Patent ID: 7252701

Claim:
A method of cleaning an electric filter during filtration, said method comprising the steps of: feeding gas containing particles to a chamber of the electric filter by feeding means, feeding the gas containing particles further to gas channels in an emission system provided in the chamber, the gas channels being formed between separation electrodes in the emission system provided in the chamber and including emission electrodes, effecting electric charging of the particles in the gas and the attachment thereof to the separation electrode, removing the gas that has been at least partly purified of particles from the gas channel of the emission system, removing the gas that has been at least partly purified of particles from the chamber of the electric filter through exhaust means, shaking the separation electrode with shaking means to remove the particles attached to the separation electrode therefrom, limiting the gas flow at least partly in such a gas channel that adjoins the separation electrode to be shaken by the shaking means when the separation electrode to be shaken by the shaking means is shaken whereby the shaking of the separator electrode with the shaking means is synchronized with the limiting of the gas flow such that the limiting of the gas flow occurs first followed thereafter by the shaking of the separation electrode, and in that the gas flow is limited by moving in a certain predetermined order a first perforated plate arranged in the gas channel and provided with first apertures in relation to a second perforated plate arranged in the same gas channel as the first perforated plate and provided with second apertures so that either the second perforated plate at least partly covers at least one of the first apertures provided in the first perforated plate and thus limits the gas flow through the first aperture or the first perforated plate at least partly covers at least one of the second apertures in the second perforated plate and thus limits the gas flow through the second aperture.