Tapping Scroll Technology for Pulse-free Air
New oil-free 0.5 hp compressor and vacuum pump taps clean, reliable scroll technology for pulse-free air in medical devices.
January 2002 – Air Squared’s new 1/2-hp scroll compressor/vacuum pump is a breath of fresh air for medical product designers needing a quiet, clean and reliable source of vacuum or compressed air. Available exclusively from Air Squared, the world’s only maker of sub-1-hp scroll compressors, the double-duty, oil-free unit can provide less than 1 Torr of vacuum or 20 psig of compressed air for use on ventilators, aspirators, oxygen concentrators and blood-pressure monitors. The single-stage compressor/vacuum pump is also ideal for laboratories, electronics manufacturing applications and in the energy industry for fuel cells and micro turbines.
Scroll design provides smooth, pulse-free operation, eliminating the noisy valves and vibration of reciprocating units. Whisper-quiet, the 1/2-hp unit operates at only 45 dB. Rotary motion allows dynamic balancing, providing nearly vibration-free operation. And with only one moving part, scroll machines are exceptionally reliable and durable, usually lasting the lifetime of the equipment into which they are integrated.
When used as a vacuum source, the 1/2-hp unit provides < 1 Torr ultimate vacuum with a pumping speed of 3.5 cfm. In compressor mode, the unit provides 3.0 cfm at 20 psig, with max open flow of 3.5 cfm. The 1/2-hp compressor/vacuum pump is powered by a dependable 4-pole AC motor. Overall size with motor is 5.7″W x 6.1″H x 13.3″L.
The Ins and Outs of Scroll Technology
The core of the revolutionary pump consists of two identical meshed scrolls (involute spirals), each attached on its “out” side to a flat base. One scroll is fixed, the other connected to an electrically driven eccentric. Indexed 180 degrees to each other so their spirals mesh, the scrolls fit together to form two halves of a chamber.
The indexing motion creates crescent-shaped pockets between the involutes of the meshed scrolls and the base plates. Air entering the pump gets trapped in these pockets. As the moving scroll orbits the fixed one, the pockets follow the spiral inward, getting progressively smaller and compressing the air. Finally the air is exhausted through an outlet at the center of the scrolls.