Definition
Steam engine- engine external combustion, which converts the energy of the steam into mechanical work.
Invention...
History of the invention of steam engines begins its countdown from the first century AD. We become aware of the device described by Heron of Alexandria, and powered by steam. The steam coming out of the tangential nozzles fixed on the ball caused the engine to rotate. The real steam turbine was invented in medieval Egypt much later. Its inventor is the Arab philosopher, astronomer and engineer of the 16th century Tagi al-Dinome. The skewer with blades began to rotate due to the steam flows directed at it. In 1629, a similar solution was proposed by the Italian engineer Giovanni Branca. The main disadvantage of these inventions was that the steam flows were dissipative, and this certainly leads to large energy losses.
Further development steam engines, could not occur without proper conditions. It was necessary and economic well-being and the need for these inventions. Naturally, these conditions did not exist and could not exist until the 16th century, in view of such low level development. At the end of the 17th century, a couple of copies of these inventions were created, but were not taken seriously. The creator of the first is the Spaniard Ayanz de Beaumont. Edward Somerset - a scientist from England in 1663 published a project and installed a steam-powered device for raising water to the wall of the Great Tower at Raglan Castle. But since everything new is difficult for a person to perceive, no one dared to finance this project. The Frenchman Denis Papin is considered the creator of the steam boiler. In the course of experiments on the displacement of air from the cylinder, by means of an explosion of gunpowder, he found out that a complete vacuum can be obtained only with the help of boiling water. And for the cycle to be automatic, it is necessary that steam is produced separately in the boiler. Papen is credited with inventing the boat, which was propelled by jet power in a combination of the concepts of Taghi-al-Din and Severi; also his invention is considered safety valve.
All described devices have not been used and found to be practical. Even the "fire plant" designed by Thomas Savery in 1698 did not last long. Due to the high pressure created by the steam in the liquid containers, they often exploded. Therefore, his invention was considered unsafe. In light of all these failures history of the invention of steam engines could stop, but no.
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The pictures show the Cugno steam tractor. As you can see, it was very bulky and inconvenient to manage.
An English blacksmith, Thomas Newcomen in 1712 demonstrated his " naturally aspirated engine". It was an improved model of the Severi steam engine. It got its use as pumping water from mines. In the mine pump, the rocker was connected to a rod that descended into the mine to the pump chamber. The reciprocating movements of the thrust were transmitted to the pump piston, which supplied water upwards. The Newcomen engine was popular and in demand. It is with the advent this engine It is customary to link the beginning of the English Industrial Revolution. In Russia, the first vacuum machine was designed by I.I. Polzunov in 1763, and a year later the project was implemented. It powered blower furs at the Barnaul Kolyvano-Voskresensky factories. The idea of Oliver Evans and Richard Trevithick to use high pressure steam has brought significant results. R. Trevithick successfully built high-pressure industrial single-stroke engines, known as "Cornish engines". Despite the increase in efficiency, the number of cases of explosions of boilers that could not withstand enormous pressure. Therefore, it was customary to use a safety valve to release excess pressure.
The French inventor Nicolas-Joseph Cugno demonstrated in 1769 the first working self-propelled steam engine. vehicle: "fardier à vapeur" (steam cart). His invention can be considered the first car. self propelled steam tractor used as a mobile source of mechanical energy, it proved to be effective, it set in motion various CX machines. In 1788, a steamboat was built by John Fitch, which provided regular service along the Delaware River between Philadelphia and Burlington. He had a capacity of only 30 people, and moved at speeds up to 12 km / h. On February 21, 1804, the first self-propelled railway steam train was demonstrated at the Penydarren Iron Works at Merthyr Tydfil in South Wales, which was built by Richard Trevithick.
15 there is no doubt that one of the main driving forces of progress is human laziness and the desire for comfort. This is confirmed by countless fairy tales, where the transport moves "at the behest of the pike", and the lucky ones have magical assistants that save the owner from having to make at least some physical effort. But since nothing is done “on its own” in reality, throughout the history of mankind, the best minds have pored over inventions that would help make these dreams come true.
Speaking in the language of physics and technology, it was necessary to invent a device that could convert one or another type of energy into useful mechanical work. Since ancient times, the main and main source of energy has been the muscular strength of man and animals, and all available technical devices in best case helped to use it more rationally and productively. Later, people learned to use the power of wind and water flowing or falling from a height, making them work in wind and water engines. However, the power of such engines was not great, and it was necessary to master more promising types of energy - thermal, chemical and electrical.
The first known thermal device powered by steam was built by the Greek scientist Archimedes in the 3rd century BC. BC e. It was a cannon, one end of which was heated, and then water was poured into it. Instantly heating up, the water turned into steam, which, expanding, pushed the core out of the vent. Two centuries later, another Greek scientist Heron of Alexandria created and described another heat engine - a hollow iron ball that can rotate around a horizontal axis. From a closed boiler with boiling water, steam entered the ball through a tube, from where it went out through curved nozzles, while the ball came into rotation.
