Fan

Fan

Ø introduction:

                      A fan may be a battery-powered machine accustomed produce flow inside a fluid, generally a gas like air. A fan consists of a rotating arrangement of vanes or blades that act on the air. The rotating assembly of blades and hub is known as an impeller, a rotor, or a runner. Usually, it's contained among some kind of housing or case. This may direct the airflow or increase safety by preventing objects from contacting the fan blades. Most fans area unit battery-powered by electrical motors, but other sources of power may be used, including hydraulic motors, hand cranks, internal combustion engines, and solar power.

Ø History:

                 The fan fan was employed in Asian nation concerning five hundred BCE. It was a hand-held fan made up of bamboo strips or different natural fiber, that could be rotated or fanned to move air. 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.

Ø Steam:

                   With the appearance of sensible steam power, fans could finally be used for ventilation. In 1837 William Furness of European country put in a steam-driven fan at city. In 1849 a 6 m radius steam driven fan, designed by William Brunton, was made operational in the Gully Gear Colliery of South Wales. The model was exhibited at the Great Exhibition of 1851. Also in 1851 David Boswell Reid, a Scottish doctor, installed four steam powered fans in the ceiling of St George's Hospital in Liverpool, so that the prssure produced by the fans would force the incoming air upward and thru vents within the ceiling.Improvements in the technology were made by James Nesmith, Frenchman Theophile Guibal and J. R. Waddle.

Ø Electrical:

                       Between 1882 and 1886 Schuyler Wheeler fabricated a lover battery-powered by electricity. it had been commercially marketed by the yank firm Crocker motor company. In 1882, Duke of Edinburgh Diehl developed the world's initial electrical ceiling fan. During this intense period of innovation, fans powered by alcohol, oil, or kerosene were common around the turn of the 20th century. In 1909, KDK of Japan pioneered the invention of factory-made electrical fans for home use. In the 1920s, industrial advances allowed steel fans to be mass-produced in different shapes, bringing fan prices down and allowing more homeowners to afford them. In the Thirties, the primary art movement fan (the "swan fan") was designed. By the 1940s, Crompton Greaves of India became the world's largest manufacturer of electric ceiling fans mainly for sale in India, Asia and the Middle East. By the 1950s, table and stand fans were manufactured in colors that were bright and eye catching.

Ø Types:

                   Mechanical revolving blade fans area unit created in an exceedingly wide selection of styles. They are used on the ground, table, desk, or hung from the ceiling (ceiling fan). They can even be engineered into a window, wall, roof, chimney, etc. Most electronic systems like computers embrace fans to cool down the circuits within, and in appliances like hair dryers and moveable area heaters and mounted/installed wall heaters. They are additionally used for moving air in air-conditioning systems, and in automotive engines, where they are driven by belts or by direct motor.

Ø Axial-flow:

                       Axial-flow fans have blades that force air to maneuver parallel to the shaft concerning that the blades rotate. This type of fan is employed in an exceedingly wide range of applications, ranging from small cooling fans for electronics to the giant fans used in wind tunnels. Axial flow fans area unit applied in air con and process applications. Standard axial flow fans have diameters of 300–400 millimeter or 1800–2000 millimeter and work beneath pressures up to 800 Pa. Special sorts of fans area unit used as low mechanical device stages in craft engines. Examples of axial fans are:

 Ø Table fan:

                   Basic parts of a typical table fan embrace the vane, base, armature and lead wires, motor, blade guard, motor housing, oscillator gearbox, and oscillator shaft. The oscillator is a mechanism that motions the fan from side to side. The armature axle shaft comes out on both ends of the motor, one end of the shaft is attached to the blade and the other is attached to the oscillator gearbox. The motor case joins to the gear case to contain the rotor and stator coil. The generator shaft combines to the weighted base and also the gear case. A motor housing covers the oscillator mechanism. The blade guard joins to the motor case for safety.