Parker CDAS HL 050 - Dryer Cycle Times and Operation

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Medium Flow Compressed Air Dryers - IOMI.
CDAS HL / OFAS HL / FBP HL OPERATION
Drying of the Compressed Air
(3 Minutes on Fixed Timing Cycle)
Having passed through the coalescing pre lters, the inlet
valves direct the incoming process air through one of the
two dryer columns containing the desiccant cartridges
(column 1 in the example image).
When a column is drying compressed air, it is referred to
as the ‘on-line’ column.
Compressed air enters the desiccant cartridge of the on-
line column at the bottom and ows upwards where it is
in contact with the bed of adsorbent desiccant material.
Water vapour in the compressed air is adsorbed by the
desiccant material.
Standard drying cycle (no EST) is 180 seconds.
As the dried compressed air reaches the top of the
desiccant cartridge, it changes direction, owing down
the column around the desiccant cartridge and into the outlet dry particulate lter (CDAS) or into the inlet of Column 3 (OFAS HL
and FBP HL).
Regeneration of the O-line Desiccant Material
Exhausting or De-pressurisation
At the same time compressed air is directed through
the on-line column to be dried, the opposite column
(column 2 in the image) will be undergoing regeneration
(referred to as the “o-line” column). To regenerate
the o-line column, the pressurised compressed air it
contains must rst be vented to atmosphere. To do this
the dryer controller will open the exhaust valve, allowing
the compressed air contained within the o-line column
to exit via the exhaust valve and silencer. is process of
exhausting the air is known as de-pressurisation. A check
valve (ball) prevents the process air from owing down
the o-line column.
Regeneration (2 ½ Minutes)
Once the o-line column has been de-pressurised, the
exhaust valve will remain open for the regeneration cycle.
Expanded, dry purge air taken from the process air will
ow up the outside of the desiccant cartridge to the top of the column then down the inside of the cartridge, across the adsorbent
desiccant bed for 150 seconds (2 ½ minutes), stripping the moisture from the desiccant material as it ows out of the dryer via the
open exhaust valve and silencer.
CDAS
CDAS HL / OFAS HL / FBP HL Dryer Cycle Times and Operation
CDAS HL / OFAS HL / FBP HL dryers are designed to use two drying columns to deliver a constant outlet dewpoint.
A full cycle is the time it takes the dryer to fully utilise the desiccant material in both columns. A full cycle on CDAS HL / OFAS HL /
FBP HL dryers operating at full load = 360 Seconds (6 minutes).
A ½ cycle is the time it takes the dryer to fully utilise the desiccant material of a single column. A ½ cycle on CDAS HL / OFAS HL /
FBP HL dryers operating at full load = 180 Seconds (3 minutes).
OFAS