Steamboat Mayflower on the Mississippi River. 1855
For a millennium and a half, the “Heron ball” was just a fun toy, and only in the 16th century. scientists thought about the possibility of practical application of thermal energy. The famous inventor Leonardo da Vinci was the first to suggest that steam could perform useful work. This is evidenced by the drawings in his manuscripts depicting a cylinder and a piston. Da Vinci argued that if water is placed under the piston in the cylinder, and the cylinder itself is heated, the resulting water vapor will expand, which will force it to look for a way out and move the piston up. At the same time, the Arab engineer Tagi al Din developed a design for a device in which steam directed to the blades fixed along the rim of the wheel rotated the spit. In the 17th century a similar machine was built by the Italian inventor Giovanni Branca. A steam-powered anchor device alternately raised and lowered a pair of pestles in mortars, as a result of which grain could be crushed. However, in these prototypes of steam turbines, the steam flow was too diffuse, resulting in a significant loss of energy.
Until the end of the XVII century. the created steam engines were rather single technical curiosities, since there were no economic prerequisites for their mass use yet. In the 1670s, the French inventor Denis Papin and the Dutch physicist Christian Huygens worked on a machine in which the piston rose due to the expansion of gases when gunpowder exploded. In 1680, Papin created a version of the engine that used water instead of gunpowder. It was poured into the cylinder under the piston, and the cylinder itself was heated from below, while the resulting steam raised the piston. Then the cylinder was cooled, and the steam in it condensed, turning back into water.
Steam engine D. Papin.
The piston, as in the case of a powder engine, fell under the influence of its weight and atmospheric pressure. Papen is also considered the inventor of the steam boiler, since it was he who realized that in order to automate the cycle, steam must be supplied to the cylinder from the outside (therefore, the steam engine is considered an external combustion engine: the fuel that heats the water is burned outside the working cylinder).
The first steam engine, which was not without success used in production, was the "fire installation" designed in 1698 by the English military engineer Thomas Savery. This device, called "the miner's friend" by the inventor himself, was a steam pump that was used to turn the wheels of a water mill and to pump water out of mines. The machine was not very efficient due to big losses heat during the cooling of the container and quite dangerous in operation, because due to the high pressure of steam, pipelines and engine tanks often exploded.
In 1712, the English blacksmith Thomas Newcomen demonstrated his "atmospheric engine". It was an improved Severi steam engine, in which operating pressure steam was significantly reduced, therefore, the engine became safer. The steam from the boiler entered the base of the cylinder and raised the piston.
How many horses?
The concept of horsepower as a unit of steam engine power was introduced by J. Watt. But T. Severi was the first to use the term back in 1698. At the same time, their approach was different. Savery estimated the power of his pump, based on the fact that it would take 10 horses to change as they get tired per day. Watt took into account only those working for this moment a pair of harnessed horses. As a result, it turned out that Severi estimated the power of almost identical steam engines at 10 "horses", and Watt only at two.
Pumping water from a coal mine using a steam engine T. Newcomen. Illustration from The Universal Magazine. 1747
K. F. von Breda. Portrait of James Watt. 1792
When cold water was injected into the cylinder, the steam condensed, a vacuum was formed, and under the influence of atmospheric pressure the piston fell. This return stroke removed water from the cylinder and, by means of a chain connected to the rocker arm, raised the pump rod. It was Newcomen's machine that was the first steam engine, with which it is customary to associate the beginning of the industrial revolution in England. It was so successful that it was used in Europe for more than 50 years. Nevertheless, some important changes were made to the design. In particular, in 1718, the Englishman Henry Bayton invented a distributing mechanism that automatically turned on or off steam and let water in. He also added a safety valve to the steam boiler.
The project of the world's first steam engine capable of directly actuating any working mechanisms was proposed in 1763 by the Russian inventor Ivan Ivanovich Polzunov, a mechanic at the Kolyvano-Voskresensky mining plants of Altai. His car was a two-cylinder vacuum unit with pistons connected by a chain thrown over a pulley. All actions in it were performed automatically. Instead of a prototype, the factory authorities demanded that they immediately build a large machine for a powerful blower. The engine was built for almost two years, and the inventor did not live to see the launch. The machine was successfully tested and put into operation. Within three months, it not only justified the costs, but also made a profit. However, after a while the boiler started leaking, and for some unknown reason, the car was not repaired.
