How does the Wet Electrostatic Precipitator collect fine particles through the action of electric field?
Publish Time: 2024-11-06
The Wet Electrostatic Precipitator collects fine particles through the action of electric field. Its working principle involves multiple physical processes such as electric field, charge transfer and droplet capture.
1. Electric field formation
The basic structure of the Wet Electrostatic Precipitator includes two main parts: a high-voltage power supply and a dust removal unit. The high-voltage power supply is usually a DC power supply with a voltage range of 25,000 volts to 100,000 volts. The dust removal unit consists of many parallel dust collecting plates (dust collecting electrodes) and discharge electrodes (corona electrodes).
2. Corona discharge
When the electric field is formed, the discharge electrode (usually a sharp wire or needle-like structure) will produce corona discharge under the action of high voltage. Corona discharge is the process of ionization of the air around the electrode, decomposing air molecules into positively charged ions (positive ions) and negatively charged electrons (negative ions).
3. Particle charge transfer
In the corona discharge area, charged ions collide with particles in the flue gas, causing the particles to be charged. There are two types of charged particles:
Positively charged particles: These particles are positively charged and will be attracted to the negatively charged dust collecting plate.
Negatively charged particles: These particles are negatively charged and will be attracted to the positively charged dust collecting plate.
4. Particle capture
The charged particles move toward the dust collecting plate under the action of the electric field force. The surface of the dust collecting plate is usually coated with a water film or a water spray device to form a liquid surface. When the charged particles contact the water film on the surface of the dust collecting plate, they will be captured by the water film and adhere to it.
5. Liquid film removal
The water film on the surface of the dust collecting plate will continue to flow or be sprayed, and the captured particles will be carried away with the water flow and eventually discharged through the drainage system. This process ensures the cleanliness of the dust collecting plate and the continuous and efficient dust removal ability.
6. Water mist assisted capture
In the Wet Electrostatic Precipitator, water mist also plays an auxiliary role in capture. The spraying of water mist can increase the probability of collision between particles and water droplets, so that smaller particles can be effectively captured. In addition, water mist can also reduce dust accumulation on the electrode surface and improve the efficiency of the electric field.
7. Efficiency improvement
The efficiency of the Wet Electrostatic Precipitator is relatively high, mainly because:
High electric field strength and high charge transfer efficiency: high voltage electric field can effectively ionize air and particles.
Liquid capture mechanism: Liquid can effectively capture and remove charged particles.
Liquid film self-cleaning: The continuously flowing water film can prevent dust accumulation on the surface of the dust collecting plate and maintain efficient dust removal ability.
The Wet Electrostatic Precipitator achieves efficient collection of fine particles through processes such as electric field formation, corona discharge, particle charge transfer, liquid capture and liquid film removal. Its high efficiency is mainly reflected in the combined effect of electric field strength, charge transfer efficiency and liquid capture mechanism. Wet Electrostatic Precipitator is widely used in coal-fired power plants, steel plants, cement plants and other industrial fields that need to handle a large amount of fine particles.
