When the gas containing dust particles in electrostatic dust precipitators passes through the high-voltage electric field formed between the cathode wire (also known as the corona electrode) connected to the high-voltage DC power supply and the grounded anode plate, corona discharge occurs due to the cathode, and the gas is ionized. The negatively charged gas ions move toward the positive plate under the action of the electric field force, and collide with the dust particles during the movement, so that the dust particles are negatively charged, and the charged dust particles also move toward the anode under the action of the electric field force. After reaching the anode, the carried electrons are released, the dust particles are deposited on the anode plate, and the purified gas is discharged out of the dust protector.
According to the airflow direction, electrostatic dust precipitators are divided into vertical and horizontal types. According to the type of precipitation electrode, they are divided into plate type and tube type. According to the method of removing dust on the precipitation electrode, they are divided into dry type and wet type. They are mainly used in the steel industry and coal-fired power plants. Electrostatic dust precipitators in the steel industry are used to purify waste gas from sintering machines, iron furnaces, cast iron cupolas, and coke ovens; coal-fired power plants mainly use fly ash electrostatic precipitators; and the application of dust precipitators in the cement industry is also quite common. The rotary kilns and dryers of newly built large and medium-sized cement plants are mostly equipped with electrostatic precipitators. Dust sources such as cement mills and coal mills can be controlled by electrostatic precipitators. Electrostatic dust precipitators are also widely used in acid mist recovery in the chemical industry, flue gas treatment in the non-ferrous metallurgy industry, and the recovery of precious metal particles.
Electrostatic dust precipitators use high-voltage electric fields to ionize the flue gas, and the dust in the airflow is separated from the airflow under the action of the electric field. The negative electrode is made of metal wires with different cross-sectional shapes, called discharge electrodes. The positive electrode is made of metal plates with different geometric shapes, called the dust collecting electrode.