Principles of Electrostatic precipitators
Electrostatic precipitation is a method of dust collection that uses electrostatic forces, and consists of discharge wires and collecting plates. A high voltage is applied to the discharge wires to form an electrical field between the wires and the collecting plates, and also ionizes the gas around the discharge wires to supply ions. When gas that contains an aerosol (dust, mist) flows between the collecting plates and the discharge wires, the aerosol particles in the gas are charged by the ions. The Coulomb force caused by the electric field causes the charged particles to be collected on the collecting plates, and the gas is purified. This is the principle of electrostatic precipitation, and Electrostatic precipitator apply this principle on an industrial scale. The particles collected on the collecting plates are removed by methods such as (1) dislodging by rapping the collecting plates, (2) scraping off with a brush, or (3) washing off with water, and removing from a hopper. When the dust is a dry solid, such as dust or fumes, and it is collected on a collecting plate in the dry state, the precipitator is referred to as “dry type”. Dry type Electrostatic precipitator can collect dust over a wide range of exhaust gas temperatures, ranging from room temperature to several hundred degrees C. Also, the collected dust or fumes are dry and easy to handle. The dust or fumes collected on the collecting plate of the dry type electrostatic precipitator is dislodged from the collecting plate and taken out from a hopper. Dust is normally removed from the plate through mechanical vibrations created by rapping the collecting plate. Our moving-electrode system uses a rotating brush to scrape off the collected dust.
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