Sterling SDA 1000-5100 specifications Corrective Maintenance, Symptoms of Worn Out Desiccant

Page 45

6-3 Corrective Maintenance

Symptoms of Worn Out Desiccant

The moisture adsorption capacity of the desiccant used in Large Dehumidifying Dryers degrades after an indefinite period of time. Useful life depends on variables such as material moisture content, plasticizer vapors in the return air and number of regeneration cycles.

Your dryer may need new desiccant if it exhibits any of the following symptoms:

•The plastic material is not being dried sufficiently (high scrap/reject rate).

•The air temperature at the top of the regenerating desiccant bed rapidly climbs to 350°F or more shortly after the start of regeneration, even though a saturated bed has just started heating.

•The process air dewpoint, measured with a portable dewpoint monitor, is higher than -10°F throughout the process drying cycle.

•Smoke or dust is being blown out of the process air outlet.

•Noticeable amounts of desiccant in the beds is a medium-brown color, or darker.

If any of these signs are noticed, the desiccant in the desiccant beds should be replaced. Desiccant replacement kits are available from the Parts Department. If you wish, the desiccant beds can be repacked at your site by a service technician.

WARNING! DESICCANT MATERIAL CAUSES EYE IRRITATION BREATHING MAY BE HARMFUL/MAY CAUSE SKIN IRRITATION!

•Do not get in eyes.

•Avoid prolonged contact with skin.

•Use with adequate ventilation.

•Wash thoroughly after handling.

FIRST AID:

In case of eye contact, immediately flush eyes with plenty of water for at least 15 minutes. If irritation persists, see a physician.

Replacing the Desiccant

Follow the procedure below to change the desiccant. See Figure 17 below for desiccant tower components.

1.Disconnect electrical power to the dryer.

2.Remove the bolts and nuts securing the covers of each desiccant canister. Remove the covers and set them aside.

3.With a shop vacuum that has a 4 micron HEPA filter, carefully remove all desiccant from each tower.

4.Inspect all screens for tears or burn-through spots.

5.Fill each canister with 13X, 8 x 12 bead desiccant.

Large Dehumidifying Dryers

Maintenance

45

Image 45

Contents SDA Large Dehumidifying Dryers With AP0 Controls Unpacking and Inspection Shipping InfoEvent of Shipping Damage If the Shipment is Not CompleteWarranty Returns ReturnsCredit Returns Table of Contents Operation Dryer Identification Serial Number Tag Technical Assistance Safety How to Use This ManualSafety Symbols Used in this Manual Wear Safety Glasses and Work Gloves Dryer Safety Tags DescriptionResponsibility General ResponsibilityOperator Responsibility Maintenance Responsibility Reporting a Safety Defect Functional Description Models Covered in This ManualGeneral Description Regeneration Cycle Process/Regeneration CycleSequence of Operation Controller Screen Descriptions Controller DescriptionStandard Features Mechanical FeaturesElectrical Features Options Closed-Loop RegenerationProcess Aftercooler Recommended Temperature Settings Process Air Dust CollectorMaterial 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 ModesSetting the High Dew Point Alarm Process Air Dew Point DisplayOptional Redundant Safety Controller Display Setting the Redundant Safety ControllerWatlow 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 Maintenance SchedulePhotocopy 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 Corrective Maintenance Symptoms of Worn Out DesiccantReplacing the Desiccant Replacing the Process Heater Electric Dryers Desiccant Tower AssemblyReplacing the Regeneration Heater Electric Dryers Process Heater Box AssemblyRegeneration Heater Box Assembly Troubleshooting Basic TroubleshootingIntroduction Large Dehumidifying Dryers Troubleshooting Alarms Alarm DescriptionsAlarm Alarm Description Alarm Effect Code Determining Temperature Controller Errors or Sensor Errors Using a ThermocoupleUsing a Platinum Resistance Thermometer Appendix WarrantyTechnical Specifications Aftercooler Design 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