Desiccant dryers are used wherever extreme dry compressed air < -40°Ctd is required. Desiccant dryers usually consist of two dryer chambers filled with desiccant.

While the drying process takes place in one chamber, where the moisture is absorbed by the desiccant, the other chamber is being re-generated by making use of some of the dry compressed air from chamber one.

The switching between the two vessels is usually timer controlled. A regeneration cycle of 10 min is typical, with for example 5 min adsorption, 4 min regeneration, and 1 min pressure build-up time. The regeneration air requirement for timer-controlled dryers is usually 14-15% of the total amount of compressed air generated. With a fixed timer control, which does not respond to the compressed air consumption, constant regeneration of air is also wasting air and hence seen as being inefficient.

The pressure dew point measuring sensor FA510 allows to precisely determine the specific load status of the compressed air network even under rapidly changing conditions. The sensor measures the actual pressure dew point and thus monitors the dryness of the desiccant directly. If the switchover point is set to the limit value of -40°C pressure dew point of the desiccant dryer, then the changeover is dependent on the load. As a result, a large part of the regeneration air can be saved.

Dew point controlled desiccant dryers are far more energy efficient then timer controlled desiccant dryers.