Sterling SDA 1000-5100 specifications Process/Regeneration Cycle

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moisture is stripped from the air by a desiccant bed. The dried process air is then re-heated and delivered back into the drying hopper to dry material again.

This system is a "closed loop", because ambient (outside) air is never introduced into the process air. The closed loop system is used by the manufacturer because the process air is typically much drier than ambient air, even after carrying moisture out of the plastic resin. Recycling process air maintains drying efficiency at a consistently high level.

The Process/Regeneration Cycle

There are two desiccant beds in a dryer up to 1500 cfm. Larger dryers have two beds each for right and left beds. While one desiccant bed is on-line in the process air loop, the other is off-line being regenerated (see Figure 1).

When a desiccant bed is on-line, it absorbs moisture from the process air. The desiccant will become saturated with moisture and need to be regenerated. The dryer automatically redirects the process airflow to the second bed and starts regenerating the first bed.

During regeneration, air is heated to approximately 550°F and forced through the saturated desiccant. The moisture driven off the desiccant is bled to the atmosphere. The regeneration heater is then turned off while the regeneration blower continues to blow air through the desiccant bed until it is cooled.

Figure 1: Regeneration Cycle

AD600-AD1500

Dryer Flow Schematic

Right Desiccant in

Regeneration

Dryer Valve

Regeneration

Blower

Regeneration

Filter Insulated

Drying

Hopper

Regeneration

Heaters

Regeneration

Exhaust

Process

Heater

Process

Filter

Left Desiccant

Right Desiccant

Process

Blower

Large Dehumidifying Dryers

Functional Description

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Contents SDA Large Dehumidifying Dryers With AP0 Controls Unpacking and Inspection Shipping InfoEvent of Shipping Damage If the Shipment is Not CompleteReturns Warranty ReturnsCredit Returns Table of Contents Operation Dryer Identification Serial Number Tag Technical Assistance How to Use This Manual SafetySafety Symbols Used in this Manual Wear Safety Glasses and Work Gloves Dryer Safety Tags DescriptionGeneral Responsibility ResponsibilityOperator Responsibility Maintenance Responsibility Reporting a Safety Defect Models Covered in This Manual Functional DescriptionGeneral Description Regeneration Cycle Process/Regeneration CycleSequence of Operation Controller Screen Descriptions Controller DescriptionMechanical Features Standard FeaturesElectrical Features Closed-Loop Regeneration OptionsProcess Aftercooler Process Air Dust Collector Recommended Temperature SettingsMaterial Overdrying Protection Electrical Options Mechanical OptionsSafety Circuit Standards Safety Devices and InterlocksSafety Device Lock-Outs Fail Safe OperationPage Uncrating the Equipment Mechanical InstallationRigging and Placing Unit Making Electrical ConnectionsChecking Blower Rotation Checking for Proper Blower RotationDryer/Drying Hopper Process Air Connections Making Dryer/Drying Hopper Process Air ConnectionsAftercooler Components & Flow Rates Connecting Aftercooler/Precooler Cooling Water OptionalDrying Hopper Air Trap Using the Drying Hopper Air TrapIndicator Lights SwitchesProcess Air Temperature Controller ControlsLit when Control Output 2 is on. Not used Lit when Control Output 1 is on. The Out1Indicator Name Description Lights in the Operation Indicator Section whenE5CN Operating Parameters Setting the Process Air TemperatureTuned prior to dryer startup Adjustment Level Indicator Name DescriptionON, OFF Entering Operating Parameters to Select ModesProcess Air Dew Point Display Setting the High Dew Point AlarmOptional Setting the Redundant Safety Controller Redundant Safety Controller DisplayWatlow Operating Parameters Manf. setting Operation Auto-Tuning the DryerInitial Start-up Pre-Startup ChecksDryer Operation Procedures Page Material Miser OFF Press + to Enable Alarm Display Messages Shutting Down the Dryer Auto-Tuning the DryerMaintenance Schedule MaintenancePhotocopy this page for your maintenance records Cleaning or Replacing the Process Air Filters Preventative MaintenanceCalibrating the Dirty Filter Alarm Cleaning or Replacing the Regeneration FilterChecking the Dewpoint Control System Symptoms of Worn Out Desiccant Corrective MaintenanceReplacing the Desiccant Replacing the Process Heater Electric Dryers Desiccant Tower AssemblyReplacing the Regeneration Heater Electric Dryers Process Heater Box AssemblyRegeneration Heater Box Assembly Basic Troubleshooting TroubleshootingIntroduction Large Dehumidifying Dryers Troubleshooting Alarm Descriptions AlarmsAlarm Alarm Description Alarm Effect Code Using a Thermocouple Determining Temperature Controller Errors or Sensor ErrorsUsing a Platinum Resistance Thermometer Appendix WarrantyAftercooler Design Specifications Technical SpecificationsAnnex B Information Drawings and Diagrams Optional dryer dust collector Spare Parts List Level 3 Mechanical Components Located on back of Dryer Dryer Identification Serial Number TagParts and Service Department Technical Assistance Service DepartmentParts Department Sales Department