Pneumatic systems are used in plants and machinery because of the advantages they offer. The pneumatics is often in competition with the hydraulics or a purely electrical solution. Knowing the benefits of pneumatics over hydraulics or electrics is important when deciding on one of the systems.
After all, each technology has its own advantages and disadvantages, so you have to weigh on a case-by-case basis which solution is best. Frequently, a mixed solution is used in which electrics, pneumatics, and hydraulics interact.
Advantages of pneumatics
Stepless switching or regulation of the speeds and forces of the cylinder
Achieving enormously high operating speeds (up to 1500 mm / s for a standard cylinder, up to 3000 mm / s for a high-performance cylinder and up to 100,000 rpm for motors)
In case of overload up to a standstill, compressed air devices have the advantage of generally remaining harmless
Compared to electrical appliances, pneumatic equipment is simply constructed; For this reason, it is generally easier, which reduces the physical strain on the manufacturing staff
unlike electrical systems, the waste heat in pneumatic systems does not fall on the decentralized electric drive units, but invariably centrally on the compressor itself
while working media of electrical systems (such as hydraulic oil) cause costs, air as a working medium of pneumatic systems – at least in a non-processed state – always and free of charge
pneumatic systems do not require return lines, as the exhaust air can escape directly into the environment; the result is simple topologies of compressed air piping systems
Periodic control of the compressed air tanks of the pneumatic system ensures explosion safety
Insensitivity of the compressed air to atomic radiation and magnetic pulses
Storage of energy in the form of compressed air possible
The use of compressed air offers numerous advantages compared to other drive technologies. But there are also disadvantages associated with the use of pneumatics. Awareness of the disadvantages of pneumatics over hydraulics or electrics is important if one has to choose one of the systems.
The efficiency of the energy used in compressed air systems is much lower than when the electric current is used directly for drives. The reason for this is that a certain amount of energy is needed to compress the air at the compressor. A considerable part of the energy is converted into heat. Despite the subsequent heat recovery, exergy is lost in the process of air compression.
Air motors and other pneumatic components that are quickly filled with air cool during operation. You can even freeze.
Limited forces compared to hydraulic drives
Piston forces are limited. The reason is that the operating pressure usually moves below 12 bar. For example, a piston with a diameter of 200 mm at 7 bar develops a theoretical force of 21000 N (about 2100 kg).
Piston Speed Uniformity Requires Special Technique
Another drawback of pneumatics is that special sealing and throttling technique is required to achieve uniform piston speeds (sine cylinder).
Fixed Stop Required Required
Because of the compressibility of the air, it is possible to approach a specific position accurately or to achieve accurate positions only with fixed stops.