What are rotary screw compressors?

rotary compresser

A rotary-screw compressor is an air compressor which uses a rotary-type positive-displacement mechanism. The compression process of a rotary screw is a continuous sweeping motion, so there is very little pulsation or surging of flow, as occurs with piston compressors.

Rotary screw compressors supply production processes in industry, trade and workshop applications with a reliable supply of quality compressed air. They are the preferred choice for users requiring constant pressure over prolonged periods.

How do they work

The power behind these machines comes from two counter-rotating screws which are housed in
a chamber. Outside air first travels through a filter to catch anything harmful which could cause damage. Once filtered, the air goes through an inlet valve and into the space between the interlocking screws. As the rotors turn, the air moves along and travels to the other end of the compression chamber.

The area in which the air is contained gets increasingly smaller as the air moves along. The smaller space in turn increases the pressure. The result is a high-volume, steady stream of compressed air.

Saving you energy

A rotary screw compressor converts 100 % of the drawn electrical energy into heat. Up to 96 % of this energy can be recovered. The fully-enclosed design of modern rotary screw compressors makes them especially suitable for heat recovery. This fact applies to both fluid-injected as well as to oil-
free compressors. This means that they can reduce energy costs and reduce CO2 footprint. Energy costs can account for up to 80% of life-cycle costs over the lifetime of a compressor. By using heat recovery, these costs can be significantly reduced. Heat recovery lowers the CO2 emissions of an organisation because energy is utilised more efficiently

You can use the HPC KAESER heat recovery calculator, to calculate the usable heating energy volume of a rotary screw compressor. Click here.


Rotary-screw compressors are generally used to supply compressed air for larger industrial applications. They are best applied in applications that have a continuous air demand such as food packaging plants and automated manufacturing systems. In larger facilities, that may have only intermittent applications, the average usage among the many work stations will place a continuous demand on the compressor


Telford Compressed Air Services (TCAS) are perfectly located to provide national coverage with fully factory trained service engineers. They are a HPC Authorised Distributor. HPC Compressors are recognised as the gold standard in the industry. There rotary-screw compressors offer quality, efficiency and reliability. For more information please visit the TCAS website.

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