Rotary Vane Vs Rotary Screw Air Compressors
January 30, 2020
When it comes to selecting an air compressor, you will come across both Rotary Vane and Rotary Screw air compressors. But what are the differences, and which one is best suited to you?
Here, we will supply some information you may need to help you decide.
Comparison Between Rotary Vane and Rotary Screw Air Compressors
Air Compressor Operation
A rotary vane compressor is made up of an offset rotor within a cylinder which has extended vanes or blades. As the rotor turns on its axis, the blades are pushed against the cylinder wall creating an airtight seal. The atmospheric air enters and is forced into the airtight seal, therefore compressing it.
A rotary screw compressor is made up of two parallel helical screw rotors, a male and a female, which intertwine when rotated inside a cylinder. As the atmospheric air enters, the two rotors rotate and intertwine, trapping the air in the space in between, therefore compressing it.
Rotary vane compressors have minimal internal air leakage which consequently means that they are more energy efficient. Due to lubrication, the blades have the ability to stay in contact with the cylinder surface constantly, so the air seal is near perfect. This lubrication is provided by oil which is also used to cool the air during compression too.
Rotary screw compressors unfortunately have a ‘blow hole’ which contributes to internal air leakage and cannot be completely eliminated with the design. This ‘blow hole’ is where the external profiles of the rotors meet due to the high pressure of air returning an area of low pressure.
Air Compressor Performance
Rotary Vane & Rotary Screw
Both of these types of air compressor are designed for continuous runtime. So, they are ideal for demanding industrial or manufacturing environments that require long-term and high volumes of compressed air.