Pneumatic (compressed-air) fireless locomotives like this were often used to haul trains in mines, where steam engines posed a risk of explosion. This one is preserved H.K. Porter, Inc. No. 3290 of 1923.
Pneumatic systems in fixed installations, such as factories, use compressed air because a sustainable supply can be made by compressing atmospheric air. The air usually has moisture removed, and a small quantity of oil is added at the compressor to prevent corrosion and lubricate mechanical components.
Factory-plumbed pneumatic-power users need not worry about poisonous leakage, as the gas is usually just air. Any compressed gas other than air is an asphyxiation hazard—including nitrogen, which makes up 78% of air. Compressed oxygen (approx. 21% of air) would not asphyxiate, but is not used in pneumatically-powered devices because it is a fire hazard, more expensive, and offers no performance advantage over air. Smaller or stand-alone systems can use other compressed gases that present an asphyxiation hazard, such as nitrogen—often referred to as OFN (oxygen-free nitrogen) when supplied in cylinders.
Portable pneumatic tools and small vehicles, such as Robot Wars machines and other hobbyist applications are often powered by compressed carbon dioxide, because containers designed to hold it such as soda stream canisters and fire extinguishers are readily available, and the phase change between liquid and gas makes it possible to obtain a larger volume of compressed gas from a lighter container than compressed air requires. Carbon dioxide is an asphyxiant and can be a freezing hazard if vented improperly.
History
The origins of pneumatics can be traced back to the first century when ancient Greek mathematician Hero of Alexandria wrote about his inventions powered by steam or the wind.
German physicist Otto von Guericke (1602 to 1686) further developed the idea. He invented the vacuum pump, a device that can draw out air or gas from the attached vessel. He demonstrated the vacuum pump to separate the pairs of copper hemispheres using air pressures. The field of pneumatics has changed considerably over the years. It has moved from small handheld devices to large machines with multiple parts that serve different functions.
Comparison to hydraulics
Both pneumatics and hydraulics are applications of fluid power. Pneumatics uses an easily compressible gas such as air or a suitable pure gas—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 (550 to 690 kPa). Hydraulics applications commonly use from 1,000 to 5,000 psi (6.9 to 34.5 MPa), but specialized applications may exceed 10,000 psi (69 MPa).[citation needed]
Advantages of pneumatics
Simplicity of design and control—Machines are easily designed using standard cylinders and other components, and operate via simple on-off control.
Reliability—Pneumatic systems generally have long operating lives and require little maintenance. Because gas is compressible, equipment is less subject to shock damage. Gas absorbs excessive force, whereas fluid in hydraulics directly transfers force. Compressed gas can be stored, so machines still run for a while if electrical power is lost.
Safety—There is a very low chance of fire compared to hydraulic oil. New machines are usually overload safe to a certain limit.
Advantages of hydraulics
Fluid does not absorb any of the supplied energy.
Capable of moving much higher loads and providing much lower forces due to the incompressibility.
The hydraulic working fluid is practically inincompressible, 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" pressurized air to release the pressure on the load.
Highly responsive compared to pneumatics.
Supply more power than pneumatics.
Can also do many purposes at one time: lubrication, cooling and power transmission.
Pneumatic logic systems (sometimes called air logic control) are sometimes used for controlling industrial processes, consisting of primary logic units like:
Fluidics amplifiers with no moving parts other than the air itself
Pneumatic logic is a reliable and functional control method for industrial processes. In recent years, these systems have largely been replaced by electronic control systems in new installations because of the smaller size, lower cost, greater precision, and more powerful features of digital controls. Pneumatic devices are still used where upgrade cost, or safety factors dominate.[1]
^KMC Controls. "Pneumatic to Digital: Open System Conversions" (PDF). Retrieved 5 October 2015.
References
Brian S. Elliott, Compressed Air Operations Manual, McGraw Hill Book Company, 2006, ISBN0-07-147526-5.
Heeresh Mistry, Fundamentals of Pneumatic Engineering, Create Space e-Publication, 2013, ISBN1-49-372758-3.
External links
Look up pneumatics in Wiktionary, the free dictionary.
