The working principle of screw compressors

The male and female rotors of a screw compressor rotate in opposite directions. This movement will draw in air. As the space between the rotor and its casing decreases, the air is compressed. Then, the compressed air is discharged into the outlet.

Each screw element has a fixed built-in pressure ratio, which depends on the length and pitch of the screw. And the shape of the exhaust port. To achieve the highest efficiency, the built-in pressure ratio must be adjusted according to the required working pressure.

The rotational speed of the rotor will be optimized to a specific level to minimize mechanical losses (caused by heat generated at extremely high speeds) and volumetric losses (caused by air loss at extremely low speeds).