - 18th century - more centuries) As a means of recording the passage of time, the 17th century was that century which lasted from 1601-1700. ... Edward Somerset, 2nd Marquess of Worcester (died April 3, 1667), was born before 1613, perhaps in 1601, to Henry Somerset, 1st Marquess of Worcester and Anne Russell. ...

Denis Papin's design for a piston-and-cylinder engine, 1680.
Denis Papin's design for a piston-and-cylinder engine, 1680.

One of Denis Papin’s centres of interest was in the creating of a vacuum in a closed cylinder and in Paris in the mid 1670s he collaborated with the Dutch physicist, Huygens’ working on an engine which drove out the air from a cylinder by exploding gunpowder inside it. Realising the incompleteness of the vacuum produced by this means and on moving to England in 1680, Papin devised a version of the same cylinder that obtained a more complete vacuum from boiling water and then allowing the steam to condense; in this way he was able to raise weights by attaching the end of the piston to a rope passing over a pulley. As a demonstration model the system worked, but in order to repeat the process the whole apparatus had to be dismantled and reassembled. Papin quickly saw that to make an automatic cycle the steam would have to be generated separately in a boiler; however as he did not take the project further all we can say is that he invented the reciprocating steam engine conceptually and thus paved the way to Newcomen’s engine. Papin also designed a paddle boat driven by a jet playing on a mill-wheel in a combination of Taqi al Din and Savery's conceptions and; he is also credited with a number of significant devices such as the safety valve. Image File history File links Papinengine. ... Image File history File links Papinengine. ... Denis Papin Denis Papin (22 August 1647 - c. ... Oxygen Safety Valve A safety valve is a valve mechanism for the automatic release of a gas from a boiler, pressure vessel, or other system when the pressure or temperature exceeds preset limits. ...


Early industrial engines

None of the foregoing developments were applied practically as a means of undertaking any early useful task. Another early industrial steam engine was the "fire-engine", designed by Thomas Savery in 1698. This was a pistonless steam pump, and apparently not very efficient. It was thus Thomas Newcomen and his "atmospheric-engine" of 1712 that demonstrated the first practical industrial engine for which there could be a commercial demand. Newcomen appears to have based his development on Papin's description of early experiments at the Royal society to which he most likely had access through acquaintance with a society member, Robert Hooke who had himself worked with Papin. Thomas Savery (c. ... Thomas Newcomen (baptised 24 February 1664; died 5 August 1729) was an ironmonger by trade, and a Baptist lay preacher by calling. ... Animation of a schematic Newcomen steam engine. ...


The first industrial applications of the Newcomen engine were in the pumping of water from deep mineshafts. In mineshaft pumps a reciprocating beam was connected to an operating rod that descended the shaft to a pump chamber. The oscillations of the operating rod were transferred to a pump piston that moved the water to the top of the shaft. The valves of early Newcomen engines were manually opened and closed by an attendant. An early improvement was the automation of valves operation by deriving the motion from that of the engine itself (Legend has it that this was first done in 1713 by a boy, Humphrey Potter, charged with opening the valves; when he grew bored and wanted to play with the other children he set up ropes to automate the process.)[6], however by 1715 this had already been achieved by an escapement system activated by a vertical plug beam suspended from the engine beam.


Humphrey Gainsborough produced a model condensing steam engine in the 1760s, which he showed to Richard Lovell Edgeworth, a member of the Lunar Society.[7] In 1769 James Watt, another member of the Lunar Society, patented the first significant improvements to the Newcomen type vacuum engine that made it much more fuel efficient. Watt's leap was to separate the condensing phase of the vacuum engine into a separate chamber, while keeping the piston and cylinder at the temperature of the steam. Gainsborough believed that Watt had used his ideas for the invention, but there is no proof of this.[7] Humphrey Gainsborough (1718–1776), a non-conformist minister, engineer and inventor. ... Condensation can refer to: The change in phase of a substance to a denser phase, such as gas to a liquid. ... Richard Edgeworth, 1812 Richard Lovell Edgeworth (May 31, 1744-June 13, 1817) was a British writer and inventor. ... The Lunar Society was a discussion club of prominent industrialists, natural philosophers and intellectuals who met regularly between 1765 and 1813 in Birmingham, England. ... For other persons named James Watt, see James Watt (disambiguation). ...


Watt, together with his business partner Matthew Boulton, developed these patents into the Watt steam engine in Birmingham, England. The increased efficiency of the Watt engine finally led to the general acceptance and use of steam power in industry. Additionally, unlike the Newcomen engine, the Watt engine operated smoothly enough to be connected to a drive shaft—via sun and planet gears—to provide rotary power. This was in all essentials the engine that we know today. In early steam engines the piston is usually connected to a balanced beam, rather than directly to a connecting rod, and these engines are therefore known as beam engines. Matthew Boulton. ... The major components of a Watt pumping engine. ... This article is about the British city. ... The sun and planet gear was a method of converting vertical motion to rotary motion and utilised a reciprocating steam engine. ... piston (top) and connecting rod from typical automotive engine (scale is in centimetres) Components of a typical, four stroke cycle, DOHC piston engine. ...

Richard Trevithick's No. 14 Engine, built by Hazeldine and Co., Bridgnorth, about 1804. This was a single-acting, stationary high pressure engine that operated at a working pressure of 50 psi (350 kPa).
Richard Trevithick's No. 14 Engine, built by Hazeldine and Co., Bridgnorth, about 1804. This was a single-acting, stationary high pressure engine that operated at a working pressure of 50 psi (350 kPa).

The next improvement in efficiency came with the American Oliver Evans and the Briton Richard Trevithick's use of high pressure steam.[8][9] Trevithick built successful industrial high pressure single-acting engines known as Cornish engines. However, with increased pressure came much danger as engines and boilers were now likely to fail mechanically by a violent outwards explosion, and there were many early disasters. The most important refinement to the high pressure engine at this point was the safety valve, which releases excess pressure. Reliable and safe operation came only with a great deal of experience and codification of construction, operating, and maintenance procedures. Download high resolution version (1200x778, 239 KB)Richard Trevithicks high-pressure steam engine, from Scientific American Supplement, Vol. ... Download high resolution version (1200x778, 239 KB)Richard Trevithicks high-pressure steam engine, from Scientific American Supplement, Vol. ... A pressure gauge reading in PSI (red scale) and kPa (black scale) The pound-force per square inch (symbol: lbf/in²) is a non-SI unit of pressure based on avoirdupois units. ... The pascal (symbol Pa) is the SI unit of pressure. ... Oliver Evans Oliver Evans (13 September 1755 – 15 April 1819) was a United States inventor. ... Richard Trevithick Richard Trevithick (April 13, 1771 – April 22, 1833) was a Cornish inventor, mining engineer and builder of the first working railway steam locomotive. ... A Cornish engine is a high-pressure steam engine developed in Cornwall, England, for pumping water from a tin mine. ...


