Earliest history

The first air compressors weren't machines, but human lungs: Primitive people blew on cinders to create a fire. We now know that healthy lungs can exert pressure of .02 to .08 bar (1 bar = 14.5 psi). However, this pressure was inadequate with the birth of metallurgy about 3000 B.C. As people began to melt metals such as gold, copper, tin and lead, higher temperatures were needed, and a more powerful compressor was required. Egyptian and Sumerian metallurgists used the wind, then blowpipes for their work. The first mechanical compressor, the hand-operated bellows, emerged soon after, and in 1500 B.C. the more efficient foot bellows came into use.

The next phase

Bellows driven by foot or by water wheel proved a reliable compressor for more than 2,000 years. But as blast furnaces developed, so did the need for increased air compression. In 1762, John Smeaton, the first professional engineer, built a water wheel-driven blowing cylinder that began to replace the bellows. Inventor John Wilkinson introduced an efficient blasting machine in England in 1776; the machine was an early prototype for all mechanical compressors.

New uses

From its human origins to the late 18th century, air compression was used mostly for the mining and fabrication of metals. Blowing machines supplied a combustion blast to metallurgic furnaces and ventilation to underground mines, although some scientists and philosophers used vacuum pumps during experiments.

The idea of using compressed air to transmit energy became popular about 1800 as metal manufacturing plants grew and emphasized the limited power of steam. A plant powered by water and compressed air was built in Wales in the 1820s, and, despite a few air leaks, new uses for compressed air began to emerge.

The first successful large-scale transmission of energy by compressed air took place in the Alps on the border of southeastern France and Italy. Railway managers decided to use a newly invented pneumatic rock drill to connect the two countries with an 8-mile (13.6 km) rail tunnel under Mt. Cenis. The work began with manual drilling in 1857, but a few years later engineers installed "wet" compressors (which used water to cool air inside the cylinders) on the French and Italian sides, and two teams drilled through the rock toward each other. When they met, there were about 4 miles (7,000 meters) behind each team, proving that compressed air could transmit energy over long distances.

Energy evolution

The Mt. Cenis tunnel attracted international publicity in newspaper and technical journals, and discussion turned to the possibility of a compressed air network that would provide energy to industries. Austrian engineer Viktor Popp made it happen in Paris in 1888, when he installed a 1,500 kW compressor plant that grew to 18,000 kW by 1891.

As compressed air's availability grew, inventors bustled to improve on it. Patent officers issued patents on machines and tools from motors to clocks to beer dispensers. The novelty of many services now available in Paris started a backlash against electricity by many engineers who saw compressed air as the energy distribution system of the future. However, electricity advocates held strong to their belief that pneumatic plants were inefficient and would eventually be trumped by electricity. Neither side was truly right.

Working together

As both energy systems have developed, compressed air has become an important complement to electricity. Pneumatic tools are lightweight and safe, and compressed air is used for monitoring, control and regulation, frequently in combination with hydraulics and electricity. The two working together have given the world new ways to use power.

Sources

Atlas Copco Manual - Produced by Atlas Copco AB, Stockholm Sweden, Edited by Torgny Rogert, Atlas Copco AB, Stockholm Sweden and S. Bertil Anderssen, Atlas Copco Airpower, NV.Printed by Ljungforetagen AB, Sweden 1975.
Bartleby.com search for Columbia Encyclopedia,
Energy Matters: Energy Through History,