Mechanical Fan is a powerful engine used to create a stream in a liquid, usually gas like air. Fans consist of a rotating propeller or a rotating knife that acts in the air. The assembly of a knife and a rotating hub is known as an impeller, rotor, or runner. Usually, it is contained in some form of housing or case. It can direct airflow or improve safety by preventing objects from contacting fan blades. Most fans are powered by electric motors, but other resources can be used, including hydraulic motors, handcranks, internal combustion engines, and solar power.
Mechanically, the fan may be a rotary blade or propeller used to generate air currents. Fans produce high volume and low pressure airflows (though higher than ambient pressure), compared to compressors that produce high pressure at relatively low volumes. A fan blade will often spin when exposed to air fluid flow, and devices that utilize this, such as anemometers and wind turbines, often have a design similar to a fan.
Typical applications include climate control and personal thermal comfort (eg, electric table fan or floor), vehicle engine cooling system (eg, in front of the radiator), engine cooling system (eg, inside computer and audio power amplifier), ventilation, extraction smoke, winnowing (eg separating cereal grain husks), removing dust (eg sucking as in a vacuum cleaner), drying (usually in combination with a heat source) and providing a draft for fire.
While fans are often used to cool people, they do not really cool the air (if any, electric fans warm it up a bit because of their motor heating), but work by evaporating the sweat and increasing the convection of heat into the surrounding air due to the airflow from the fans. Thus, fans can become ineffective in cooling the body if the surrounding air is close to body temperature and contains high humidity. During periods of high heat and humidity, the government actually advised against using fans.
Video Fan (machine)
Histori
Fans were used in India around 500 BC. It is a hand-held fan made from bamboo pieces or other plant fibers, which can be rotated or fanned to move air. During British rule, the word was used by the Anglo-Indians to mean a large, swinging flat fan, fixed on the ceiling, and pulled by a maid, called punkawallah.
For air conditioning purposes, Han Dynasty craftsmen and engineers, Ding Huan (fl.17 CE) created a manually operated fan with seven wheels having a diameter of 3 m (10 ft); in the 8th century, during the Tang Dynasty (618-907), China applied hydraulic power to turn the fan wheel for air conditioning, while the spinning fan became more common during the Song Dynasty (960-1279).
In the 17th century, experiments of scientists including Otto von Guericke, Robert Hooke and Robert Boyle, established the basic principles of vacuum and airflow. British architect Sir Christopher Wren applies an early ventilation system in the Houses of Parliament which uses bellows for air circulation. Wren's design will be a catalyst for many improvements and innovations in the future. The first swivel fan used in Europe was for mine ventilation during the 16th century, as illustrated by Georg Agricola (1494-1555).
John Theophilus Desaguliers, a British engineer, demonstrated the successful use of the fan system to pull out the stagnant air from a coal mine in 1727 and soon after that he installed a similar tool in Parliament. Good ventilation is essential in coal mines to reduce the toll of asphyxia. Civil engineer John Smeaton, and later John Buddle installed reciprocating air pumps at a mine in Northern England. However, this arrangement is not ideal because the machine is likely to be damaged.
Steam
With the emergence of practical steam power, fans can finally be used for ventilation. In 1837, William Fourness of England installed a steam fan in Leeds. In 1849, a 6m steam fan, designed by William Brunton, operated at the Gelly Gaer Colliery of South Wales. The model was exhibited at the Great Exhibition of 1851. Also in 1851 David Boswell Reid, a Scottish physician, installed four steam-powered fans at the ceiling of St George's Hospital in Liverpool, so the pressure generated by fans would force air up and through the ceiling vents. Improvements in technology were made by James Nasmyth, the Frenchman Theophile Guibal and J. R. Waddle.
