An Oil injection-free Single Screw Compressor is basically an SSC in which liquid refrigerant injection can be employed for cooling the compressor instead of oil.

Though only with liquid refrigerant present in the clearance the sealing effect may be less than with oil injection, the leakage losses can be reduced satisfactorily by means of minimizing the clearance gaps because the compressor temperature is always at or close to saturation condition by cooling effect of liquid refrigerant.

Additionally, to improve the potential for system performance an economizer cycle is adopted as standard by incorporating into the compressor a centrifugal separator "centrifugal economizer" driven from the compressor main shaft.

This paper presents the performance of the new Oil Injection-Free production model. The performance of these compressors will enable them to compete with conventional reciprocating and oil-injected screw compressors.

Units: SI