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Compressed air

Many technical applications of compressed air can be recalled from the early days of mankind.

In order to establish when compressed air was applied for the first time in order to carry out work, one has to look back to the day when hunters tried out blowpipes with arrows in order to shoot wild animals.

Considerably later in time, hand operated bellows were used when goldsmiths in ancient Egypt started to melt metals such as gold and copper. Copper and tin were alloyed to form bronze and this developed into an established method of production with the help of “air compression”.

Further development towards an air compressor proceeded through the blower cylinder, invented by John Smeaton, which was powered by a water wheel.

The first blower machine was built by Wilkinson around 1776. This blower provided compressed air with a pressure of about 1 bar gauge.

Only by the year 1800, was compressed air.seriously discussed as a carrier of energy. The first attempt failed, in 1820 in Wales. The blowing machines functioned as expected but the ducting system made from ceramic pipes was totally inadequate.

The first successful transmission of energy by compressed air and on a large scale succeeded when the Mt. Cenis tunnel was built in the Swiss Alps.

When the 13.6 km long tunnel was built, compressors with a pressure of 6 bar were used. These worked according to the principle of the falling water column (Fig. 2.0.1). The exemplary engineering achievements shown by the construction of the tunnel were acknowledged throughout the entire world.

The final break-through for compressed air succeeded in the year 1888, when the city of Paris installed a compressed air distribution system which supplied wide areas of the city with this form of energy. A 7 km long principal network with 50 km of auxiliary lines was supplied with compressed air generated by a 1500 kW compressor. This station was extended up to the year 1891 and reached a total compressor power of 18000 kW.

Thus compressed air stood at the threshold of great times. Technicians in many industrial countries became active with a view to utilising compressed air for the most varied applications.

Today, compressed air forms an essential supplement to electricity, and industry without it can no longer be imagined. The rapid development and spread of compressed air is due to the fact that it is both, carrier of energy and working medium, as opposed to electric current which can be used exclusively as a carrier of energy.

In addition to electric current and hydraulics, compressed air enjoys widespread use in present day technology and the fields of application are increasing all the time.

Compressed air is compressed atmospheric air. Air in the compressed state is a carrier of energy and offers the possibility of transmitting this energy over large distances and then utilising it upon release.

Particularly in medium size and large industrial works, we find machine and hand tools of all types which are powered by compressed air. To this have to be added pneumatic displacement and feed units, lifting tackle, blow guns, sand and shot blasting installations or, in paint shops, spray guns.

Furthermore, conveying appliances for bulk goods such as wheat, using pneumatic pressure or air suction power, are used in port installation or silos, also pneumatic or pneumatic/hydraulic control and activation equipment, and finally pneumatic logic elements are used in industry.

Mining forms another important field. Likewise the manufacture of pharmaceutical products such as with the production of vaccines or antibiotics, then numerous applications in the food and beverage industry and, last but not least, the hospitals, nursing homes and fire and rescue stations equipped with compressed air.

All these users of compressed air, of which are listed only the most important ones, do not only depend on compressed air but, in addition, compressed air must be fed to the operating process in a treated, i.e. filtered and dried, state.