Rotary fluid compressor

Claim 1

A ROTARY AIR COMPRESSOR COMPRISING A LOW PRESSURE COMPRESSION STAGE AND A HIGH PRESSURE COMPRESSION STAGE, AN INTERSTAGE PIPE CONNECTING THE DISCHARGE END OF THE LOW PRESSURE STAGE WITH THE INLET OF THE HIGH PRESSURE STAGE, ROTOR MEANS FOR COMPRESSING THE AIR IN BOTH STAGES, AN OIL STORAGE TANK, AN OIL PUMP SYSTEM DRIVINGLY COUPLED TO THE ROTOR MEANS FOR PUMPING OIL FROM THE OIL STORAGE TANK INTO THE HIGH AND LOW COMPRESSOR STAGES, AN AIR RECEIVER TANK DISPOSED ABOVE THE OIL STORAGE TANK HAVING AN OPENING IN ITS BOTTOM AREA IN COMMUNICATION WITH AN OPENING IN THE UPPER AREA OF THE OIL STORAGE TANK AND HAVING A CONNECTION WITH THE DISCHARGE END OF THE HIGH PRESSURE STAGE FOR RECEIVING COMPRESSED AIR CHARGED WITH OIL FROM THE LATTER, THE COMMUNICATION OF THE RECEIVER TANK WITH THE OIL STORAGE TANK PERMITTING OIL SETTLING OUT OF THE AIR ADMITTED TO THE RECEIVER TO DROP INTO THE OIL STORAGE TANK AN OIL SEPARATOR TANK DISPOSED ABOVE THE RECEIVER TANK AND HAVING AN OPENING IN ITS BOTTOM AREA IN COMMUNICATION WITH AN OPENING IN THE UPPER AREA OF THE RECEIVER TANK, FILTERING MEANS IN THE SEPARATOR FOR FILTERING RESIDUAL OIL OUT OF AIR ADMITTED TO THE LATTER, AND A CONDUIT CONNECTING THE SEPARATOR TANK WITH THE INTERSTAGE PIPE FOR RETURNING RESIDUAL OIL FROM THE SEPARATOR UNDER PRESSURE OF AIR IN THE LATTER TO THE INTERSTAGE PIPE, THE PRESSURE OF AIR IN THE LATTER BEING LESS THAN THAT IN THE SEPARATOR.