Мегаобучалка Главная | О нас | Обратная связь


Important technological development



2015-12-07 617 Обсуждений (0)
Important technological development 0.00 из 5.00 0 оценок




The commencement of the Industrial Revolution is closely linked to a small number of innovations,[20] beginning in the second half of the 18th century. By the 1830s the following gains had been made in important technologies:

· Textiles – Mechanised cotton spinning powered by steam or water increased the output of a worker by a factor of about 1000. The power loom increased the output of a worker by a factor of over 40.[21] The cotton gin increased productivity of removing seed from cotton by a factor of 50.[15] Large gains in productivity also occurred in spinning and weaving of wool and linen, but they were not as great as in cotton.[22]

· Steam power – The efficiency of steam engines increased so that they used between one-fifth and one-tenth as much fuel. The adaptation of stationary steam engines to rotary motion made them suitable for industrial uses. The high pressure engine had a high power to weight ratio, making it suitable for transportation. Steam power underwent a rapid expansion after 1800.

· Iron making – The substitution of coke for charcoal greatly lowered the fuel cost for pig iron and wrought iron production.[23] Using coke also allowed larger blast furnaces,[24][25] resulting in economies of scale. The cast iron blowing cylinder was first used in 1760. It was later improved by making it double acting, which allowed higher furnace temperatures. The puddling process produced a structural grade iron at a lower cost than the finery forge. The rolling mill was fifteen times faster than hammering wrought iron. Hot blast (1828) greatly increased fuel efficiency in iron production in the following decades.

 

Steam power

 

The 1698 Savery Engine – the world's first commercially useful steam engine: built byThomas Savery

The development of the stationary steam engine was an important element of the Industrial Revolution; however, for most of the period of the Industrial Revolution, the majority of industrial power was supplied by water and wind. In Britain by 1800 an estimated 10,000 horsepower was being supplied by steam. By 1815 steam power had grown to 210,000 hp.[46] Small power requirements continued to be provided by animal and human muscle until the late 19th century.

The first real attempt at industrial use of steam power was due to Thomas Savery in 1698. He constructed and patented in London a low-lift combined vacuum and pressure water pump, that generated about one horsepower (hp) and was used in numerous water works and tried in a few mines (hence its "brand name", The Miner's Friend). Savery's pump was economical in small horspower ranges, but was prone to boiler explosions in larger sizes. Savery pumps continued to be produced until the late 18th century.

Newcomen's steam powered atmospheric engine was the first practical engine. Subsequent steam engines were to power the Industrial Revolution.

The first safe and successful steam power plant was introduced by Thomas Newcomen before 1712. A number of Newcomen engines were successfully put to use in Britain for draining hitherto unworkable deep mines, with the engine on the surface; these were large machines, requiring a lot of capital to build, and produced about 5 hp (3.7 kW). They were extremely inefficient by modern standards, but when located where coal was cheap at pit heads, opened up a great expansion in coal mining by allowing mines to go deeper. Despite their disadvantages, Newcomen engines were reliable and easy to maintain and continued to be used in the coalfields until the early decades of the 19th century. By 1729, when Newcomen died, his engines had spread (first) to Hungary in 1722, Germany, Austria, and Sweden. A total of 110 are known to have been built by 1733 when the joint patent expired, of which 14 were abroad. In the 1770s, the engineer John Smeaton built some very large examples and introduced a number of improvements. A total of 1,454 engines had been built by 1800.

Scottish mechanical engineer and inventor James Watt

A fundamental change in working principles was brought about by Scotsman James Watt. In close collaboration with EnglishmanMatthew Boulton, he had succeeded by 1778 in perfecting his steam engine, which incorporated a series of radical improvements, notably the closing off of the upper part of the cylinder thereby making the low pressure steam drive the top of the piston instead of the atmosphere, use of a steam jacket and the celebrated separate steam condenser chamber. The separate condenser did away with the cooling water that had been injected directly into the cylinder, which cooled the cylinder and wasted steam. Likewise, the steam jacket kept steam from condensing in the cylinder, also improving efficiency. These improvements increased engine efficiency so that Boulton & Watts engines used only 20-25% as much coal per horsepower-hour as Newcomen's. Boulton and Watt opened theSoho Foundry, for the manufacture of such engines, in 1795.

By 1783 the Watt steam engine had been fully developed into a double-acting rotative type, which meant that it could be used to directly drive the rotary machinery of a factory or mill. Both of Watt's basic engine types were commercially very successful, and by 1800, the firm Boulton & Watt had constructed 496 engines, with 164 driving reciprocating pumps, 24 serving blast furnaces, and 308 powering mill machinery; most of the engines generated from 5 to 10 hp (7.5 kW).

