Measures and methods to improve dust removal efficiency

fromElectrostatic precipitatorFrom the perspective of dust removal process, improving dust removal efficiency can be achieved in three stages. Phase 1: Starting from the entry of smoke and dust. In electrostatic precipitator, the capture of dust is related to its own parameters, such as the specific resistance, dielectric constant and density of the dust, gas flow rate, temperature and humidity, volt ampere characteristics of the electric field, and surface state of the dust collector electrode.

Add one level before the smoke enters the electrostatic precipitatordust collectorRemove some large particles and heavy dust. If cyclone dust removal is used, the smoke and dust pass through the cyclone separator at high speed, causing the dusty gas to spiral downwards along the axis, using centrifugal force to remove coarser particles of dust, effectively controlling the initial dust concentration entering the electric field.

Water film dust removal can also be used, and water mist is used to control the specific resistance and dielectric constant of dust, so that the flue gas has a stronger charging capacity after entering the dust collector. But it is necessary to control the amount of water used for dust removal to prevent condensation. Phase 2: Starting with smoke and dust treatment. By tapping into the dust removal potential of electrostatic precipitator itself, we focus on solving static problemsElectrostatic precipitatorThe defects and problems inherent in the dust removal process can effectively improve the dust removal efficiency. The main measures include the following. (1) Improve the uneven distribution of flue gas velocity and adjust the technical parameters of the airflow distribution device.

(2) Adjust the material of the electrode plate according to the chemical composition of the flue gas, in order to increase the corrosion resistance strength of the electrode plate, prevent electrode plate corrosion, and prevent short circuits.

(3) Adjust the vibration cycle and force of the electrode to increase corona power and reduce dust re flying.

(4) Increasing the capacity or dust collection area of the electrostatic precipitator, that is, adding an electric field, or raising or widening the electric field of the electrostatic precipitator

（5) Improve the sealing of the dust collection system to ensure that the air leakage rate of the dust collection system is less than 3%. Electric dust collectors are usually operated under negative pressure, so in usePay attention to sealing and reduce air leakage to ensure its working performance. Due to the entry of external air, there are three adverse consequences: ① Lowering the temperature of the gas inside the dust collector may lead to condensation, especially in the cold winter season, causing the above-mentioned condensation problems. ② Increasing the wind speed of the electric field shortens the residence time of dusty gases in the electric field, thereby reducing the dust collection efficiency. ③ If there is air leakage at the ash collection hopper and ash discharge outlet, the leaked air will directly blow up the settled dust and lift it into the airflow, causing serious secondary dust and reducing the dust collection efficiency.

(6) Pay attention to the insulation of the dust collection system and ensure the material and thickness of the insulation layer. The insulation layer outside the dust collector will directly affect the temperature of the dust collection gas, as the external environment containsOnce the temperature of the gas drops below the dew point due to the amount of moisture, condensation will occur. Due to condensation, dust adheres to the dust collector and corona electrode, and even vibration cannot effectively remove them. The amount of adhered dust reachesWhen the degree is reached, it will prevent the corona electrode from producing corona, thereby reducing the dust collection efficiency and preventing the electrostatic precipitator from working properly. In addition, condensation can cause corrosion of the electrode system, housing, and storage hopper of the dust collector, thereby shortening its service life.

(7) Adjust the control mode and power supply mode of the power supply equipment. The application of high-frequency (20-50kHz) high-voltage switching power supply provides a new technological approach for upgrading and improving the efficiency of electrostatic precipitators. The frequency of high-frequency high-voltage switching power supply (SIR) is 400-1000 times that of conventional transformer/rectifier (T/R). Conventional T/R power supplies often cannot output high power in situations where spark discharge is severe. The operation of multiple electrostatic precipitators shows that the output current of SIR is generally more than twice that of conventional T/R power sources, so the efficiency of electrostatic precipitators will be significantly improved.Price of electrostatic precipitatorWhen there is high specific resistance dust in the electric field causing back corona, the spark of the electric field will further increase, which will lead to a sharp decrease in output power, sometimes even dropping to tens of milliamps, seriously affecting the improvement of dust collection efficiency.

The situation with SIR is different, as its output voltage frequency is 500 times that of conventional power sources. When spark discharge occurs, its voltage fluctuation is very small, and it can produce almost smooth high-voltage DC output. Therefore, SIR can provide a larger current to the electric field.

Three stages: Starting from exhaust gas treatment. Three stage dust removal can also be added after electrostatic precipitator, such as using bag dust removal, which can be more effectiveTo remove some smaller particles of dust and improve the purification effect, in order to achieveThe purpose of emissions.