Sterling 60 cfm Functional Description, Models Covered in This Manual, General Description

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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, 30, & 60 cfm Compact Dehumidifying Dryers Event of Shipping Damage Shipping InformationUnpacking and Inspection If the Shipment is Not CompleteTable of Contents Maintenance How to Use This Manual SafetySafety Symbols Used in this Manual Safety Tag Information Wear Safety Glasses and Work GlovesGeneral Responsibility ResponsibilityOperator Responsibility Remember Maintenance Responsibility Reporting a Safety DefectModels Covered in This Manual Functional DescriptionGeneral Description Mechanical Features Standard FeaturesElectrical Features Controller Features Safety Devices and InterlocksOptions Safety Device Lock-Outs Safety Circuit StandardsFail Safe Operation Uncrating the Equipment InstallationRigging and Placing the Dryer Suggested Lift Rigging for Cart Mount Dryers Electrical Connections Suggested Lift Rigging for Machine Mounted DryersSetup Procedures Checking for Proper Blower Rotation Three-Phase ModelsDrying Hopper Air Trap Considerations Installing Water LinesInitial Start-up Optional AftercoolerAuto-Tuning the Dryer Shutting Down the DryerOperation SwitchesIndicator Lights Controller Description and OperationProcess Air Temperature Controller Indicator Name Description Lit when Control Output 1 is on. The Out1Lit when Control Output 2 is on. Not used Lights in the Operation Indicator Section whenAdjustment Level Indicator Name Description Setting the Process Air TemperatureE5CN Operating Parameters Entering Operating Parameters to Select Modes Process Air Dew Point Display Setting the High Dew Point AlarmOptional Dryer Operation Procedures Controller OperationAlarm Display Messages High Temp Valve MTR Maintenance Preventative Maintenance ScheduleServicing Process Air Filters Preventative MaintenanceRecommendations for Cleaning and Replacing Filters VacuumingSymptoms of Worn Desiccant Corrective MaintenanceCleaning with Compressed Air Servicing the Dew Point Monitor+ First AID + Replacing Worn DesiccantDesiccant Bed Location and Disassembly Procedures Replacing the Process/Regeneration HeaterReplacing/Cleaning the Cooling Coil Replacement ProceduresPage Troubleshooting IntroductionProc Blwr Determining Temperature Controller Errors or Sensor Errors Using a ThermocoupleTechnical Specifications AppendixDrawings and Diagrams Aftercooler Design SpecificationsHigh Heat Model 180F to 400F Air Flow Schematic Spare Parts List Level 1 Spare Parts List Electrical & MechanicalHI-CORE Desiccant Dryer 15/30/60 CFM Units 30 CFM 60 CFM 120V Control Common Parts 220V Control Common Parts Returned Material Policy Dryer Identification Serial Number TagParts Department Service DepartmentTechnical Assistance Sales Department
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