Electricity
Between 1882 and 1886 Schuyler Wheeler invented an electrically driven fan. It is commercially marketed by American company Crocker & amp; Curtis electric motor company. In 1882, Philip Diehl developed the world's first electric ceiling fan. During this intense period of innovation, fans powered by alcohol, oil, or kerosene are common around the turn of the 20th century. In 1909, KDK of Japan pioneered the invention of mass-produced electric fans for home use. In the 1920s, industrial advancements allowed steel fans to be mass-produced in various forms, lowering fan prices and allowing more homeowners to buy them. In the 1930s, the first art deco fans ("goose fans") were designed. In the 1940s, Crompton Greaves of India became the world's largest producer of electric ceiling fans, mainly sold in India, Asia and the Middle East. In the 1950s, desks and stand fans were produced in bright and eye catching colors.
Central windows and air conditioners in the 1960s caused many companies to stop fan production. But in the mid-1970s, with increasing awareness of the cost of electricity and the amount of energy used to heat and cool the house, the medieval ceiling fan became very popular again as an efficient decorative and energy unit.
In 1998, Walter K. Boyd invented the HVLS ceiling fan. A lifelong inventor, Boyd was assigned to develop a system to cool diary cattle. Dairy cattle, when overheated, lower milk production. Using the laws of physics and airflow, Boyd developed a slow-moving fan that incorporated 10 aluminum blades and an 8 foot diameter. Unlike traditional fast-moving ceiling fans, this large fan moves slowly. Due to its diameter size, the fan moves a large column of air down and out 360 degrees and keeps mixing fresh air with the stuffy air inside the warehouse. They are used in many industrial and agricultural settings, because of their energy efficiency. It also cools the inside of the granary without causing stress on dairy cows or kicking dust.
After much testing, Boyd found the HVLS fan technology to be energy efficient because it costs less to run one HVLS fan than to run 50 small high-speed fans. Due to skyrocketing energy costs, HVLS commercial ceiling fans are used today to complement HVAC systems in industrial and commercial settings, including warehouses, manufacturing facilities and malls, as HVLS fans help lower heating and cooling costs.
Maps Fan (machine)
Type
Mechanical rotary blade fans are made in various designs. They are used on floors, tables, tables, or hanging on the ceiling (ceiling fans). They can also be built into windows, walls, roofs, chimneys, etc. Most electronic systems such as computers include fans to cool circuits inside, and appliances such as hairdryers and portable room heaters and wall mounted/installed heaters. They are also used to move air in an air-conditioning system, and in automotive engines, where they are driven by a belt or by a direct motor. The fan used for comfort creates a cold wind by increasing the heat transfer coefficient, but does not lower the temperature directly. Fans used to cool electrical appliances or in machines or other machines cool the equipment directly by forcing hot air into a cooler environment outside the machine.
There are three main types of fans that are used to move the air, axial , centrifugal (also called radial ) and cross flow (Also called tangential ). American Society of Mechanical Engineers Performance Testing Code 11 (PTC) provides standard procedures for performing and reporting tests on fans, including centrifugal, axial, and blend streams.
Axial flow
An axial flow fan has a blade that forces air to move parallel to the axis at which the blades rotate. This type of fan is used in a variety of applications, ranging from small electronic cooling fans to giant fans used in wind tunnels. Axial flow fan is applied in AC and industrial process applications. The standard axial flow fan has a diameter of 300-400 mm or 1800 to 2000 mm and works under pressure up to 800 Pa. The special type of fan is used as a low pressure compressor stage in aircraft engines. Examples of axial fans are:
- Table Fan: The basic elements of typical table fans include fan blades, base, armature and lead cables, motors, knife shields, motor homes, gearbox oscillators, and oscillator shafts. An oscillator is a mechanism that directs the fan from side to side. The shaft of the armature shaft exits at both ends of the motor, one end of the shaft attached to the blade and the other attached to the oscillator gearbox. The motor casing joins the gearbox to load the rotor and stator. The oscillator shaft joins the weighted base and gearbox. A motor home includes an oscillator mechanism. The blade shield joins the motor casing for safety.