Nicolas-Joseph Cugnot demonstrated the first functional self-propelled steam vehicle, his "fardier" (steam wagon), in 1769. Arguably, this was the first automobile. While not generally successful as a transportation device, the self-propelled steam tractor proved very useful as a self mobile power source to drive other farm machinery such as grain threshers or hay balers. In 1788, a steamboat built by John Fitch operated in regular commercial service along the Delaware river between Philadelphia PA and Burlington NJ, carrying as many as 30 passengers. This boat could typically make 7 to 8 miles per hour, and traveled more than 2,000 miles (3,200 km) during its short length of service. The Fitch steamboat was not a commercial success, as this travel route was adequately covered by relatively good wagon roads. In 1802 William Symington built a practical steamboat, and in 1807 Robert Fulton used the Watt steam engine to power the first commercially successful steamboat. On February 21, 1804 at the Penydarren ironworks at Merthyr Tydfil in South Wales, the first self-propelled railway steam engine or steam locomotive, built by Richard Trevithick, was demonstrated. Nicolas-Joseph Cugnot (26 February 1725 – 2 October 1804) was a French inventor who is claimed by the French government to have built the first self-propelled mechanical vehicle or automobile. ... “Car” and “Cars” redirect here. ... The thrashing machine, or, in modern spelling, threshing machine (or simply thresher), was a machine first invented by Scottish mechanical engineer Andrew Meikle for use in agriculture. ... A round baler A baler is a piece of farm machinery that is used to compress a cut, raked, crop (such as hay or straw) into bales and bind the bales with twine. ... The first practieal steamboat was built by the engineer William Symington,1764 - 1831, born in the lead mining village of Leadhills, Lanarkshire, Scotland. ... For other persons named Robert Fulton, see Robert Fulton (disambiguation). ... For other uses, see Steamboat (disambiguation). ... is the 52nd day of the year in the Gregorian calendar. ... 1804 was a leap year starting on Sunday (see link for calendar). ... Penydarren was the fourth of the great ironworks established at Merthyr Tydfil. ... Merthyr Tydfil (Welsh: ) is a town and county borough in Wales, with a population of about 55,000. ... This article is about the country. ...


Reciprocating engines

Reciprocating engines use the action of steam to move a piston in a sealed chamber or cylinder. The reciprocating action of the piston can be translated via a mechanical linkage into either linear motion, usually for working water or air pumps, or else into rotary motion to drive the flywheel of a stationary engine, or else the wheel(s) of a vehicle.


Vacuum engines

Early steam engines, or "fire engines" as they were at first called such as "atmospheric" and Watt's "condensing" engines, worked on the vacuum principle and are thus known as vacuum engines Although Savery's patent of 2 July 1698 claimed, in addition to "the raising of water", the ability to "occasion... motion to all sorts of mill-works" there is no evidence that they were used for any purpose other than pumping.[4] Such engines operate by admitting low pressure steam into an operating chamber or cylinder. The inlet valve is then closed and the steam cooled, condensing it to a smaller volume and thus creating a vacuum in the cylinder The upper end of the cylinder being open to the atmospheric pressure operates on the opposite side of a piston, pushing the piston to the bottom of the cylinder. is the 183rd day of the year (184th in leap years) in the Gregorian calendar. ... Events January 4 - Palace of Whitehall in London is destroyed by fire. ... Diurnal (daily) rhythm of air pressure in northern Germany (black curve is air pressure) Atmospheric pressure is the pressure at any point in the Earths atmosphere. ...

Engraving of Newcomen engine. This appears to be copied from a drawing in Desaguliers' 1744 work: "A course of experimental philosophy", itself believed to have been a reversed copy of Henry Beighton's engraving dated 1717 representing what is probably the second Newcomen engine erected around 1714 at Griff colliery, Warwickshire. (See Hulse p.84)

The piston is connected by a chain to the end of a large beam pivoted near its middle. A weighted force pump is connected by a chain to the opposite end of the beam which gives the pumping stroke and returns the piston to the top of the cylinder by force of gravity, the low pressure steam being insufficient to move the piston upwards. In the Newcomen engine the cooling water is sprayed directly into the cylinder the still-warm condensate running off into a hot well. [1][10] Repeated and wasteful cooling and reheating of the working cylinder was a source of inefficiency, however these engines enabled the pumping of greater volumes of water and/or from greater depths than had been hitherto possible. Watt's version of this engine as developed and marketed from 1774 onwards in partnership with Matthew Boulton, was meant to improve efficiency through use of a separate condensing chamber immersed in a bath of cold water, connected to the working cylinder by a pipe and controlled by a valve. A small vacuum pump connected to the pump side of the beam drew off the warm condensate and delivered it to the hot well, at the same time helping to create the vacuum and draw the condensate out of the cylinder. Image File history File links Size of this preview: 593 × 600 pixelsFull resolution (1354 × 1369 pixel, file size: 667 KB, MIME type: image/jpeg) Figuer, Louis Merveilles de la science Furne Jouvet et Cie, Paris 1868 This image is in the public domain because its copyright has expired in the... Image File history File links Size of this preview: 593 × 600 pixelsFull resolution (1354 × 1369 pixel, file size: 667 KB, MIME type: image/jpeg) Figuer, Louis Merveilles de la science Furne Jouvet et Cie, Paris 1868 This image is in the public domain because its copyright has expired in the... The major components of a Watt pumping engine. ... Chesma Column in Tsarskoe Selo, commemorating the end of the Russo-Turkish War. ... Matthew Boulton. ...

Early Watt pumping engine.

The hot well was also a source of pre-heated water for the boiler. Another radical change was to close off the top of the cylinder and introduce low pressure steam above the piston and inside steam jackets that maintained cylinder temperature constant. On the upward return stroke, the steam on top was transferred through a pipe to the underside of the piston to be condensed for the downward stroke. Thus the engine was thus no longer "atmospheric", the power stroke depending on the differential between the low-pressure steam and the partial vacuum. Sealing of the piston on a Newcomen engine was achieved by maintaining a small quantity of water on its upper side. This was no longer possible in Watt's engine due to the presence of the steam; so sealing of the piston and its lubrication was obtained by using a mixture of tallow and oil. The piston rod also passed through a gland on the top cylinder cover sealed in a similar way.[2] Image File history File links Size of this preview: 631 × 600 pixel Image in higher resolution (2367 × 2250 pixel, file size: 591 KB, MIME type: image/jpeg) Thurston Robert H: History of the Growth of the Steam engine, D. Appleton & Co 1878 This image is in the public domain in... Image File history File links Size of this preview: 631 × 600 pixel Image in higher resolution (2367 × 2250 pixel, file size: 591 KB, MIME type: image/jpeg) Thurston Robert H: History of the Growth of the Steam engine, D. Appleton & Co 1878 This image is in the public domain in... Diagram of the Newcomen steam engine Thomas Newcomens atmospheric engine, today referred to as a Newcomen steam engine, was the first practical device to harness the power of steam to produce mechanical work. ...


