Victorian Trade Card

RARE Large Advertising Trade Card W Stowasser Sohne Band Brass Instruments 1890

RARE Large Advertising Trade Card W Stowasser Sohne Band Brass Instruments 1890
RARE Large Advertising Trade Card W Stowasser Sohne Band Brass Instruments 1890

RARE Large Advertising Trade Card W Stowasser Sohne Band Brass Instruments 1890

RARE - Large Advertising Trade Card. For offer - a very nice old piece of ephemera! Fresh from an estate in Upstate NY. Never offered on the market until now. Vintage, Old, antique, Original - NOT Reproductions - Guaranteed!!

Embossed, gilt, on heavy card stock. Manufacture of band instruments with steam engine - Graslitz Austria and Verona Italia. Card measres 6 x 4 inches. Please see photos for details. If you collect advertising, 19th century Austrian / German music history, Bohemia, musicology, brass and wind instruments, etc.

This is a nice one for your paper or ephemera collection. A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. Brass instruments are also called labrosones[1] or labrophones, from Latin and Greek elements meaning'lip' and'sound'. There are several factors involved in producing different pitches on a brass instrument.

Slides, valves, crooks (though they are rarely used today), or keys are used to change vibratory length of tubing, thus changing the available harmonic series, while the player's embouchure, lip tension and air flow serve to select the specific harmonic produced from the available series. The view of most scholars (see organology) is that the term "brass instrument" should be defined by the way the sound is made, as above, and not by whether the instrument is actually made of brass.

Thus one finds brass instruments made of wood, like the alphorn, the cornett, the serpent and the didgeridoo, while some woodwind instruments are made of brass, like the saxophone. Modern brass instruments generally come in one of two families. Valved brass instruments use a set of valves (typically three or four but as many as seven or more in some cases) operated by the player's fingers that introduce additional tubing, or crooks, into the instrument, changing its overall length.

This family includes all of the modern brass instruments except the trombone: the trumpet, horn (also called French horn), euphonium, and tuba, as well as the cornet, flugelhorn, tenor horn (alto horn), baritone horn, sousaphone, and the mellophone. As valved instruments are predominant among the brasses today, a more thorough discussion of their workings can be found below. The valves are usually piston valves, but can be rotary valves; the latter are the norm for the horn (except in France) and are also common on the tuba. Slide brass instruments use a slide to change the length of tubing.

The main instruments in this category are the trombone family, though valve trombones are occasionally used, especially in jazz. The trombone family's ancestor, the sackbut, and the folk instrument bazooka are also in the slide family. Part of a series on.

There are two other families that have, in general, become functionally obsolete for practical purposes. Instruments of both types, however, are sometimes used for period-instrument performances of Baroque or Classical pieces. In more modern compositions, they are occasionally used for their intonation or tone color. Natural brass instruments only play notes in the instrument's harmonic series.

These include the bugle and older variants of the trumpet and horn. The trumpet was a natural brass instrument prior to about 1795, and the horn before about 1820. In the 18th century, makers developed interchangeable crooks of different lengths, which let players use a single instrument in more than one key.

Natural instruments are still played for period performances and some ceremonial functions, and are occasionally found in more modern scores, such as those by Richard Wagner and Richard Strauss. Keyed or Fingered brass instruments used holes along the body of the instrument, which were covered by fingers or by finger-operated pads (keys) in a similar way to a woodwind instrument.

These included the cornett, serpent, ophicleide, keyed bugle and keyed trumpet. They are more difficult to play than valved instruments. Brass instruments may also be characterised by two generalizations about geometry of the bore, that is, the tubing between the mouthpiece and the flaring of the tubing into the bell.

Those two generalizations are with regard to. The degree of taper or conicity of the bore and.

The diameter of the bore with respect to its length. While all modern valved and slide brass instruments consist in part of conical and in part of cylindrical tubing, they are divided as follows. Cylindrical bore brass instruments are those in which approximately constant diameter tubing predominates.

Cylindrical bore brass instruments are generally perceived as having a brighter, more penetrating tone quality compared to conical bore brass instruments. The trumpet, and all trombones are cylindrical bore. In particular, the slide design of the trombone necessitates this. Conical bore brass instruments are those in which tubing of constantly increasing diameter predominates.

Conical bore instruments are generally perceived as having a more mellow tone quality than the cylindrical bore brass instruments. The "British brass band" group of instruments fall into this category. This includes the flugelhorn, cornet, tenor horn (alto horn), baritone horn, horn, euphonium and tuba. Some conical bore brass instruments are more conical than others.

For example, the flugelhorn differs from the cornet by having a higher percentage of its tubing length conical than does the cornet, in addition to possessing a wider bore than the cornet. In the 1910s and 1920s, the E. Couturier company built brass band instruments utilizing a patent for a continuous conical bore without cylindrical portions even for the valves or tuning slide.

The resonances of a brass instrument resemble a harmonic series, with the exception of the lowest resonance, which is significantly lower than the fundamental frequency of the series that the other resonances are overtones of. [2] Depending on the instrument and the skill of the player, the missing fundamental of the series can still be played as a pedal tone, which relies mainly on vibration at the overtone frequencies to produce the fundamental pitch. [3][4] The bore diameter in relation to length determines whether the fundamental tone or the first overtone is the lowest partial practically available to the player in terms of playability and musicality, dividing brass instruments into whole-tube and half-tube instruments. These terms stem from a comparison to organ pipes, which produce the same pitch as the fundamental pedal tone of a brass instrument of equal length.

Neither the horns nor the trumpet could produce the 1st note of the harmonic series... A horn giving the C of an open 8 ft organ pipe had to be 16 ft (5 m). Half its length was practically useless...

It was found that if the calibre of tube was sufficiently enlarged in proportion to its length, the instrument could be relied upon to give its fundamental note in all normal circumstances. Whole-tube instruments have larger bores in relation to tubing length, and can play the fundamental tone with ease and precision. The tuba and euphonium are examples of whole-tube brass instruments. Half-tube instruments have smaller bores in relation to tubing length and cannot easily or accurately play the fundamental tone.

The second partial (first overtone) is the lowest note of each tubing length practical to play on half-tube instruments. The trumpet and horn are examples of half-tube brass instruments. The instruments in this list fall for various reasons outside the scope of much of the discussion above regarding families of brass instruments. Natural horn (no valves or slides-except tuning crooks in some cases). Vuvuzela (simple short horn, origins disputed but achieved fame or notoriety through many plastic examples in the 2010 World Cup).

