James Watt

James Watt [ d͡ʒe̯ɪmz wɔt ] (born 19 Januarjul / January 30 1736greg in Greenock, .. † August 25, 1819 at his home in Heathfield, Staffordshire ) was a Scottish inventor. His most influential invention was to improve the efficiency of steam engines by shifting the condensation process from the cylinder into a separate condenser. Watt himself held the he designed linkage Watt's parallelogram, for his greatest invention.

Life

Childhood and youth

James Watt was born as the son of poor but well-educated parents. His father was a carpenter and builder of nautical equipment, Watts grandfather had been a national Scottish - set mathematics teacher. James was a sickly child who suffered from chronic headaches, among others. Therefore, the parents taught him partially itself Even as a boy he experimented happy and to have the functionality of every object he could get his hands explored. In addition, Watts was an avid collector of plants and stones, read everything there was to read, and invented stories themselves.

For the study of medicine, for which Watt was interested, but his parents were too poor. Therefore Watt began in London an unofficial apprenticeship as a mechanic after he could not find a teaching master in Glasgow, Scotland. As these, however, had to offer him soon nothing new, he broke it off before the prescribed seven years. Our own workshop, he could not open because of the incomplete training, as the Glasgow guilds objected. Watt received a 1757 point as an instrument maker at the University of Glasgow. There he made ​​and repaired for the University of instruments such as compasses and quadrants. His one-room laboratory, which he by a second after one year - facing the street - extended space with windows, it soon became the meeting place for faculty and students. Watt held at the University a lot of friends, even though he "only" was a craftsman. Among other things, he was a friend of the economist Adam Smith. He was described by his contemporaries as extremely humble and gracious.

1760 Watt married his cousin and childhood sweetheart, Margaret Miller, born in 1736. Margaret Watt died in 1773 at the birth of the sixth child. From their common children survived only born 1769 son James. 1775 Watt married Anne Macgregor.

Further development of the steam engine

1764 Watt received a university mechanic commissioned to repair the poorly functioning model of a steam engine as the type of Thomas Newcomen. Watt realized that the problem was rooted in unfavorable heat balance of the basic design. A large part of the incoming water vapor is consumed thereby, to heat the cylinder to 100 ° C. In the model this situation occurred more apparent than in the original machines due to the different ratio of cylinder surface and volume. Watt decided the machine - based on previous work by Denis Papin - to improve. He learned alongside French and Italian also German to read German writings on the theory of heat. To avoid the perpetual, alternately heating and cooling of the cylinder, he moved the necessary condensation of water vapor in a separate container, the condenser. In addition, he had the cylinder from the outside into the so-called ' Steam Jacket' ( German as: steam jacket) wash over with steam to reduce the heat losses in the cylinder. This Dampfumspülung he insulated from the outside with vertically mounted wooden boards. It was not until much later, he designed the cylinder on double effect to: While in the previous machines the piston dropped by the atmospheric air pressure down, the process has now been supported by steam power. For this seemingly small change in the cylinder cover on the piston rod had to be sealed and the force transmitting linkage be completely redesigned. Watt invented for this purpose, the Watt's parallelogram whose meaning he saw above that of the remote condenser.

Watt resigned from his job at the University of Glasgow, to devote himself more to the development of the steam engine. Although he casually worked as a surveyor, he amassed in the following years of debt. Also, he was often sick. It was not until 1769 he found in the iron master John Roebuck ( 1718-1794 ) a financier and received on 5 January 1769 British Patent No. 913 Watts improvements made ​​possible with respect to the optimized John Smeaton Newcomen steam engine in a saving of coal by about 60 percent.

