Parker CDAS HL 050 - Energy Saving Technologies (EST & Purge Economy)

39
Medium Flow Compressed Air Dryers - IOMI.
Important Note: Purge air volume must be set up during commission to supply the correct amount of purge air required for
ecient regeneration. Refer to page 21 for purge volume setting.
Re-pressurisation (30 seconds)
After 150 seconds (2 ½ minutes) of regeneration, the
exhaust valve will close, and the purge air will re-
pressurise the o-line column. is is to ensure there is
no drop in downstream pressure as the drying columns
change over. Repressurisation time is 30 seconds.
At column changeover, the
dewpoint display on the screen will
change to show the total overall
energy savings as a percentage. is
total will be visible for 4 seconds
at the beginning of each ½ cycle.
e energy saving percentage is
calculated from initial start-up of the dryer
Changeover (Fixed Timing Cycle)
Following re-pressurisation, the controller will instruct the dryer to “changeover”. On a xed timing cycle, drying & regeneration is
180 seconds (3 minutes). Using the inlet valves, the process air ow will be redirected over to the newly regenerated desiccant bed,
allowing the wet adsorbent material of the opposite column to be regenerated.
CDAS HL / OFAS HL / FBP HL Dryer Timing Cycles
All adsorption dryers have a standard xed cycle to ensure drying / regeneration / changeover is continuous. e diagram below
illustrates the xed timing cycle of a CDAS HL / OFAS HL / FBP HL dryer.
FBP
1 Full Cycle = 360 Seconds (6 minutes)
½ Cycle = 180 Seconds (3 minutes)
CDAS HL / OFAS HL / FBP HL Energy Saving Technologies
To provide a consistent outlet dewpoint, the desiccant bed of an adsorption air dryer must be “sized” to match the maximum water
vapour loading of the site and ensure that the adsorption bed is large enough to deliver a consistent outlet dewpoint based upon the
xed timing cycle.
e energy consumed by a heatless adsorption dryer comes from generation of the process air used as purge air to regenerate the o-
line desiccant bed.
In periods of low demand and or in winter, when the water vapour loading of the incoming compressed air can be reduced, operating
on a xed timing cycle will consume more energy than is required. To signicantly reduce this energy loss, each CDAS HL / OFAS HL
/ FBP HL dryer is tted with two energy saving functions as standard, called EST & Purge Economy.
1
2
1
1
Drying
DryingRepressurisationRegeneration
RepressurisationRegeneration
Column
1 Full Cycle
1/2 Cycle 1/2 Cycle
Seconds