Vacuum engines, although in general limited in their efficiency, were at least relatively safe, use of very low pressure steam being preferable due to the primitive state of 18th century boiler technology. Power was limited by the low pressure, the displacement of the cylinder, combustion and evaporation rates and—where present— condenser capacity. Maximum theoretical efficiency was limited by the relatively low temperature differential on either side of the piston; this meant that for a vacuum engine to provide a usable amount of power, the first industrial production engines had to be very large, and were thus expensive to build and install. A boiler is a closed vessel in which water or other fluid is heated. ...

Trevithick pumping engine (Cornish system).
Trevithick pumping engine (Cornish system).

Around 1811 Richard Trevithick was required to update a Watt pumping engine in order to adapt it to one of his new Cornish boilers. Steam pressure above the piston was increased eventually reaching 40 psi (2.8 bars) and now provided much of the power for the downward stroke; at the same time condensing was improved. This considerably raised efficiency and further pumping engines on the Cornish system (often known as Cornish engines) were built new throughout the 19th century, older Watt engines being updated to conform. Many of these engines were supplied worldwide and gave reliable and efficient service over a great many years with greatly reduced coal consumption. Some of them were very large and the type continued to be built right down to the 1890’s. Image File history File links Size of this preview: 412 × 599 pixelsFull resolution (1360 × 1976 pixel, file size: 1. ... Image File history File links Size of this preview: 412 × 599 pixelsFull resolution (1360 × 1976 pixel, file size: 1. ... A Cornish engine is a high-pressure steam engine developed in Cornwall, England, for pumping water from a tin mine. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Watt Steam Engine - showing the improvement of the separate condenser, which was not found on the Newcomen steam engine. ...

High pressure engines

In a high pressure engine, steam is raised in a boiler to a high pressure and temperature, it is then admitted to a working chamber where it expands and acts upon a piston. In "Cornish engines" steam pressure and vacuum are applied to the piston simultaneously. As pressure is applied to the top of the piston, the steam from the previous cycle is condensed to provide a vacuum below the piston. At the end of the stroke the equilibrium valve opens to allow the steam above the piston to be transferred to the lower part of the cylinder as the piston is lifted by the weight of the pump end of the beam. The piston consequently reciprocates, much like in the vacuum engine. A Cornish engine is a high-pressure steam engine developed in Cornwall, England, for pumping water from a tin mine. ...


The importance of raising steam under pressure (from a thermodynamic standpoint) is that it attains a higher temperature. Thus, any engine using such steam operates at a higher temperature differential than is possible with a low pressure vacuum engine. After displacing the vacuum engine, the high pressure engine became the basis for further development of reciprocating steam technology. Thermodynamics (from the Greek θερμη, therme, meaning heat and δυναμις, dynamis, meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ...


High pressure steam also has the advantage that engines can be much smaller for a given power range, and thus less expensive. There is also the benefit that steam engines then could be developed that were small enough and powerful enough to propel themselves while doing useful work. As a result, steam power for transportation became a practicality, most notably steam locomotives and ships, which revolutionised cargo businesses, travel, military strategy, and essentially every aspect of society at the time.

A labeled schematic diagram of a typical single cylinder, simple expansion, double-acting high pressure horizontal steam engine. Power takeoff from the engine is by way of a belt. 1 - Piston 2 - Piston rod 3 - Crosshead bearing 4 - Connecting rod 5 - Crank 6 - Eccentric valve motion 7 - Flywheel 8 - Sliding valve 9 - Centrifugal governor.
A labeled schematic diagram of a typical single cylinder, simple expansion, double-acting high pressure horizontal steam engine. Power takeoff from the engine is by way of a belt.
1 - Piston
2 - Piston rod
3 - Crosshead bearing
4 - Connecting rod
5 - Crank
6 - Eccentric valve motion
7 - Flywheel
8 - Sliding valve
9 - Centrifugal governor.

Image File history File links Download high resolution version (892x532, 32 KB) Description Object: Steam engine nomenclature Description: Made to avoid some licence problems with this image. ... Image File history File links Download high resolution version (892x532, 32 KB) Description Object: Steam engine nomenclature Description: Made to avoid some licence problems with this image. ...

Double-acting engine

The next major advance in high pressure steam engines was to make them double-acting. In the single-acting high pressure engine above, the cylinder is vertical and the piston returns to the start—or bottom—of the stroke by the momentum of the flywheel (not shown).


In the double-acting engine, steam is admitted alternately to each side of the piston while the other is exhausting. This requires inlet and exhaust ports at either end of the cylinder (see the animated expansion engine below) with steam flow being controlled by valves. This system increases the speed and smoothness of the reciprocation and allows the cylinder to be mounted horizontally or at an angle.


Power is transmitted from the piston by a sliding rod—sealed to the cylinder to prevent the escape of steam— which in turn drives a connecting rod via a sliding crosshead). This in combination with the connecting rod converts the reciprocating motion to rotary motion. The inlet and exhaust valves have their reciprocating motion derived from the rotary motion by way of an additional crank mounted eccentrically (i.e. off centre) from the drive shaft. The valve gear may include a reversing mechanism to allow reversal of the rotary motion. A crosshead bearing (or simply crosshead) is used in large reciprocating engines, whether internal combustion engines or steam engines. ... piston (top) and connecting rod from typical automotive engine (scale is in centimetres) Components of a typical, four stroke cycle, DOHC piston engine. ... (This page refers to eccitricity in mechanical engineering. ... The Walschaert valve gear on a steam locomotive (a PRR E6s). ...


A double-acting piston engine provides as much power as a more expensive 2-piston single-acting engine, and also allows the use of a much smaller flywheel than what would be required by a one-piston single-acting engine. Both of these considerations made the double-acting piston engine smaller and less expensive for a given power range.


Most reciprocating steam engines now use this technology, notable examples including steam locomotives and marine engines. When a pair (or more) of double acting cylinders, for instance in a steam locomotive, are connected to a common driveshaft their crank phasing is offset by an angle of 90°. This is called quartering and ensures that the engine will always start, no matter what position the crank is in.


Some marine engines have used only a single double-acting cylinder, driving paddlewheels on each side. When shutting down such an engine it was important that the piston be away from either extreme range of its travel so that it could be readily restarted (as there was not a second quartered piston to facilitate this).


