AD DRYER
NP-DK50 2V-A-4_10-2022-AD 42 10/2022
AD DRYER
18. PRINCIPLE OF OPERATION
The dryer is controlled by a signal from the compressor pressure switch.
When the compressor is running, compressed air enters the cooler where it is cooled, and a portion
of the condensed moisture is separated in the integrated cyclical separator. Solenoid valve V3 is
located in the bottom of the separator, and it drains off the condensate from the separator at regular
intervals.
Air then passes to the chamber of logic valve OR1, which senses the pressure. If the pressure in
the valve chamber does not reach P1 = 3 bar, regeneration solenoid valves V1 and V2 (normally
closed type) remain closed and regeneration is not initiated. If the pressure in the logic valve
chamber exceeds a minimum of 3 bar, the chambers switch based on the logic described in
Subsection 18.1.
When the signal from the compressor pressure switch deactivates, regeneration valves V1 and V2
open for a short time to vent the compressor aggregate and to vent the dryer chambers.
Dryer venting and regeneration is completed via the hose shared with the condensate separator
drain and for this reason the condensate outlet cannot be connected directly to a drain.
18.1. Dryer regeneration
Dryer regeneration is initiated when working pressure P1 = 3 bar. During regeneration, valves V1
and V2 switch cyclically, whereby there is a short delay (dT) to equalise the pressures in the
chambers and during which both valves are closed before each switching cycle.
Working pressure is in chamber 1 and the chamber is in the drying phase, while there is atmospheric
pressure in chamber 2 and this chamber is in the regeneration phase. The chamber is regenerated
by air passing through the dryer nozzle.
18.2. Energy saving mode (only for models with a dew point sensor)
Dryers equipped with a dew point sensor have additional control over the purge air so as to maintain
the defined dew point.
Once the required dew point is met, regeneration is stopped to optimise the quantity of purge air.
When regeneration is stopped, both valves V1 and V2 are closed (and therefore chamber purging
with dry air is stopped).
They continue to alternate following their standard interval to equalise the loading on the chambers.
If the dew point increases, Energy saving mode is deactivated and the dryer continues to operate
with regeneration activated.
Duration of deactivated regeneration mode
Energy saving mode with deactivated regeneration is time limited. One cycle with the standard
regeneration of both chambers is added after the end of a defined interval (4 chamber switches).
18.3. Waring system
Every warning is indicated by a corresponding visual signal (see chapter 21) and the visual signal
flashes. Call an authorised service provider to conduct repairs required in the event of a failure.
Warning states indicate a potential failure of the device. Therefore, warning signals may not be
deactivated.
All warning signals are intermittent – when the cause of the warning no longer exists, the warning
signals are deactivated.
Operator’s position. No specific operator’s position is required. The operator may remain within
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