Most problems are identified by an alarm.
All alarms should be proven/verified and addressed.
The common ESP problems and causes are as follows:
| Symptom |
Cause |
Solution |
| Under voltage trip or low voltage |
- Full hopper
- Broken, tracking or cracked insulator
- Internal electrode misalignment
|
- Make sure hoppers are empty
- Make sure ash removal system is working properly
- Clean and inspect all insulators, replace any broken or cracked insulators (outage)
- Check all collector plates and discharge electrodes for proper alignment
- Make sure no collector plates and discharge electrodes are bowed or bent (outage)
- Contact HRC for inspection
|
| Low ESP electrical readings |
- Full hopper
- Broken, tracking or cracked insulator
- Internal electrode misalignment
- Excessive gas volume or loading to ESP
- Rappers not working
|
- Follow above procedures plus:
- Check and verify all process conditions
- Make sure all rappers are working
- Contact HRC for site visit and evaluation
|
| Overload trips (H.V. controls) |
- Excessive ESP sparking
- Shorted SCR in controller
- Faulty gate signal to SCR
|
- Note ESP sparking and, if excessive, lower operating level
- Check control and SCR and firing circuit
- Contact HRC for service visit
|
| Heavy build up on collector plates and/or discharge electrodes |
- Improper or poor rapping sequence
- Rappers are not working
- Damaged or broken rapper shafts
- Moisture/condensation
- Change in process conditions
- Low operating temperatures
|
- Optimize rapping sequence
- Repair any defective rappers or rapper controls
- Repair any broken rapper shafts
- Note and correct any moisture conditions (i.e., corrosion, boot seals etc.)
- Review process conditions
- Check flue gas temperatures
- Contact HRC for inspection and evaluation
|
| High stack opacity/high outlet emissions |
- Excessive gas volume or loading to the ESP
- Low power levels in ESP
- Poor rapping
|
- Check process conditions
- Review ESP electrical readings
- Check for proper rapper operation
- Contact HRC for evaluation
|
| Stack “puffing” |
- Improper or poor rapping
- High velocity zones in ESP
|
- Check and optimize rappers
- Check for pluggage on gas flow distribution devices
- Contact HRC for inspection and possible flow study
|
