Specifications

28
Aircel Programmable Controller
Step 1: Vessel 2 Depressurizing (0-5 secs)
 Vessel2(T2)purgeexhaustpilotsolenoidvalveisenergized
 whichsuppliescontrolairtothepurgeexhaustvalve(V4)
 whichopensslowly,depressurizingvessel2(T2).Simultaneously
 theinletvalvesV1andV2shiftpositionswithapneumaticsignal
 fromvessel2(T2)purgeexhaustpilotsolenoidvalvetotheinlet
tower selector pneumatic pilot valve which in-turn supplies a
 pneumaticsignaltotheinletvalvestoopenvalve(V1)andclosevalve(V2),directingtheinletair
tovessel1(T1)tobedryingtheair.Theairflowsupthroughthedesiccantbedandexitstothe
outletvalve(V5)totheoutletparticulatefilterthentothecustomerdryprocessairsystem.
Step 2: Vessel 2 Regenerating (6-240 secs)
 Step2isacontinuationofstep1exceptvessel2(T2)willbe
 regenerating,vessel2(T2)purgeexhaustvalve(V4)isstillopen,
 vessel1(T1)isdryingtheinletair.Asmallportionofdryoutletair
 fromvessel1(T1)(15%averagebasedonstandarddesigncapacity
 of100psig,100°Finletair,100°FambientairandPDPof-40°F)
 istakenthroughasmallorificeintheoutletlineandusedto
 regeneratethedesiccantbedinvessel2(T2)until240secondshasbeenreached.Thescreenalso
showstherelativehumidityreadingaswellasthe(optional)dewpointwhenapplicable.Thetimer
onthisstepcountsto240seconds(4-minutes).Thereisawarningsignthatwillflashintheupper
righthandportionofthescreenforanyalarm.ThereisalsoaredLEDalarmlightthatwillflash
onthePLCdisplayforanyalarm.Theusermustscrolltothealarmscreentoviewthealarms
(presstheleftarrowoncefromthemainscreentoviewthealarmscreen).
Step 3: Vessel 2 Repressurizing (241-300 secs)
 Vessel2(T2)purgeexhaustpilotsolenoidvalvewillde-energize
 causingvessel2(T2)purgeexhaustvalve(V4)toclose,this
 allowsvessel2(T2)torepressurizetolinepressure,sinceair
continues flowing though the small outlet orifice pressurizing
 vessel2(T2).Theinlettowerselectorpneumaticpilotvalve
 maintainstheinletvalve(V1&V2)positions.
Step 4: Extended Drying Vessel 1
AfewsecondsbeforetheendofrepressurizationtheAHLD
 E-SERIESController’sintegratedEnergyManagementPurge
 ReductionSystemlooksatthemoisturesensor,ifthemoisture
 loadislowenough,vessel1(T1)willcontinuetodryforan
 extendeddryingperioduntilthemoistureloadhasreachedaset
 highlevel,thecontrollerwillthenadvancetostep5andthevessels
will switch. This feature reduces the overall purge consumption saving energy and money. The
extendeddryingcycletimerwillcountto30minutesunlesstheEMSrelativehumiditysensoris
higherthanthesetpoint.After30minutes,theunitwillswitchandcontinuenormaloperation
untilthenextextendedsavingsstep.AtthestartofeachextendedsavingsstepthePLCchecksfor
faults,EMSrelativehumiditysensorvalueandhighoutletdewpointsetting(optional)toensureif
thedryerneedstocontinuedryingandthedryerwillgointoextendeddrying.Ifthedryerneedsto
continuetothenextsteptoregenerate,theextendedsavingsstep4willbeskipped.
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AircelAHLDE-Series-Models1000-5000