- Electro-mechanical fans: Among collectors, rated according to condition, size, age, and number of blades. The four-blade design is the most common. The design of five blades or six knives is rare. The material from which components are made, such as brass, is an important factor in the desires of fans.
- Ceiling fan: The ceiling fan hanging on the ceiling is a ceiling fan. Most ceiling fans rotate at relatively low speeds and do not have a knife shield. Ceiling fans can be found in residential and industrial/commercial settings.
- In the car, the mechanical fan provides engine cooling and prevents the engine from overheating by blowing or pulling air through the cooled radiator. The fan may be driven with a belt and pulley of the engine crankshaft or electric motor that is turned on or off by a thermostatic switch.
- The computer cooling fan to cool the electrical components
- Fans inside audio power amplifiers help draw heat from electrical components.
- fan variable-pitch: A variable-pitch fan is used where precise control of static pressure in the supply line is required. The vanes are set to spin on the control pitch hub. The fan wheel will rotate at a constant speed. The blades follow the control pitch hub. When the hub moves toward the rotor, the propellers increase their angle of attack and increase the flow yield.
Centrifugal
Often called "squirrel cages" (due to common similarity in appearance to exercise wheels for pet rodents) or "scroll fan", the centrifugal fan has a moving component (called an impeller) consisting of a central axle about a set of spiral blades, or ribs, positioned. Centrifugal fans blow air from the right angle to the fan intake, and rotate the air out into an outlet (with deflection and centrifugal force). The impeller rotates, causing air to enter the fan near the shaft and moving perpendicularly from the shaft to the hole in the rolled fan case. The centrifugal fan produces more pressure for the given air volume, and is used where it is desirable as in leaf blowers, blowdryers, inflators of air mattresses, wind structures, climate control, and various industrial purposes. They are usually quieter than comparable axial fans.
Cross-flow Fan
The cross-flow or tangential fan, sometimes known as the tubular fan, was patented in 1893 by Paul Mortier, and is widely used in HVAC Industry. The fan is usually long in relation to the diameter, so the flow is approximately two dimensional left over from the tip. CFF uses an impeller with a curved blade forward, placed in a housing comprising a back wall and a vortex wall. Unlike radial machines, the main stream travels across the impeller, passing the blading twice.
Flow in the cross-flow fan can be broken down into three different areas: the vortex area near the fan discharge, called the eccentric swirl, the pass-by region, and the direct-facing rowing area. Both the vortex and paddling regions are dissipative, and as a result, only a portion of the impeller instills useful work on the flow. Cross-flow fan, or transversal fan, is thus a two-stage partial entry engine. The popularity of the crossflow fan in the HVAC industry comes from compactness, shape, quiet operation, and the ability to deliver high pressure coefficients. Effectively rectangular fan in terms of inlet geometry and outlet, the diameter is ready to adjust to available space, and the length is adjusted to meet the flow rate requirements for a particular application.
Fans of common household towers are also cross-flow fans. Much of the initial work focuses on developing cross-flow fans for both high- and low-level flow conditions, and generates many patents. The main contributions are made by Coester, Ilberg and Sadeh, Porter and Markland, and Eck. One particularly interesting phenomenon for cross-flow fans is that, as the blades rotate, the local air angle changes. The result is that at certain positions the blade acts as a compressor (pressure increase), while at other azimuth sites the blade acts as a turbine (pressure drop).
Since the inlet and outflows of the impeller are radial, the crossflow fan is perfect for aircraft applications. Due to the nature of the 2D flow, the fan is easily integrated into the wings for use in the production of thrust and boundary layer control. The configuration that uses a crossflow fan located on the front wing is fanwing. This design creates lift by turning the direction down because of the fan rotation direction, causing a large Magnus force, similar to the rotating front cylinder. Another configuration that utilizes crossflow fan for thrust and flow control is the propulsive wing. In this design, a crossflow fan is placed near the trailing edge of the thick wing, and draws air from the wing suction surface (top). By doing this, the propulsive wing almost without a drill, even at a very high angle of attack, produces a very high lift. The external links section provides links to these concepts.