Main article: Brass instrument valves. Valves are used to change the length of tubing of a brass instrument allowing the player to reach the notes of various harmonic series. Each valve pressed diverts the air stream through additional tubing, individually or in conjunction with other valves. This lengthens the vibrating air column thus lowering the fundamental tone and associated harmonic series produced by the instrument. Designs exist, although rare, in which this behaviour is reversed, i.

Pressing a valve removes a length of tubing rather than adding one. One modern example of such an ascending valve is the Yamaha YSL-350C trombone, [7] in which the extra valve tubing is normally engaged to pitch the instrument in B? And pressing the thumb lever removes a whole step to pitch the instrument in C. A core standard valve layout based on the action of three valves had become almost universal by (at latest) 1864 as witnessed by Arban's method published in that year. The effect of a particular combination of valves may be seen in the table below. This table is correct for the core three-valve layout on almost any modern valved brass instrument. The most common four-valve layout is a superset of the well-established three-valve layout and is noted in the table, despite the exposition of four-valve and also five-valve systems (the latter used on the tuba) being incomplete in this article. Valve combination and effect on pitch. Since valves lower the pitch, a valve that makes a pitch too low (flat) creates an interval wider than desired, while a valve that plays sharp creates an interval narrower than desired. Intonation deficiencies of brass instruments that are independent of the tuning or temperament system are inherent in the physics of the most popular valve design, which uses a small number of valves in combination to avoid redundant and heavy lengths of tubing[8] this is entirely separate from the slight deficiencies between Western music's dominant equal (even) temperament system and the just (not equal) temperament of the harmonic series itself. Since each lengthening of the tubing has an inversely proportional effect on pitch (Pitch of brass instruments), while pitch perception is logarithmic, there is no way for a simple, uncompensated addition of length to be correct in every combination when compared with the pitches of the open tubing and the other valves. For example, given a length of tubing equaling 100 units of length when open, one may obtain the following tuning discrepancies.

Valve combination and creation of pitch discrepancies. Playing notes using valves (notably 1st + 3rd and 1st + 2nd + 3rd) requires compensation to adjust the tuning appropriately, either by the player's lip-and-breath control, via mechanical assistance of some sort, or, in the case of horns, by the position of the stopping hand in the bell.

T' stands for trigger on a trombone. Traditionally[10] the valves lower the pitch of the instrument by adding extra lengths of tubing based on a just tuning. 1/8 of main tube, making an interval of 9:8, a pythagorean major second.

1/15 of main tube, making an interval of 16:15, a just minor second. 1/5 of main tube, making an interval of 6:5, a just minor third. Combining the valves and the harmonics of the instrument leads to the following ratios and comparisons to 12-tone equal tuning and to a common five-limit tuning in C. The additional tubing for each valve usually features a short tuning slide of its own for fine adjustment of the valve's tuning, except when it is too short to make this practicable.

For the first and third valves this is often designed to be adjusted as the instrument is played, to account for the deficiencies in the valve system. In most trumpets and cornets, the compensation must be provided by extending the third valve slide with the third or fourth finger, and the first valve slide with the left hand thumb (see Trigger or throw below). This is used to lower the pitch of the 1-3 and 1-2-3 valve combinations.

On the trumpet and cornet, these valve combinations correspond to low D, low C? Low G, and low F? So chromatically, to stay in tune, one must use this method.

In instruments with a fourth valve, such as tubas, euphoniums, piccolo trumpets, etc. That valve lowers the pitch by a perfect fourth; this is used to compensate for the sharpness of the valve combinations 1-3 and 1-2-3 (4 replaces 1-3, 2-4 replaces 1-2-3). All three normal valves may be used in addition to the fourth to increase the instrument's range downwards by a perfect fourth, although with increasingly severe intonation problems.

When four-valved models without any kind of compensation play in the corresponding register, the sharpness becomes so severe that players must finger the note a half-step below the one they are trying to play. This eliminates the note a half-step above their open fundamental. Manufacturers of low brass instruments may choose one or a combination of four basic approaches to compensate for the tuning difficulties, whose respective merits are subject to debate. In the Compensation system, each of the first two (or three) valves has an additional set of tubing extending from the back of the valve. When the third (or fourth) valve is depressed in combination with another one, the air is routed through both the usual set of tubing plus the extra one, so that the pitch is lowered by an appropriate amount. This allows compensating instruments to play with accurate intonation in the octave below their open second partial, which is critical for tubas and euphoniums in much of their repertoire. The compensating system was applied to horns to serve a different purpose. It was used to allow a double horn in F and B? To ease playing difficulties in the high register.

In contrast to the system in use in tubas and euphoniums, the default'side' of the horn is the longer F horn, with secondary lengths of tubing coming into play when the first, second or third valves are pressed; pressing the thumb valve takes these secondary valve slides and the extra length of main tubing out of play to produce a shorter B? A later "full double" design has completely separate valve section tubing for the two sides, and is considered superior, although rather heavier in weight.

Initially, compensated instruments tended to sound stuffy and blow less freely due to the air being doubled back through the main valves. In early designs, this led to sharp bends in the tubing and other obstructions of the air-flow. Some manufacturers therefore preferred adding more'straight' valves instead, which for example could be pitched a little lower than the 2nd and 1st valves and were intended to be used instead of these in the respective valve combinations. While no longer featured in euphoniums for decades, many professional tubas are still built like this, with five valves being common on CC- and BB? Tubas and five or six valves on F-tubas.

Compensating double horns can also suffer from the stuffiness resulting from the air being passed through the valve section twice, but as this really only affects the longer F side, a compensating double can be very useful for a 1st or 3rd horn player, who uses the F side less. Additional sets of slides on each valve. Another approach was the addition of two sets of slides for different parts of the range. Some euphoniums and tubas were built like this, but today, this approach has become highly exotic for all instruments except horns, where it is the norm, usually in a double, sometimes even triple configuration.

Flugelhorn with three pistons and a trigger. Some valved brass instruments provide triggers or throws that manually lengthen (or, less commonly, shorten) the main tuning slide, a valve slide, or the main tubing. These mechanisms alter the pitch of notes that are naturally sharp in a specific register of the instrument, or shift the instrument to another playing range. Triggers and throws permit speedy adjustment while playing. Trigger is used in two senses.

