Aircel DHT-20 User manual

Installation
and Operation Manual
Aircel
High Inlet Temperature Refrigerated Air Dryer
Models DHT-20, 40, 50, 75, 100, and 125
Installation,
Operation, and
Service Information
This manual is property of the owner. Leave with the unit when set-up and
start-up are complete. Aircel LLC. reserves the right to change design and
specifications without prior notice.
Throughout this manual,
signal words are present
to advise of safety
precautions and/or
standard practices. Obey these
signal words as defined below:
DANGER! - indicates an
imminently hazardous
situation which, if not
avoided, will result in death
or serious injury.
WARNING! - indicates a
potentially hazardous
situation which, if not
avoided, could result in
death or serious injury.
CAUTION! - indicates a
potentially hazardous
situation which, if not
avoided, may result in
minor or moderate injury.
Notice: - used to address
practices not related to
personal injury.
Illustrations are for reference
only, as actual product may vary.
Patent Number for DHT-50 to 125:
6,691,428

2
WARNING!
General Safety Procedures
• Improperinstallation,operation,serviceormaintenancemaycontributetoconditions
in the work area or facility that could result in personal injury and product or property
damage. Check that all equipment is properly selected and sized for the intended use.
• Consultandcomplywithnationalandlocalcodesrelatingtofireorexplosionandall
other appropriate codes when determining the location and operation of this equipment.
• Safeandefficientoperationoftheunitdependsonproperinstallationandservice.
• Authoritieswithjurisdictionshouldbeconsultedbeforeinstallingtoverifylocalcodesand
installation procedures. In the absence of such codes, install unit according to the National
Electric Code, NFPA No. 70-latest edition.
• Aqualifiedinstallationandserviceagentmustcompleteinstallationandserviceofthis
equipment.
• DONOTweldon/topressurevesselormodifyitinanyway.
• DONOTremove,modify,oradjustprotectiveorsafetydevices.
• Lockoutpowersupplyanddepressurizesystembeforeperformingmaintenanceorservice
work.
• DONOToperatetheequipmentwiththecontrolpaneldooropen.
Notice: For optimum performance, use only original equipment replacement parts.
Notice: For information and notes specific to a custom designed and built dryer, reference the
drawing package provided with the unit.
AircelDHTSeries-Models20-125

HighInletTemperatureRefrigeratedAirDryer
3
Contents
SafetyStatements .................................................. 2
DataSheet............................................................. 3
RefrigeratedDryerSerialPlateLabel .................... 4
RefrigerantSafetyPrecautions .............................. 5
DesignParameters................................................. 6
Description............................................................ 6
 System.......................................................... 6
 RefrigerationCircuit .................................... 7
Compressed Air Circuit................................ 7
Purpose and Intended Use..................................... 9
Inspection on Arrival ............................................ 9
Lifting Information ............................................. 10
Installation Codes and Procedures ...................... 10
Installation.......................................................... 11
Typical Installation ............................................. 12
PreliminaryStart-UpChecklist............................ 13
AutomaticDrainValveAdjustments................... 14
Operating Procedure ........................................... 14
AirCooledCondenserRequirements .................. 14
Data Sheet
This manual contains specific precautionary statements relative to worker safety.
 Readthoroughlyandcomplyasdirected.Discusstheuseandapplicationofthisequipment 
with a representative listed on the manual back cover. Instruct all personnel on safe use and
maintenance procedures. Understand and obey the following signal words used in this manual.
  •DANGER! - indicates an imminently hazardous situation which, if not avoided, will
result in death or serious injury.
  •WARNING! - indicates a potentially hazardous situation which, if not avoided, could result
in death or serious injury.
  •CAUTION! - indicates a potentially hazardous situation which, if not avoided, may result in
minor or moderate injury.
  •Notice: - used to address practices not related to personal injury.
Shut-DownProcedures........................................ 15
 Shut-DownEmergency............................... 15
 Short-TermShut-Down.............................. 15
ServiceInformation............................................. 16
 Maintenance............................................... 16
Troubleshooting.................................................. 18
Electrical ................................................... 18
 Refrigeration .............................................. 18
 CondensateRemoval.................................. 19
Other.......................................................... 19
Troubleshooting Table........................................ 20
Appendix ............................................................ 25
 RefrigerantMaterialSafetyDataSheet ...... 25
 WiringDiagram ......................................... 30
ServiceNotes ...................................................... 33
Warranty............................................................. 36
ModelNumber________________________________ SerialNumber ___________________________________
DateofManufacture ___________________________
ShipDate _____________________________________ InstallationDate _________________________________
Customer Name _________________________________________________________________________________
Address __________________________________________________________________________________
__________________________________________________________________________________
A c c e s s o r i e s ___________________________________________________________________________________________________________________
O t h e r _____________________________________________________________________________________________________________________

