Legislation worldwide has become more stringent with regards to the disposal of oil-injected air compressor condensate and in order to protect the environment has set the general limit of oil contamination in disposed water at 20 parts per million. This requirement creates the need to separate oil and water from each other within the compressor condensate and therefore it is recommended that an oil-injected compressor is combined with an oil-water separator.

Atlas Copco's OSCi oil-water separator has successfully achieved certification from DIBt, an independent agency that specialises in technical approvals for civil engineering. The certificate guarantees that the OSCi unit meets the standards demanded by international regulations for oil-water separators therefore enabling operators to ensure they meet the ISO standards for oil contamination in disposed water.

When it comes to oil-water separation, most separators can cope with unstable emulsion but stable emulsion is more difficult to separate. Atlas Copco engineers have now developed a new method to deal with this problem.

Basically, the OSCi provides filtration in three stages, each located in a different tower. In the first tower, there is a separation, based on gravity, of oil and water. A special new filter, combined with aeration in the second tower, is designed for removing stable emulsion while preventing anaerobic bacteria growth and odour. Finally, an activated carbon filter in the last tower addresses the remaining oil.

This combination of different filtration methods makes it possible to separate oil and water in compressor condensate while preventing bacterial growth, even when a stable emulsion is present. Knowing that both the compressor and the environment are being kept clean, and international standards are met, creates peace of mind for plant operators.

By integrating the OSCi unit within the compressor, it is now possible to use the compressor's electronic controller to monitor the oil-water separator. While the display informs on the filter status, the overflow risk and service requirements are announced by an alarm. Combining all of these features makes it possible to obtain the most efficient use of the compressor configuration - and preventing unnecessary servicing saves both time and money.

While other external oil-water separators can occupy up to 2m2 of the production area, the floor space requirements for the integrated OSCi are reduced to zero. This improves the efficiency of the production site, while minimising the risk of leakages and reducing installation time and expense. All that needs to be done is to add clear water, connect to the sewage system and the OSCi is set to efficiently separate the compressor's condensate.

Finally, an inspection drain allows condensate samples to be obtained without having to open the compressor, making turbidity comparisons a quick and easy control method. This provides an extra tool for checking the accuracy of the oil-water separator in order to keep within standard limits.

Following the continuous improvements on the GA range, the OSCi contributes to the total compressor products provided by Atlas Copco. On top of the GA's energy savings and enhanced performance, comfort and peace of mind are the added benefits for the operator and disposal of compressor condensate becomes a more efficient and environmentally friendly procedure.

This innovation is made possible by Atlas Copco's knowledge and expertise, built up over several decades of compressor and air treatment development and production.

*all GA 37 - 90 kW models (including FF, + and VSD versions) except the GA 37 and GA 45.