A trigger can be a mechanical lever that lengthens a slide when pressed in a contrary direction. Triggers are sprung in such a way that they return the slide to its original position when released. The term "trigger" also describes a device engaging a valve to lengthen the main tubing, e. Lowering the key of certain trombones from B? A throw is a simple metal grip for the player's finger or thumb, attached to a valve slide.

The general term "throw" can describe a u-hook, a saddle (u-shaped grips), or a ring (ring-shape grip) in which a player's finger or thumb rests. A player extends a finger or thumb to lengthen a slide, and retracts the finger to return the slide to its original position.

Examples of instruments that use triggers or throws. Triggers or throws are sometimes found on the first valve slide. They are operated by the player's thumb and are used to adjust a large range of notes using the first valve, most notably the player's written top line F, the A above directly above that, and the B? Other notes that require the first valve slide, but are not as problematic without it include the first line E, the F above that, the A above that, and the third line B?

Triggers or throws are often found on the third valve slide. They are operated by the player's fourth finger, and are used to adjust the lower D and C? Trumpets typically use throws, whilst cornets may have a throw or trigger. Main article: Types of trombone § F attachment. Trombone triggers are primarily but not exclusively[7] installed on the F-trigger, bass, and contrabass trombones[11] to alter the length of tubing, thus making certain ranges and pitches more accessible.

A euphonium occasionally has a trigger on valves other than 2 (especially 3), although many professional quality euphoniums, and indeed other brass band instruments, have a trigger for the main tuning slide. The two major types of valve mechanisms are rotary valves and piston valves. The first piston valve instruments were developed just after the start of the 19th century. The Stölzel valve (invented by Heinrich Stölzel in 1814) was an early variety.

In the mid 19th century the Vienna valve was an improved design. However many professional musicians preferred rotary valves for quicker, more reliable action, until better designs of piston valves were mass manufactured towards the end of the 19th century. Since the early decades of the 20th century, piston valves have been the most common on brass instruments except for the orchestral horn and the tuba. [13] See also the article Brass Instrument Valves. Sound production in brass instruments.

Because the player of a brass instrument has direct control of the prime vibrator (the lips), brass instruments exploit the player's ability to select the harmonic at which the instrument's column of air vibrates. By making the instrument about twice as long as the equivalent woodwind instrument and starting with the second harmonic, players can get a good range of notes simply by varying the tension of their lips (see embouchure). Most brass instruments are fitted with a removable mouthpiece. Different shapes, sizes and styles of mouthpiece may be used to suit different embouchures, or to more easily produce certain tonal characteristics.

Trumpets, trombones, and tubas are characteristically fitted with a cupped mouthpiece, while horns are fitted with a conical mouthpiece. One interesting difference between a woodwind instrument and a brass instrument is that woodwind instruments are non-directional. This means that the sound produced propagates in all directions with approximately equal volume.

Brass instruments, on the other hand, are highly directional, with most of the sound produced traveling straight outward from the bell. This difference makes it significantly more difficult to record a brass instrument accurately. It also plays a major role in some performance situations, such as in marching bands.

Traditionally the instruments are normally made of brass, polished and then lacquered to prevent corrosion. Some higher quality and higher cost instruments use gold or silver plating to prevent corrosion.

Alternatives to brass include other alloys containing significant amounts of copper or silver. These alloys are biostatic due to the oligodynamic effect, and thus suppress growth of molds, fungi or bacteria. Brass instruments constructed from stainless steel or aluminium have good sound quality but are rapidly colonized by microorganisms and become unpleasant to play. Most higher quality instruments are designed to prevent or reduce galvanic corrosion between any steel in the valves and springs, and the brass of the tubing. This may take the form of desiccant design, to keep the valves dry, sacrificial zincs, replaceable valve cores and springs, plastic insulating washers, or nonconductive or noble materials for the valve cores and springs.

Some instruments use several such features. [not specific enough to verify]. The process of making the large open end (bell) of a brass instrument is called metal beating.

In making the bell of, for example, a trumpet, a person lays out a pattern and shapes sheet metal into a bell-shape using templates, machine tools, handtools, and blueprints. The maker cuts out the bell blank, using hand or power shears.

He hammers the blank over a bell-shaped mandrel, and butts the seam, using a notching tool. The seam is brazed, using a torch and smoothed using a hammer or file. A draw bench or arbor press equipped with expandable lead plug is used to shape and smooth the bell and bell neck over a mandrel. A lathe is used to spin the bell head and to form a bead at the edge of bell head.

Previously shaped bell necks are annealed, using a hand torch to soften the metal for further bending. Scratches are removed from the bell using abrasive-coated cloth. A few specialty instruments are made from wood.

Instruments made mostly from plastic emerged in the 2010s as a cheaper and more robust alternative to brass. [14][15] Plastic instruments could come in almost any colour. The sound plastic instruments produce is different from the one of brass, lacquer, gold or silver. While originally seen as a gimmick, these plastic models have found increasing popularity of the last decade and are now viewed as practice tools that make for more convenient travel as well as a cheaper option for beginning players. Brass instruments are one of the major classical instrument families and are played across a range of musical ensembles.

Orchestras include a varying number of brass instruments depending on music style and era, typically. Two to four French horns.

Baroque and classical period orchestras may include valveless trumpets or bugles, or have valved trumpets/cornets playing these parts, and they may include valveless horns, or have valved horns playing these parts. Romantic, modern, and contemporary orchestras may include larger numbers of brass including more exotic instruments. Concert bands generally have a larger brass section than an orchestra, typically. Four to six trumpets or cornets. Two to four tenor trombones.

One to two bass trombones. Two to three euphoniums or baritone horns.

British brass bands are made up entirely of brass, mostly conical bore instruments. Quintets are common small brass ensembles; a quintet typically contains. One tuba or bass trombone. Big bands and other jazz bands commonly contain cylindrical bore brass instruments. A big band typically includes. One bass trombone (in place of one of the tenor trombones). Smaller jazz ensembles may include a single trumpet or trombone soloist. Two alto horns, also called "charchetas" and "saxores". Single brass instruments are also often used to accompany other instruments or ensembles such as an organ or a choir.