Cross-flow Fan, is a centrifugal fan in which air flows through the fan, not through the inlet. The cross flow fan rotor is closed to create a pressure differential. When used in household fans, cross flow fans have a smaller opening on one side and a larger opening on the other. Crosslinking fans have openings of different sizes on the front and back. The resulting pressure difference allows air to flow straight through the fan, even though the fan blades fight against the airflow on one side of the rotation. Cross-stream fans provide airflow along the fan width, however, they are more noisy than the usual centrifugal fans allegedly because the fan blades fight the airflow on one side of the rotation unlike the normal squirrel cage fan. Cross-flow Fans are often used in air conditioning, car-ventilation systems, and for cooling in medium-sized appliances such as photocopiers.
Fan or blower action causes little pressure on the atmosphere, called the plenum.
Bladeless indirect viscose shaving fan
It is an indirect blower system that collects pressurized airflow from a standard blower device which can be of any type mentioned in this article, and directs the airflow collected through a vacuum tube or toroid, blows high-speed laminar airflow thin from the hole or slot continuously on the surface of the tube or toroid. This fan has a three dimensional mix impeller flow in the lower compartment. Air is drawn and compressed, before being ejected through the annulus, and accelerated through an airfoil lamp. Pushing and pulling the surrounding air through a shear shift, the circular upper part doubling the airflow over and over again. The high velocity of the laminar airflow tends to draw ambient air with it, due to thick shear. Only about 7% of the total airflow actually passes through the fan itself.
Unconverted fan type
Bellow
Bellows are also used to move the air, although generally not considered fans. A hand-operated bellows are basically a bag with nozzles and handles, which can be filled with air by one movement, and air released by another. Usually it will consist of two rigid flat surfaces that depend on one end, where the nozzle is installed, and with the handle on the other end.
The sides of the surface are combined with flexible and air-resistant materials such as leather; Surfaces and concomitants consist of a bag sealed everywhere but in the nozzle. (The joining material usually has a distinctive common pleated construction so that the same expansion fabric settings are not used for moving air, as in folding cameras, called bellows.) Separating the grip expands the bag, which fills with air; squeezing them together driving the air out. Simple valves (eg flaps) can be mounted so that air enters without having to come from the nozzle, which may be close to fire.
The bellows produce a pressure-directed air flow; Airflow volume is usually low with medium pressure. They are an older technology, which is used primarily to generate strong and directed airflow unlike non bladed electrically mechanized fans, before the introduction of electricity.
- A single acting bellows will only generate airflow during a stroke.
- Double bellows are a pair of bellows capable of blowing air from one moment of breathing air into other air, but the airflow is still paused when the direction of the stroke is reversed.
- Combining multiple bellows in the third cycle or quarter cycle cycle of the crank arm allows continuous airflow from multiple bellows at once; each in a different phase inhaling and tiring during the cycle.
Coand? effects
Fans of the Dyson Air Multiplier, and fan fan series of the Imperial C2000 series, do not have open fan blades or other parts that are visible to move unless the head oscillates and tilts. Airflow generated using Coand? effect; a small amount of air from a high-pressure bladed impeller fan, located on the base, and not exposed, pushes large air through the low pressure area created by airfoil. US Patent & amp; The Trademark Office originally ruled that Dyson patents were not an improvement on Toshiba's patents on nearly identical bladeless desktop fans provided in 1981. Air curtains and air doors also use this effect to help keep warm or cold air in exposed areas that do not have a cover or doors. Air blinds are commonly used in open face milk products, freezers, and vegetables to help keep cold air in the cabinet using laminar airflow that is circulated throughout the screen opening. Airflow is usually generated by any type of mechanical fan described in this article hidden in the bottom of the display cabinet.
