Specifications

16
Sequence of Operation (cont’d)
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.
Step 5: Vessel 1 Depressurizing (0-5 secs)
 Vessel1(T1)purgeexhaustpilotsolenoidvalveisenergizedwhichsupplies
  controlairtothepurgeexhaustvalve(V3)whichopensslowly,depressurizing
  vessel1(T1).SimultaneouslytheinletvalvesV2andV1shiftpositions
  withapneumaticsignalfromvessel1(T1)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(V2)and
  closevalve(V1),directingtheinletairtovessel2(T2)tobedryingtheair.
  Theairflowsupthroughthedesiccantbedandexitstotheoutletvalve(V6)
to the outlet particulate filter then to the customer dry process air system.
Step 6: Vessel 1 Regenerating (6-240 secs)
 Step6isacontinuationofstep5exceptvessel1(T1)willberegenerating,
  vessel1(T1)purgeexhaustvalve(V3)isstillopen,vessel2(T2)isdryingthe
  inletair.Asmallportionofdryoutletairfromvessel2(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1(T1)until240secondshasbeenreached.
Step 7: Vessel 1 Repressurizing (241-300 secs)
 Vessel1(T1)purgeexhaustpilotsolenoidvalvewillde-energizecausing
  vessel1(T1)purgeexhaustvalve(V3)toclose,thisallowsvessel1(T1)
to repressurize to line pressure, since air continues flowing though the small
  outletorificepressurizingvessel1(T1).Theinlettowerselectorpneumaticpilot
  valvemaintainstheinletvalve(V2andV1)positions.
Step 8: Extended Drying Vessel 2
 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2(T2)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1andthevesselswillswitch.
This feature reduces the overall purge consumption saving energy and money.
AircelAHLDE-Series-Models1000-5000