How Does an Air Compressor Work?

How does an air compressor work?

Air compressors function from one of two ways; through positive displacement or dynamic displacement. Both of these types of compressors vary in the way their components work to generate air pressure, and the subtypes of compressors under these main two types also have slight differences in terms of their function.

Positive displacement

With air compressors that work by positive displacement, the machine stores air inside a cavity which is then slowly compressed, in turn increasing the air pressure and potential energy inside the machine. Common air compressors which work by positive displacement include rotary screw compressors and reciprocating compressors. Rotary screw compressors contain two internal rotors that turn in opposite directions. When this happens, the air becomes trapped between them and pressure builds up, which is then often used in industrial settings due to its large size and the internal cooling system which can facilitate continuous use.

Reciprocating compressors are, on the other hand, used on smaller work sites. A piston-driven crankshaft in a cylinder compresses and displaces air to build pressure. Reciprocating compressors can be single stage or multistage, the latter being used to generate more power.

Dynamic displacement

Air compressors that work by dynamic displacement store kinetic energy as static energy within the compressor. The machine brings in air through rapidly spinning blades, and this air is then restricted to create pressure. This type of compressor includes axial compressors, which are usually reserved for high speed engines on ships or planes due to their high efficiency rate, but also expensive cost.

Another type of compressor which works through dynamic displacement is the centrifugal compressor. These build up potential energy by slowing and cooling the air through a diffuser. The process within this compressor is multi-phasal which facilitates the generation of a high amount of energy and is therefore typically used in chemical plants or steel manufacturing centres.

Why would I need an air compressor?

Air compressors have a wide variety of applications, from large scale industry and oil rigs, to professional usage, leisure applications and domestic use.

For people looking to fill their own tires or operate a pressure washer, small-scale air compressors can be used at home. Similarly, home workshops or professional workshops and construction sites also benefit from reciprocating compressors to power pneumatic tools, many of which can power multiple tools at once.

The leisure sector also makes use of compressed air, as scuba divers carry a tank of pressurised air to safely remain underwater for longer, while compressed air is also used in canisters which fire ammunition from paint guns.

Even smaller, everyday applications of air compressors are present in cooling systems, such as refrigerators, freezers and air conditioning units, where reciprocating, rotary and centrifugal compressors chill the air.

Industrial-grade applications for air compressors include pneumatic machinery in factories, including cutting, sanding, clamping and for actuators and controls within manufacturing. The food and beverage industry also requires compressed air for bottling, dehydration, and packing, to name just a few of the many possible applications within the sector. Furthermore, agricultural uses of air compressors include crop protection through spraying, and pneumatically controlled dairy machines.

At Maziak we have over 60 years of experience and are industry experts in the distribution of air compressor systems. We work with leading industry experts to supply high-quality equipment, such as HPC compressors, to our customers. To find out more about the compressed air solutions and specialist builds we offer, fill out an enquiry form or call us today on 01933 222000, for specialised and expert advice.