Initially it was not possible to produce a vapor-tight cylinder. About the tests his patron John Roebuck went bankrupt. The industry Baron Matthew Boulton agreed to take over Roebuck's estate if he could obtain an extension of the patent by 25 years until 1800. After successfully lobbying the firm Boulton & Watt was established for the duration of the validity of the patent. Boulton secured for his share to 2/3 of the revenue. The first operational steam engine in accordance with the principle of Watt's 1776 was installed in the factory of John Wilkinson. Wilkinson company had managed to produce a cylinder of iron in the required quality: He used a developed and patented his invention for drilling in iron cannons in which the drill bit is fixed and the workpiece rotates around it. As a result, presented ' Boulton & Watt in Soho at Birmingham important parts such as condenser and air pump here, the steam engines were assembled only when customer. Wilkinson delivered the cylinder directly to the site and other required materials were purchased and adapted to spot. It is a feature that ' Boulton & Watt steam engines initially not sold, but leased them about the patent term. As a user fee they demanded a third of the over the optimized Newcomen steam engine saved fuel costs. At its better calculation, Watt specially a tamper-proof counter for the piston movements.

1781 Watt changed the piston by means of a slider crank mechanism into rotational motion. In 1782, he designed a steam engine, in which the piston is moved from both sides with steam. So James Watt had developed a steam engine in which the complete work has been done by the steam, and no longer a part of the work of relatively low natural air pressure. In this way, much more powerful machines were possible. In this steam engine, the piston pushes the balancing upward and pulls him down. So that these forces acting in two directions could be transmitted, a piston rod is used instead of a chain. For the linear guide of the piston rod on the pendulum balancing Watt invented 1784, the Watt's parallelogram. Since 1788, he furnished his steam engines with the already successfully used in windmills centrifugal force regulators to control the rotational speed of the drive shaft under load variations. He also led the horsepower ( hp) as a measure of performance.

The steam engine of Watt finally reached an efficiency of 3%, three times the optimized Newcomen steam engines. The construction of a high pressure steam engine was delayed due to fear of explosions Watts and his extended until the 1800 patent for the steam condensation outside the cylinder. When Richard Trevithick (1771-1833) in 1804 constructed a traveling on wheels and rails high pressure steam engine and operate five times atmospheric pressure, Watt wished him whether the levity of the rope around his neck.

Watt and Boulton disabled during the time in which the Watt patents granted were valid, the successful development of the steam engine by competing engineers. So they sued Jonathan Hornblower, whose composite steam engine made ​​a higher efficiency possible for patent infringement and were able to stop their further development.

Evening of life and death

Watts rose in 1800 out of his company and handed over his shares to his sons James and Gregory. He retired to his house Heathfield in Handsworth, Birmingham, back where he worked on various other inventions, including things that were conceived in the pastime as the serious technical use. He lived very sociable and his guests raved that they could talk to him about all topics. The Scottish national poet Walter Scott once remarked relieved that Watt had become engineer. Whose talent for storytelling would otherwise have made ​​him serious competition.

On August 25, 1819 died watts. He was buried in St. Mary's Church in Handsworth in Birmingham.

In Westminster Abbey him a memorial ( cenotaph ) was built, which bears the following inscription, almost anthemic:

" Not to perpetuate a name which has so long are, as the arts of peace will flourish, but to show that people know how to honor those who deserve their gratitude to the most, have the king, his ministers and many nobles and other citizens of the Kingdom of this monument to the James Watt which turned the force of a creative, scientific research early trained mind to the improvement of the steam engine, by the resources of his country increased, enlarged the power of the people, and to a excellent position arose among the most famous men of science and the real benefactors of the world. "

Honors

The SI unit of power is named with Watt and replaced the previously used PS, introduced by him.

The British Institution of Mechanical Engineers named its highest award, the " James Watt Medal". This is now considered the world's most prestigious award in the field of mechanical engineering.

In addition, the lunar crater Watt was named in 1935 by the IAU for him.

James Watt was awarded, among others, the honorary doctorate from the University of Glasgow. He was a corresponding member of the French Academy of Sciences.

Inventions at a glance

• Separate capacitor with simultaneous steam jacket for the cylinder.
• Adaptation of the governor for regulating the steam supply to the steam engine.
• Cal Watt parallelogram ( the basis for the double-acting cylinder).
• Pv diagram (indicator - diagram ) to study thermodynamic processes.
• Discovery and use of the steam expansion.
• Developed by William Murdoch and Watt patented: planetary gear of the compound Balancing flywheel shaft to bypass the patent on the crankshaft by James Pickard, since Watt rejected a proposed Pickard of cross-licensing.
• Watt's press.