|
The steam engine laid the foundation for industrialisation. Within a few years it became the driving force behind work in factories and mining.
One of the first piston engines was developed by the French physicist Denis Papin as early as 1690. This simple device consisting of a single cylinder which simultaneously served as a boiler, mainly functioned with air rather than steam pressure.
Towards the end of the 17th century, engineers such as the Marquis of Worcester and Thomas Savery also constructed some of the first steam engines. Savery’s engine was used as a pump to drain water from mining tunnels.
In 1705, Englishman, Thomas Newcomen, developed the first effective steam engines with a steam boiler, cylinder and piston. In this so-called beam engine, a large beam rocked upwards and downwards, transferring the energy to the piston which moved inside the cylinder. When the piston rose, steam entered into the cylinder and condensed; the air pressure forced the piston back down again.
The Scottish engineer James Watt improved upon Newcomen’s construction which was not cost-effective due to great heat loss. He is therefore considered to be the father of the modern steam engine. The first important advance which he made was to build an engine with a separate space for condensing the steam. This construction, which was patented in 1769, improved efficiency considerably. Steam loss resulting from the alternating heating and cooling of the cylinder was almost completely eliminated with this engine. The use of water vapour rather than air pressure in Watt’s engines was another crucial difference. Moreover, Watt invented a procedure with which a piston moving back and forth in an engine could drive a revolving flywheel. He accomplished this first with a system of cogwheels and later with a crankshaft. In addition, Watt equipped his power engines with throttle valves for regulating speed. He attained a constant speed of operation with the aid of governors.
At the beginning of the 19th century, the British mining engineer, Richard Trevithick, and the American inventor Oliver Evans succeeded in constructing the first high-pressure steam engine. Trevithick used his model to power the world’s first steam locomotive.
|