Drum and bugle corps (modern). A steam engine is a heat engine that performs mechanical work using steam as its working fluid.

The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force is transformed, by a connecting rod and flywheel, into rotational force for work. The term "steam engine" is generally applied only to reciprocating engines as just described, not to the steam turbine. Steam engines are external combustion engines, [1] where the working fluid is separated from the combustion products.

The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle. A steam ploughing engine by Kemna. In general usage, the term steam engine can refer to either complete steam plants including boilers etc. Such as railway steam locomotives and portable engines, or may refer to the piston or turbine machinery alone, as in the beam engine and stationary steam engine. Although steam-driven devices were known as early as the aeolipile in the first century AD, with a few other uses recorded in the 16th and 17th century, Thomas Savery is considered the inventor of the first commercially-used steam powered device, a steam pump that used steam pressure operating directly on the water. The first commercially successful engine that could transmit continuous power to a machine was developed in 1712 by Thomas Newcomen. James Watt made a critical improvement by removing spent steam to a separate vessel for condensation, greatly improving the amount of work obtained per unit of fuel consumed. By the 19th century, stationary steam engines powered the factories of the Industrial Revolution. Reciprocating piston type steam engines were the dominant source of power until the early 20th century, when advances in the design of electric motors and internal combustion engines gradually resulted in the replacement of reciprocating (piston) steam engines in commercial usage. Steam turbines replaced reciprocating engines in power generation, due to lower cost, higher operating speed, and higher efficiency. Main article: History of the steam engine. The first recorded rudimentary steam-powered "engine" was the aeolipile described by Hero of Alexandria, a Greek mathematician and engineer in Roman Egypt in the first century AD.

[3] In the following centuries, the few steam-powered "engines" known were, like the aeolipile, [4] essentially experimental devices used by inventors to demonstrate the properties of steam. A rudimentary steam turbine device was described by Taqi al-Din[5] in Ottoman Egypt in 1551 and by Giovanni Branca[6] in Italy in 1629. [7] Jerónimo de Ayanz y Beaumont received patents in 1606 for 50 steam-powered inventions, including a water pump for draining inundated mines. [8] Denis Papin, a Huguenot, did some useful work on the steam digester in 1679, and first used a piston to raise weights in 1690.

The first commercial steam-powered device was a water pump, developed in 1698 by Thomas Savery. [10] It used condensing steam to create a vacuum which raised water from below and then used steam pressure to raise it higher.

Small engines were effective though larger models were problematic. They had a limited lift height and were prone to boiler explosions. Savery's engine was used in mines, pumping stations and supplying water to water wheels that powered textile machinery.

[11] Savery's engine was of low cost. [12] It continued to be manufactured until the late 18th century. [13] One engine was still known to be operating in 1820. Jacob Leupold's steam engine, 1720. The first commercially successful engine that could transmit continuous power to a machine was the atmospheric engine, invented by Thomas Newcomen around 1712.

[b][16] It improved on Savery's steam pump, using a piston as proposed by Papin. Newcomen's engine was relatively inefficient, and mostly used for pumping water. It worked by creating a partial vacuum by condensing steam under a piston within a cylinder. It was employed for draining mine workings at depths originally impractical using traditional means, and for providing reusable water for driving waterwheels at factories sited away from a suitable "head". Water that passed over the wheel was pumped up into a storage reservoir above the wheel.

[17][18] In 1780 James Pickard patented the use of a flywheel and crankshaft to provide rotative motion from an improved Newcomen engine. In 1720, Jacob Leupold described a two-cylinder high-pressure steam engine. [20] The invention was published in his major work "Theatri Machinarum Hydraulicarum".

[21] The engine used two heavy pistons to provide motion to a water pump. The two pistons shared a common four-way rotary valve connected directly to a steam boiler.

Boulton and Watt's early engines used half as much coal as John Smeaton's improved version of Newcomen's. [22] Newcomen's and Watt's early engines were "atmospheric". They were powered by air pressure pushing a piston into the partial vacuum generated by condensing steam, instead of the pressure of expanding steam. The engine cylinders had to be large because the only usable force acting on them was atmospheric pressure. Watt developed his engine further, modifying it to provide a rotary motion suitable for driving machinery.

This enabled factories to be sited away from rivers, and accelerated the pace of the Industrial Revolution. The meaning of high pressure, together with an actual value above ambient, depends on the era in which the term was used. For early use of the term Van Reimsdijk[25] refers to steam being at a sufficiently high pressure that it could be exhausted to atmosphere without reliance on a vacuum to enable it to perform useful work. 22 states that Watt's condensing engines were known, at the time, as low pressure compared to high pressure, non-condensing engines of the same period. Watt's patent prevented others from making high pressure and compound engines.

Shortly after Watt's patent expired in 1800, Richard Trevithick and, separately, Oliver Evans in 1801[24][26] introduced engines using high-pressure steam; Trevithick obtained his high-pressure engine patent in 1802, [27] and Evans had made several working models before then. [28] These were much more powerful for a given cylinder size than previous engines and could be made small enough for transport applications. Thereafter, technological developments and improvements in manufacturing techniques (partly brought about by the adoption of the steam engine as a power source) resulted in the design of more efficient engines that could be smaller, faster, or more powerful, depending on the intended application. The Cornish engine was developed by Trevithick and others in the 1810s. [29] It was a compound cycle engine that used high-pressure steam expansively, then condensed the low-pressure steam, making it relatively efficient. The Cornish engine had irregular motion and torque though the cycle, limiting it mainly to pumping. Cornish engines were used in mines and for water supply until the late 19th century. Main article: Stationary steam engine.

Early builders of stationary steam engines considered that horizontal cylinders would be subject to excessive wear. Their engines were therefore arranged with the piston axis vertical. In time the horizontal arrangement became more popular, allowing compact, but powerful engines to be fitted in smaller spaces. The acme of the horizontal engine was the Corliss steam engine, patented in 1849, which was a four-valve counter flow engine with separate steam admission and exhaust valves and automatic variable steam cutoff. When Corliss was given the Rumford Medal, the committee said that "no one invention since Watt's time has so enhanced the efficiency of the steam engine".

[31] In addition to using 30% less steam, it provided more uniform speed due to variable steam cut off, making it well suited to manufacturing, especially cotton spinning. Main article: History of steam road vehicles.