Convection
Air temperature differences will affect air density and can be used to induce air circulation through heating or cooling air masses only. This effect is very smooth and works at low air pressure that seems incompatible with the definition of fan technology. However, prior to the development of electricity, convective airflow is the main method to encourage airflow in living spaces. The old oil and coal furnaces are not electric and are operated only by the convection principle to drive warm air. The huge volume air ducts upward from the top of the stove to the floor and the wall above the stove. Cold air is returned through the same large canal to the bottom of the furnace. Older homes than before electrification often have open channels that lead from lower level ceilings to upper level floors, to allow convective airflow to slowly board buildings from one floor to the next. Outhouses usually rely on simple closed air ducts at the corners of the structure to remove the stinging odor. Exposed to the sun, the channel is warmed and the slow convective air currents are released from the top of the building, while fresh air enters the hole through the hole.
Electrostatic
An electrostatic fluid accelerator promotes airflow by inducing motion in charged air particles. High-voltage electrical fields (typically 25,000 to 50,000 volts) are formed between open-charged anodes and cathode surfaces capable of driving airflow through a principle known as ionic wind. Airflow pressure is usually very low but the air volume can be large. However, a high enough voltage potential may also lead to the formation of ozone and nitrous oxide, which are reactive and irritate the mucous membranes.
Noise
The fan produces sound from the rapid airflow around the blades and obstacles, and sometimes from the motor. The fan noise has been found to be approximately proportional to the fifth power of the fan speed; reducing half the speed reduces noise by about 15 dB.
Fan motor drive method
Standalone fans are usually powered by an electric motor, often mounted directly to the motor output, without gears or belts. This motor is hidden in the center of the fan hub or extends behind it. For large industry enthusiasts, three-phase asynchronous motors are usually used, placed near the fan and driving through belts and pulleys. Smaller fans are often supported by shaded polar air conditioners, or brushed or brushed DC motors. The AC-powered fan typically uses an electric voltage, while the DC-powered fan uses low voltage, usually 24.V, 12.V, or 5V. The cooling fan for computer equipment always uses a brushless DC motor, which produces less electromagnetic interference than other types.
On machines with rotating parts, fans are often connected to it rather than powered separately. This is usually seen in motor vehicles with internal combustion engines, large cooling systems, locomotives, and caught machines, where fans are connected to the drive shaft or through belts and pulleys. Another common configuration is a dual-axle motor, where one end of the shaft moves the mechanism, while the other has a fan mounted on it to cool the motor itself. Window windows typically use a dual-axle fan to operate a separate blower for interior and exterior parts of the device.
Where electrical power or rotating parts are not available, fans may be driven by other methods. High-pressure gases such as steam can be used to drive small turbines, and high-pressure liquids can be used to drive the pelton wheels, which can provide rotational drives for fans.
A large and slow-moving energy source such as a flowing river can also drive the fan using a water wheel and a series of gears or pulleys to increase the rotational speed to the required for efficient fan operation.
Solar powered fan
The electric fan used for ventilation may be supported by solar panels instead of electric current. This is an interesting option because once the capital cost of the solar panels has been closed, the electricity generated is free. In addition, electricity is always available when the sun is shining and the fan needs to be run.
Typical examples use 10-watt, 12x12 inch (30x30 cm) solar panels and are equipped with proper brackets, cables, and connectors. It can be used for ventilation up to 1250 square feet (100 m2) of area and can move air up to 800 cubic feet per minute (400 L/s). Due to the wide availability of 12 brushless DC electric motors and the comfort of cables such as low voltage, the fan usually operates at 12 volts.
Separate solar panels are usually installed in places that get most of the sunlight and then connect to a fan installed for 20 to 25 feet (6 to 7 m). Other permanently installed small and small portable fans include integrated (non-removable) solar panels.
See also
- Legal affinity
- Axial fan design
- Air conditioning
- Balancing engine
- Dyson Air Multiplier
- Fan death
- Industrial fans
- Pump
- Special fan power
- Turbomachinery
- Fan fan
- Fans of the whole house
- Turbine
- Wind turbine
- Window fans
- Box Fan
- Impeller
- Computer fans
References
External links
Source of the article : Wikipedia
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