Steam distribution

Schematic Indicator diagram showing the four events in a double piston stroke

In most reciprocating piston engines the steam reverses its direction of flow at each stroke (counterflow), entering and exhausting from the cylinder by the same port. The complete engine cycle occupies one rotation of the crank and two piston strokes; the cycle also comprises four events — admission, expansion, exhaust, compression. These events are controlled by valves often working inside a steam chest adjacent to the cylinder; the valves distribute the steam by opening and closing steam ports communicating with the cylinder end(s) and are driven by valve gear, of which there are many types. The simplest valve gears give events of fixed length during the engine cycle and often make the engine rotate in only one direction. Most however have a reversing mechanism which additionally can provide means for saving steam as speed and momentum are gained by gradually "shortening the cutoff" or rather, shortening the admission event; this in turn proportionately lengthens the expansion period. However, as one and the same valve usually controls both steam flows, a short cutoff at admission adversely affects the exhaust and compression periods which should ideally always be kept fairly constant; if the exhaust event is too brief, the totality of the exhaust steam cannot evacuate the cylinder, choking it and giving excessive compression ("kick back"). In the 1840s and 50s there were attempts to overcome this problem by means of various patent valve gears with separate variable cutoff valves riding on the back of the main slide valve; the latter usually had fixed or limited cutoff. The combined setup gave a fair approximation of the ideal events, at the expense of increased friction and wear, and the mechanism tended to be complicated. The usual compromise solution has ever since been to provide lap by lengthening rubbing surfaces of the valve in such a way as to overlap the port on the admission side, with the effect that the exhaust side remains open for a longer period after cut-off on the admission side has occurred. This expedient has since been generally considered satisfactory for most purposes and makes possible the use of the simpler Stephenson, Joy and Walschaerts motions. Later, poppet valve gears had separate admission and exhaust valves driven by cams profiled so as to give ideal events; nevertheless most of these gears never succeeded in ousting conventional gears due to various other issues including leakage and more delicate mechanisms.[11][12] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... In the technology of the steam engine, the indicator diagram was a device developed by James Watt and his employee John Southern to improve the efficiency of engines. ... A stroke is a single action of certain engines. ... The Walschaert valve gear on a steam locomotive (a PRR E6s). ... In a steam engine, cutoff is the early closing of the cylinder inlet valve, to increase efficiency. ... Stephenson valve gear is the oldest and simplest standard design of steam locomotive valve gear. ... Joy Valve Gear Diagram Joy valve gear is a type of locomotive valve gear, Patented in 1870, where the movement is derived from a vertical link connected to the connecting rod. ... The Walschaert valve gear on a Pennyslvania Railroad K4s. ... A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. ... For other uses, see CAM. Animation showing rotating cams and cam followers producing reciprocating motion. ...

Compression

Before the exhaust phase is quite complete, the exhaust side of the valve closes, shutting a portion of the exhaust steam inside the cylinder. This determines the compression phase where a cushion of steam is formed against which the piston does work whilst its velocity is rapidly decreasing; it moreover obviates the pressure and temperature shock, which would otherwise be caused by the sudden admission of the high pressure steam at the beginning of the following cycle.


Lead

The above effects are further enhanced by providing lead: as was later discovered with the internal combustion engine, it has been found advantageous since the late 1830s to advance the admission phase, giving the valve lead so that admission occurs a little before the end of the exhaust stroke in order to fill the clearance volume comprising the ports and the cylinder ends (not part of the piston-swept volume) before the steam begins to exert effort on the piston. [13] A colorized automobile engine The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. ...


Simple expansion

This means that a charge of steam works only once in the cylinder. It is then exhausted directly into the atmosphere or into a condenser, but remaining heat can be recuperated if needed to heat a living space, or to provide warm feedwater for the boiler. Steam locomotive condensing apparatus Differs in purpose from the usual closed cycle steam engine condenser, in that its function is primarily either to recover water, or to avoid excessive emissions to the atmosphere, rather than maintaining a vacuum to improve both efficiency and power. ...


Compounding

As steam expands in a high pressure engine its temperature drops; because no heat is released from the system, this is known as adiabatic expansion and results in steam entering the cylinder at high temperature and leaving at low temperature. This causes a cycle of heating and cooling of the cylinder with every stroke which is a source of inefficiency. In thermodynamics, an adiabatic process or an isocaloric process is a thermodynamic process in which no heat is transferred to or from the working fluid. ...


A method to lessen the magnitude of this heating and cooling was invented in 1804 by British engineer Arthur Woolf, who patented his Woolf high pressure compound engine in 1805. In the compound engine, high pressure steam from the boiler expands in a high pressure (HP) cylinder and then enters one or more subsequent lower pressure (LP) cylinders. The complete expansion of the steam now occurs across multiple cylinders and as less expansion now occurs in each cylinder so less heat is lost by the steam in each. This reduces the magnitude of cylinder heating and cooling, increasing the efficiency of the engine. To derive equal work from lower pressure steam requires a larger cylinder volume as this steam occupies a greater volume. Therefore the bore, and often the stroke, are increased in low pressure cylinders resulting in larger cylinders. Arthur Woolf (born November 1766, Camborne, Cornwall; died October 26, 1837, Guernsey) was an English engineer. ...


Double expansion (usually known as compound) engines expanded the steam in two stages. The pairs may be duplicated or the work of the large LP cylinder can be split with one HP cylinder exhausting into one or the other, giving a 3-cylinder layout where cylinder and piston diameter are about the same making the reciprocating masses easier to balance.


Two-cylinder compounds can be arranged as:

  • Cross compounds - The cylinders are side by side.
  • Tandem compounds - The cylinders are end to end, driving a common connecting rod
  • Angle compounds - The cylinders are arranged in a vee (usually at a 90° angle) and drive a common crank.

With two-cylinder compounds used in railway work, the pistons are connected to the cranks as with a two-cylinder simple at 90° out of phase with each other (quartered). When the double expansion group is duplicated, producing a 4-cylinder compound, the individual pistons within the group are usually balanced at 180°, the groups being set at 90° to each other. In one case (the first type of Vauclain compound), the pistons worked in the same phase driving a common crosshead and crank, again set at 90° as for a two-cylinder engine. With the 3-cylinder compound arrangement, the LP cranks were either set at 90° with the HP one at 135° to the other two, or in some cases all three cranks were set at 120°.


The adoption of compounding was common for industrial units, for road engines and almost universal for marine engines after 1880; it was not universally popular in railway locomotives where it was often perceived as complicated. This is partly due to the harsh railway operating environment and limited space afforded by the loading gauge (particularly in Britain, where compounding was never common and not employed after 1930). However although never in the majority it was popular in many other countries [14] A loading gauge is the envelope or contoured shape within which all railway vehicles, engines, coaches, and trucks must fit. ...


