Let’s talk now about contamination and in particular we will see how to remove harmful substances from compressed air, in order to guarantee its quality and efficiency. One of the factors that can contaminate the compressed air of a compressor is undoubtedly the residual oil. It is indeed very complicated, despite the use of special filters, to know precisely how much oil remains in the compressed air as a result of its filtration. In fact, the high temperature does not allow a perfect separation of the components, and this results in traces of oil that are not perfectly filtered. Added to this is the same ambient temperature, which can affect the temperature of a running compressor.
In order to remedy this, one of the most used methods is to keep the air as dry as possible and avoid free water that can damage the fiber filters. In fact, they are able to remove the oil only if in liquid form (droplets) while they are unable to capture the vapors which must instead be removed with activated carbon filters. Using a combination of filters can be a good solution for oil contamination of the compressed air. Clearly the problem is reduced to zero if we replace our compressors with oil-free compressors for which oil filters are not needed. This type of compressor works at a lower delivery pressure but proves to be excellent in terms of energy consumption, guaranteeing considerable economic savings. Riem Italy has been dealing with oil-free compression for generations, if you want to know more READ ALSO: Spare Parts Production
Another method to remove harmful substances from compressed air is the use of an aftercoolerable to reduce the water content and lower the compressed air temperature values. Normally the chiller is included in the plant installations, downstream of the compressor and is air or water-cooled.
Third method is the use of a water separator that separates condensate and compressed air. The job of this separator is to draw out as much condensation water as possible once the air has been compressed. With proper regulation, up to 80% – 90% efficiency can be achieved.