The model was exhibited at the Great Exhibition of 1851. In 1849 a 6m radius steam-driven fan, designed by William Brunton, was made operational in the Gelly Gaer Colliery of South Wales. However, this arrangement was not as ideal as the machinery was liable to breaking down. The civil engineer John Smeaton, and later John Buddle installed reciprocating air pumps in the mines in the North of England. Good ventilation was particularly important in coal mines to reduce casualties from asphyxiation. John Theophilus Desaguliers, a British engineer, demonstrated the successful use of a fan system to draw out stagnant air from coal mines in 1727 and soon afterward he installed a similar apparatus in Parliament. The first rotary fan used in Europe was for mine ventilation during the 16th century, as illustrated by Georg Agricola (1494–1555). Wren's design would be the catalyst for much later improvement and innovation. The English architect Sir Christopher Wren applied an early ventilation system in the Houses of Parliament that used bellows to circulate air. In the 17th century, the experiments of scientists including Otto von Guericke, Robert Hooke and Robert Boyle, established the basic principles of vacuum and airflow. The weapon paralleled the mannerisms of the Japanese. What started off as a mechanism to cool oneself and a symbol of respect and wealth soon became a weapon used by samurais when Katanas were not ideal. The Tessen, a Japanese fan used for the Feudal times, was a dangerous weapon that was hidden in plain sight in the shape regular fan. ĭuring the Heian period (794-1185) in Japan, fans adapted the role of symbolizing social class as well as a mechanical role. 180 CE) invented a manually operated rotary fan with seven wheels that measured 3 m (10 ft) in diameter in the 8th century, during the Tang dynasty (618–907), the Chinese applied hydraulic power to rotate the fan wheels for air conditioning, while the rotary fan became even more common during the Song dynasty (960–1279). During British rule, the word came to be used by Anglo-Indians to mean a large swinging flat fan, fixed to the ceiling and pulled by a servant called the punkawallah.įor purposes of air conditioning, the Han dynasty craftsman and engineer Ding Huan (fl. It was a handheld fan made from bamboo strips or other plant fiber, that could be rotated or fanned to move air. The punkah (fan) was used in India about 500 BCE. History Patent drawing for a Fan Moved by Mechanism, November 27, 1830 Thus, fans may become less effective at cooling the body if the surrounding air is near body temperature and contains high humidity. While fans are effective at cooling people, they do not cool air, but rather work by evaporative cooling of sweat and increased heat convection into the surrounding air, due to the airflow from the fans. Some fans may be indirectly used for cooling in the case of industrial heat exchangers. sucking as in a vacuum cleaner), drying (usually in combination with a heat source) and providing draft for a fire. Typical applications include climate control and personal thermal comfort (e.g., an electric table or floor fan), vehicle engine cooling systems (e.g., in front of a radiator), machinery cooling systems (e.g., inside computers and audio power amplifiers), ventilation, fume extraction, winnowing (e.g., separating chaff of cereal grains), removing dust (e.g. A fan blade will often rotate when exposed to an air-fluid stream, and devices that take advantage of this, such as anemometers and wind turbines, often have designs similar to that of a fan. Fans produce air flows with high volume and low pressure (although higher than ambient pressure), as opposed to compressors which produce high pressures at a comparatively low volume. Mechanically, a fan can be any revolving vane, or vanes used for producing currents of air. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Usually, it is contained within some form of housing, or case. The rotating assembly of blades and hub is known as an impeller, rotor, or runner. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. A typical electric fan A table fan Fans are used to force air into low and high bypass jet engines, seen here on a Boeing 777.Ī fan /f/n is a powered machine used to create a flow of air. For other uses, see Fan (disambiguation).
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