Around the same time, the Scotsman James Watt worked on the creation of a steam engine in England. He was engaged in the improvement of the Newcomen engine. It was clear that the main drawback of Newcomen's machine was the alternating heating and cooling of the cylinder. Watt suggested that the cylinder could remain hot all the time if the steam was diverted to a separate reservoir through a pipeline with a valve before condensation. Moreover, the cylinder can remain hot and the condenser cold if they are covered with heat-insulating material on the outside. In 1768, he received a patent for his invention, but he was able to build a machine only in 1776. It turned out to be twice more efficient than a car Newcomen.
Polzunov's steam engine.
I. I. Polzunov.
In 1782, the first universal steam engine created by Watt appeared double action. Its cover was equipped with an oil seal, which provided the piston with free movement of the rod and at the same time prevented steam from escaping from the cylinder. Steam entered the cylinder from both sides of the piston alternately, so the piston made both a working and a reverse stroke with the help of steam, which was not the case in previous machines. Watt received a patent for his "rotary steam engine", and it began to be widely used to drive machine tools and machines, first in spinning and weaving mills, and then in other industrial enterprises.
Locomotive "Puffing Billy".
Model of the steam engine by J. Watt.
In addition to industry, steam engines have firmly taken their place in agriculture and in transport. Back in 1850, the English inventor William Howard used a compact mobile steam engine for plowing. In 1879, the peasant Fyodor Blinov from the Saratov province built and patented the world's first crawler powered by a 20 hp steam engine. With.
The first model of a car with a steam engine in 1769 was tested by the French inventor Nicolas José Cugno, his creation became known as the "small steam cart of Cugno". A year later, the public was presented with the “big steam cart of Cugno”. In 1788, a steamboat service was organized in the United States along the Delaware River between the cities of Philadelphia and Burlington. The steamer designed by John Fitch could take on board 30 passengers and carry them at a speed of 7-8 miles per hour. And in 1804, Richard Trevithick demonstrated the first steam-powered self-propelled railway locomotive, built at the Penydarren ironworks in Mer Tyr Tydville (South Wales).
Despite all the efforts of engineers, the rather low efficiency of steam engines could not be increased, and by the end of the 19th century. with full dedication, the machines that served technical progress began to gradually lose ground. On road transport they gave way to engines internal combustion, on the railway and in the industry of electric motors. However, steam engines (in particular steam turbines) are still widely used in heat power engineering and in certain types of transport.
Steam turbine of a steel mill.
The history of steam engines goes back to the 1st century AD, when Heron of Alexandria first described the aeolipil. More than 1500 years later, in 1551, the Ottoman scientist Takiyuddin al-Shami described primitive turbines driven by steam, and in 1629 a similar discovery was made by Giovanni Branca. These devices were steam roasting skewers or small gears. Basically, such designs were used by inventors to demonstrate the power of steam, and proof that it should not be underestimated.
In the 1700s, miners faced a serious challenge - the need to pump water out of deep mines. The same power of steam came to the rescue. With the help of steam energy, it was possible to pump water out of the mines. This application unlocked the potential power of steam and led to the invention of the steam engine. Steam power plants came later. Main principle, on which steam engines operate, is to "condense water vapor to create a partial vacuum."
Thomas Savery and the first industrial engines
Thomas Savery first invented the steam pump in 1698 to pump water. This invention is often referred to as the "fire engine" or engine for "raising water with fire". The steam pump, patented by Severi, worked by boiling water until it was completely converted to steam. Then each droplet of steam rose into the tank, and a vacuum formed in the container where the water was originally. This vacuum was used to pump water from deep mines. But the solution turned out to be temporary, since the steam energy was only enough to pump out water from a depth of several meters. Another disadvantage of this design was the use of steam pressure to draw out the water sucked into the tank. The pressure was too high for the boilers, which caused a series of violent explosions.
Low pressure machines
The high coal consumption of Newcomen steam engines was reduced by the innovations of James Watt. machine cylinder low pressure was equipped with thermal protection, a separate condenser and a drain mechanism for condensed water. Thus, coal consumption in low-pressure machines has been reduced by more than 50%.
Ivan Polzunov and the first two-cylinder steam engine
Ivan Polzunov invented the first steam engine in Russia. His two-cylinder steam engine was more powerful than British naturally aspirated engines. They reached a power of 24 kW. A model of Polzunov's two-cylinder steam engine is on display at the Barnaul Museum.
Thomas Newcomen steam engine
In 1712, Thomas Newcomen invented the steam engine, which was very successful from a practical point of view. His model consisted of a piston or cylinder that propelled a huge wooden deck to run a water pump. The reverse stroke in the machine was due to gravity, which pushed down the end of the deck from the side of the pump. Newcomen's machine was in active use for 50 years. Then it was recognized as ineffective, since it required a lot of energy to actively function. It was necessary to heat the cylinder, as it constantly cooled down, as a result of which a lot of fuel was burned.