4
Refrigerated Dryer Serial Plate Label
ForMfgPersonnel:AffixLabelHereif
DataSheetonpg.3wasnotcompleted.
AircelDHTSeries-Models20-125

HighInletTemperatureRefrigeratedAirDryer
5
Refrigerant Safety Precautions
Refrigerant First Aid Recommendations
Inhalation
If high concentrations are inhaled, immediately
remove individual from affected area to an area
with a fresh air supply. Keep individual calm.
If not breathing, give artificial respiration or if
havingdifficultybreathing,giveoxygenandcallfor
emergency services.
Skin Contact
In case of contact with the skin, immediately flush
skinwithcleanwaterforatleast15minutes.Treat
for frostbite if necessary by gently warming affected
areasandcallforemergencyservices.Removeany
contaminated clothing or shoes.
Eye Contact
In case of contact with the eyes, immediately flush
eye(s)withcleanwaterforatleast15minutesand
call for emergency services.
CAUTION!
Inhalation, Skin, & Eye Irritant
 • Usepropersafetyandprotective
equipment, including chemical
safety goggles or face shield and
impervious gloves when handling
refrigerants.
 • Exercisecaretoensurethatliquid
refrigerant does not come in contact
with your skin or eyes.
 • DONOTSMOKE.
 • Ventilationinworkareamustbe
adequate to keep the concentration
of refrigerant below 1,000 ppm.
 • Systemmustbefreeofallrefrigerant
before any welding or brazing can be
performed and must be done in a
well ventilated area.
 • Decompositionofrefrigerantsis
hazardous! This material can be
decomposed by high temperatures
caused by an open flame.
 Hydrofluoricacidandpossibly
carbonyl fluoride can form in a
liquid or gaseous state. Avoid
 exposuretothesetoxicfumesand
irritating materials.
 • Leavetheworkareaimmediatelyif
 youexperienceanyofthefollowing:
smell something unusual, feel light-
 headed,experienceshortnessof
breath, feel a tingling sensation in
your fingers or toes, suddenly feel
warm or a rapid heartbeat.