The development of machine tools, such as the lathe, planing and shaping machines powered by these engines, enabled all the metal parts of the engines to be easily and accurately cut and in turn made it possible to build larger and more powerful engines.

Until about 1800, the most common pattern of steam engine was the beam engine, built as an integral part of a stone or brick engine-house, but soon various patterns of self-contained portative engines (readily removable, but not on wheels) were developed, such as the table engine. Around the start of the 19th century, the Cornish engineer Richard Trevithick, and the American, Oliver Evansbegan to construct higher pressure non-condensing steam engines, exhausting against the atmosphere. This allowed an engine and boiler to be combined into a single unit compact enough to be used on mobile road and rail locomotives and steam boats.

In the early 19th century after the expiration of Watt's patent, the steam engine underwent many improvements by a host of inventors and engineers.

Machine tools

The Industrial Revolution created a demand for metal parts used in machinery. This led to the development of several machine tools for cutting metal parts. They have their origins in the tools developed in the 18th century by makers of clocks and watches and scientific instrument makers to enable them to batch-produce small mechanisms.

Before the advent of machine tools, metal was worked manually using the basic hand tools of hammers, files, scrapers, saws and chisels. Consequently, the use of metal was kept to a minimum. Wooden components had the disadvantage of changing dimensions with temperature and humidity, and the various joints tended to rack (work loose) over time. As the Industrial Revolution progressed, machines with metal parts and frames became more common. Hand methods of production were very laborious and costly and precision was difficult to achieve. Pre-industrial machinery was built by various craftsmen—millwrights built water and wind mills, carpentersmade wooden framing, and smiths and turners made metal parts.

The first large machine tool was the cylinder boring machine used for boring the large-diameter cylinders on early steam engines. The planing machine, the milling machine and the shaping machine were developed in the early decades of the 19th century. Although the milling machine was invented at this time, it was not developed as a serious workshop tool until somewhat later in the 19th century.

Henry Maudslay, who trained a school of machine tool makers early in the 19th century, was a mechanic with superior ability who had been employed at the Royal Arsenal, Woolwich. He was hired away by Joseph Bramah for the production of high security metal locks that required precision craftsmanship. Bramah patented a lathe that had similarities to the slide rest lathe. Maudslay perfected the slide rest lathe, which could cut machine screws of different thread pitches by using changeable gears between the spindle and the lead screw. Before its invention screws could not be cut to any precision using various earlier lathe designs, some of which copied from a template.[49] Maudslay's lathe was called one of history's most important inventions.

Maudslay left Bramah's employment and set up his own shop. He was engaged to build the machinery for making ships' pulley blocks for the Royal Navy in the Portsmouth Block Mills. These machines were all-metal and were the first machines for mass production and making components with a degree of interchangeability. The lessons Maudslay learned about the need for stability and precision he adapted to the development of machine tools, and in his workshops he trained a generation of men to build on his work, such asRichard Roberts, Joseph Clement and Joseph Whitworth.

James Fox of Derby had a healthy export trade in machine tools for the first third of the century, as did Matthew Murray of Leeds. Roberts was a maker of high-quality machine tools and a pioneer of the use of jigs and gauges for precision workshop measurement.

In half century following the invention of the fundamental machine tools the machine industry would become the largest segment of the economy, by value added, in the U.S.

Chemicals

The large scale production of chemicals was an important development during the Industrial Revolution. The first of these was the production of sulphuric acid by the lead chamber process invented by the Englishman John Roebuck (James Watt's first partner) in 1746. He was able to greatly increase the scale of the manufacture by replacing the relatively expensive glass vessels formerly used with larger, less expensive chambers made of riveted sheets of lead. Instead of making a small amount each time, he was able to make around 100 pounds (50 kg) in each of the chambers, at least a tenfold increase.

The production of an alkali on a large scale became an important goal as well, and Nicolas Leblanc succeeded in 1791 in introducing a method for the production of sodium carbonate. The Leblanc process was a reaction of sulphuric acid with sodium chloride to give sodium sulphate and hydrochloric acid. The sodium sulphate was heated with limestone (calcium carbonate) and coal to give a mixture of sodium carbonate and calcium sulphide. Adding water separated the soluble sodium carbonate from the calcium sulphide. The process produced a large amount of pollution (the hydrochloric acid was initially vented to the air, and calcium sulphide was a useless waste product). Nonetheless, this synthetic soda ash proved economical compared to that from burning specific plants (barilla) or from kelp, which were the previously dominant sources of soda ash,[50] and also to potash(potassium carbonate) derived from hardwood ashes.