Improvements by James Watt
James Watt made a real revolution in the history of the development of steam engines by introducing a separate capacitor into the original design. He introduced this innovation in 1765. But only 11 years later, it was possible to achieve a design that could be used on an industrial scale. The most a big problem in the implementation of Watt's idea was the technology of creating a huge piston to maintain the required amount of vacuum. But soon the technology made great progress, and as soon as the patent received sufficient funding, the Watt steam engine began to be actively used on railways and ships. In the US, more than 60,000 cars were powered by steam engines from 1897 to 1927.
High pressure machines
In 1800 Richard Trevithick invented the high pressure steam engine. Compared to all previously invented designs of steam engines, this option was the most powerful. But the design proposed by Oliver Evans was truly successful. It was based on the idea of driving the engine with steam rather than condensing the steam to create a vacuum. Evans invented the first non-condensing steam engine powered by high pressure, in 1805. The machine was stationary and developed 30 revolutions per minute. This machine was originally used to power saws. Such machines were supported by huge reservoirs of water, which was heated by a heat source placed directly under the reservoir, which made it possible to efficiently generate the right amount of steam.
Soon these steam engines were widely used in motor boats and on the railroads, in 1802 and 1829 respectively. Almost half a century later, the first steam cars appeared. Charles Algernon Parsons invented the first steam turbine in 1880. By the early 20th century, steam engines were widely used in automobile and shipbuilding.
Cornish steam engines
Richard Trevetick tried to improve the steam pump invented by Watt. It was modified for use in the Cornish cauldrons invented by Trevetick. The efficiency of the Cornish steam engine was greatly improved by William Sims, Arthur Woolf and Samuel Gruz. Updated Cornish steam engines consisted of insulated pipes, engine and boilers for increased efficiency.
WATT, JAMES (Watt, James, 1736-1819), Scottish engineer and inventor. Born January 19, 1736 in Greenock, near Glasgow (Scotland), in the family of a merchant. Due to poor health, Watt formally studied little, but learned a lot on his own. As a teenager, he was fond of astronomy, chemical experiments, learned to do everything with his own hands, and even earned the title of “jack of all trades” from those around him.
Most people consider him the inventor of the steam engine, but this is not entirely true.
Steam engines built by D. Papin, T. Severi, I. Polzunov, T. Newcomen began to work in the mines long before D. Watt. They differed constructively, but the main thing in them was that the movement of the piston was caused by alternate heating and cooling of the working cylinder. Because of this, they were slow and consumed a lot of fuel.
January 19, 1736 was born James Watt (James Watt, 1736-1819), an outstanding Scottish engineer and inventor, who became famous primarily as the creator of an improved steam engine. But he also left a bright mark on the history of critical care medicine with his collaboration with the Pneumatic Medical Institute of Thomas Beddoes (Beddoes, Thomas, 1760-1808). James Watt supplied the laboratories of the institute with the necessary equipment. Thanks to his participation, the first inhalers, spirometers, gas meters, etc. were created and tested at the Pneumatic Institute.
James Watt himself, as well as his wife and one of his sons, have repeatedly participated in scientific experiments. "Pneumatic Institute" became a real scientific center, which studied the properties of various gases and their effect on the human body. It can be said that Thomas Beddoe and his collaborators were the pioneers and forerunners of modern respiratory therapy. Unfortunately, Thomas Beddoe erroneously believed that tuberculosis was caused by excess oxygen.
Therefore, the son of James Watt, Gregory, underwent a completely useless course of treatment with carbon dioxide inhalations at the Pneumatic Institute. However, it was at the Pneumatic Institute that oxygen was first used for therapeutic purposes; the basics of aerosol therapy were developed; for the first time, the total lung capacity was measured by the hydrogen dilution method (G. Davy), etc. Watt and Beddoe's collaboration on the therapeutic use of various gases was crowned by their joint book Materials on the Medical Use of Artificial Airs, which came out in two editions (1794, 1795), and became the first special textbook on oxygen therapy.
In 1755 Watt went to London to study as a mechanic and a master in the manufacture of mathematical and astronomical instruments. After completing a seven-year training program in a year, Watt returned to Scotland and got a job as a mechanic at the University of Glasgow. At the same time, he opened his own repair shop.
At the university, Watt met the great Scottish chemist Joseph Black (1728-1799), who discovered carbon dioxide in 1754. This meeting contributed to the development of a number of new chemical instruments needed in further research Black, for example, an ice calorimeter. At this time, Joseph Black was working on the problem of determining the heat of vaporization, and Watt was involved in providing technical side experiments.
In 1763, as a university mechanic, he was asked to repair the university model of the T. Newcomen steam engine.