Four Ways to Boost Pneumatic Efficiency
May 09, 2023
pneumatics, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, 2023, learn, wh. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Pneumatics news newspapers books scholar JSTOR May 2023 Learn how and when to remove this template message Pneumatic redirects here For the highest order of humans in Gnosticism see Pneumatic Gnosticism Pneumatics from Greek pneῦma pneuma wind breath is a branch of engineering that makes use of gas or pressurized air Pneumatic compressed air fireless locomotives like this were often used to haul trains in mines where steam engines posed a risk of explosion This one is preserved H K Porter Inc No 3290 of 1923 Pneumatic systems used in industry are commonly powered by compressed air or compressed inert gases A centrally located and electrically powered compressor powers cylinders air motors pneumatic actuators and other pneumatic devices A pneumatic system controlled through manual or automatic solenoid valves is selected when it provides a lower cost more flexible or safer alternative to electric motors and hydraulic actuators Pneumatics also has applications in dentistry construction mining and other areas Contents 1 Gases used in pneumatic systems 2 History 3 Comparison to hydraulics 3 1 Advantages of pneumatics 3 2 Advantages of hydraulics 4 Pneumatic logic 5 Examples of pneumatic systems and components 6 See also 7 Notes 8 References 9 External linksGases used in pneumatic systems Edit A pneumatic butterfly valve Pneumatic systems in fixed installations such as factories use compressed air because a sustainable supply can be made by compressing atmospheric air The air usually has moisture removed and a small quantity of oil is added at the compressor to prevent corrosion and lubricate mechanical components Factory plumbed pneumatic power users need not worry about poisonous leakage as the gas is usually just air Any compressed gas other than air is an asphyxiation hazard including nitrogen which makes up 78 of air Compressed oxygen approx 21 of air would not asphyxiate but is not used in pneumatically powered devices because it is a fire hazard more expensive and offers no performance advantage over air Smaller or stand alone systems can use other compressed gases that present an asphyxiation hazard such as nitrogen often referred to as OFN oxygen free nitrogen when supplied in cylinders Portable pneumatic tools and small vehicles such as Robot Wars machines and other hobbyist applications are often powered by compressed carbon dioxide because containers designed to hold it such as soda stream canisters and fire extinguishers are readily available and the phase change between liquid and gas makes it possible to obtain a larger volume of compressed gas from a lighter container than compressed air requires Carbon dioxide is an asphyxiant and can be a freezing hazard if vented improperly History EditThe origins of pneumatics can be traced back to the first century when ancient Greek mathematician Hero of Alexandria wrote about his inventions powered by steam or the wind German physicist Otto von Guericke 1602 to 1686 further developed the idea He invented the vacuum pump a device that can draw out air or gas from the attached vessel He demonstrated the vacuum pump to separate the pairs of copper hemispheres using air pressures The field of pneumatics has changed considerably over the years It has moved from small handheld devices to large machines with multiple parts that serve different functions Comparison to hydraulics EditBoth pneumatics and hydraulics are applications of fluid power Pneumatics uses an easily compressible gas such as air or a suitable pure gas 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 550 to 690 kPa Hydraulics applications commonly use from 1 000 to 5 000 psi 6 9 to 34 5 MPa but specialized applications may exceed 10 000 psi 69 MPa citation needed Advantages of pneumatics Edit Simplicity of design and control Machines are easily designed using standard cylinders and other components and operate via simple on off control Reliability Pneumatic systems generally have long operating lives and require little maintenance Because gas is compressible equipment is less subject to shock damage Gas absorbs excessive force whereas fluid in hydraulics directly transfers force Compressed gas can be stored so machines still run for a while if electrical power is lost Safety There is a very low chance of fire compared to hydraulic oil New machines are usually overload safe to a certain limit Advantages of hydraulics Edit Fluid does not absorb any of the supplied energy Capable of moving much higher loads and providing much lower forces due to the incompressibility The hydraulic working fluid is practically inincompressible 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 pressurized air to release the pressure on the load Highly responsive compared to pneumatics Supply more power than pneumatics Can also do many purposes at one time lubrication cooling and power transmission Pneumatic logic EditFurther information Pneumatic circuit Pneumatic logic systems sometimes called air logic control are sometimes used for controlling industrial processes consisting of primary logic units like And units Or units Relay or booster units Latching units Timer units Fluidics amplifiers with no moving parts other than the air itselfPneumatic logic is a reliable and functional control method for industrial processes In recent years these systems have largely been replaced by electronic control systems in new installations because of the smaller size lower cost greater precision and more powerful features of digital controls Pneumatic devices are still used where upgrade cost or safety factors dominate 1 Examples of pneumatic systems and components EditAir brakes on buses and trucks Air brakes on trains Air compressors Air engines for pneumatically powered vehicles Barostat systems used in neurogastroenterology and for researching electricity Cable jetting a way to install cables in ducts Dental drill Compressed air engine and compressed air vehicles Gas Chromatography Gas operated reloading Holman Projector a pneumatic anti aircraft weapon HVAC control systems Inflatable structures Lego pneumatics can be used to build pneumatic models Pipe organ Electro pneumatic action Tubular pneumatic action Player piano Pneumatic actuator Pneumatic air guns Pneumatic bladder Pneumatic cylinder Pneumatic launchers a type of spud gun Pneumatic mail systems Pneumatic motor Pneumatic tire Pneumatic tools Jackhammer used by road workers Pneumatic nailgun Pressure regulator Pressure sensor Pressure switch Launched roller coaster Vacuum pump Vacuum sewerSee also EditCompressed air Ozone cracking can affect pneumatic seals Pneudraulics History of pneumatic powerNotes Edit KMC Controls Pneumatic to Digital Open System Conversions PDF Retrieved 5 October 2015 References EditBrian S Elliott Compressed Air Operations Manual McGraw Hill Book Company 2006 ISBN 0 07 147526 5 Heeresh Mistry Fundamentals of Pneumatic Engineering Create Space e Publication 2013 ISBN 1 49 372758 3 External links Edit Look up pneumatics in Wiktionary the free dictionary Four Ways to Boost Pneumatic Efficiency Retrieved from https en wikipedia org w index php title Pneumatics amp oldid 1153408599, wikipedia, wiki, book, books, library,
