The working principle of the electrostatic precipitator […]
The working principle of the electrostatic precipitator is to use a high-voltage electric field to ionize the flue gas, and the dust charge in the gas stream is separated from the gas flow by the electric field. The negative electrode is made of a metal wire of different cross-sectional shape, called a discharge electrode.
The positive electrode is made of a metal plate of different geometric shapes, called a dust collecting electrode. The performance of electrostatic precipitators is affected by three factors: dust properties, equipment construction and flue gas flow rate. The specific resistance of dust is an indicator for evaluating conductivity, which has a direct impact on dust removal efficiency. The specific resistance is too low, and it is difficult for the dust particles to remain on the dust collecting electrode, causing it to return to the airflow. If the specific resistance is too high, the dust particles reaching the dust collecting electrode are not easily released, and a voltage gradient is formed between the dust layers to cause local breakdown and discharge. These conditions will cause the dust removal efficiency to drop.
The power supply of the electrostatic precipitator consists of a control box, a step-up transformer and a rectifier. The voltage level of the power supply also has a great influence on the dust removal efficiency. Therefore, the operating voltage of the electrostatic precipitator needs to be maintained at 40 to 75 kV or even 100 kV or more.
The electrostatic precipitator consists of two parts: one is the electrostatic precipitator body system; the other is a high-voltage DC power supply unit and a low-voltage automatic control system. The structural schematic diagram of the electrostatic precipitator is shown in Figure 1. The high-voltage power supply system supplies power to the step-up transformer, and the dust collector is grounded. The low-voltage control system is used to control the temperature of the electromagnetic vibratory hammer, the ash discharge electrode, the ash electrode, and several components.