Low Pressure Screw Compressors and Screw Blowers

Robuschi's latest product innovation is the Low Pressure Screw Compressor range, available in pressure up to 2,500 mbar(g) and vacuum up to 300 mbar(a) configurations with a maximum air flow of 10,100 m³/h. It combines the features of the proven PD blower range with innovative components, cutting-edge design and outstanding efficiency. Now the range includes the state of the art Robox Energy, which meets the unique characteristics of the RSW "core" (patent) with the innovative motor with permanent magnets and integrated electrical panel, offering maximum efficiency, compactness, simple maintenance and flexibility for wastewater treatment plant requirements.

How the RSW Low Pressure Screw Compressor Airend Works

The RSW oil-free low pressure screw compressor airend is a positive displacement machine with rotary motion, also known as “helical screw” compressor. 

It delivers constant flow (volume) and variable pressure, which means that at a given speed (rpm), the RSW compressor airend always supply the same amount of air, independently by the pressure variation. 
The RSW low pressure screw compressor airend consists of a pair of helical profile rotors (one male rotor with 3 convex lobes and one female rotor with 5 concave lobes or “flutes”), contained in a casing. 
The rotors turn in opposite direction maintaining precise alignment by means of timing; meshing they form a series of working chambers between the rotors and the casing wall. 
The gas is sucked from the intake side (suction), trapped between the rotors and the casing (radially) and the cover (axially), transported to the compression side (discharge) where the working chamber shrinks, and compressed.     

The internal compression leads to supply a steady, non-pulsating air flow, minimizing vibration and maintenance and maximizing lifetime. 
Due to the fact that there is no oil for sealing (oil-free screw), the rotors have very precise and small tolerances to maintain a very small air-gap between the two in order to guarantee optimal performance without touching each other. 

The RSW low pressure screw compressor airend, air cooled, can reach a maximum pressure ratio (outlet pressure divided by inlet pressure) of 3,5.