These two chemicals were very important because they enabled the introduction of a host of other inventions, replacing many small-scale operations with more cost-effective and controllable processes. Sodium carbonate had many uses in the glass, textile, soap, and paper industries. Early uses for sulphuric acid included pickling (removing rust) iron and steel, and for bleaching cloth.

The development of bleaching powder (calcium hypochlorite) by Scottish chemist Charles Tennant in about 1800, based on the discoveries of French chemistClaude Louis Berthollet, revolutionised the bleaching processes in the textile industry by dramatically reducing the time required (from months to days) for the traditional process then in use, which required repeated exposure to the sun in bleach fields after soaking the textiles with alkali or sour milk. Tennant's factory at St Rollox, North Glasgow, became the largest chemical plant in the world.

After 1860 the focus on chemical innovation was in dyestuffs, and Germany took world leadership, building a strong chemical industry.[51] Aspring chemists flocked to German universities in the 1860–1914 era to learn the latest techniques. British scientists by contrast, lacked research universities and did not train advanced students; instead the practice was to hire German-trained chemists.[52]

Cement

In 1824 Joseph Aspdin, a British bricklayer turned builder, patented a chemical process for making portland cement which was an important advance in the building trades. This process involves sintering a mixture of clay and limestone to about 1,400 °C (2,552 °F), then grinding it into a fine powder which is then mixed with water, sand and gravel to produce concrete. Portland cement was used by the famous English engineer Marc Isambard Brunel several years later when constructing theThames Tunnel.[53] Cement was used on a large scale in the construction of the London sewerage system a generation later.

Gas lighting

Another major industry of the later Industrial Revolution was gas lighting. Though others made a similar innovation elsewhere, the large-scale introduction of this was the work of William Murdoch, an employee of Boulton and Watt, the Birmingham steam engine pioneers. The process consisted of the large-scale gasification of coal in furnaces, the purification of the gas (removal of sulphur, ammonia, and heavy hydrocarbons), and its storage and distribution. The first gas lighting utilities were established in London between 1812 and 1820. They soon became one of the major consumers of coal in the UK. Gas lighting had an impact on social and industrial organisation because it allowed factories and stores to remain open longer than with tallow candles or oil. Its introduction allowed night life to flourish in cities and towns as interiors and streets could be lighted on a larger scale than before.

Glass making

A new method of producing glass, known as the cylinder process, was developed in Europe during the early 19th century. In 1832, this process was used by the Chance Brothers to create sheet glass. They became the leading producers of window and plate glass. This advancement allowed for larger panes of glass to be created without interruption, thus freeing up the space planning in interiors as well as the fenestration of buildings. The Crystal Palace is the supreme example of the use of sheet glass in a new and innovative structure..

Paper machine

A machine for making a continuous sheet of paper on a loop of wire fabric was patented in 1798 by Nicholas Louis Robert who worked for Saint-Léger Didot family in France. The paper machine is known as a Fourdrinier after the financiers, brothers Sealy and Henry Fourdrinier, who were stationers in London. Although greatly improved and with many variations, the Fourdriner machine is the predominant means of paper production today.

The method of continuous production demonstrated by the paper machine influenced the development of continuous rolling of iron and later steel and othercontinuous production processes.[54]

Questions:

 

1. Changes in the nation

2. Inventors and their important inventions,

3. Industrial giants

 



2015-12-07 617 Обсуждений (0)
Important technological development 0.00 из 5.00 0 оценок









Обсуждение в статье: Important technological development

Обсуждений еще не было, будьте первым... ↓↓↓

Отправить сообщение

Популярное:
Модели организации как закрытой, открытой, частично открытой системы: Закрытая система имеет жесткие фиксированные границы, ее действия относительно независимы...
Как вы ведете себя при стрессе?: Вы можете самостоятельно управлять стрессом! Каждый из нас имеет право и возможность уменьшить его воздействие на нас...
Почему двоичная система счисления так распространена?: Каждая цифра должна быть как-то представлена на физическом носителе...



©2015-2020 megaobuchalka.ru Все материалы представленные на сайте исключительно с целью ознакомления читателями и не преследуют коммерческих целей или нарушение авторских прав. (617)

Почему 1285321 студент выбрали МегаОбучалку...

Система поиска информации

Мобильная версия сайта

Удобная навигация

Нет шокирующей рекламы



(0.009 сек.)