What is the service life of an electrostatic precipitator's discharge electrode (also known as cathode wire or corona wire)?
Simply put, a discharge electrode that is well-designed, made of appropriate materials, and operates under normal conditions typically has a design life aligned with the major overhaul cycle of the entire electrostatic precipitator, generally ranging from 8 to 15 years, or even longer. However, in practical applications, its actual service life can vary significantly due to factors such as flue gas properties, the material and type of the discharge electrode, and operating conditions.
How to Select the Material for Discharge Electrodes?
Before selecting the material, the following characteristics of the flue gas must be thoroughly analyzed:1. Temperature and Humidity: Could condensation form on the material surface? 2. Concentration of Acidic Components: What are the concentrations of SOₓ (sulfur oxides), NOₓ (nitrogen oxides), HCl (hydrochloric acid), and HF (hydrofluoric acid)? 3. Other Corrosive Substances: Are alkaline substances, chloride ions (Cl⁻), etc., present? 1. Start with comprehensive flue gas analysis 2. Assess the overall corrosivity level 3. Branch into appropriate material selection paths: · Weak corrosion: Economical carbon steel · Medium corrosion: Stainless steels (304 vs 316/L based on chloride content) · Strong corrosion: Premium high-nickel alloys 4. Converge to final material selection
Can a bent collecting electrode continue to be used?
Once a collecting electrode (anode plate) becomes bent, it is generally not recommended to continue using it. The unit must be immediately shut down for inspection and repair. A bent electrode will not only severely impact the performance of the electrostatic precipitator but may also cause chain-reaction failures and even lead to safety incidents.
How to handle bent collecting electrodes?
The correct handling procedure is as follows: Shutdown→ Inspection → Decide between straightening or replacement based on the severity of bending → Comprehensive inspection and verification → Resume operation.
Can insulators continue to be used after damage?
It is absolutely not recommended to continue usage. Once insulators are damaged, operations must be immediately stopped and the insulators replaced. Continued operation poses serious safety risks and performance issues, the consequences of which far outweigh the cost of shutdown maintenance. Insulators play two critical roles in electrostatic precipitators: "isolation" and "support". They isolate the high-voltage electricity (typically 40-72kV) from the grounded casing while physically supporting the heavy cathode frame (discharge electrode system).
How Should Damaged Insulators Be Properly Handled?
1. Immediate Shutdown: Cut off the high-voltage power supply to the affected electric field and implement a lockout-tagout procedure. 2. Inspection and Diagnosis: Remove the damaged insulator, identify its type and the nature of the damage, and determine the root cause (e.g., condensation, dust accumulation, mechanical stress from rapping, or failure of the heating system?). 3. Replacement with New Unit: Install a new insulator of the same model and specifications. 4. Eliminate the Root Cause: Clean the insulator compartment, inspect and repair the tracing/heating system, adjust the rapping mechanism, and ensure that the purge air system for the insulator compartment is functioning properly. 5. Test Run: After replacement, conduct a no-load power-on test first. Confirm that the electric field voltage and current have returned to normal levels before resuming formal operation.
