Sterling SDA 1000-5100 Benutzerhandbuch

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Large Dehumidifying Dryers 
Functional Description 
14 
Regeneration
Filter
Regeneration 
Blower
Process 
Blower
Regeneration
Exhaust
Process 
Heater
Process 
Filter
Insulated 
Drying 
Hopper
Right Desiccant
Regeneration 
Heaters
Dryer Valve
Left Desiccant
AD600-AD1500
Dryer Flow Schematic
Left Desiccant in 
Regeneration
 
Sequence of Operation 
When the dryer is started, the main air valve rotates 360º and then moves to place the last 
successfully regenerated desiccant bed online. If the dryer was powered off using the main 
power disconnect or E-stopped, then the regenerating bed is placed back into regeneration, 
and the regeneration cycle is started over. The main air valve is allowed a period of time to 
move from one position to the other. If the main air valve does not complete positioning 
within the allotted time, then a “Main Air Valve Fail” alarm is generated and the dryer stops 
the process air blower and disables the drying hoppers and regeneration circuit.  
If the closed loop regeneration option is enabled, the regeneration closed loop valve moves to 
the open loop position. The system always begins the cooling phase for a regeneration cycle 
using ambient (open loop) air. The closed loop regeneration valve is allowed a period of time 
to move from the closed to the open loop position and a “Closed Loop Valve” alarm is 
generated if the valve fails to reach the commanded position within this time. This alarm will 
disable the regeneration circuit but does not stop the process air system or drying hoppers. 
Once the main air valve and closed loop regeneration valve are in place, the process air 
blower starts. The system monitors the process air blower’s overload, starter auxiliary contact 
feedback and air pressure. Loss of any of these items when the process air blower is running 
will cause the process air blower and the drying hopper’s process heaters to shut down. 
The process air heaters will turn on after a delay to allow the process air blower to accelerate 
the operating speed.  
During normal operation, one set of desiccant beds is connected to the process air circuit 
while the other set is being regenerated. When the offline beds are done regenerating, they 
will be switched into the process air circuit and the other beds will be regenerated. The 
default bed switch setting is based on time. If the Dewpoint Switch option is enabled, the 
beds will switch when the process air dewpoint reaches the dewpoint switch point. The 
dewpoint option will automatically disable itself and an alarm will be generated if the 
dewpoint sensor or related electronics fail.