AEC AP Series Large Dehumidifying Dryer - Manual (Page 93)

Large Dehumidifying Dryers Troubleshooting 92
Problem Possible Cause Corrective Action
Process heaters are faulty. Replace.
Desiccant beds are contaminated. Replace desiccant.
Material being dried differs from
material specified at the time of
purchase.
Drying systems are designed for
the material that was originally
specified. Different materials may
need a longer residence time or
different drying temperature.
Break in flex hose to/from drying
hopper. Inspect for air leaks; replace if
necessary.
Loss or reduction in
drying capacity.
Blower fins filled with dust or
contaminants. Remove blower side plate, clean
baffles, replace. Replace filter
elements.
Process temperature set too high
due to operator error.
Check resin manufacturer's data
sheet for proper drying
temperature. Make sure plant
personnel are aware of the correct
process temperature Set Point.
High temperature alarm not set
properly. See Section “Temperature Screen
Setup”
on page 34.
Material in drying
hopper cakes, or
meltdown occurs.
Process set point is out of
acceptable range.
Restore temperature controller to
factory pre-sets. Auto-Tune if
necessary.
Burned out regeneration heater. Repair or replace.
Contaminated or worn out
desiccant. Replace.
Leaking process air hoses. Repair or replace.
Dryer is being operated beyond its
capacity. Check dryer and drying hopper
sizing.
Bad dew point sensor. Replace.
Poor Dew Point
Performance.
Fouled dew point sensor manifold. Clear obstruction. Air should flow
freely through sensor.