Common-used MVR: Roots Compressor

 

    The commonly used vapor compressors mainly include: Roots compressor, axial flow compressor, centrifugal fan and centrifugal compressor. The centrifugal compressor is a speed type blower, providing a small differential pressure, and of large single unit capacity. And the Roots compressor is mainly used for small flow conditions.

    The roots compressor is based on same principle as the conventional roots type blower, is displacement type blower, and the air delivery capacity is proportional to the rotating speed. A small gap is always maintained between the impeller end face and the front and rear end covers of the fan and between the fan impellers. Driven by the synchronous gear, the air is conveyed from the air inlet along the inner wall of the casing to the outlet side. And it is steam conveyed in the roots compressor instead of air.

    The roots compressor is able to provide an effective temperature rise up to 25°C(in the case of water vapor), it is suitable for working condition of smaller evaporation capacity and bigger boiling point elevation. Generally, Roots compressors can be used for conditions of evaporation capacity no greater than 8 ton/hour and the boiling point elevation no exceed 25 °C.