Steam powered road-locomotive from England. The first experimental road-going steam-powered vehicles were built in the late 18th century, but it was not until after Richard Trevithick had developed the use of high-pressure steam, around 1800, that mobile steam engines became a practical proposition.

The first half of the 19th century saw great progress in steam vehicle design, and by the 1850s it was becoming viable to produce them on a commercial basis. This progress was dampened by legislation which limited or prohibited the use of steam-powered vehicles on roads.

Improvements in vehicle technology continued from the 1860s to the 1920s. Steam road vehicles were used for many applications.

In the 20th century, the rapid development of internal combustion engine technology led to the demise of the steam engine as a source of propulsion of vehicles on a commercial basis, with relatively few remaining in use beyond the Second World War. Many of these vehicles were acquired by enthusiasts for preservation, and numerous examples are still in existence. In the 1960s, the air pollution problems in California gave rise to a brief period of interest in developing and studying steam-powered vehicles as a possible means of reducing the pollution. Apart from interest by steam enthusiasts, the occasional replica vehicle, and experimental technology, no steam vehicles are in production at present. A triple-expansion marine steam engine on the 1907 oceangoing tug Hercules. Main article: Marine steam engine.

Near the end of the 19th century, compound engines came into widespread use. Compound engines exhausted steam into successively larger cylinders to accommodate the higher volumes at reduced pressures, giving improved efficiency. Main articles: Steam locomotive, Traction engine, and Steam tractor.

Vintage image of steam train. As the development of steam engines progressed through the 18th century, various attempts were made to apply them to road and railway use. [32] In 1784, William Murdoch, a Scottish inventor, built a model steam road locomotive. [33] An early working model of a steam rail locomotive was designed and constructed by steamboat pioneer John Fitch in the United States probably during the 1780s or 1790s. [34] His steam locomotive used interior bladed wheels[clarification needed] guided by rails or tracks.

Steam train [Grand Trunk 600] and operators, Glengarry County, Ontario, [between 1895 and 1910]. The first full-scale working railway steam locomotive was built by Richard Trevithick in the United Kingdom and, on 21 February 1804, the world's first railway journey took place as Trevithick's unnamed steam locomotive hauled a train along the tramway from the Pen-y-darren ironworks, near Merthyr Tydfil to Abercynon in south Wales. [32][35][36] The design incorporated a number of important innovations that included using high-pressure steam which reduced the weight of the engine and increased its efficiency. Trevithick visited the Newcastle area later in 1804 and the colliery railways in north-east England became the leading centre for experimentation and development of steam locomotives. Trevithick continued his own experiments using a trio of locomotives, concluding with the Catch Me Who Can in 1808.

Only four years later, the successful twin-cylinder locomotive Salamanca by Matthew Murray was used by the edge railed rack and pinion Middleton Railway. [38] In 1825 George Stephenson built the Locomotion for the Stockton and Darlington Railway. This was the first public steam railway in the world and then in 1829, he built The Rocket which was entered in and won the Rainhill Trials. Steam locomotives continued to be manufactured until the late twentieth century in places such as China and the former East Germany (where the DR Class 52.80 was produced).

The final major evolution of the steam engine design was the use of steam turbines starting in the late part of the 19th century. Steam turbines are generally more efficient than reciprocating piston type steam engines (for outputs above several hundred horsepower), have fewer moving parts, and provide rotary power directly instead of through a connecting rod system or similar means. [41] Steam turbines virtually replaced reciprocating engines in electricity generating stations early in the 20th century, where their efficiency, higher speed appropriate to generator service, and smooth rotation were advantages. Today most electric power is provided by steam turbines. In the United States, 90% of the electric power is produced in this way using a variety of heat sources.

Main article: Advanced steam technology. Although the reciprocating steam engine is no longer in widespread commercial use, various companies are exploring or exploiting the potential of the engine as an alternative to internal combustion engines. The company Energiprojekt AB in Sweden has made progress in using modern materials for harnessing the power of steam. The efficiency of Energiprojekt's steam engine reaches some 27-30% on high-pressure engines.

It is a single-step, 5-cylinder engine (no compound) with superheated steam and consumes approx. 4 kg (8.8 lb) of steam per kWh. Components and accessories of steam engines. There are two fundamental components of a steam plant: the boiler or steam generator, and the "motor unit", referred to itself as a "steam engine".

Stationary steam engines in fixed buildings may have the boiler and engine in separate buildings some distance apart. For portable or mobile use, such as steam locomotives, the two are mounted together. The widely used reciprocating engine typically consisted of a cast-iron cylinder, piston, connecting rod and beam or a crank and flywheel, and miscellaneous linkages. Steam was alternately supplied and exhausted by one or more valves.

Speed control was either automatic, using a governor, or by a manual valve. The cylinder casting contained steam supply and exhaust ports. Engines equipped with a condenser are a separate type than those that exhaust to the atmosphere. Other components are often present; pumps (such as an injector) to supply water to the boiler during operation, condensers to recirculate the water and recover the latent heat of vaporisation, and superheaters to raise the temperature of the steam above its saturated vapour point, and various mechanisms to increase the draft for fireboxes.

When coal is used, a chain or screw stoking mechanism and its drive engine or motor may be included to move the fuel from a supply bin (bunker) to the firebox. The heat required for boiling the water and raising the temperature of the steam can be derived from various sources, most commonly from burning combustible materials with an appropriate supply of air in a closed space e.

In the case of model or toy steam engines and a few full scale cases, the heat source can be an electric heating element. Main article: Boiler (steam generator). An industrial boiler used for a stationary steam engine. Boilers are pressure vessels that contain water to be boiled, and features that transfer the heat to the water as effectively as possible. The two most common types are.

Water-tube boiler - water is passed through tubes surrounded by hot gas. Fire-tube boiler - hot gas is passed through tubes immersed in water, the same water also circulates in a water jacket surrounding the firebox and, in high-output locomotive boilers, also passes through tubes in the firebox itself (thermic syphons and security circulators). Fire-tube boilers were the main type used for early high-pressure steam (typical steam locomotive practice), but they were to a large extent displaced by more economical water tube boilers in the late 19th century for marine propulsion and large stationary applications.

