Compressed air 101: What is it, how is it measured, and how is it used?

Would you like to know more about compressed air and how its technology comes together? The first step is learning about air itself!

Estimated time to read: 7 mins

Air is a necessity in everything we do and is the beginning of how we use compressed air technology. Life on earth depends on a gas bubble, the atmosphere, that surrounds our globe. The protective bubble extends approx. 100 km into space. What we commonly call air is a gas mixture consisting mainly of nitrogen, oxygen and a larger or smaller amount of water vapor. The air also contains small amounts of inert gas and, unfortunately, a lot of pollution in the form of hydrocarbons produced by man. The air composition remains largely the same up to about two miles altitude.

Now that the basics are covered, let us look at how this air is utilized for what we call compressed air, and understand how it is used or measured. 

What is compressed air?

Estimated time to read: 7 minutes

About compressed air graphic

Almost all of us certainly have come across the production of compressed air in a simpler version. Whether it was inflating a balloon with your mouth or inflating the tire on a wheel or car with a hand pump.

Unlike liquids, air can be compressed, i.e., a given volume of air can be reduced with increased pressure within the new volume as a result. Compression is carried out in a machine with a power source, a compressor. In its simplest form, a compressor can be a football pump with a human as the power source. air is drawn into the pump and compressed to about 1/4 of its original volume. The air pressure inside the football therefore rises to four times the atmospheric pressure and can be harnessed for various operations.

In the more demanding applications, different types of compressors are used to produce compressed air. Compressed air is characterized by three basic parameters: pressure, volume and air quality which is closely relates to the warm environment. These parameters are an important factor in choosing the right compressed air systems.

What is the pressure of compressed air?

Pressure is generally defined as the force acting on a unit of area. If we convert this definition into atmospheric (ambient) air, its pressure will be the force acting on the unit of the Earth's surface. The magnitude of this pressure to 0m above sea level is 101.3 kPa. The atmospheric air is then compressed to the required pressure, the value of which is most often given in bars. To demonstrate, 1 bar = 100 kPa = 0.1 MPa

How is the quantity of compressed air measured?

Based on the consumption of required equipment, the amount of compressed air required to ensure trouble-free operation of the entire system is determined. Most often the amount of compressed air is given in m³/h or l/s.

What is the quality of compressed air?

The term compressed air quality is an indicator of the amount of solids (dust), moisture and oil in the compressed air. The quality of compressed air significantly affects production processes. In recent years, when technologies that require high-quality compressed air free of any undesirable substances have developed rapidly, the focus has also been on compressed air treatment equipment. The main factors influencing the quality of compressed air is the ambient temperature and the environment in which the compressor station is located.

Air quality is defined by the international standard ISO 8573-1, where the quality classes of compressed air are determined. According to these classes, it is necessary to choose the right set of compressed air treatment equipment to achieve the required quality. 

What are the uses and applications of compressed air?

Much like regular air from which it originates, compressed air is virtually everywhere. When you take vacations, use a computer, drive or even go scuba diving, compressed air has a big, big role to play. Compressed air can be used in two ways, as energy (Energy air) or as a part of a process (Active air).

Energy air is stored to carry out mechanical operations. It is primarily used to power pneumatic production equipment, air operated lathe chucks, pressure clean parts and to convey or cool components during production. For example, a compressed air dryer is used to separate moisture from industrial process air.

Active air is used in key industries as a part of their processes in manufacturing, and therefore clean air quality is crucial in this case. This quality can be enhanced by using an oil-free air compressor and through compressed air treatment technology. Active air is used in industries such as Chemicals, Pharmaceuticals, Food & Beverage, Electronics and more.

Compressed air can be applied to almost any piece of technology. Roller coasters, school busses, and washing machines are among countless examples. It drives various industries and applying it in the best way aids profitability as well as productivity.

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