The air drier consists of two separate adsorbent chambers, which operate in tandem in that while the one chamber is supplying dry air, the other chamber is being reactivated. On exiting the drier the dried air again passes through a particulate filter.
Vessel sequence
Only one of the two vessels is on line at any one time, the other being reactivated. Every 4 minutes, the vessels swap between being on line and being reactivated. (Feedback must be received to open the next valve)
Online mode
In this mode, the respective vessel’s inlet and outlet valves are open and the vent valve is closed.
Reactivation mode
In this mode, the vessel’s inlet and outlet valves are closed and the vent valve is open.
Alternating between modes
When the duties of the respective vessels are swapped, the vessel which is currently in the reactivation mode is pressurized by closing its vent valve and opening the pressurization valve for 60 seconds. Thereafter, this vessel is put on line by opening its inlet and outlet valves, at which time the pressurization valve is closed.
The vessel, which is to be reactivated, is then taken off line by closing its inlet and outlet valves and opening its vent valve.
The sequence is thus:
Step 1: Close vessel 1 vent valve
Condition: Wait for vessel 1 vent valve close limit
Step 2: Open vessel 1 outlet valve
Condition: Wait for vessel 1 outlet valve open limit
Step 3: Open vessel 1 inlet valve
Condition: Wait for vessel 1 inlet valve open limit
Step 4: Close vessel 2 inlet valve
Condition: Wait for vessel 2 inlet valve close limit
Step 5: Open vessel 2 vent valve
Condition: Wait for vessel 2 vent valve open limit
Step 6: Wait for 60 seconds
Condition: 60 seconds elapsed
Step 7: Close vessel 2 inlet valve
Condition: Wait for vessel 2 inlet valve close limit
Step 8: Wait for 4 minutes
Condition: 4 Minutes elapsed
Step 9: Close vessel 2 vent valve
Condition: Wait for vessel 2 vent valve close limit
Step 10: Open vessel 2 outlet valve
Condition: Wait for vessel 2 outlet valve open limit
Step 11: Open vessel 2 inlet valve
Condition: Wait for vessel 2 inlet valve open limit
Step 12: Close vessel 1 inlet valve
Condition: Wait for vessel 1 inlet valve close limit
Step 13: Open vessel 1 vent valve
Condition: Wait for vessel 1 vent valve open limit
Step 14: Wait for 60 seconds
Condition: 60 seconds elapsed
Step 15: Close vessel 1 inlet valve
Condition: Wait for vessel 1 inlet valve close limit
With this sequence there should always be one vessel online and should run continuously while there are no failures on the valves. An alarm can be added to notify the operator in the event of valve failure, as this will result in the sequence halting until the problem has been fixed.
The times stated depends on the model of air drier as well as recommendations from the manufacturer. This sequence is not fixed to Tegnon driers and can be modified to work on other makes and models.
For pragmatic information about – make sure to study this web site. The time has come when concise info is really at your fingertips, use this possibility.