Problem | Possible Cause | Corrective Action |
Loss or reduction in | Process heaters are faulty. | Replace. |
drying capacity. | Desiccant beds are contaminated. | Replace desiccant. |
| Material being dried differs from | Drying systems are designed for |
| material specified at the time of | the material that was originally |
| purchase. | specified. Different materials may |
|
| need a longer residence time or |
|
| different drying temperature. |
| Break in flex hose to/from drying | Inspect for air leaks; replace if |
| hopper. | necessary. |
| Blower fins filled with dust or | Remove blower side plate, clean |
| contaminants. | baffles, replace. Replace filter |
|
| elements. |
Material in drying | Process temperature set too high | Check resin manufacturer's data |
hopper cakes, or | due to operator error. | sheet for proper drying |
meltdown occurs. |
| temperature. Make sure plant |
|
| personnel are aware of the correct |
|
| process temperature Set Point. |
| High temperature alarm not set | See Section “Temperature Screen |
| properly. | Setup” on page 29. |
| Process set point is out of | Restore temperature controller to |
| acceptable range. | factory |
|
| necessary. |
Poor Dew Point | Burned out regeneration heater. | Repair or replace. |
Performance. | Contaminated or worn out | Replace. |
| desiccant. |
|
| Leaking process air hoses. | Repair or replace. |
| Dryer is being operated beyond its | Check dryer and drying hopper |
| capacity. | sizing. |
| Bad dew point sensor. | Replace. |
| Fouled dew point sensor manifold. | Clear obstruction. Air should flow |
|
| freely through sensor. |
Large Dehumidifying Dryers | Troubleshooting | 50 |