Multiple expansion

An animation of a simplified triple-expansion engine.
High-pressure steam (red) enters from the boiler and passes through the engine, exhausting as low-pressure steam (blue) to the condenser.
1890s vintage triple-expansion (three cylinders of 26, 42 and 70 inch diameters in a common frame with a 42 inch stroke) marine engine that powered the SS Christopher Columbus
1890s vintage triple-expansion (three cylinders of 26, 42 and 70 inch diameters in a common frame with a 42 inch stroke) marine engine that powered the SS Christopher Columbus

It is a logical extension of the compound engine above to split the expansion into yet more stages to increase efficiency. The result is the multiple expansion engine. Such engines use either three or four expansion stages and are known as triple and quadruple expansion engines respectively. These engines use a series of double-acting cylinders of progressively increasing diameter and/or stroke and hence volume. These cylinders are designed to divide the work into three or four, as appropriate, equal portions for each expansion stage. As with the double expansion engine, where space is at a premium, two smaller cylinders of a large sum volume may be used for the low pressure stage. Multiple expansion engines typically had the cylinders arranged inline, but various other formations were used. Image File history File links Triple_expansion_engine_animation. ... Image File history File links Triple_expansion_engine_animation. ... Image File history File links Size of this preview: 450 × 600 pixelsFull resolution (600 × 800 pixel, file size: 126 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 450 × 600 pixelsFull resolution (600 × 800 pixel, file size: 126 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... The S.S. Christopher Columbus was a whaleback excursion liner designed by Alexander McDougall. ...


The images to the left show a model and an animation of a triple expansion engine. The steam travels through the engine from left to right. The valve chest for each of the cylinders is to the left of the corresponding cylinder.


The development of this type of engine was important for its use in steamships as by exhausting to a condenser the water can be reclaimed to feed the boiler, which is unable to use seawater. Land-based steam engines could exhaust much of their steam, as feed water was usually readily available. Prior to and during World War II, the expansion engine dominated marine applications where high vessel speed was not essential. It was however superseded by the British invention steam turbine where speed was required, for instance in warships and ocean liners. HMS Dreadnought of 1905 was the first major warship to replace the proven technology of the reciprocating engine with the then-novel steam turbine. Annual mean sea surface salinity for the World Ocean. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ... This article does not cite any references or sources. ... The sixth HMS Dreadnought of the Royal Navy was a revolutionary battleship which entered service in 1906. ...

Model of a triple expansion engine
S/S Ukkopekka Triple expansion steam engine
S/S Ukkopekka Triple expansion steam engine

Download high resolution version (1024x768, 124 KB)Model of a triple expansion steam engine locatated in a museum at Monterey, California. ... Download high resolution version (1024x768, 124 KB)Model of a triple expansion steam engine locatated in a museum at Monterey, California. ... Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Finnish steamer S/S Ukkopekka. ...

Uniflow (or unaflow) engine

Main article: Uniflow steam engine

This is intended to remedy the difficulties arising from the usual counterflow cycle mentioned above which means that at each stroke the port and the cylinder walls will be cooled by the passing exhaust steam, whilst the hotter incoming admission steam will waste some of its energy in restoring working temperature. The aim of the uniflow is to remedy this defect by providing an additional port uncovered by the piston at the end of its half-stroke making the steam flow only in one direction. By this means, thermal efficiency is improved by having a steady temperature gradient along the cylinder bore. The simple-expansion uniflow engine is reported to give efficiency equivalent to that of classic compound systems with the added advantage of superior part-load performance. It is also readily adaptable to high-speed uses and was a common way to drive electricity generators towards the end of the 19th century before the coming of the steam turbine. This article or section does not adequately cite its references or sources. ...


Uniflow engines have been produced in single-acting, double-acting, simple, and compound versions. Skinner 4-crank 8-cylinder single-acting tandem compound [3] engines power two Great Lakes ships still trading today (2007). These are the Saint Marys Challenger,[4] that in 2005 completed 100 years of continuous operation as a powered carrier (the Skinner engine was fitted in 1950) and the car ferry, Badger.[5] The Great Lakes from space The Laurentian Great Lakes are a group of five large lakes in North America on or near the Canada-United States border. ...


In the early 1950s the Ultimax engine, a 2-crank 4-cylinder arrangement similar to Skinner’s, was developed by Abner Doble for the Paxton car project with tandem opposed single-acting cylinders giving effective double-action. [6] Abner Doble (March 26, 1890 – July 16, 1961), was an American mechanical engineer who built and sold steam-powered automobiles. ...


Turbine engines

Main article: Steam turbine

A steam turbine consists of an alternating series of rotating discs mounted on a drive shaft, rotors, and static discs fixed to the turbine casing, stators. The rotors have a propeller-like arrangement of blades at the outer edge. Steam acts upon these blades, producing rotary motion. The stator consists of a similar, but fixed, series of blades that serve to redirect the steam flow onto the next rotor stage. A steam turbine exhausts into a condenser that provides a vacuum. The stages of a steam turbine are typically arranged to extract the maximum potential work from a specific velocity and pressure of steam, giving rise to a series of variably sized high and low pressure stages. Turbines rotate at very high speed, therefore are usually connected to reduction gearing to drive another mechanism, such as a ship's propeller, at a lower speed. A turbine rotor is also capable of providing power when rotating in one direction only. Therefore a reversing stage or gearbox is usually required where power is required in the opposite direction. A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ... A Siemens steam turbine with the case opened. ... The stator is the fixed part of a rotating machine. ... Look up condenser in Wiktionary, the free dictionary. ...


Steam turbines provide direct rotational force and therefore do not require a linkage mechanism to convert reciprocating to rotary motion. Thus, they produce smoother rotational forces on the output shaft. This contributes to a lower maintenance requirement and less wear on the machinery they power than a comparable reciprocating engine.


The main use for steam turbines is in electricity generation (about 86% of the world's electric production is by use of steam turbines)[citation needed] and to a lesser extent as marine prime movers. In the former, the high speed of rotation is an advantage, and in both cases the relative bulk is not a disadvantage. Virtually all nuclear power plants and some nuclear submarines, generate electricity by heating water to provide steam that drives a turbine connected to an electrical generator for main propulsion. A limited number of steam turbine railroad locomotives were manufactured. Some non-condensing direct-drive locomotives did meet with some success for long haul freight operations in Sweden, but were not repeated. Elsewhere, notably in the U.S.A., more advanced designs with electric transmission were built experimentally, but not reproduced. It was found that steam turbines were not ideally suited to the railroad environment and these locomotives failed to oust the classic reciprocating steam unit in the way that modern diesel and electric traction has done. World-wide electricity production for 1980 to 2005. ... This article is about applications of nuclear fission reactors as power sources. ... USS Los Angeles A submarine is a specialized watercraft that can operate underwater. ... This article is about machines that produce electricity. ... A steam turbine locomotive is a steam locomotive which transmits steam power to the wheels via a steam turbine. ...


