Pneumatics

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Please improve this article if you can. (November 2007)

Pneumatics, a subsection of an area called fluid power, is the use of pressurized air to effect mechanical motion.

Pneumatic power is used in industry, where it is common to have industrial factory unit plumbed for compressed air. It also has applications in, among other things, dentistry, construction, and mining. Pneumatic power users need not worry about hazardous leakages as the fuel is commonly just air, although other compressed gases, such as carbon dioxide, may be used.


Examples of pneumatic systems:

Contents

[edit] Comparison to hydraulics

Both pneumatics and hydraulics are applications of fluid power. Pneumatics uses air, which is compressible, while hydraulics uses relatively incompressible liquid media such as oil. Most industrial pneumatic applications use pressures of about 80 to 100 pounds per square inch (psi) (500 to 700 kilopascals). Hydraulics applications commonly use from 1,000 to 5,000 psi (7 to 35 MPa), but specialized applications may exceed 10,000 psi (70 MPa).

[edit] Advantages of pneumatics

Clean

  • Air is used by a machine & is then exhausted to the atmosphere - no return line necessary.
  • Any leaks will be of air (which is much less of a problem than oil leaks in Hydraulics).

Availability

  • Air is freely available in the pneumatics
  • Most factories are pre-plumbed for compressed air distribution - which makes it very easy to set up a manufacturing process

Simplicity of Design And Control

  • Machines are easily designed using standard cylinders & other components. Control is as easy as its simple ON - OFF type control

Reliability

  • Pneumatic systems tend to have long operating lives and require very little maintenance.
  • Because air is compressable, the equipment is less likely to be damaged by shock. The air in pneumatics absorbs excessive force, whereas the fluid of hydraulics directly transfers force.

Storage

  • Compressed Air can be stored, allowing the use of machines when electrical power is lost.

Safety

  • Very small fire hazard (compared to Hydraulic Oil)
  • Machines can be designed to be overload safe.

[edit] Advantages of hydraulics

  • Fluid does not absorb any of the supplied energy.
  • Capable of moving much higher loads and providing much higher forces due to the incompressibility.
  • The hydraulic working fluid is basically incompressible, leading to a minimum of spring action. When hydraulic fluid flow is stopped, the slightest motion of the load releases the pressure on the load; there is no need to "bleed off" pressurised air to release the pressure on the load.

[edit] Pneumatic Logic

Main article: Fluidics

Pneumatic logic systems are often used to control industrial processes, consisting of primary logic units such as:

  • And Units
  • Or Units
  • 'Relay or Booster' Units
  • Latching Units
  • 'Timer' Units

Pneumatic logic is a reliable and functional control method for industrial processes. In recent years, these systems have largely been replaced by electrical control systems, due to the smaller size and lower cost of electrical components. Pneumatic devices are still used in processes where compressed air is the only energy source available or upgrade cost, safety, and other considerations outweigh the advantage of modern digital control.

[edit] External links

Look up Pneumatics in
Wiktionary, the free dictionary.

[edit] See also