Bladeless Fan Presented By– SHAILEN M. PATEL (B.E. Mechanical)
INTRODUCTION In October 2009, James Dyson's consumer electronics company, introduced a new device to the market called Dyson Bladeless Fan or Dyson Air Multiplier. They don’t have fast-spinning blades that chop the air and cause uncomfortable buffeting. Instead, they use Air Multiplier™ technology to draw in air and amplify it up to 15 times, producing an uninterrupted stream of smooth air.
INVENTED BY: Sir James Dyson He is a British Industrial Engineer and founder of Dyson company.
NEED FOR DEVELOPMENT This invention relates to the domestic fan, such as desk fan, ceiling fan for creating air circulation and air current in domestic environment. A conventional domestic fan typically includes set of blades or vanes mounted for rotation about an axis.
DEMERITS OF CONVENTIONAL FAN
Bulky in structure. Air current produced is choppy or uneven. Noisy when in operation. Cooling effect reduces with distance. Reduced working area on desk. Difficult to clean. Parts projected outward which is less safer.
TECHNICAL SPECIFICATIONS OF BLADELESS FAN Manufacturer
Dyson
Model Name
Dyson Air Multiplier AM01 10 Inch Desk Fan
Type of fan
Desk Fan
Thickness
10 inch
Technology
Air multiplier
Controls
Touch operations
Air flow Settings
Fully Variable
Oscillations
90ᵒ
Touch Tilt
10ᵒ ( Both Sides)
Dimensions
19.53 x 12.01 x 5.98 inches
DIFFERENT SHAPES AVAILABLE IN MARKET
CONSTRUCTION Bladeless fan comes in two pieces, the outer ring piece and the cylindrical base which could fit together in a matter of seconds.
MAIN COMPONENTS
Outer ring Cylindrical base Mixed Flow Impeller Brushless DC Motor Controls
Outer Ring It is a nozzle comprising an interior passage. Nozzle comprises a surface tapering away from axis, over which the mouth is arranged to direct air flow. The tapered diffusor portion enhances amplification properties whilst minimizing noise and frictional losses. Preferably the angle subtended between the diffuser portion and the axis is in range of 7ᵒ to 20ᵒ, more preferably about 15ᵒ. It provides more efficient air flow. The nozzle may comprise a Coanda surface located adjacent to the mouth. The fluid flows close (almost clinging or hugging) to the surface exhibits Coanda effect.
Cylindrical base The air is sucked through the tiny holes on the body of the fan. It also contains lots of tiny holes of 1.3mm diameter.
Mixed Flow Impeller To draw in the air required to generate a powerful enough jet, Dyson engineers developed a mixed flow impeller. It combines the technologies used in turbochargers and jet engines. It has nine asymmetrically aligned fins with rows of tiny holes that reduce the friction caused by colliding high and low air pressure.
Mixed flow impeller
Brushless DC Motor For generating a jet of air and making it powerful enough to function properly, the motor should be designed in a way so as to suck in more than 32 litres of air/second. It is powered by a brushless 40-Watt DC motor. This is about the same power used for a conventional fan.
Other components
Power Switches Air Speed controls Indicating lights Oscillations control buttons
MATERIAL USED It is constructed from tough Acrylonitrile butadiene styrene – ABS. ABS is a tough thermoplastic used to make light, rigid and moulded products. It has shock absorbing properties and is used to make car bumpers, crash helmets and modern golf club heads.
WORKING Working of bladeless fan is divided into mainly four stages:1) 2) 3) 4)
Air is drawn in Air is accelerated Air is induced Air is entrained
Air is drawn in Motor draws in almost 32 litres of air per second. Air is drawn in from the little vents in base.
Air is accelerated Air is forced up into loop amplifier and is accelerated out through an annular aperture creating a jet of air. It passes over the 16ᵒ airfoil shaped ramp, which channels its direction.
Air is induced As the air passes over the ramp, it draws air from behind the fan, this process is known as inducement.
The air comes out of a 3mm slit built in the frame at a speed of 55mph.
Air is entrained Air around the machine is also drawn into the airflow, through a process known as entrainment.
FEATURES
ADVANTAGES
Uniform Air flow Easy to control and maintain Swivel and Tilt all work well Well built and looks & feels good No buffeting Energy saving & smooth air flow Sturdy design & Good material quality Safer for kids as no moving blades
DISADVANTAGES • Too pricey a machine • No sleep mode (i.e. switch off after 1, 2, 3 hours) or remote control
Conclusion • Dyson Air Multiplier is more efficient ergonomically and more efficient than conventional fan. • It can be improved by reducing the price. Even at this price lack of remote is a negative point. • Design is sturdy and gives a clean and modern look. • Use of Acrylonitrile butadiene styrene as material makes it light in weight and more rigid, thus reducing its chances of breakage.
Reference 1) http://en.wikipedia.org/wiki/List_of_Dyson_products 2) http://www.g-mark.org/english/archive/2010/award-best15.html 3) http://www.airmultiplier.org/dyson-am01-10-inch-air-multiplierreviews.php 4) http://www.cravingtech.com/dyson-air-multiplier-a-k-a-bladeless-fanreview.html 5) http://www.airmultiplier.org/technology.php 6) United States Patent, Patent No.: US 7,931,449 B2; Date of patent: Apr.26, 2011 7) http://www.dyson.com/fans/fans.asp 8) http://www.efunda.com/formulae/fluids/calc_reynolds.cfm#calc
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