Other engines

Other types of steam engine have been produced and proposed, but have not been nearly so widely adopted as reciprocating or turbine engines.


Rotary steam engines

It is possible to use a mechanism based on a pistonless rotary engine such as the Wankel engine in place of the cylinders and valve gear of a conventional reciprocating steam engine. Many such engines have been designed, from the time of James Watt to the present day, but relatively few were actually built and even fewer went into quantity production; see link at bottom of article for more details. The major problem is the difficulty of sealing the rotors to make them steam-tight in the face of wear and thermal expansion; the resulting leakage made them very inefficient. Lack of expansive working, or any means of control of the cutoff is also a serious problem with many such designs. By the 1840s it was clear that the concept had inherent problems and rotary engines were treated with some derision in the technical press. However, the arrival of electricity on the scene, and the obvious advantages of driving a dynamo directly from a high-speed engine, led to something of a revival in interest in the 1880s and 1890s, and a few designs had some limited success. A pistonless rotary engine is an internal combustion engine that does not use pistons in the way a reciprocating engine does, but instead uses one or more rotors, sometimes called rotary pistons. ... Wankel Engine in Deutsches Museum Munich, Germany The Wankel rotary engine is a type of internal combustion engine, invented by German engineer Felix Wankel, which uses a rotor instead of reciprocating pistons. ... The Walschaert valve gear on a steam locomotive (a PRR E6s). ... In a steam engine, cutoff is the early closing of the cylinder inlet valve, to increase efficiency. ...


Of the few designs that were manufactured in quantity, those of the Hult Brothers Rotary Steam Engine Company of Stockholm, Sweden, and the spherical engine of Beauchamp Tower are notable. Tower's engines were used by the Great Eastern Railway to drive lighting dynamos on their locomotives, and by the Admiralty for driving dynamos on board the ships of the Royal Navy. They were eventually replaced in these niche applications by steam turbines. Beauchamp Tower (1845 – 1904) was an English inventor and engineer who is chiefly known for his discovery of full-film or hydrodynamic lubrication. ... The Great Eastern Railway (GER) was formed in 1862 as an amalgamation of the Eastern Counties Railway; and also with several other smaller railways: Norfolk, the Eastern Union, the Newmarket, the Harwich, the East Anglian Light and the East Suffolk; among others. ... Flag of the Lord High Admiral The Admiralty was formerly the authority in the United Kingdom responsible for the command of the Royal Navy. ... This article is about the navy of the United Kingdom. ...


Jet type

Invented by Australian engineer Alan Burns and developed in Britain by engineers at Pursuit Dynamics, this underwater jet engine uses high pressure steam to draw in water through an intake at the front and expel it at high speed through the rear. When steam condenses in water, a shock wave is created and is focused by the chamber to blast water out of the back. To improve the engine's efficiency, the engine draws in air through a vent ahead of the steam jet, which creates air bubbles and changes the way the steam mixes with the water. Professor Alan Burns (currently beardless) Professor Alan Burns is currently the head of the University of York Computer Science Department. ... A Pratt and Whitney turbofan engine for the F-15 Eagle is tested at Robins Air Force Base, Georgia, USA. The tunnel behind the engine muffles noise and allows exhaust to escape. ...


Unlike in conventional steam engines, there are no moving parts to wear out, and the exhaust water is only several degrees warmer in tests. The engine can also serve as pump and mixer. This type of system is referred to as 'PDX Technology' by Pursuit Dynamics.


Rocket type

The aeolipile represents the use of steam by the rocket-reaction principle, although not for direct propulsion. An illustration of Herons aeolipile An aeolipile is a device consisting of an air-tight chamber (usually a sphere or cylinder) with bent or curved pipes projecting from it, through which steam is expelled perpendicular to the radius of rotation. ...


In more modern times there has been limited use of steam for rocketry—particularly for rocket cars. The technique is simple in concept, simply fill a pressure vessel with hot water at high pressure, and open a valve leading to a suitable nozzle. The drop in pressure immediately boils some of the water and the steam leaves through a nozzle, giving a significant propulsive force.


It might be expected that water in the pressure vessel should be at high pressure; but in practice the pressure vessel has considerable mass, which reduces the acceleration of the vehicle. Therefore a much lower pressure is used, which permits a lighter pressure vessel, which in turn gives the highest final speed.


There are even speculative plans for interplanetary use. Although steam rockets are relatively inefficient in their use of propellant, this very well may not matter as the solar system is believed to have extremely large stores of water ice which can be used as propellant. Extracting this water and using it in interplanetary rockets requires several orders of magnitude less equipment than breaking it down to hydrogen and oxygen for conventional rocketry.[15]


Applications

Steam engines can be classified by their application:


Stationary engines

Stationary steam engines can be classified into two main types: A stationary steam engine, preserved at Tower Bridge in London. ...

The steam donkey is technically a stationary engine but is mounted on skids to be semi-portable. It is designed for logging use and can drag itself to a new location. Having secured the winch cable to a sturdy tree at the desired destination, the machine will move towards the anchor point as the cable is winched in. A winding engine is a stationary engine used to control a cable, for example at a pit head. ... A rolling mill is a machine or factory for shaping metal by passing it between rollers. ... A steam donkey is a type of stationary steam engine, constituted of frame, a boiler, & at least one winch. ... For other uses, see Power station (disambiguation). ... An ancient Chinese tomb model of a foot-powered mill, Eastern Han Dynasty (25 - 220 AD), Freer Gallery of Art. ... This article or section does not cite any references or sources. ... Cable railways are railways with very steep gradients and use stationary engines to haul the wagons up and down the hills. ... Cable Car in San Francisco A San Francisco cable car Winding drums on the London and Blackwall cable-operated railway, 1840. ... For delivered electrical power, see Electrical power industry. ... Tourists are entertained by the Vancouver steam clock A steam clock is a clock powered by steam. ... A steam donkey is a type of stationary steam engine, constituted of frame, a boiler, & at least one winch. ... Logging is the process in which trees are cut down usually as part of a timber harvest which is good for the environment. ...


Vehicle engines

Steam engines have been used to power a wide array of types of vehicle:

For other uses, see Steamboat (disambiguation). ... Paddle steamers - Lucerne-Switzerland Left: original paddlewheel from a paddle steamer on the lake of Lucerne. ... One of the last mainline steam locomotives built in the UK: British Railways Standard Class 9F 2-10-0 no. ... The 1923 Stanley Steam Car A steam car is a car (automobile) powered by a steam engine. ... Lorry Look up Lorry in Wiktionary, the free dictionary Can mean: A truck, in the sense of a commercial large goods vehicle. ... This article is about the construction vehicle. ... A steam shovel is a large steam-powered excavating machine designed for lifting and moving material such as rock and soil. ... // A traction engine (sometimes called a road locomotive) is a wheeled steam engine used to move heavy loads, plough ground or to provide power at a chosen location. ... Steam aircraft were unusual devices because of the difficulty in producing a powerplant with a high enough power to weight ratio to be practical. ...