Here we should make a small digression into the history of the creation of steam engines. Once we were taught at school, bringing up "great-power chauvinism", that the steam engine was invented by the Russian serf mechanic Ivan Polzunov, and not some kind of James Watt, whose role in the creation of steam engines could sometimes be read in the "wrong" with patriotic point of view of the books. But in fact, the inventor of the steam engine is not Ivan Polzunov, and not James Watt, but the English engineer Thomas Newcomen (Thomas Newcomen, 1663-1729).
Moreover, the first attempt to put steam at the service of man was made in England as early as 1698 by the military engineer Thomas Savery (1650?-1715). He created a steam water lift, intended for draining mines and pumping water, and became the prototype of the steam engine.
Savery's machine worked as follows: first, a sealed tank was filled with steam, then the outer surface of the tank was cooled with cold water, causing the steam to condense, and a partial vacuum was created in the tank. After that, water, for example, from the bottom of the mine was sucked into the reservoir through the intake pipe and, after the next portion of steam was admitted, was thrown out through the outlet pipe. Then the cycle was repeated, but the water could only be lifted from a depth of less than 10.36 m, since in reality it was pushed out by atmospheric pressure.
This machine was not very successful, but it gave Papen the bright idea to replace gunpowder with water. And in 1698, he built a steam engine (in the same year, the Englishman Savery built his "fiery engine"). The water was heated inside a vertical cylinder with a piston inside, and the resulting steam pushed the piston up. As the steam cooled and condensed, the piston was pushed down by atmospheric pressure. Thus, through a system of blocks, the Papin machine could drive various mechanisms, such as pumps.
The English inventor Thomas Newcomen (Thomas Newcomen, 1663 - 1729), who often visited the mines in the West Country, where he worked as a blacksmith, was familiar with the steam engines of Savery and Papen, and therefore understood well how reliable pumps to prevent mine flooding. He joined forces with plumber and glazier John Calley in an attempt to build a better model. Their first steam engine was installed in a collieries in Staffordshire in 1712.
As in Papen's machine, the piston moved in a vertical cylinder, but on the whole Newcomen's machine was much more advanced. To eliminate the gap between the cylinder and the piston, Newcomen fixed a flexible leather disk on the end of the latter and poured some water on it.
Steam from the boiler entered the base of the cylinder and lifted the piston up. When cold water was injected into the cylinder, the steam condensed, a vacuum was formed in the cylinder, and under the influence of atmospheric pressure the piston went down. This return stroke removed the water from the cylinder and, by means of a chain connected to a rocker, moving like a swing, raised the pump rod upwards. When the piston was at the bottom of its stroke, steam again entered the cylinder, and with the help of a counterweight mounted on the pump rod or on the rocker, the piston rose to its original position. After that, the cycle was repeated.
Newcomen's machine was remarkably successful for its time and was used throughout Europe for more than 50 years. It was used to pump water from numerous mines in the UK. It was the first large-scale product in the history of technology (several thousand pieces were produced).
In 1740, a machine with a cylinder 2.74 m long and 76 cm in diameter did in one day the work that teams of 25 people and 10 horses, working in shifts, had previously done in a week.
In 1775 even more big car, built by John Smeaton (the creator of the Eddystone lighthouse), drained the dock in Kronstadt (Russia) in two weeks. Previously, with the use of high windmills, it took a whole year.
And yet, Newcomen's machine was far from perfect. It converted only about 1% of thermal energy into mechanical energy and, as a result, ate a huge amount of fuel, which, however, did not special significance when the machine worked in coal mines.
In general, Newcomen's machines played a huge role in the preservation of the coal industry. With their help, it was possible to resume coal mining in many flooded mines.
About the invention of Newcomen, we can say that it was really a steam engine, or rather, a vapor-atmospheric engine. From previous prototypes of steam engines, it was distinguished by the following:
* the driving force in it was atmospheric pressure, and rarefaction was achieved during the condensation of steam;
* there was a piston in the cylinder, which made a working stroke under the action of steam;
* vacuum was achieved as a result of steam condensation when cold water was injected into the cylinder.
Therefore, in fact, the inventor of the steam engine is rightfully the Englishman Thomas Newcomen, who developed his steam-atmospheric engine in 1712 (half a century before Watt).
Making brief digression in the history of the creation of steam engines, one cannot ignore the personality of our outstanding compatriot Ivan Ivanovich Polzunov (1729-1766), who built a steam-atmospheric engine earlier than James Watt did. As a mechanic at the Kolyvano-Voskresensky mining plants in Altai, on April 25, 1763, he proposed a project and description of a "fire-acting machine." The project got on the table to the head of the factories, who approved it and sent it to St. Petersburg, from where the answer soon came: "... This invention of his should be honored for a new invention."
