Air Dryers

As supplied by Airpower

Airpower supplyies, installs, commissions and services refrigerant and desiccant air dryers.

Airpower designs the air dryer system to suite your factory and our local weather conditions.

It is of utmost importance that the dryer is correctly sized for your air reticulation system. If the dryer and filters are maintained correctly, you will have a trouble free pneumatic and air system.

Compressed air:

All compressors suck the same air from the atmosphere. This air has a certain percentage of moisture. The cooler the compressor runs, the more moisture will condence out in the receiver. These are the better compressors. If the compressor runs warm, less moisture is condensed in the receiver and that moisture is carried with the air to the point of use and causes pneumatic failures. Water is non compressable and in a pneumatic system, it reacts as a solid and damages the equipment.

Refrigerated air dryers:

To cool water down, takes much more energy, than to cool compressed air. This is why Airpower installs an automatic drain, pre- filter. This filter removes all the condensate, before the dryer and reduces the load on the dryer. The refrigerated dryer cools the air to approximately 4°C and filters the air at this temperature. The air is then heated back to room temperature and will have an under pressure dew point of 4°C.. After the dryer, Airpower installs, an additional, after filter. This is to take odours and other impurities out of the air system.

Desiccant air dryers:

Also called heatless dryers.

Desiccant are crystals, which adapt to its enviroment. If the enviroment is wet, the crystals absorb water until they get as wet as the enviroment, in this case, compressed air. If the enviroment is dry, the crystals give moisture off, until it gets to the same moisture content.

The desiccant dryer has two containers filled with desiccant crystals. The compressed air flows through one container. The crystals absorb the moisture and the air comming out of this container is dry. About 15% of this dry air, is fed back to the other container. This container is at very low pressure and is dried by the dry purging air. Once this container is dry and the other unit wet, the two containers are swopped around.

The dryness of the air, depends on the percentage purged air and the speed the air flows through the container. A dew point of -60°C, under pressure and even more can be obtained by this type of dryer.

This dryer also needs a pre and after filter to remove condensate as well as any oil in the air. Oil damages the crystals.


Many times called water traps.

When compressed air flows through a filter, the filter catches about 98 % of the droplets in the air. The air coming out of the filter, is still saturated at that temperature and pressure. If you regulate the pressure to a lower pressure, the air is dry at that lower pressure and same temperature.