Sterling SDAA 25-100 Standard Features, What is desiccant?, Process/Regeneration Cycle

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A small amount of ambient air is introduced into the process air stream to make up for the air lost during the bed regeneration. Because the process air is typically much drier than the ambient air, the air mixture maintains drying efficiency at a consistently high level. This air is heated to 500° F (260° C) before entering the bed that is on regeneration forcing moisture from the desiccant before exhausting. 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 air and forces it through the desiccant bed. The moisture driven off the bed bleeds to the atmosphere.

2-3 Standard Features

Mechanical Features

•Dual desiccant beds

•Electrically-actuated air valve

•13X Molecular Sieve

•Single regenerative process blower

•Drying temperature range of 180ºF to 250ºF (71° C to 121° C).

•2.5” hose connections

Electrical Features

•Process thermocouple to be connected to drying hopper air inlet.

•Nema 12 control enclosure

Dehumidifying Dryers

Chapter 2: Functional Description

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Contents Sdaa 25-100 15-60 cfm Dehumidifying Dryers Shipping Information Table of Contents Maintenance Service Department Sales Department Contract Department How to Use This Manual SafetySafety Symbols Used in this Manual Wear Safety Glasses and Work Gloves General Responsibility ResponsibilityRemember Operator ResponsibilityReporting a Safety Defect Maintenance ResponsibilityDehumidifying Dryers Safety Models Covered in This Manual Functional DescriptionGeneral Description What is desiccant? Standard FeaturesMechanical Features Electrical FeaturesController Features Safety Devices and InterlocksOptions Safety Device Lock-Outs Safety Circuit StandardsFail Safe Operation Uncrating the Equipment InstallationRigging and Placing the Dryer Machine-Mount Dryer Dimensions Floor-Mount Dryer Dimensions Recommended Dryer Lifting Hardware Suggested Lift Rigging for Cart Mounted DryersSuggested Lift Rigging for Machine Mounted Dryers Electrical ConnectionsThree-Phase Models Setup ProceduresChecking for Proper Blower Rotation Making Dryer/Drying Hopper Process Air ConnectionsDrying Hopper Air Trap Considerations Installing Water Lines Hose and Hose ClampOptional Aftercooler Initial Start-up Auto-Tuning the DryerPre-Startup Checks Starting Up the DryerShutting Down the Dryer Start-up OperationIndicator Lights SwitchesController Description and Operation Lit when Control Output 1 is on. The Out1 Process Air Temperature ControllerLit when Control Output 2 is on. Not used Lights in the Operation Indicator Section when Indicator Name DescriptionIdentifying Temperature Controller Keys Setting the Process Air TemperatureE5CN Operating Parameters Tuned 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 Mode Parameter Setting range Default Manf. setting Dryer Operation Procedures Model Heating Cooling 15 cfm 30 cfm 60 cfm Page Controller Operation With Optional Alarm Horn & Reset Button Page Alarm Display Messages Shutting Down the Dryer Auto-Tuning the DryerPreventative Maintenance Schedule MaintenancePhotocopy this page for your maintenance records Recommendations for Cleaning and Replacing Filters Preventative MaintenanceServicing Process Air Filters VacuumingServicing the Dew Point Monitor Cleaning with Compressed AirSymptoms of Worn Desiccant Corrective MaintenanceReplacing Worn Desiccant First AIDConsult local disposal regulations for more information Replacing the Process Heater ProceduresProblem Possible cause Corrective action TroubleshootingIntroduction Problem Possible cause Corrective action Check resin manufacturer’s data Using a Thermocouple Determining Temperature Controller Errors or Sensor ErrorsUsing a Platinum Resistance Thermometer Warranty Specifications WarrantyWarranty Restrictions AppendixOptional Components Warranty LiabilitiesCustomer Responsibilities Annex B Information Technical SpecificationsAftercooler Design Specifications Drawings and Diagrams Spare Parts ListLevel 2 & 3 Spare Parts List Electrical & Mechanical Warranty Returns Safety Tag InformationDryer Safety Tags Returned Material PolicyLocated on back of Dryer Dryer Identification Serial Number TagTechnical Assistance Service DepartmentParts Department Sales Department