Polzunov proposed to build at first small car, on which it would be possible to identify and eliminate all the shortcomings that are inevitable in the new invention. The factory authorities did not agree with this and decided to build immediately huge car for a powerful blower. In April 1764, Polzunov began building a machine that was 15 times more powerful than the 1763 project.
He took the idea of a steam-atmospheric engine from the book by I. Schlatter "A detailed instruction to the mining business ..." (St. Petersburg, 1760).
But Polzunov's engine was fundamentally different from English cars Savery and Newcomen. Those were single-cylinder and suitable only for pumping water from mines. Two cylinder engine continuous action Polzunova could supply blast in the furnace and pump out water. In the future, the inventor hoped to adapt it to other needs.
The construction of the machine was entrusted to Polzunov, to whom "those who do not know, but only have one inclination to do so, two of the local artisans" were allocated, and even several auxiliary workers. With this "staff" Polzunov set about building his car. It was built for a year and nine months. When the machine had already passed the first test, the inventor fell ill with transient consumption and on May 16 (28), 1766, a few days before the final tests, he died.
On May 23, 1766, Polzunov's students Levzin and Chernitsyn alone set about last test steam engine. In the “Day Note” dated July 4, “correct engine operation” was noted, and on August 7, 1766, the entire installation, steam engine and powerful blower, was put into operation. In just three months of work, Polzunov's machine not only justified all the costs of its construction in the amount of 7233 rubles 55 kopecks, but also gave a net profit of 12640 rubles 28 kopecks. However, on November 10, 1766, after the boiler burned out at the machine, it stood idle for 15 years, 5 months and 10 days. In 1782 the car was dismantled. (Encyclopedia of the Altai Territory. Barnaul. 1996. Vol. 2. S. 281-282; Barnaul. Chronicle of the city. Barnaul. 1994. part 1. p. 30).
At the same time, James Watt also worked on the creation of a steam engine in England. In 1763, as a university mechanic, he was asked to repair the university model of the T. Newcomen steam engine.
While debugging the university model of T. Newcomen's steam-atmospheric machine, Watt became convinced of the low efficiency of such machines. He set about trying to improve the parameters of the steam engine. It was clear to him that the main drawback of Newcomen's machine was the alternating heating and cooling of the cylinder. How can this be avoided? The answer came to Watt on a Sunday spring afternoon in 1765. He realized that the cylinder could remain hot all the time if, before condensation, the steam was diverted into a separate reservoir through a pipeline with a valve. In this case, the transfer of the steam condensation process outside the cylinder should help reduce the steam consumption. Moreover, the cylinder can remain hot and the condenser cold if they are covered with heat-insulating material on the outside.
The improvements that Watt made to the steam engine ( centrifugal regulator, a separate steam condenser, seals, etc.), not only raised the coefficient useful action machines, but also finally turned the steam-atmospheric machine into a steam one, and most importantly, the machine became easily controllable.
In 1768 he applied for a patent for his invention. He received a patent in 1769, but he did not manage to build a steam engine for a long time. And only in 1776, with the financial support of Dr. Rebeck, the founder of the first metallurgical plant in Scotland, Watt's steam engine was finally built and successfully passed the test.
Watt's first machine was twice as efficient as Newcomen's. Interestingly, the developments that followed Newcomen's original invention were based on the concept of "capacity" of the engine, which meant the number of foot-pounds of water that was pumped into a bushel of coal. Who owned the idea of this unit is now unknown. This man did not go down in the history of science, but he was probably some tight-fisted mine owner who noticed that some engines worked more efficiently than others, and could not allow a neighboring mine to have a large production rate.
And although the tests of the machine were successful, during its further operation it became clear that Watt's first model was not entirely successful, and cooperation with Rebeck was interrupted. Despite the lack of funds, Watt continued to work on improving the steam engine. His work interested Matthew Boulton (Matthew Boulton), an engineer and a wealthy manufacturer, the owner of a metalworking plant in the town of Soho near Birmingham. In 1775, Watt and Boulton entered into a partnership agreement.
In 1781, James Watt received a patent for the invention of the second model of his machine. Among the innovations made to it and to subsequent models were:
* double-acting cylinder, in which steam was supplied alternately along different sides from the piston, while the exhaust steam entered the condenser;
* a heat jacket that surrounded the working cylinder to reduce heat loss, and a spool;
* conversion of the reciprocating movement of the piston into the rotational movement of the shaft, first by means of a connecting rod-crank mechanism, and then by means of a gear transmission, which was the prototype planetary gear;
* centrifugal governor to maintain a constant shaft speed and a flywheel to reduce uneven rotation.
