There are two types of compressors: volumetric compressors and centrifugal compressors (also called dynamic ones). Most compressors are volumetric compressors, which means air compressor for industrial use that a mechanism reduces the volume of air to compress it. These compressors are usually driven by electric motors. There are different technologies:
They can be single-cylinder. This type of compressor can be up to 10 bar pressure. They can also be multi-stage to increase the pressure in steps and up to 400 bar. Piston compressors are generally the most economical. You can choose this type of compressor for intermittent operation: the duty cycle is at most 60%, that is to say, it can only work 35 minutes per hour. A potential defect of this type of compressor is that it rejects oil with compressed air. If the air you need must be pure, you must provide a filtration system or direct you to an oil-free compressor This is the case, for example, for the electronics, pharmaceutical, food industry or a clean room air compressor for industrial use . Also, the piston compressors are relatively noisy, which can cause discomfort for people working nearby.
This is the most common industrial model. He uses helical screws instead of the piston. The pressure obtained can vary from 5 bars for a single-stage model to 13 bars for a multi-stage model. This type of compressor generally offers a high flow rate and a high compression ratio with a single-stage, which allows manufacturers to offer compressors with reduced dimensions compared to a similar piston model (which should be multi-stage to propose an identical pressure). The screw compressor can have a duty cycle of 100 %, which allows it to operate continuously. Some screw compressors are variable speed. They can adapt their rotational speed to the need for compressed air to optimize their energy needs.