During the lifetime of an electrostatic precipitator (ESP), many factors can affect its performance, reducing its expected efficiency.

Reduced Electrical Clearances

Reduced electrical clearances is the leading contributor to poor electrostatic precipitator performance. Oftentimes electrode clearances are set incorrectly or damage may have occurred by a temperature excursion causing warping in the collecting plates or discharge electrodes. Close clearances, even in one area, can cause an entire electrical field to underperform or short out entirely.

Rapping System

Over many years of operation, the rapping system can become less and less effective. Reduced rapping performance from weak or damaged rappers can cause excessive dust buildup on plates and electrodes causing less power applied to the field.

High Voltage (HV) Electrical System

The HV system is the backbone of the device; but as ESPs age, ceramic insulators can crack or deteriorate causing an intermittent or direct short, in turn causing a field to underperform. Leaking fluids or erratic electrical readings from a transformer/recitifier (TR) set could be an indication of a potential failure.

Control System

Several adjustments to the control system by different operators over time may have resulted in adjustments made during an upset condition, leading to less than optimum performance.


  •  Check electrical clearances in collecting system
  •  Look for corrosion on casing walls, hot roof and ash hoppers
  •  Verify the operation of all rappers and connected components
  •  Verify the automatic voltage control (AVC) settings match the TR set ratings


  • Running your precipitator too cold may cause corrosion and have adverse effects on performance
  •  Inadequate HV purge air may contribute to condensation and buildup on insulators
  •  Inadequate ash removal can cause re-entrainment or damage to components
  •  Many older control systems may have obsolete repair parts or lack technical support

Dürr Megtec Field Services

Our inspection services and retrofit group help ensure your equipment is running optimally and stays that way. Services can be tailored to your needs preventing lost production and unnecessary downtime.

Brian Lahtela
Service Director, americas
830 Prosper Street
54115 De Pere, WI
United States