Compressed Air & Pneumatics – What is compressed air?

Compressed air, also called compressed air in everyday life, is so-called compressed air. It is used in pneumatics as follows:

as a carrier for energy, such as for driving in underground mining
in the signal transmission analogous to the electric current
for cleaning purposes
as a gas to breathe
as a coolant
for nitrogen production

If you do not use air but special gases or mixtures, you call these compressed gases.

Air – Definition & Composition

The gas mixture of our earth’s atmosphere is called air. The air in the dry state contains predominantly the gases nitrogen with approx. 78.08 volume% and oxygen with approx. 20.95 volume%. The remainder is argon at 0.93% by volume, carbon dioxide at 0.04% by volume and traces of other gases. Water in gaseous form, ie water vapor, is present at an average of 1.3% by volume near the ground and 0.4% by volume in the rest of the earth’s atmosphere but was not included in the above values. Air is usually odorless, colorless and tasteless.

Production of compressed air

Depending on the intended use, the air in the pneumatic system can be put under increased pressure by compressors, so-called compressors, and otherwise treated. Compressing requires high energy expenditure since heat energy escapes unused. So far, compressed air has been an expensive carrier of energy. Thanks to new energy-saving process technologies, the cost balance for compressed air is better today: Heat recovery and leak prevention can also save a lot of CO2 and reduce production costs.

The production of compressed air is usually based on two different processes: A mostly two-stage reciprocating compressor or screw compressor or three-stage reciprocating compressors can produce a compression pressure of 3000 bar. Likewise, rotary compressors and, to some extent, diaphragm compressors are used. The compressor capacity is given with l / min or m³ // h and represents the so-called delivery performance of the compressor.

Compressed air distribution
Compressed air is thus generated, stored, processed and used. The most important component in pneumatics, however, is the distribution in the compressed air system. In many installations, this is often neglected because technically supposedly sophisticated. However, high operating costs arise in particular in the improper distribution of compressed air in systems in planning and execution.

using pressure
When compressed air is used for cleaning or as an energy source, it requires a pressure of 6 to 8 bar, sometimes even up to 16 bar. When diving or breathing apparatus, the breathing air is used in bottles or cartridges at 200 to 300 bar. Special containers made of carbon withstand pressures of 300 bar and are at the heart of transportable pneumatic tools, for example for nailing, or in so-called air rifles. If bulk materials are conveyed with the aid of pneumatics, pressures of up to 4.5 bar are required.