In 1782 this remarkable machine, the first universal "double-acting" steam engine, was built. Watt equipped the cylinder cover with a gland invented shortly before that, which ensured the free movement of the piston rod, but prevented steam from escaping from the cylinder. Steam entered the cylinder alternately from one side of the piston, then from the other, creating a vacuum on the opposite side of the cylinder. Therefore, the piston made both a working and a return stroke with the help of steam, which was not the case in previous machines.
In addition, in 1782 James Watt introduced the principle of expansion action, dividing the flow of steam in a cylinder at the beginning of its flow so that it began to expand the rest of the cycle under its own pressure. The expansion action means some loss in power, but gain in "performance". Of all these ideas of Watt's, the most useful was that of expansive action. It helped a lot in its further practical implementation. indicator diagram, created around 1790 by Watt's assistant James Southern.
The indicator was a recording device that could be attached to the engine in order to mark the pressure in the cylinder depending on the volume of steam entering at a given stroke. The area under such a curve was a measure of the work done in a given cycle. The indicator was used in order to tune the engine as efficiently as possible. This very diagram subsequently became part of the famous Carnot cycle (Sadie Carnot, 1796-1832) in theoretical thermodynamics.
Since the piston rod in a double-acting steam engine performed a pulling and pushing action, the old drive system of chains and rocker arms, which responded only to traction, had to be redone. Watt developed a system of linked rods and used a planetary mechanism to convert the reciprocating motion of the piston rod into rotational motion, used a heavy flywheel, a centrifugal speed controller, a disk valve and a pressure gauge to measure steam pressure.
The universal continuous-rotating double-acting steam engine (Watt's steam engine) became widespread and played a significant role in the transition to machine production.
The “rotary steam engine” patented by James Watt was first widely used to power machines and machine tools of spinning and weaving mills, and later other industrial enterprises. This led to sharp increase labor productivity. It was from this moment that the British counted the beginning of the great industrial revolution, which brought England to a leading position in the world.
The James Watt engine was suitable for any car, and the inventors of self-propelled mechanisms were not slow to take advantage of this. So the steam engine came to transport (Fulton's steamer, 1807; Stephenson's steam locomotive, 1815). Thanks to the advantage in means of transportation, England became the leading power in the world.
In 1785 Watt patented the invention of a new boiler furnace, and in the same year one of Watt's machines was installed in London at Samuel Whitbread's brewery for grinding malt. The machine did the work instead of 24 horses. Its cylinder diameter was 63 cm, the piston stroke was 1.83 m, and the flywheel diameter reached 4.27 m. The machine has survived to this day, and today it can be seen in action in the Sydney Powerhouse Museum.
Boulton and Watt, founded in 1775, has experienced all the vicissitudes of life, from falling demand for its products to the protection of its inventor's rights in the courts. However, since 1783, the business of this company, which monopolized the production of steam engines, went uphill. So James Watt became a very wealthy man, and assistance to the “Pneumatic Medical Institute” of Thomas Beddoes (Beddoes, Thomas, 1760-1808), with whom he began cooperation at this time, Watt provided very, very significant.
Despite the stormy activity in the creation of steam engines, Watt retired from his position at the University of Glasgow only in 1800. Eight years after his resignation, he established the Watt Prize for the best students and teachers of the university. The university technical laboratory, where he started his activity, began to bear his name. The name of James Watt is also a college in Greenock (Scotland), the hometown of the inventor.
The evolution of the steam engine J. Watt
1774 Steam
sump pump 1781 Steam engine
with torque on the shaft 1784 Steam engine
double action with KShM
Interestingly, at one time, as a unit of power, Watt proposed such a unit as " Horsepower". This unit of measurement has survived to this day. But in England, where Watt is revered as a pioneer of the industrial revolution, they decided otherwise. In 1882 the British Association of Engineers decided to name the unit of power after him. Now the name of James Watt can be read on any light bulb. This was the first case in the history of technology of assigning own name unit of measure. From this incident, the tradition of assigning proper names to units of measurement began.
watt lived long life and died August 19, 1819 at Heathfield near Birmingham. On the monument to James Watt it is written: "Increased the power of man over nature." This is how contemporaries assessed the activities of the famous English inventor.
The invention of the steam engine was turning point industrial and general history of mankind. At the turn of the 17th-18th centuries, prerequisites appeared for replacing low-power and inefficient living "engines", windmills and water wheels with mechanisms of a completely new type - steam engines. It was steam engines that made possible the industrial revolution and the achievement of modern level technology development.
It is believed that invented the first steam engine Scottish mechanic James Watt - after all, it is not for nothing that the international unit of power Watt is named after him! However, in reality, Watt made a lot of improvements and proposed new type engine, and the history of steam engines dates back much earlier.
