Operating Cycles - Quincy QHD750 Instruction Book

Instruction book
control the pneumatic actuator and the pneumatic valves. After a certain period, the cycle will restart. The
fully regenerated tower will be pressurized. Later, the inlet air switches tower and the wet tower is
depressurized via the silencers. Then regeneration starts and the purge air flows through the vessel and a
big silencer. The PDP-sensor measures the pressure dewpoint of the air which is leaving the drying tower.
When the PDP temperature is below the set point then the drying tower will keep on drying until the PDP
temperature exceeds the set point. Then the regenerated tower will start drying the compressed air and the
other tower will be regenerated.
2.5

Operating cycles

Description
The dryer is controlled by an Airlogic regulator.
The main cycle steps are as follows:
Step Function of tower A
0 Adsorbing
1 Adsorbing
2 Blow-off and regenerating
3 Pressurizing
The regulator will display a warning if the operating pressure drops below the minimum setting of 4.5bar(e)
(65.3 psig).
When the dryer is restarted (e.g. after a power failure or a shut-down) from a step in which one of the
vessels was depressurized, the blow-off valve will open for some time to make sure that the pressure is
released. The dryer will continue the cycle, starting from the cycle step where it was stopped or where the
power failure or shut-down occurred.
The display shows which cycle steps the towers are working in, making it easy to follow the operation. The
display can also indicate inlet temperature, pressure and time settings, as well as the pressure dewpoint,
etc
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For working applications below 4.5 bar(e) (65.3 psig) special provisions are to be taken
on the dryer selection (consult Quincy).
Function of tower B
Blow-off and regenerating
Pressurizing
Adsorbing
Adsorbing
Time
195 s
55 s
195 s
55 s
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