Advantages

The strength of the steam engine for modern purposes is in its ability to convert heat from almost any source into mechanical work. Unlike the internal combustion engine, the steam engine is not particular about the source of heat. Most notably, without the use of a steam engine nuclear energy could not be harnessed for useful work, as a nuclear reactor does not directly generate either mechanical work or electrical energy—the reactor itself simply heats or boils water. It is the steam engine which converts the heat energy into useful work. Steam may also be produced without combustion of fuel, through solar concentrators. A demonstration power plant has been built using a central heat collecting tower and a large number of solar tracking mirrors, (called heliostats). (see Whitecliffs Project[7]) This article concerns the energy stored in the nuclei of atoms; for the use of nuclear fission as a power source, see Nuclear power. ... A Heliostat is a device that tracks the movement of the sun. ... White Cliffs Solar Power Station is Australias first solar power station. ...


Similar advantages are found in a different type of external combustion engine, the Stirling engine, which can offer efficient power (with advanced regenerators and large radiators) at the cost of a much lower power-to-size/weight ratio than even modern steam engines with compact boilers. Cut away diagram of a Rhombic Drive Beta Stirling Engine Design Pink - Hot cylinder wall Dark Grey - Cold cylinder wall (with coolant inlet and outlet pipes in Yellow) Dark Green - Thermal insulation separating the two cylinder ends Light Green - Displacer piston Dark Blue - Power piston Light Blue - Flywheels Not Shown...


Steam locomotives are especially advantageous at high elevations as they are not adversely affected by the lower atmospheric pressure. This was inadvertently discovered when steam locomotives operated at high altitudes in the mountains of South America were replaced by diesel-electric units of equivalent sea level power. These were quickly replaced by much more powerful locomotives capable of producing sufficient power at high altitude.


In Switzerland (Brienz Rothhorn) and Austria (Schafberg Bahn) new rack steam locomotives have proved very successful. They were designed based on a 1930s design of Swiss Locomotive and Machine Works (SLM) but with all of today's possible improvements like roller bearings, heat insulation, light-oil firing, improved inner streamlining, one-man-driving and so on. These resulted in 60 percent lower fuel consumption per passenger and massively reduced costs for maintenance and handling. Economics now are similar or better than with most advanced diesel or electric systems. Also a steam train with similar speed and capacity is 50 percent lighter than an electric or diesel train, thus, especially on rack railways, significantly reducing wear and tear on the track. Also, a new steam engine for a paddle steam ship on Lake Geneva, the Montreux, was designed and built, being the world's first full-size ship steam engine with an electronic remote control[8]. The steam group of SLM in 2000 created a wholly-owned company called DLM to design modern steam engines and steam locomotives. This radio control airplane is carrying a scale model of X-33 and is taking part in NASA research. ...


Efficiency

The efficiency of an engine can be calculated by dividing the number of joules of mechanical work that the engine produces by the number of joules of energy input to the engine by the burning fuel. The rest of the energy is dumped into the environment as heat. Thermodynamic efficiency (e) is defined as: where W is the absolute value of the work done in one thermodynamic cycle. ...


No pure heat engine can be more efficient than the Carnot cycle, in which heat is moved from a high temperature reservoir to one at a low temperature, and the efficiency depends on the temperature difference. Hence, steam engines should ideally be operated at the highest steam temperature possible (superheated steam), and release the waste heat at the lowest temperature possible. The Carnot cycle is a particular thermodynamic cycle, modeled on the Carnot heat engine, studied by Nicolas Léonard Sadi Carnot in the 1820s and expanded upon by Benoit Paul Émile Clapeyron in the 1830s and 40s. ... General arrangement of a superheater installation in a steam locomotive. ...


In practice, a steam engine exhausting the steam to atmosphere will have an efficiency (including the boiler) of 1% to 8%, but with the addition of a condenser and multiple expansion engines the efficiency may be greatly improved to 25% or better. A power station with steam reheat, etc. will achieve 30% to 42% efficiency. Combined cycle in which the burning material is first used to drive a gas turbine can produce 50% to 60% efficiency. It is also possible to capture the waste heat using cogeneration in which the residual steam is used for heating. It is therefore possible to use about 90% of the energy produced by burning fuel—only 10% of the energy produced by the combustion of the fuel goes wasted into the atmosphere. A combined cycle is characteristic of a power producing engine or plant that employs more than one thermodynamic cycle. ... This machine has a single-stage centrifugal compressor and turbine, a recuperator, and foil bearings. ... Not to be confused with California Highway Patrol. ...


The reason for varying efficiencies is because of the thermodynamic rule of the Carnot Cycle. The efficiency is the absolute temperature of the cold reservoir over the absolute temperature of the steam, subtracted from one. As the temperature changes in seasons, the efficiency changes with it, unless the cold reservoir is kept in an isothermal state. It should be noted that the Carnot Cycle calculations require absolute temperatures. Thermodynamics (Greek: thermos = heat and dynamic = change) is the physics of energy, heat, work, entropy and the spontaneity of processes. ... The Carnot cycle is a particular thermodynamic cycle, modeled on the Carnot heat engine, studied by Nicolas Léonard Sadi Carnot in the 1820s and expanded upon by Benoit Paul Émile Clapeyron in the 1830s and 40s. ... Absolute zero is the lowest temperature that can be obtained in any macroscopic system. ... An isothermal process is a thermodynamic process in which the temperature of the system stays constant; ΔT = 0. ...


One source of inefficiency is that the condenser causes losses by being somewhat hotter than the outside world, although this can be mitigated by condensing the steam in a heat exchanger and using the recovered heat, for example to pre-heat the air being used in the burner of an external combustion engine. A heat exchanger is a device built for efficient heat transfer from one fluid to another, whether the fluids are separated by a solid wall so that they never mix, or the fluids are directly contacted. ...


The operation of the engine portion alone is not dependent upon steam; any pressurized gas may be used. Compressed air is sometimes used to test or demonstrate small model "steam" engines.


See also

Wikimedia Commons has media related to:
Steam engines

Image File history File links Commons-logo. ... See Steam engine, Steam power during the Industrial Revolution. ... During the Industrial Revolution, steam power replaced water power and muscle power (which often came from horses) as the primary source of power in use in industry. ... A boiler is a closed vessel in which water or other fluid is heated. ... The Walschaert valve gear on a steam locomotive (a PRR E6s). ... LMS Compound 4-4-0 41199 at Derby in 1948, recently outshopped with British Railways on her tender. ... A Live Steam Festival displaying equipment ranging from small stationary engines to full-size locomotives. ... Tourists are entertained by the Vancouver steam clock A steam clock is a clock powered by steam. ... The 1923 Stanley Steam Car A steam car is a car (automobile) powered by a steam engine. ... For other uses, see Steamboat (disambiguation). ... Internal combustion piston engine Components of a typical, four stroke cycle, internal combustion piston engine. ... The Heat Regenerative Cyclone Engine is a new approach to an old design, the steam engine developed by James Watt in the 18th century. ...

