What Is A Positive Displacement Air Compressor

Rotary Screw Compressor — The rotary positive displacement compressor is the most common type of compressor in use today. It works by drawing air in, sealing the opening, and then compressing the air with two rotors that continuously rotate and pass through the cavity. With each rotation, the air is increasingly pressurized until it reaches the set pressure.

This type of compressor is lubricated with an air-oil mixture, which collects contaminants from the air, self-lubricates compressor components, and reduces operating temperature. While the oil must be filtered from the air before it is used in the end application, the presence of oil creates greater operational efficiency. Rotary compressors are typically available in up to 600 HP.

Reciprocating Piston Compressor — This type of compressor uses a piston in constant motion to draw in and then compress air. In general, one movement of the piston draws in the air, while the reverse movement compresses it. Reciprocating piston compressors are available in single- or double-chamber designs, meaning that the air is compressed on only one side of the piston or on both. These types of compressors are air- or water-cooled and can offer up to 1000 HP.

Rotary Vane Compressor — Working on a principle similar to the rotary screw compressor, this type of compressor uses vanes instead of helical blades on a rotor to compress air that enters the cavity. Like the rotary screw compressor, it is oil-cooled.

You may also be familiar with dynamic compressors. The difference between a dynamic and positive displacement compressor is that a dynamic compressor moves air at a high speed, creating kinetic energy that is then sent through a diffuser and converted into static pressure.

At Kaishan Compressor USA, we offer a wide range of compressor solutions and await the opportunity to help you choose the right equipment for your application and requirements. For more information, contact us today.