We compress air every time we breathe, so the idea of compressing air is an innate concept. However, air compression becomes an intentional, goal-oriented action when we blow air into a balloon, or when blacksmiths use bellows to work their forges. The science behind air compression technology has come a long way from the old days though, especially for industrial usage. From hair dryers and spray paint bottles to pneumatic presses and electric motors, numerous modern gadgets and industrial equipment would not even exist without them. Let’s get to know the air compressor and the core mechanism behind it a bit next.
Mechanism: How Do Air Compressors Work?
The exact mechanism behind air compressors will vary depending on the kind of air compressor we are discussing. Nevertheless, the core mechanism of air compression still revolves around containing and releasing pressurized air under control to complete a desired task. The resulting air displacement is what allows a spray bottle to release puffs of perfume and a pneumatic press to go through metal like its paper.
Variable Speed Air Compressors
Air compressors that allow users to control the amount, speed, pressure, and rate of air release are called variable speed air compressors. Variable air compressors are power almost all types of industrial pumps, vacuum cleaners, blowers, electric motors, speed drivers, and more. Click here to learn more about variable speed air compressors and their wide range of industrial applications.
Single-Speed Air Compressors
Single-speed air compressors, on the other hand, are basic compressors that do not allow users any control over the speed or pressure of each release. However, they are uniform and that is very useful in some instances. For example, every puff from an inhaler is a guaranteed, metered dose that will never deliver any more or less than the specified amount.
Positive Air Displacement
There are two variations in air displacement techniques which we see inside air compressors. Positive air displacement is the mechanism that powers spray bottles and bicycle handpumps. The idea behind positive air displacement is to draw in, store, pressurize, and then release air through compression.
Positive displacement uses the principles of vacuum to draw in and pressurize air inside an airtight container. Releasing the air requires either squeezing (compressing) that container directly (water balloons) or by utilizing atmospheric pressure (plunger of a spray bottle) to release the contained air at high speed.
Dynamic Air Displacement
Dynamic air displacement is relatively more complex in its mechanism, as it involves two steps.
- Air is passed over rotating blades or impellers to increase air pressure when needed.
- High-pressure air is passed over a set of stator vanes to decrease the air pressure as needed.
Axial and centrifugal air compressors are the only two types of air compressors that use dynamic air displacement. You will find axial air compressors inside blast furnaces used in metal manufacturing plants, electrical power generators, sewage treatment facilities, etc. Centrifugal air compressors are used in jet engines, turboshaft engines, chemical plants, ONGC mining equipment, and gas injection equipment among others.