Steam Fairs

UK
  • Carter's Steam Fair - touring vintage fairground, including several rides powered by steam engines
  • Great Dorset Steam Fair - 5-day annual show in England - specialises in showing engines being used in their original context: heavy haulage, threshing, ploughing, sawing, road making, etc
USA

Carters Steam Fair - Pinkneys Green May 2007 Carters Steam Fair - Pinkneys Green May 2007 Carters Steam Fair - Pinkneys Green May 2007 Carters Royal Berkshire Steam Fair is a traveling fair based in southeast England. ... The Great Dorset Steam Fair is an annual show featuring steam powered vehicles and machinery. ... The Antique Gas & Steam Engine Museum (AGSEM) is a living-history museum founded in 1969 located on 55 acres of county-owned land on the outskirts of Vista, California. ...

Steam museums

See also: List of pumping stations, many of which are, or were, steam-powered.
UK
Canada

Pumping station Van Sasse in Grave, the Netherlands Pumping station Van Sasse in Grave, the Netherlands Pumping stations are facilities including pumps and equipment for pumping fluids from one place to another. ... There are very few or no other articles that link to this one. ... The pumping station viewed from the canal; showing tunnel under railway, boilerhouse, enginehouse and chimney Wilton Water, the canal and railway from the pumping station The boilerhouse The beam gallery with the 1812 engine in operation Crofton Pumping Station is a pumping station, located near the village of Great Bedwyn... Hollycombe steam fair holds Edwardian rides originating from the 1870s. ... At Kempton Park are two large triple expansion steam engines, each engine of simular size to that used in titanic and rated at about 1008hp. ... Kew Bridge Steam Museum houses a museum of water delivery and a collection of steam engines including the worlds largest running steam engine. ... The Ontario Agricultural Museum is located in Milton, Ontario and recreates rural life in the 1800s in Ontario. ... Coordinates: , Country Province Region Halton Established 1818 Government  - Town Mayor Gord Krantzz [1]  - MPs Bonnie Brown, Garth Turner  - MPPs Ted Chudleigh, Kevin Flynn Population (2006)  - Town 53,939 Time zone Eastern (EST) (UTC-5) Area code(s) L9T Website: Town of Milton Milton (2006 census population 53,939) is a... Steam Era is a festival held every Labour Day Weekend in the Town of Milton, Ontario featuring historic steam powered tractors. ...

References

  1. ^ Heron Alexandrinus (Hero of Alexandria) (c. 62 CE): Spiritalia seu Pneumatica. Reprinted 1998 by K G Saur GmbH, Munich. ISBN 3-519-01413-0.
  2. ^ Fundamentals of Jet Propulsion with Applications
  3. ^ Ahmad Y Hassan (1976). Taqi al-Din and Arabic Mechanical Engineering, p. 34-35. Institute for the History of Arabic Science, University of Aleppo.
  4. ^ a b University of Rochester, NY, The growth of the steam engine online history resource, chapter one.
  5. ^ Thurston, Robert Henry (1883). A History of the Growth of the Steam-Engine. London: Keegan Paul and Trench (reprinted Adamant 2001), pp21-22. ISBN 1402162057. 
  6. ^ University of Rochester, NY, The growth of the steam engine online history resource, chapter seven.
  7. ^ a b Tyler, David (2004): Oxford Dictionary of National Biography. Oxford University Press.
  8. ^ Suttcliffe, Andrea (2004): Steam: The Untold Story of America's First Great Invention. Paulgrave Macmillan, New York. ISBN 1-4039-6261-8.
  9. ^ Burton, Anthony (2000): Richard Trevithick, Giant of Steam. Aurum Press, London. ISBN 1-85410-728-3.
  10. ^ Hulse David K (1999): "The early development of the steam engine"; TEE Publishing, Leamington Spa, UK, ISBN, 85761 107 1
  11. ^ Riemsdijk, John van: (1994) Compound Locomotives, pp. 2-3; Atlantic Publishers Penrhyn, England. ISBN No 0 906899 61 3
  12. ^ Carpenter, George W. & contributors (2000): La locomotive à vapeur (English translation of André Chapelon's seminal work (1938): pp. 56-72; 120 et seq; Camden Miniature Steam Services, UK. ISBN 0 9536523 0 0
  13. ^ Bell, A.M. (1950). Locomotives. London: Virtue and Company, pp61-63. 
  14. ^ Riemsdijk, John van: (1994) Compound Locomotives, Atlantic Publishers Penrhyn, England. ISBN No 0 906899 61 3
  15. ^ Near Earth Object Fuel website, accessed on 2 November 2006.

BCE redirects here. ... Ahmad Y. al Hassan (born 1925) Chevalier of the Legion d’Honneur: Historian of Islamic and Arabic science and technology. ... University of Aleppo (also called Aleppo University, the University freely uses both English names) is a []public university]] located in Aleppo, Syria. ... is the 306th day of the year (307th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...

External links

Steam museums

  • Bancroft Mill Engine[9], Barnoldswick. Movie of engine operating here [10]
  • Country Living Museum in Dudley, Staffs UK: full-size working replica of the first Newcomen atmospheric engine of 1712.
  • Newcomen Engine House, Dartmouth, Devon, England, UK
  • Hamilton Museum of Steam and Technology in Hamilton, Ontario. An old municipal pumphouse dating to 1860 with its original two Woolf Compound Rotative Beam Engines, one of which still operates.

  Results from FactBites:
 
Steam engine - Wikipedia, the free encyclopedia (5391 words)
Steam engines were used as the prime mover in pumps, locomotives, steam ships, traction engines, steam lorries and other road vehicles, and were essential to the Industrial Revolution.
Steam turbines, technically a type of steam engine, are still widely used for generating electricity, but older types have been almost entirely replaced by internal combustion engines and electric motors.
One of the advantages of the steam engine is that any heat source can be used to raise steam in the boiler; but the most common is a fire fueled by wood, coal or oil or the utilisation of the heat energy generated in a nuclear reactor.
Steam Engine - MSN Encarta (1998 words)
Steam that is to be used for power or heating purposes is usually generated in a boiler.
By varying the point in the engine cycle at which steam is admitted to the cylinder, it is possible to vary the amount of compression and expansion in the cylinder and hence to vary the power output of the engine.
Further improvement in the design of steam engines is afforded by the uniflow engine, which uses the piston itself as a valve and in which all portions of the cylinder remain at approximately the same temperature when the engine is operating.
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