3.2.8. Roots compressor


Fig. 3.17: Symbol of Roots compressor
The Roots compressor belongs to the displacement family of compressors.

Two symmetrically shaped rotary pistons turn in opposite directions inside a cylindrical chamber. They are connected by a synchronised transmission and operate without contact.

The air to be compressed is directed from the intake side into the compressor case. It is enclosed in the chamber between the wing and case. At the moment in which the piston releases the edge to the pressure side the gas flows into the discharge outlet and fills the pressure chamber. When the wing turns further, the content of the transport chamber is pressed out against the full counter pressure. Constant compression takes place. The compressor must always work against the full dynamic pressure.<BR><BR>


Fig. 3.18: Op. diagram of Roots compressor
    • No wear on the rotary piston, and therefore no lubrication is required.
    • Air contains no oil.
    • Sensitive to dust and sand.