When planning a compressor installation, the user must specify the minimum quality the compressed air should achieve with regard to solids, residual oil and water content. Highly purified compressed air for less sensitive applications has to be equally avoided. The cost and time implications of compressed air treatment should bear a sensible relationship to the application, in certain cases the purification of small branched-off compressed air flows (ie. terminal applications) is sufficient. Oil free compressed air, generated by oil-free compressors are used for many applications in the chemical, pharmaceutical and food & beverage industries. However, not every compressor with oil free compressing chambers does, in reality, feed oil free compressed air into the network. From the ambient air, solids, moisture, hydrocarbons and other contaminants are drawn into the compressor. It is not sufficient to expect better compressed air quality solely through the use of oil-free compressors. Special requirements must, therefore, be implemented by the installation of downstream equipment such as separators, coolers, dryers and receivers. The question of the required quality of compressed air has to be answered by the:-
- Moisture content of the compressed air
- Oil content of the compressed air
- Solids content of the compressed air
It is correct to say that compressed air treatment is necessary. It is likewise correct to say that the resources in cost and time devoted to the purification of compressed air must always bear a sensible relation to the application concerned. While solutions are possible, it is also disproportionately cost intensive. Every step in the improvement of compressed air quality is costly. However, deterioration in compressed air quality through inadequate treatment is often far more expensive through product rejection and machine/equipment downtime.
