An air compressor consists of an electrical motor that compresses the air into a tank. When required, the compressed air can be expelled at the picked pressure. How does an air compressor work? What are the requirements for choosing a suitable air compressor? Well there are a range of various compressor types.
Let’s continue with a summary. Normally compressors used in automation and workshops are the so-called positive displacement compressors. Here pressure is created when air is drawn into a container and the volume of that space is lowered. For this article we wish to limit ourselves to this kind of compressor. Let’s take a more detailed look at the reciprocating compressor.
The crankshaft turns which moves the piston inside the cylindrical chamber. An inlet valve also called an intake valve allows fresh air to get in the cylinder. This is done throughout a suction blow from the cylinder. The vacuum valve opens or deflates at high pressure throughout the pressure paddle.
The air is warmed when it is compressed. This is a problem for each compressor. The result is not just a less effective compression cycle, but also the threat of a genuine surge if any flammable compounds, such as oil or lubes, are in contact with the piston and air. The pressure of a single phase compressor is limited to an output pressure of about 10 bar or 145 pounds To attain higher pressures, you can use a multi-step compressor.
In a two phase compressor, the large piston develops the first stage. The air that exits the first stage can now be cooled prior to getting in the 2nd phase. With a two-stage compressor, you can attain pressure in excess of 20 bar or 290 psi. Multistage compressors can also be used with high-power water-cooled jackets to avoid getting too hot. Based on its working principle, the reciprocating compressor offers just pulse compressed air.
So this kind of compressor is used in conjunction with a tank. The usage of a tank offers the benefit that the compressor can be run with a two-point controller, resulting in less power usage and wear.
The diaphragm compressor comes from the piston compressor family. Here the suction chamber of the piston is closed by a diaphragm. The benefit of a diaphragm compressor is the compressed air in the compression chamber does not come in contact with the piston and is lubricated. Thus it can be kept devoid of oil. These are a few examples:
The weak point of a diaphragm compressor is usually its diaphragm itself because flexibility is limited. Diaphragm compressors are used for instance in the food market or for filling divers bottles.
The working principle is totally unique from the so-called rotary compressor, which is also called a vane compressor. A typical rotary compressor has a cylindrical chamber. Adjustable rotors with their center point on the drive shaft are linked to the chamber.
So when the pivot rotates, these rotors create a chamber of various sizes. Air is compressed into the biggest chamber, then compressed and left in the tiniest chamber. A benefit here is in pulsed free circulation in contrast to piston compressors. So an air tank might be optional. Additionally, these compressors are quiet and relatively insensitive to dirt.