The use of steam to actuate a mechanism was first described by the ancient Greek scientist Heron of Alexandria, who worked around the 1st century AD. e. It was Heron who invented the famous Eolipil (or "Eol's ball") - a sphere fixed on an axis with nozzles coming out of it. A ball filled with water was heated on fire, and the steam coming out of the nozzles caused the sphere to rotate.
Of course, all this is nothing more than a toy, but it has been forgotten for more than a millennium and a half. For the first time after Heron, the Arab engineer and philosopher Tagi al-Dinome tried to use the power of steam - in the 16th century he created a prototype steam turbine, rotating the spit. Almost a century later - in 1615 - the Frenchman Solomon de Caux describes a device that, with the help of steam, can raise water. And in 1629, the Italian Giovanni Branca also creates turbine-like machine, - heated steam came out of the tube and hit the blades on the wheel, thereby causing this wheel to rotate.
Around the same time, the Spanish engineer Jeronimo Ayanz de Beaumont created steam engine with cylinder- this mechanism had some influence on the development of events in the field of improving steam engines. And in 1663, the Englishman Edward Somerset describes a steam engine for lifting water from wells and mines, and subsequently receives a patent for this invention. The machine created by Somerset worked for some time in one of the English castles, but showed far from the best results.
Two people played a huge role in the development of steam engines: the Frenchman Denis Papin and the Englishman Thomas Savery. Pa-pen invented a cylinder in the mid-70s of the 17th century, in which a vacuum is created by the explosion of gunpowder, and then (in 1680) he adapted this cylinder to work from steam. By the end of the century, a French scientist approached the creation of an industrial model of a steam engine, but Savery was ahead of him - in 1698 an Englishman received a patent for a machine, and in 1702 the mechanism of its design began to be used to lift and pump out water. However, these steam engines received a very limited distribution - they were too imperfect.
But if the devices of Papin and Savery were little used in practice, then why did these people play important role in the history of technology? The thing is that the ideas of these engineers-inventors formed the basis of the steam engine, created in 1712 by the Englishman Thomas Newcomen. The inventor combined a Savery-designed machine with a Papin cylinder, resulting in a fairly perfect steam-powered engine. Interesting detail: the machine was controlled manually - for these purposes a special person was hired, whose tasks included opening and closing valves at certain intervals. According to legend, in 1713, a boy named Humphrey Potter, who worked on one of the machines, figured out how to make the valves work on their own. And only in 1715 on steam engines Newcomen's system appeared completely automatic system steam distribution.
Two important remarks must be made here. First, all of the above steam engines are vacuum(or atmospheric). In machines of this type, steam was used only to heat the cylinder in which the piston moved. The principle is simple: steam enters the cylinder, heating it to a high temperature, after which cold water is poured onto the cylinder. As a result, a sharp cooling occurs, and a rarefaction (vacuum) is formed in the cylinder, due to which, under the influence of atmospheric pressure, the piston enters deep into the cylinder, while doing work. Secondly, all these machines were used only for lifting and moving water - it never occurred to the inventors that various mechanisms could be set in motion with the help of steam. So even Newcomen's car often referred to as a steam pump.
For more than half a century, Newcomen's steam engines were the only machines suitable for industrial use. It was only in the early 1760s that progress occurred in this area - Humphrey Gainsborough created improved steam engine, which, however, has not received significant distribution. And the Scottish engineer and inventor James Watt was destined to make a real revolution in this area.
In 1765, Watt put forward the idea that it is not necessary to cool the cylinder, but it is better to use the force of steam pressure, and not vacuum. Already in 1769 he received a patent for this invention, but the machine itself new design was created only in 1776 - Watt at that time was tight with money and he simply had nothing to implement his ideas.
But the most important invention of James Watt, which made him famous, appeared only in 1781: it was then that the engineer created a steam engine capable of doing any job. This was made possible by converting the reciprocating motion of the piston into the rotation of the flywheel using the so-called planetary gear. And in 1784, Watt's steam engine acquired its final form - it appeared more convenient and simple. crank mechanism and many small improvements. It was this development that became known as universal steam engine, and not in vain: the machine soon appeared in factories and factories, and at the beginning of the 19th century, the Watt system engines were installed on the first steam locomotive and steamboat.
It is interesting that a functioning steam engine (and not even one) was also created in Russia - that's all famous cars Ivan Polzunov, built between 1763 and 1766. Polzunov's first engines showed good results, and in 1764 construction began on a large steam engine for a metal foundry. Construction ended in 1766, and the launch was made after the death of the inventor. Unfortunately, Polzunov's steam engine worked for only 42 days - after a breakdown, it ceased to be used, and after some time it was dismantled.
As you can see, the history of steam engines does not begin with the discovery of James Watt, but it was this inventor who created a truly efficient and comfortable car which had a huge impact on the development of industry and technology. For these merits, in 1882, the unit of power, known to us as the watt, began to be named after Watt.
