Rotary Scroll Air Compressors
Oil Free Scroll compressors are positive-displacement devices that work by internal compression. Air (or other gas) is drawn in, trapped, reduced in volume and, finally, discharged at the outlet port. The concept of a scroll compressor has been around for more than a century, but it took more-recent advances in manufacturing technology to make the product viable.
The design of the discharge port determines the amount of internal compression, similar to that in a screw compressor. However, there are practical limits on the maximum amount of compression, mainly due to the size, shape, wall thickness and strength of the scrolls, and the size and geometry of the outlet port. Nonetheless, scroll compressors can typically generate relatively high pressures — 100 to 150 psi — in single-stage units.
Scroll compressors have become an important alternative to reciprocating and screw compressors for compressed air. For instance, they are quite important for generating medical and laboratory air.