Patent attributes
An electric dust collecting device according to the invention includes an electric charging unit for electrically charging dust in air, a first filter unit including a plurality of discharge electrode plates spaced apart from each other to define passages therebetween through which dust electrically charged by the electric charging unit passes, and a second filter unit disposed downstream of the plurality of discharge electrode plates in an air flow direction and connected to a ground to cause corona discharge between the plurality of discharge electrode plates and the second filter unit and to collect electrically charged dust. Dust particles electrically charged by the electric charging unit pass through the passages of the first filter unit and then are collected at the second filter unit, and dust particles electrically charged between the first filter unit and the second filter unit are electrically charged by the second filter unit, thus improving electric charging efficiency and dust collecting efficiency.