DPD-3 Thermal Conduction Vacuum Dryer  
Issues > Check/Troubleshooting
Primary Convey Alarm is displayed on the Alarm Screen.
  1. No materials in the source primary transport.
  2. Full Level Meter in Hood Unit not working properly.
  3. Materials "bridging" in the Suction Hopper for Primary Transport.
  4. Primary Convey timer and Feeding timer are not set properly.
  5. Convey ability is declining.

1. No materials in the source primary transport.
Will occur when the initial feeding does not complete even after conducting the specified feed counts (DPD-5: more than 14 times, DPD-15: more than 29 times) during auto run. Will also occur if the drying hopper is not full (i.e. demand signal OFF) even after completing material feeding from the Primary Convey Suction Hopper to the Drying Hopper twice.
  1. Feed material to the primary convey source.
If problem persists
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2. Full Level Meter in Hood Unit not working properly.
Primary Convey Alarm will occur if the convey does not stop as a result of the level meter not detecting full load.
  1. Check to see if the level meter is functioning normally.
  2. Adjust or replace the level meter.
If problem persists
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3. Materials "bridging" in the Suction Hopper for Primary Transport.
If materials are "bridging" in the hopper, the materials will not be fed into the drying hopper and cause a Primary Convey Alarm.
  1. Check the condition of the Suction Hopper.
  2. Clear the bridging materials. If this happens frequently, either conduct double grinding or reduce the feeding rate.
If problem persists
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4. Primary Convey timer and Feeding timer are not set properly.
  1. Display the primary convey settings on the touch panel and check the settings.

    [Point]
    Primary Feed - Set the material feed time from the feeding hopper to the drying hopper (feeding valve open time). Set the feed time to insure that all materials sent to feeding hopper can be fed.
    Primary Convey - Set the material convey time to the feeding hopper (batch convey time). Set proper time to ensure that the amount in the feeding hopper can be conveyed based on transferring distance and types of materials.

  2. Input the setting time suitable for the quantity of the suction hopper.
If problem persists
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5. Convey ability is declining.
  1. See Material clog occuring in the primary convey hose (decline of conveying).
If problem persists
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