Sterling SDA Series 25-100 specifications Functional Description, 2-1Models Covered in This Manual

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Chapter 2: Functional Description

Chapter 2: Functional Description

2-1 Models Covered in This Manual

This manual provides operation, installation, and maintenance instructions for 15, 30 and 60 cfm dehumidifying dryers. Model numbers are listed on the serial tag. Make sure you know the model and serial number of your equipment before contacting the manufacturer for parts or service.

Our dehumidifying mini dryers are designed to generate heated dehumidified air (at a very low dew point) at carefully controlled temperatures for use in plastic drying systems. The dryer circulates hot air through a column of plastic resin in the large drying hopper. The resin in the hopper is discharged through a slide gate in a “first in, first out” manner.

2-2 General Description

The Drying System

Dehumidifying dryers are used to generate very low dew point air heated to a controlled temperature for drying plastic pellets and regrind.

Our dryers force hot, dry air through resin in a drying hopper, where air picks up moisture from the material and draws it back to the dryer. In the dryer, a desiccant bed strips moisture from the air. The dried process air is then re-heated and delivered back into the drying hopper for more moisture removal.

Portion of the low dew point process air is directed to the desiccant tank that is off process. This air is heated to approximately 450°F (232°C) before entering the bed that is in regeneration. The moisture is then forced from the desiccant before being exhausted into the atmosphere. A small amount of ambient air is introduced into the process return air filter to make up for the air lost during the bed regeneration. To compensate for the humidity content in the air, this dryer is supplied with the proper amount of desiccant.

What is desiccant?

Desiccant is a material that attracts and holds (absorbs) water from the air. The desiccant our dryers use is a synthetic crystalline metal aluminosilicate blended with a clay binder and formed into beads.

The Process/Regeneration Cycle

Our dryers have two desiccant beds. While one bed is on-line in the process air loop, the other is off-line, being regenerated.

When a desiccant bed is on-line, it absorbs moisture from the process air. In time, the bed becomes saturated with moisture and needs to be regenerated. The dryer automatically redirects the process airflow to the second bed, and starts the regeneration cycle on the first bed.

During regeneration, the dryer system heats the very low dew point air and forces it through the desiccant bed. The moisture driven off the bed bleeds to the atmosphere.

15, 30, & 60 cfm Compact Dryers

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Contents SDA Series 15-60cfm Compact Dehumidifying Dryers In the Event of Shipping Damage Shipping InformationUnpacking and Inspection If the Shipment is Not CompleteCHAPTER 1 SAFETY Table of ContentsCHAPTER 3 INSTALLATION CHAPTER 2: FUNCTIONAL DESCRIPTIONCHAPTER 7 APPENDIX CHAPTER 5 MAINTENANCECHAPTER 6 TROUBLESHOOTING 15, 30, & 60 cfm Compact Dryers1-1How to Use This Manual Chapter 1 SafetySafety Symbols Used in this Manual Read Operation and Installation Manual 1-2Safety Tag Information1-3Warnings and Precautions Dryer Safety TagsGeneral Responsibility 1-4ResponsibilityOperator Responsibility REMEMBER Maintenance Responsibility Reporting a Safety Defect2-2General Description Chapter 2 Functional Description2-1Models Covered in This Manual What is desiccant?Mechanical Features 2-3Standard FeaturesFigure 1 Typical Dryer Air Flow Schematic Electrical Features2-4Options 2-5Safety Devices and InterlocksController Features Safety Device Lock-Outs Safety Circuit StandardsFail Safe Operation 3-1Uncrating the Equipment Chapter 3 Installation3-2Rigging and Placing the Dryer 15, 30, & 60 cfm Compact Dryers POWER ONDEW POINT 3-3Electrical Connections Checking for Proper Blower Rotation 3-4Setup ProceduresThree-PhaseModels Floor Mount ModelsDrying Hopper Air Trap Considerations 3-5Initial Start-upInstalling Water Lines Optional AftercoolerAuto-Tuningthe Dryer Shutting Down the DryerSwitches Chapter 4 Operation4-1Controller Description and Operation Indicator LightsProcess Air Temperature Controller PV SVLit when Control Output 2 is on. Not used in IndicatorLit when Control Output 1 is on. The Out1 IndicatorAdjustment Level Setting the Process Air TemperatureIndicator IndicatorDescription IndicatorName Entering Operating Parameters to Select ModesProcess Air Dew Point Display Setting the High Dew Point AlarmOptional 4-2Dryer Operation Procedures Controller OperationAlarm Display Messages Valve Motor Time-Out Blower Overload No Alarms HIGH TEMP VALVE MTRHEAT COOL 50 SYSTEM NORMAL PROC BLWREvery Day Chapter 5 Maintenance5-1Preventative Maintenance Schedule Every weekServicing Process Air Filters 5-2Preventative MaintenanceFigure 9 Air Filter Location and Disassembly VacuumingSymptoms of Worn Desiccant 5-3Corrective MaintenanceCleaning with Compressed Air Servicing the Dew Point Monitor+ FIRST AID + Replacing Worn DesiccantFigure 10 Desiccant Bed Location and Disassembly Figure 11 Required Desiccant Amounts 13X TypeReplacing the Process/Regeneration Heater ProceduresWARNING! Hazardous electrical current present Replacement Procedures Replacing/Cleaning the Cooling CoilFigure 13 Cooling Coil Location and Disassembly If used as an after-Cooler 3 to 4 GPM @ 85F9.Turn the water to the cooling coil back on 8.Inset the four 10-32bolts back in place15, 30, & 60 cfm Compact Dryers 6-1Introduction Chapter 6 TroubleshootingHIGH TEMP HIGH TEMP PROC BLWRAlarm Message CauseAlarm Message VALVE MTRUsing a Thermocouple CauseWarranty Specifications 7-1WarrantyChapter 7 Appendix Warranty RestrictionsCustomer Responsibilities 7-2Technical SpecificationsAnnex B Information Regeneration MoistureMake Up Air Exhaust 7-3Drawings and DiagramsAftercooler Design Specifications High Pressure Peripheral BlowerExhaust Figure 16 Low Heat Model 120F to 250F Air FlowAfter-Cooler Regeneration MoistureMake Up Air High Pressure Peripheral Blower15, 30, & 60 cfm Compact Dryers 7-4Spare Parts ListDRYER SPARE PARTS LIST 15, 30, 60 cfm Models Mechanical Components15, 30, & 60 cfm Compact Dryers HI-COREDESICCANT DRYER 15/30/60 CFM UNITS30 CFM 15, 30, & 60 cfm Compact DryersDescription 60 CFM 15, 30, & 60 cfm Compact DryersDescription 120V CONTROL COMMON PARTS 15, 30, & 60 cfm Compact DryersA0571672 Description7-5Returned Material Policy Credit ReturnsWarranty Returns 7-6Dryer Identification Serial Number Tag7-7Technical Assistance Service DepartmentContract Department 15, 30, & 60 cfm Compact Dryers
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