Discharge electrodes are the high-voltage heart of every electrostatic precipitator, generating a corona discharge that electrically charges dust particles for collection. LIMING supplies all major types — spiral wire, barbed wire, rigid mast, and star wire — engineered for stable corona discharge and long-term reliability in cement plant ESPs.
In an electrostatic precipitator (ESP), the discharge electrode (also called the emitting electrode or corona electrode) is connected to a high-voltage DC power supply (typically 30-100 kV). When energized, the electrode generates a corona discharge — a region of ionized gas around its surface where electrons are emitted. As dust-laden gas passes through the ESP, the dust particles collide with these ions and become electrically charged.
Charged particles are then attracted to the oppositely-charged collecting electrodes (plates), where they accumulate and are periodically removed by rapping. The efficiency of the entire ESP depends fundamentally on the quality of the corona discharge: it must be uniform, stable at the operating voltage, and produce sufficient ion current to charge all particles entering the ESP.
Different discharge electrode designs are optimized for different applications. LIMING manufactures all major types, and our engineering team can recommend the optimal electrode configuration for your ESP based on gas characteristics, dust properties (resistivity, particle size), and collection efficiency targets.
| Type | Design | Corona Characteristics | Best Application |
|---|---|---|---|
| Spiral Wire | Round wire formed into a spiral/helix shape, creating multiple corona points along the spiral edges | Uniform corona along entire length; good at low-moderate voltages | Cement kiln ESP (moderate resistivity dust), general industrial ESP |
| Barbed Wire | Round wire with sharp barbs/pins attached at regular intervals; barbs concentrate corona at points | High current density at barb tips; excellent for high-resistivity dust | High-resistivity dust (cement kiln raw meal), cold-side ESP |
| Rigid Mast (Rigid Discharge) | Rigid structural mast with attached corona-generating elements (pins, stars, or spikes) | Very stable, no sway or vibration; excellent alignment | Large modern ESPs, high gas velocity, hot gas ESP |
| Star Wire | Solid wire with a star-shaped cross-section; corona from sharp edge points along entire length | Consistent corona along the four edges; mechanically robust | General cement ESP, coal mill ESP, moderate dust loads |
Discharge electrode material selection depends on the gas temperature, chemical composition (especially SO2/SO3 content), and dust properties:
Quality electrodes engineered for stable corona and long service life in cement plant ESPs.
Precision-manufactured electrodes with consistent corona point geometry ensure uniform and stable current distribution across the ESP field.
Stainless steel (304/316L) options for cement kiln ESPs operating below acid dew point or with high sulfur fuels.
Rigid discharge electrodes with factory-straightened masts ensure perfect centering between collecting plates for spark-free operation.
Electrodes supplied as complete kits with hangers, weights (for wire types), and all attachment hardware — ready for installation.
| Parameter | Spiral Wire | Barbed Wire | Rigid Mast | Star Wire |
|---|---|---|---|---|
| Wire/Mast Diameter | 2.5-4.0 mm | 2.5-4.0 mm (wire) | 25-50 mm (mast tube) | 4-6 mm (across flats) |
| Electrode Length | Up to 15 m | Up to 15 m | Up to 15 m | Up to 12 m |
| Material Options | CS, SS304, SS316L | CS, SS304, SS316L | CS, SS304, SS316L | CS, SS304, SS316L |
| Corona Voltage | 30-50 kV | 40-80 kV | 40-100 kV | 30-60 kV |
| Current Density | 0.2-0.4 mA/m | 0.3-0.8 mA/m | 0.3-0.8 mA/m | 0.2-0.5 mA/m |
| Alignment Precision | Moderate (needs tensioning) | Moderate (needs tensioning) | Excellent (rigid frame) | Good |
| Weight System | Bottom weight required | Bottom weight required | None (self-supporting) | Bottom weight required |
| Gas Temperature Limit | Up to 400°C | Up to 400°C | Up to 450°C | Up to 400°C |