Many boilers raise the temperature of the steam after it has left that part of the boiler where it is in contact with the water. Known as superheating it turns'wet steam' into'superheated steam'.

It avoids the steam condensing in the engine cylinders, and gives a significantly higher efficiency. Further information: § Types of motor units. In a steam engine, a piston or steam turbine or any other similar device for doing mechanical work takes a supply of steam at high pressure and temperature and gives out a supply of steam at lower pressure and temperature, using as much of the difference in steam energy as possible to do mechanical work.

These "motor units" are often called'steam engines' in their own right. Engines using compressed air or other gases differ from steam engines only in details that depend on the nature of the gas although compressed air has been used in steam engines without change. As with all heat engines, the majority of primary energy must be emitted as waste heat at relatively low temperature. The simplest cold sink is to vent the steam to the environment. This is often used on steam locomotives to avoid the weight and bulk of condensers.

Some of the released steam is vented up the chimney so as to increase the draw on the fire, which greatly increases engine power, but reduces efficiency. Sometimes the waste heat from the engine is useful itself, and in those cases, very high overall efficiency can be obtained. Steam engines in stationary power plants use surface condensers as a cold sink. The condensers are cooled by water flow from oceans, rivers, lakes, and often by cooling towers which evaporate water to provide cooling energy removal. The resulting condensed hot water (condensate), is then pumped back up to pressure and sent back to the boiler. A dry-type cooling tower is similar to an automobile radiator and is used in locations where water is costly. Waste heat can also be ejected by evaporative (wet) cooling towers, which use a secondary external water circuit that evaporates some of flow to the air. River boats initially used a jet condenser in which cold water from the river is injected into the exhaust steam from the engine. Cooling water and condensate mix. While this was also applied for sea-going vessels, generally after only a few days of operation the boiler would become coated with deposited salt, reducing performance and increasing the risk of a boiler explosion. Evaporated water cannot be used for subsequent purposes (other than rain somewhere), whereas river water can be re-used.

In all cases, the steam plant boiler feed water, which must be kept pure, is kept separate from the cooling water or air. An injector uses a jet of steam to force water into the boiler. Injectors are inefficient but simple enough to be suitable for use on locomotives. Most steam engines have a means to supply boiler water whilst at pressure, so that they may be run continuously.

Utility and industrial boilers commonly use multi-stage centrifugal pumps; however, other types are used. Another means of supplying lower-pressure boiler feed water is an injector, which uses a steam jet usually supplied from the boiler. Injectors became popular in the 1850s but are no longer widely used, except in applications such as steam locomotives. [50] It is the pressurization of the water that circulates through the steam boiler that allows the water to be raised to temperatures well above 100 °C (212 °F) boiling point of water at one atmospheric pressure, and by that means to increase the efficiency of the steam cycle. Richard's indicator instrument of 1875.

For safety reasons, nearly all steam engines are equipped with mechanisms to monitor the boiler, such as a pressure gauge and a sight glass to monitor the water level. Many engines, stationary and mobile, are also fitted with a governor to regulate the speed of the engine without the need for human interference. The most useful instrument for analyzing the performance of steam engines is the steam engine indicator.

[24] The steam engine indicator traces on paper the pressure in the cylinder throughout the cycle, which can be used to spot various problems and calculate developed horsepower. The engine indicator can also be used on internal combustion engines. See image of indicator diagram below (in Types of motor units section). Centrifugal governor in the Boulton & Watt engine 1788 Lap Engine.

The centrifugal governor was adopted by James Watt for use on a steam engine in 1788 after Watt's partner Boulton saw one on the equipment of a flour mill Boulton & Watt were building. [53] The governor could not actually hold a set speed, because it would assume a new constant speed in response to load changes. The governor was able to handle smaller variations such as those caused by fluctuating heat load to the boiler. Also, there was a tendency for oscillation whenever there was a speed change. As a consequence, engines equipped only with this governor were not suitable for operations requiring constant speed, such as cotton spinning. [54] The governor was improved over time and coupled with variable steam cut off, good speed control in response to changes in load was attainable near the end of the 19th century.

In a simple engine, or "single expansion engine" the charge of steam passes through the entire expansion process in an individual cylinder, although a simple engine may have one or more individual cylinders. [55] It is then exhausted directly into the atmosphere or into a condenser.

As steam expands in passing through a high-pressure engine, its temperature drops because no heat is being added to the system; this is known as adiabatic expansion and results in steam entering the cylinder at high temperature and leaving at lower temperature. This causes a cycle of heating and cooling of the cylinder with every stroke, which is a source of inefficiency. The dominant efficiency loss in reciprocating steam engines is cylinder condensation and re-evaporation.

The steam cylinder and adjacent metal parts/ports operate at a temperature about halfway between the steam admission saturation temperature and the saturation temperature corresponding to the exhaust pressure. As high-pressure steam is admitted into the working cylinder, much of the high-temperature steam is condensed as water droplets onto the metal surfaces, significantly reducing the steam available for expansive work. When the expanding steam reaches low pressure (especially during the exhaust stroke), the previously deposited water droplets that had just been formed within the cylinder/ports now boil away (re-evaporation) and this steam does no further work in the cylinder. There are practical limits on the expansion ratio of a steam engine cylinder, as increasing cylinder surface area tends to exacerbate the cylinder condensation and re-evaporation issues.

This negates the theoretical advantages associated with a high ratio of expansion in an individual cylinder. A method to lessen the magnitude of energy loss to a very long cylinder 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, with the overall temperature drop within each cylinder reduced considerably. By expanding the steam in steps with smaller temperature range (within each cylinder) the condensation and re-evaporation efficiency issue (described above) is reduced.

This reduces the magnitude of cylinder heating and cooling, increasing the efficiency of the engine. By staging the expansion in multiple cylinders, variations of torque can be reduced. [17] To derive equal work from lower-pressure cylinder requires a larger cylinder volume as this steam occupies a greater volume. Therefore, the bore, and in rare cases the stroke, are increased in low-pressure cylinders, resulting in larger cylinders. Double-expansion (usually known as compound) engines expanded the steam in two stages.

The pairs may be duplicated or the work of the large low-pressure cylinder can be split with one high-pressure cylinder exhausting into one or the other, giving a three-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 V (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 four-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 three-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. 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), usually to a condenser. It is a logical extension of the compound engine (described 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 cylinders of progressively increasing diameter. These cylinders are designed to divide the work into equal shares for each expansion stage.