6
Design Parameters
Typeofdryer:Refrigerated
Powersupply:115,230Volt/singlephase/60Hz
Refrigeranttype:R-134A
 ChemicalComposition:HFC
Parameter
Description
Optimum Maximum Minimum
Air Pressure
(PSIG) 150-175 200 80
Air Inlet
Temperature (°F) 100-180 200 40
Ambient
Temperature (°F) 75 100 32
SuctionGauge
Reading(psig) 28-40 60 28
DischargeGauge
Reading(psig) 160-250 350 80
Evaporator
Temperature (°F) 38-42 60 33
Description
System
A broad range of non-cycling refrigerated
compressed air dryers from 10 to 10,000 scfm is
offered.TheHighInletTemperatureRefrigerated
AirDryerseriescoversaflowrangefrom20to
125scfmprovidingreliable,constantdewpoint
performance in all flow conditions. Through
optimization of critical dryer components – heat
exchanger,separator,andcondensateremoval–the
system ensures the highest performance at full-
andpartial-loadconditions.R-134arefrigerant
is used in all refrigerated compressed air dryers
asstandard.R-134aistheindustry’spreferred
choice because of its 0.0 ozone depletion factor and
globalwarmingpotential.R-134aisaone-blend
refrigerant providing consistent performance (no
temperatureglide)andeasyservice(nomixtureof
different refrigerants).
Hotsaturatedairenterstheair-to-airheat
exchangeroftheHighInletTemperature
RefrigeratedAirDryerandisprecooledbythe
outgoing dry air. Precooling saves energy by
reducingtheheatloadonthedryer’scompressor.
The cool saturated air enters the air-to-refrigerant
heatexchangerwhereairtemperatureislowered
tothe48to50°Frange.Thisdramatictemperature
drop condenses water and oil.
Themixtureofcoldairandcondensationthen
flows into the two-stage separator filter where
liquids and contaminants are removed by
centrifugal action, directional flow change, and
velocity reduction. Once bulk liquids have been
removed, the compressed air goes through a
stainless steel mist eliminating filter that coalesces
oilaerosolsandoilvaporswithinthe50-micron
range, and then separates and removes them. At
this point, the compressed air is dry and virtually
oil-free.
Cold,dryairexitsthroughtheprecoolerheat
exchangerandisreheatedbyincominghotair.
Reheatingrestoresenergyandalsoprevents
condensation from forming on the outside of air
distribution piping. In the refrigeration unit, the
compressor pumps hot, high-pressure gaseous
refrigerant to the condenser where it is cooled
and liquefied by ambient air. From the condenser,
liquid refrigerant first flows through the receiver,
then through a filter/dryer, and finally through the
expansionvalvewherepressureandtemperature
are reduced. This reduction in pressure causes
the liquid refrigerant to boil until it reaches the
saturation temperature that corresponds to its
pressure. As the low-pressure refrigerant passes
through the evaporator, heat flows from the
compressed air to the refrigerant, causing the
boiling to continue until all refrigerant is vaporized.
Refrigerantgasisreturnedtothecompressorand
the cycle is repeated. A hot gas by-pass valve is used
to control temperature in the evaporator.
AircelDHTSeries-Models20-125

HighInletTemperatureRefrigeratedAirDryer
7
Refrigeration Circuit
Refrigerantiscycledthroughaclosedloop
system commonly known as high pressure and
lowpressure.Refrigerantiscompressedbythe
compressor to a gas with high temperature and
high pressure, which then travels to the condenser
(air/water cooled) to drop the temperature and
change from gas to liquid. Liquid travels through
to the evaporator (refrigerant-to-air part of the heat
exchanger)andbacktothecompressorsuctionside
andtheprocessrepeatsitself.Athermalexpansion
hot gas by-pass valve is used on the non-cycling
dryers from the high side to low side as a freeze
protectorinlowloadconditions(125scfm).
Compressed Air Circuit
The compressed air dryer circuit uses a patented
air-to-airheatexchanger,whichactsasaprecooler/
reheater(40scfmratedmodelandhigher).Hot,
saturated, compressed air first enters the air-to-air
heatexchanger,whereitispre-cooledbyoutgoing
airfromtheair-to-refrigerantheatexchanger.
Thisenergysavingheatexchangerprovides
several advantages, such as a reduction of the heat
load imposed on the refrigerant compressor and
condenser, providing more energy to the outlet air,
and preventing condensation of moisture on the
outside of the plant distribution air line piping.
Fromtheair-to-airheatexchanger,airwillenter
into the evaporator further reducing its temperature
to a desired pressure dew point. As the air is
cooled, moisture will be condensed, where it is then
separated and discharged through the condensate
drain. The cooled air then reenters the air-to-air
heatexchanger,inadirectionoppositetotheflow
of the warm, saturated incoming air. This counter
flow action assures high temperature differential
throughouttheheatexchanger,resultinginamore
effective heat transfer.
compressor liquid
receiver
air out
air in
refrigerant
inlet
refrigerant
outlet
air cooled
condensor
suction
accumulator
Air to Refrigerant Heat Exchanger
Refrigerant Circuit
TypicalSchematicFlowDiagram(20scfmratedmodels)

8
air inlet air outlet
separation cell
air to refrigerant
heat exchanger
refrigerant
inlet
air
refrigerant refrigerant outlet
exiting air
incoming air
stainless steel mist eliminator
pre-cooler / heater
TypicalSchematicFlowDiagram(40-125scfmratedmodels)
AircelDHTSeries-Models20-125

