Pneumatics

Pneumatics is the use of compressed air for mechanical motion.  It has many uses.In dentistry applications, pneumatic drills are lighter, faster, and simpler than an electric drill of the same power rating (because the compressor, is separate from the drill and pumped air is capable of rotating the drill bit at extremely high rpm). 

Pneumatic transfer systems are employed in many industries to move powders and devices. Pneumatic devices are also used where electric motors cannot be used for safety reasons, such as deep in a mine where explosive dust or gases may be present.

 Examples of pneumatic tools 

 Pneumatic drill (jackhammer) used by road workers
 Pneumatic nailgun
 Pneumatic switches
 Pneumatic actuators
 Air compressors
 Vacuum pumps
 Barostat systems used in Neurogastroenterology and for researching
electricity
 Cable Jetting - a way to install cables in ducts
 Pneumatic mail systems
 Air brakes on buses, trains, and trucks

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 or water.  

 Advantages of pneumatics 

 The working fluid is very light in weight so supply hoses are not heavy.

 Because the working fluid is (mostly) just air, there is usually no need for a return line for the working fluid and leaks of the working fluid tend not to be messy.

 Because air is compressible, 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.

 Advantages of hydraulics 

 Higher energy density owing to the much higher working pressures usually employed.

 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...

References

 Other websites 

 www.pneumatics.be  - didactic website - for students - how pneumatics works
 U.S. Department of Energy  - Improving Compressed Air System Performance
 Fluid Power Educational Foundation  - Advancing and Supporting Hydraulic & Pneumatic Education
 Pneumatics Glossary  - Glossary of Pneumatic Terms

Category:Fluid mechanics
Category:Engineering
Category:Technology