As with the double-expansion engine, if space is at a premium, then two smaller cylinders may be used for the low-pressure stage. Multiple-expansion engines typically had the cylinders arranged inline, but various other formations were used. In the late 19th century, the Yarrow-Schlick-Tweedy balancing "system" was used on some marine triple-expansion engines. Y-S-T engines divided the low-pressure expansion stages between two cylinders, one at each end of the engine. This allowed the crankshaft to be better balanced, resulting in a smoother, faster-responding engine which ran with less vibration.

This made the four-cylinder triple-expansion engine popular with large passenger liners (such as the Olympic class), but this was ultimately replaced by the virtually vibration-free turbine engine. The image in this section shows 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. Land-based steam engines could exhaust their steam to atmosphere, as feed water was usually readily available.

Prior to and during World War I, 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, such as the dreadnought battleships, 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.

This was the common mill engine of the mid 19th century. Note the slide valve with concave, almost "D" shaped, underside. Schematic Indicator diagram showing the four events in a double piston stroke. See: Monitoring and control (above).

In most reciprocating piston engines, the steam reverses its direction of flow at each stroke (counterflow), entering and exhausting from the same end of the cylinder. 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. Many 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 1850s, there were attempts to overcome this problem by means of various patent valve gears with a separate, variable cutoff expansion valve 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 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.

Corliss, and later, poppet valve gears had separate admission and exhaust valves driven by trip mechanisms or cams profiled so as to give ideal events; most of these gears never succeeded outside of the stationary marketplace due to various other issues including leakage and more delicate mechanisms. 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. 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.

Schematic animation of a uniflow steam engine. The poppet valves are controlled by the rotating camshaft at the top. High-pressure steam enters, red, and exhausts, yellow. Main article: Uniflow steam engine.

Uniflow engines attempt to remedy the difficulties arising from the usual counterflow cycle where, during 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 the working temperature. The aim of the uniflow is to remedy this defect and improve efficiency by providing an additional port uncovered by the piston at the end of each stroke making the steam flow only in one direction. By this means, the simple-expansion uniflow engine gives efficiency equivalent to that of classic compound systems with the added advantage of superior part-load performance, and comparable efficiency to turbines for smaller engines below one thousand horsepower. However, the thermal expansion gradient uniflow engines produce along the cylinder wall gives practical difficulties.

A rotor of a modern steam turbine, used in a power plant. A steam turbine consists of one or more rotors (rotating discs) mounted on a drive shaft, alternating with a series of stators (static discs) fixed to the turbine casing. 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 often exhausts into a surface 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. In the vast majority of large electric generating stations, turbines are directly connected to generators with no reduction gearing. Typical speeds are 3600 revolutions per minute (RPM) in the United States with 60 Hertz power, and 3000 RPM in Europe and other countries with 50 Hertz electric power systems. In nuclear power applications, the turbines typically run at half these speeds, 1800 RPM and 1500 RPM.

A turbine rotor is also only capable of providing power when rotating in one direction. Therefore, a reversing stage or gearbox is usually required where power is required in the opposite direction.

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 (in the 1990s about 90% of the world's electric production was by use of steam turbines)[2] however the recent widespread application of large gas turbine units and typical combined cycle power plants has resulted in reduction of this percentage to the 80% regime for steam turbines.

In electricity production, the high speed of turbine rotation matches well with the speed of modern electric generators, which are typically direct connected to their driving turbines. In recent decades, reciprocating Diesel engines, and gas turbines, have almost entirely supplanted steam propulsion for marine applications.

Virtually all nuclear power plants generate electricity by heating water to provide steam that drives a turbine connected to an electrical generator. A limited number of steam turbine railroad locomotives were manufactured. Elsewhere, notably in the United States, 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. Operation of a simple oscillating cylinder steam engine. Main article: Oscillating cylinder steam engine. An oscillating cylinder steam engine is a variant of the simple expansion steam engine which does not require valves to direct steam into and out of the cylinder.

Instead of valves, the entire cylinder rocks, or oscillates, such that one or more holes in the cylinder line up with holes in a fixed port face or in the pivot mounting (trunnion). 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. 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. They were eventually replaced in these niche applications by steam turbines. Line drawing of a sphere suspended between two uprights forming a horizontal axis.

Two right-angle jet arms at the circumference expel steam that has been produced by boiling water in a closed vessel under the two uprights, which are hollow and let steam flow into the interior of the sphere. An aeolipile rotates due to the steam escaping from the arms. No practical use was made of this effect.

The aeolipile represents the use of steam by the rocket-reaction principle, although not for direct propulsion. In more modern times there has been limited use of steam for rocketry - particularly for rocket cars. Steam rocketry works by filling a pressure vessel with hot water at high pressure and opening a valve leading to a suitable nozzle.

The drop in pressure immediately boils some of the water and the steam leaves through a nozzle, creating a propulsive force. Ferdinand Verbiest's carriage was powered by an aeolipile in 1679. Steam engines possess boilers and other components that are pressure vessels that contain a great deal of potential energy. Steam escapes and boiler explosions (typically BLEVEs) can and have in the past caused great loss of life.

While variations in standards may exist in different countries, stringent legal, testing, training, care with manufacture, operation and certification is applied to ensure safety. Insufficient water in the boiler causing overheating and vessel failure. Buildup of sediment and scale which cause local hot spots, especially in riverboats using dirty feed water. Pressure vessel failure of the boiler due to inadequate construction or maintenance.

Escape of steam from pipework/boiler causing scalding. Steam engines frequently possess two independent mechanisms for ensuring that the pressure in the boiler does not go too high; one may be adjusted by the user, the second is typically designed as an ultimate fail-safe. Such safety valves traditionally used a simple lever to restrain a plug valve in the top of a boiler. One end of the lever carried a weight or spring that restrained the valve against steam pressure. Early valves could be adjusted by engine drivers, leading to many accidents when a driver fastened the valve down to allow greater steam pressure and more power from the engine. The more recent type of safety valve uses an adjustable spring-loaded valve, which is locked such that operators may not tamper with its adjustment unless a seal is illegally broken. This arrangement is considerably safer. Lead fusible plugs may be present in the crown of the boiler's firebox.

