ESP Troubleshooting Guide

We undertake all types of works for Dry ESP  under Overhauling, Performance Enhancement, Technical troubleshooting and Erection Works. Visit our site for details.

Electrostatic precipitators (ESP's) are used to reduce particulate emissions from blast furnaces, sintering operations in the steel industry, and for fly ash control from industrial and utility boilers. ESPs have been designed to collect particles with diameters of from 0.1µm to 10µm; collection efficiency is considered high, sometimes exceeding 99%. The ability of ESP's is to handle large exhaust gas volumes at temperatures between 175 and 700C.

An electrostatic precipitator contains the following:

• Discharge electrodes

• Collection electrodes

• Electrical system  

• Rappers

• Hoppers

• Shell                         

The discharge electrode is usually a small-diameter metal wire. This electrode is used to ionize the gas that charges the particles and to create a strong electric field. The collection electrode is either a tube or a flat plate with an opposite charge relative to that of the discharge electrode. The collection electrode collects charged particles. The electrical system consists of high voltage components used to control the strength of the electric field between the discharge and collection electrodes. The rapper imparts a vibration or shock to the electrodes, removing the collected dust. Rappers remove dust that has accumulated on both collection electrodes and discharge electrodes. Occasionally, water sprays are used to remove dust from collection electrodes. These precipitators are called water –walled ESPs. Hoppers are located at the bottom of the precipitator. Hoppers are used to collect and temporarily store the dust removed during the rapping process. The shell structure encloses the electrodes and supports the entire ESP.

 Electrostatic Precipitator Troubleshooting Guide

 

Symptom	Cause	Solutions
Corrosion Damage	Air Leakage	- Replace leaking door gaskets - Replace damaged rapper penetration seals - Replace damaged hammer drive seals - Repair leaking duct work test ports - Repair/replace leaking expansion joints - Repair leaking weld seams - Repair holes in casing - Check for reduced gas temperature
	Poor insulation design	- Re-insulate ESP hot roof to penthouse corners - Check/replace/install new hopper heaters
Deposits on Plates & Electrodes	Improper or poor rapping	- Verify rapper / vibrator systems operating - Inspect for binding or broken rapper shafts - Inspect for bound collecting plates
	Moisture / Condensation	- Check for air leakage, repair as noted above - Check for improper or poor insulation
	Change in gas chemistry	- Check for air leakage, repair as noted above - Check for reduced gas temperature - Check for change in operating conditions, fuels
Stack puffing (re-entrainment)	Improper or poor rapping	- Verify rapper / vibrator systems operating - Inspect for binding or broken rapper shafts - Inspect for bound collecting plates - Adjust control rapping schedule & intensity
Heavy dust buildup	Gas flow distribution	- Check for damage to inlet and outlet nozzles, baffles, louvers and perforated plates - Modify turning vanes or baffles
Control tripping	Grounding	- Clean insulators of all dust & condensation to prevent tracking - Check insulators for cracking - Check plate & electrodes for clearances & straightness - Check for broken wires - Check hopper level