Corporate Buyers Guide

An oil water separator is a large container where the condensate output from compressed air dryers and after coolers rests at atmospheric pressure to allow the oil to rise to the surface. It can then be skimmed off. The clean water is drawn from the bottom of the container and flows through an activated carbon filter before being discharged. The oil content in the remaining liquid is in the 15 to 20 ppm range oil.

If the oil is to be recycled, coalescing filters are used to separate the oil from the remaining water. The trapped oil is collected and the water is discharged after going through carbon filters. For many applications, the water can be used rather than be disposed of.

All oil water separators have multiple input ports for the condensate, because most compressed air systems have more than one location where condensate is withdrawn.  

Added traps and filters are used by different manufacturers to improve the performance of their systems. The activated carbon filters have to be replaced periodically, like all filters.

The size and capacity of the separator depends not only on the size of the compressed air system, but also on: 1 will any of the condensate be reused;      2. what are the local regulations for discharge or purity requirements for reuse;   3. the climate. Southern, humid climate create a higher moisture level in the compressed air. 4. Is the compressor oil free?An oil water separator is a large container where the condensate output from compressed air dryers and after coolers rests at atmospheric pressure to allow the oil to rise to the surface. It can then be skimmed off. The clean water is drawn from the bottom of the container and flows through an activated carbon filter before being discharged. The oil content in the remaining liquid is in the 15 to 20 ppm range oil.

If the oil is to be recycled, coalescing filters are used to separate the oil from the remaining water. The trapped oil is collected and the water is discharged after going through carbon filters. For many applications, the water can be used rather than be disposed of.

All oil water separators have multiple input ports for the condensate, because most compressed air systems have more than one location where condensate is withdrawn.  

Added traps and filters are used by different manufacturers to improve the performance of their systems. The activated carbon filters have to be replaced periodically, like all filters.

The size and capacity of the separator depends not only on the size of the compressed air system, but also on: 1 will any of the condensate be reused;      2. what are the local regulations for discharge or purity requirements for reuse;   3. the climate. Southern, humid climate create a higher moisture level in the compressed air. 4. Is the compressor oil free?

What is a refrigerated air dryer? In a refrigerated air dryer, the compressed air first goes thru an air-to-air heat exchanger which removes a small amount of heat from the compressed air. Then it flows past refrigeration coils to cool the compressed air to about 40 F (5C) which causes the water vapors to condense from the compressed air. The condensate is drained off. In another heat exchanger, the cold compressed air then flows past the warm air from the first exchanger. This warms the compressed air and prevents sweating of the pipes.

The air drying process has three steps. air-to-air cooling, refrigerant cooling, air-to-air warming. It is a continuous process that is simple to install and maintain. The dryer is less expensive to purchase and to maintain than desiccant air dryers, however, the electric power consumption is high.

The compressed air at the output has a dew point of about 35 F. For general industrial applications this may be sufficient. If it is not, a desiccant air dryer may be placed in series for additional drying bringing the dew point into the – 40 to – 100 F range.

To specify or select a compressed air dryer, the capacity is measured in scfm at the input to the unit. The ratings are to standard CAGI ADF100. That is at 100 psig input pressure, 100 F input temp and 5 psi max pressure drop. The standard dryness measurement is the dew point.