If the water level drops, such that the temperature of the firebox crown increases significantly, the lead melts and the steam escapes, warning the operators, who may then manually suppress the fire. Except in the smallest of boilers the steam escape has little effect on dampening the fire. The plugs are also too small in area to lower steam pressure significantly, depressurizing the boiler. If they were any larger, the volume of escaping steam would itself endanger the crew.

See also: Thermodynamics and Heat transfer. Flow diagram of the four main devices used in the Rankine cycle. Boiler or steam generator 3. Condenser; where Q=heat and W=work.

Most of the heat is rejected as waste. The Rankine cycle is the fundamental thermodynamic underpinning of the steam engine. The cycle is an arrangement of components as is typically used for simple power production, and utilizes the phase change of water (boiling water producing steam, condensing exhaust steam, producing liquid water) to provide a practical heat/power conversion system. The heat is supplied externally to a closed loop with some of the heat added being converted to work and the waste heat being removed in a condenser.

The Rankine cycle is used in virtually all steam power production applications. In the 1990s, Rankine steam cycles generated about 90% of all electric power used throughout the world, including virtually all solar, biomass, coal and nuclear power plants. It is named after William John Macquorn Rankine, a Scottish polymath. The Rankine cycle is sometimes referred to as a practical Carnot cycle because, when an efficient turbine is used, the TS diagram begins to resemble the Carnot cycle. The main difference is that heat addition (in the boiler) and rejection (in the condenser) are isobaric (constant pressure) processes in the Rankine cycle and isothermal (constant temperature) processes in the theoretical Carnot cycle. In this cycle, a pump is used to pressurize the working fluid which is received from the condenser as a liquid not as a gas. Pumping the working fluid in liquid form during the cycle requires a small fraction of the energy to transport it compared to the energy needed to compress the working fluid in gaseous form in a compressor (as in the Carnot cycle). The cycle of a reciprocating steam engine differs from that of turbines because of condensation and re-evaporation occurring in the cylinder or in the steam inlet passages. The working fluid in a Rankine cycle can operate as a closed loop system, where the working fluid is recycled continuously, or may be an "open loop" system, where the exhaust steam is directly released to the atmosphere, and a separate source of water feeding the boiler is supplied. Normally water is the fluid of choice due to its favourable properties, such as non-toxic and unreactive chemistry, abundance, low cost, and its thermodynamic properties. Mercury is the working fluid in the mercury vapor turbine. Low boiling hydrocarbons can be used in a binary cycle.

The steam engine contributed much to the development of thermodynamic theory; however, the only applications of scientific theory that influenced the steam engine were the original concepts of harnessing the power of steam and atmospheric pressure and knowledge of properties of heat and steam. The experimental measurements made by Watt on a model steam engine led to the development of the separate condenser. Watt independently discovered latent heat, which was confirmed by the original discoverer Joseph Black, who also advised Watt on experimental procedures. Watt was also aware of the change in the boiling point of water with pressure.

Otherwise, the improvements to the engine itself were more mechanical in nature. [13] The thermodynamic concepts of the Rankine cycle did give engineers the understanding needed to calculate efficiency which aided the development of modern high-pressure and -temperature boilers and the steam turbine. See also: Engine efficiency § Steam engine. The efficiency of an engine cycle can be calculated by dividing the energy output of mechanical work that the engine produces by the energy put into the engine by the burning fuel. The historical measure of a steam engine's energy efficiency was its "duty".

The concept of duty was first introduced by Watt in order to illustrate how much more efficient his engines were over the earlier Newcomen designs. Duty is the number of foot-pounds of work delivered by burning one bushel (94 pounds) of coal.

The best examples of Newcomen designs had a duty of about 7 million, but most were closer to 5 million. Watt's original low-pressure designs were able to deliver duty as high as 25 million, but averaged about 17. This was a three-fold improvement over the average Newcomen design. Early Watt engines equipped with high-pressure steam improved this to 65 million.

No 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. For the greatest efficiency, steam engines should be operated at the highest steam temperature possible (superheated steam), and release the waste heat at the lowest temperature possible. The efficiency of a Rankine cycle is usually limited by the working fluid. Without the pressure reaching supercritical levels for the working fluid, the temperature range over which the cycle can operate is small; in steam turbines, turbine entry temperatures are typically 565 °C (the creep limit of stainless steel) and condenser temperatures are around 30 °C. This gives a theoretical Carnot efficiency of about 63% compared with an actual efficiency of 42% for a modern coal-fired power station.

This low turbine entry temperature (compared with a gas turbine) is why the Rankine cycle is often used as a bottoming cycle in combined-cycle gas turbine power stations. One principal advantage the Rankine cycle holds over others is that during the compression stage relatively little work is required to drive the pump, the working fluid being in its liquid phase at this point.

By condensing the fluid, the work required by the pump consumes only 1% to 3% of the turbine (or reciprocating engine) power and contributes to a much higher efficiency for a real cycle. The benefit of this is lost somewhat due to the lower heat addition temperature. Gas turbines, for instance, have turbine entry temperatures approaching 1500 °C. Nonetheless, the efficiencies of actual large steam cycles and large modern simple cycle gas turbines are fairly well matched. In practice, a reciprocating steam engine cycle exhausting the steam to atmosphere will typically have an efficiency (including the boiler) in the range of 1-10%, but with the addition of a condenser, Corliss valves, multiple expansion, and high steam pressure/temperature, it may be greatly improved, historically into the range of 10-20%, and very rarely slightly higher.

A modern, large electrical power station (producing several hundred megawatts of electrical output) with steam reheat, economizer etc. Will achieve efficiency in the mid 40% range, with the most efficient units approaching 50% thermal efficiency. It is also possible to capture the waste heat using cogeneration in which the waste heat is used for heating a lower boiling point working fluid or as a heat source for district heating via saturated low-pressure steam. This item is in the category "Collectibles\Advertising\Merchandise & Memorabilia\Victorian Trade Cards\Other Victorian Trade Cards". The seller is "dalebooks" and is located in this country: US.

This item can be shipped worldwide.

  • Type of Advertising: Trade Card
  • Modified Item: No
  • Country/Region of Manufacture: Austria
  • Date of Creation: 1890
  • Brand: Stowasser

RARE Large Advertising Trade Card W Stowasser Sohne Band Brass Instruments 1890