Page 26 of catalogue Compressed air treatment of Boge Kompressoren Otto Boge GmbH & Co. KG

Condensate treatment and removal

Why does condensate from oil-lubricated Compressors need to be treated?
Unless condensate is treated or removed completely, then serious environmental damage can occur. Only 1 Litre of condensate is required to contaminate 1.000.000 Litres of water ! All industrial nations now forbid the drainage of condensate from oil-lubricated compressors into main drains. Laws now require the separation of condensate into oil and water and only allow water to be drained away. In Oil\-free compressors, the compressed air does not come into contact with oil. Therefore, it follows that the condensate has no contact with oil. Clearly, any airborne traces of oil drawn in are also found in the condensate; the amount depends on the compressor’s location.

Condensate test
There is a simple test to determine whether the condensate is an emulsion or a dispersed mixture. Fill a clean Glass with condensate. Stir the liquid and after a short time, the oil separates from the water. The oil floats to the surface. The remaining water is clear. The dispersed mixture can be separated out, using an oil/water separator. If, after stirring, the condensate forms as cloudy water under the layer of oil, then you can assume that it is an emulsion which can only be separated out using an emulsion separating unit.

Condensate treatment options
Depending on national regulations and the operator’s environmental policy, the condensate from oil-lubricated compressors must be treated before it is disposed of into the main drain system. There are two possibilities: 1. Collect the condensate and have it removed by a specialist company; this is generally very expensive. 2. Treat it directly on site. As the condensate consists of 99% water and only 1% oil, “on-site treatment” using the BOGE oil/water separator is the most economic solution.

Method of operation at a glance The dirt collection tank retains solid impurities Oil/water separation by gravity Pre-filter Adsorption filter

Types of condensate
Condensate from oil-lubricated compressors can occur in the form of: emulsions dispersed mixtures An analysis of the condensate will determine the scope of separation required. Can a simple oil/water separator be used or should an expensive separation or filtration system be used, or does the condensate collected require the services of a specialist company ?

Emulsions
Emulsions (milky mixtures) are a bond of oil and water which cannot be separated by gravity. Emulsions can only be purified using expensive and costly emulsion separating equipment.

Dispersed mixtures
Unlike emulsions, dispersed mixtures can be purified by gravity, using relatively inexpensive oil/water separators.

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