HighInletTemperatureRefrigeratedAirDryer
9
Purpose and Intended Use
Highinlettemperaturerefrigeratedairdryersare
designed for the purpose of removing moisture
from the compressed air by using mechanical
refrigeration and providing dew points as low as
(48°F-50°F).Thesedryersareusedtoprotect
industrial compressed air systems, machinery, and
tools. They are designed to deliver the required
dew point at specified inlet air temperature, inlet
air pressure, inlet flow and ambient temperature
conditions.Toensuremaximumperformanceand
safe operation of this dryer, everyone associated
with its installation, operation, and maintenance
must read and carefully follow the instructions of
this manual.
CAUTION!
• Misuseormodificationofthis
equipment may result in personal
injury.
• Donotmisuseormodify.
Inspection on Arrival
All high inlet temperature series dryers are tested
andoperatedbeforeshipment.However,shipping
vibration may cause damage such as loosening of
certain parts. To ensure smooth installation, it is
recommended that immediately upon receipt of the
unit, the system is checked for the following:
1. Inspect unit on delivery.
2. Reportanydamagetothedeliverycarrier.
3. Requestawritteninspectionreportfromthe
Claims Inspector to substantiate the claim.
4. File claims with the delivery carrier.
5. Compareunitreceivedwithdescriptionof
product ordered. Check the data label and
makesurethatitisthecorrectModelthatyou
had ordered. Note the equipment Capacity and
PowerSupplyrequirementsandensurethatthey
are in accordance with your specifications. The
rated conditions of the dryer are indicated on
the serial plate label. If there is any discrepancy,
contact your representative listed on the manual
back cover.
6. Vibrationduringshippingcanloosenthe
connections.Soinspectallpipeandtubingand
make sure they are all tightened and secured.
7. Observe pressure of refrigerant analyzer gauge
(suction) to determine if refrigerant has leaked
out during transit. If the gauge reading does not
match that mentioned on the serial plate label,
immediatelycontactTechnicalSupportlistedon
the manual back cover.
8. Reportincompleteshipmentstothedelivery
carrier and your service representative.

10
Lifting Information
1. Useallliftingpointsprovided.Specialcaremust
be used when lifting the dryer to prevent tip-
over.
2. Use clevis connectors, not hooks, on lifting
slings.
3. Only lift unit under support frame/base by using
theforkliftopeningsprovided.Donotliftby
piping.
4. Checktheapproximateweightprovidedon
the specification control drawing to ensure
adequate lift truck capacity.
5. Allowonlyqualifiedoperatorstoliftthe
equipment.
6. RefertoapplicableOSHAregulationsandlocal
codes when using cranes, forklifts, and other
lifting equipment.
WARNING!
• Failuretolifttheunitcorrectlycan
result in severe personal injury or
property damage.
• Useappropriateliftingequipment
and adopt all safety precautions
needed for moving and handling the
equipment.
• Ahandcart,forkliftorcraneis
recommended for unloading and
installation.
• Liftunitbyliftinglugsandframe
only.Donotliftbypiping.
Installation Codes and Procedures
WARNING!
• Followproperlockout/tagout
procedures before performing
service or maintenance work.
• Electricalinstallationmustbe
performed by a qualified electrician
and comply with all applicable
national and local codes.
1. Safeandefficientoperationoftheunitdepends
on proper installation.
2. Authorities with jurisdiction should be
consulted before installing to verify local codes
and installation procedures. In the absence
of such codes, install unit according to the
National Electric Code and NFPA No. 70-latest
edition.
3. A qualified installation and service agent
versed in all regulatory codes must complete
installation of this unit.
CAUTION!
• AcopyoftheOperationManual
must be made available to all
personnel involved with the
installation, operation and
maintenance of the equipment,
to avoid injury to personnel or
property damage.
• Appropriatetoolsmustbeusedfor
all installation and maintenance
work, to avoid injury to personnel
or property damage.
AircelDHTSeries-Models20-125