Posted to News on 4th Oct 2009, 20:47
Oil-free scroll compressors suit sensitive applications
Atlas Copco Compressors is launching new oil-free scroll compressors that offer both flexibility and 100 per cent oil-free air. The new SF 17-22kW range is designed for sensitive, point-of-use, oil-free air applications in locations such as laboratories, hospitals, breweries, university departments or within pharmaceuticals production environments. These innovative units are claimed to offer significant advances in application flexibility, reduced operating costs and improved ease of use.
The SF 17 and 22 oil-free multi-scroll compressors consist of up to four new 5.5 kW compressor element modules, making it possible to adapt the compressor to the required application air demand with increased flexibility in comparison to the previous 3.7kW element used in the SF 11 to 15 kW models.
These new element modules can be combined in two different ways: the SF multi-core and the SF multi-duplex. The cost-efficient SF multi-core configuration enables economic operation by combining several 5.5kW elements within one canopy. To save energy, one or more of the modules can be shut down whenever there is a reduction in air demand. Equally, if there is a future increase in plant air demand, the SF 17 can be upgraded to an SF 22 kW with the aid of a simple kit. This makes the SF 17-22 a very cost-efficient source of oil-free air at a low initial investment, both for current and foreseeable future requirements.
The SF multi-duplex consists of one or two elements, backed up respectively by one or two additional elements, integrated within a sound-insulated enclosure. This SF multi-duplex design complies with all the stringent redundancy standards that apply within the medical sector.
Scroll compressor operation
In scroll compressors, air compression is achieved by the interaction of fixed and orbiting scrolls. Air at inlet pressure enters the compression chamber at the exterior side of the scroll element and, once the air is drawn in, the orbiting scroll seals off the inlet port. As the scroll continues to orbit, the air is progressively compressed into an increasingly smaller 'pocket'. A continuous flow of compressed air leaves the scroll element through the discharge port in the centre of the fixed scroll. This process is continuous, resulting in the delivery of pulse-free, 100 per cent oil-free compressed air.
Atlas Copco's 100 per cent oil-free scroll compressor technology protects both the application/production process and the end product quality, while fulfilling the most stringent requirements for pure and clean oil-free air.
By optimising cooling flow design, pressure drop and lower inlet air temperature, Atlas Copco has increased the compressors' reliability and performance levels. This results in a free air delivery (FAD) up to 51 per cent higher and specific energy requirements (SER) down 6 per cent for the new SF 17-22 range in comparison to the previous multi-scroll models.
The compressors' integrated Energy Saver System (ESi) monitors and controls the running hours of each element module and equalises wear so that service visits can be combined to assist in optimising application processes and minimising plant downtime. To the same end, the compressor design provides convenient access to each of the element modules to expedite servicing operations.
Thanks to a silenced enclosure, which reduces noise levels to 65 dB(A), mean that the SF 17-22 units can be placed at the point of use. The integrated dryer, full-feature concept reduces installation costs and minimises pressure drops, thereby saving energy. Equally, there is no increase in the compressor footprint requirement, even with the enhanced performance which these scroll units offer.
