Rotary Screw Air Compressor

Overview

A rotary screw air compressor delivers a smooth, continuous stream of compressed air by trapping air between two intermeshing helical rotors and squeezing it as it travels down their length. Compared with a reciprocating compressor it has far fewer wearing parts, almost no pulsation, and runs continuously at full load, which makes it the standard prime mover for plant and instrument air in factories, workshops and process plants. The oil-flooded design floods the rotor pair with oil that seals the clearances, carries away the heat of compression and lubricates the bearings in one circuit.

The package integrates everything needed to turn motor shaft power into clean, cool, dry compressed air: the compression element itself, an oil-management circuit, air and oil cooling, intake and discharge valving, and a controller, all mounted on one acoustically enclosed skid.

How it works

Air is drawn through the Inlet / Unloader Valve, which both filters the intake and unloads the machine when demand falls. Inside the Airend the Male Rotor and Female Rotor mesh inside a close-tolerance housing; as they rotate, the trapped pocket of air shrinks toward the discharge port, raising its pressure. Power reaches the airend from the Drive Motor through the Drive Transmission, either a V-belt set or a direct coupling.

Because the airend runs oil-flooded, the discharge is a hot mix of air and oil that must be separated and conditioned. The Oil System sends that mixture to an oil separator tank whose coalescing element strips the oil mist back out, then filters and temperature-regulates the oil before re-injecting it. The recovered compressed air still carries heat and moisture, so it passes through the Cooler & Fan aftercooler and a moisture separator, with a fan moving ambient air across both the air and oil cooler cores.

Downstream, the Minimum Pressure / Check Valve holds a minimum system pressure so the separator stays effective and prevents air flowing backward when the machine unloads. Overseeing all of it, the Controller reads discharge pressure and temperatures, sequences load and unload (or commands a VFD), and protects the machine against over-temperature and over-pressure faults from its operator touchscreen.