Five parameters For Screw Compressor Selection

2024-04-27 23:04:41 admin

Screw Compressors: Classification, Working Principle, and Selection Parameters

Screw compressors are a type of positive displacement compressor that is commonly used in a variety of industrial and commercial applications. They are known for their efficiency, reliability, and ability to handle a wide range of gases.

Keepwin Screw air compressor


Screw compressors can be classified into two main types: oil-free and oil-lubricated.

  • Oil-free screw compressors are used in applications where the presence of oil in the compressed gas is unacceptable. These compressors typically use a dry seal to prevent oil from entering the compression chamber.

  • Oil-lubricated screw compressors are more common than oil-free compressors. They use oil to lubricate the rotors and to seal the compression chamber. The oil also helps to cool the gas and to remove contaminants.

Screw compressors can also be classified by their size and capacity. Small screw compressors are typically used in light-duty applications, such as powering pneumatic tools. Large screw compressors are used in heavy-duty applications, such as powering industrial processes.

Keepwin screw air compressor

Working Principle

Screw compressors work by using two intermeshing rotors to trap and compress gas. The rotors are typically helical in shape and have a complex tooth profile. As the rotors rotate, they trap gas in the spaces between their teeth. The gas is then compressed as the rotors move along the compression chamber.

The working principle of a screw compressor can be illustrated by the following steps:

  1. Intake: The rotors rotate in opposite directions, creating an intake port. Gas is drawn into the compression chamber through the intake port.

  2. Trapping: As the rotors continue to rotate, the gas is trapped in the spaces between their teeth.

  3. Compression: The gas is compressed as the rotors move along the compression chamber.

  4. Discharge: The compressed gas is discharged from the compression chamber through an exhaust port.

Selection Parameters

There are several factors to consider when selecting a screw compressor. These factors include:

  • Capacity: The amount of gas that the compressor must deliver per unit of time.

  • Pressure: The pressure to which the gas must be compressed.

  • Duty cycle: The percentage of time that the compressor will be running.

  • Environment: The environment in which the compressor will be used.

  • Special requirements: Any special requirements that the compressor must meet, such as the need for an oil-free compressor or a compressor that can handle a specific type of gas.

In addition to these factors, it is also important to consider the reputation of the compressor manufacturer and the availability of spare parts and service.


Screw compressors are a versatile and reliable type of compressor that is used in a wide variety of applications. By carefully considering the selection parameters, users can choose a screw compressor that will meet their specific needs.