Electrostatic precipitator

Claim 2

The method according to claim 1 wherein said collection surface comprises first and second plates biased to opposite polarities and wherein first and second ion showers each having a polarity matching the polarity of the corresponding one of said plates are provided.

Claim 3

In a particle precipitator wherein particles entrained in a gas stream are subjected to a corona saturation charging field and thereafter to a passive precipitation field in a particle collection zone, the improvement characterized in that a particle pre-charging zone is established prior to the corona field to impart at least some minimal charge to substantially all particles entering the corona field, and in that local ion showers are provided over the aerodynamic surface boundary region of the collection surface of the particle collection zone.

Claim 4

Apparatus including a gas stream duct for electrostatically precipitating particles entrained in a gas stream comprising non-emitting particle pre-charging means position in said gas duct, corona field particle charge means positioned in said duct downstream of said pre-charging means, non-emitting collection field producing means positioned in said duct downstream of said corona field particle charging means and defining a particle collection region of said gas duct, and a plurality of emitting means positioned adjacent the surface boundary region of said particle collection region.

Claim 5

Apparatus according to claim 5 wherein said plurality of emitting means is biased to provide a confined electric wind turbulence in said surface boundary region of said particle collection region of said duct walls.

Claim 6

Apparatus according to claim 6 wherein said plurality of emitting means provides ion showers to said surface boundary region of said duct.

Claim 7

Apparatus according to claim 5 wherein said particle pre-charging means includes a plurality of closed Configuration electrodes porous to particle and gas flow.

Claim 8

Apparatus according to claim 5 further comprising gas stream channeling means inserted in said gas duct in the area thereof defined by said particle pre-charging and particle charging means for dividing said gas stream duct into a number of subducts each including one of said particle pre-charging means and one of said particle charging means, and means for individually biasing the particle pre-charging and particle charging means located within a continuous one of said subducts.

Claim 9

Apparatus according to claim 9 wherein said particle pre-charging means and said particle charging means contained within the same one of said subducts are each biased to the same electric polarity.

Claim 10

Apparatus for electrically precipitating particles entrained in a gas stream comprising a gas stream duct having an inlet and an outlet and conductive wall surfaces connected to a source of reference potential, particle pre-charging means disposed at the inlet of said duct and connected to a potential source for establishing a non-emitting electric field in the vicinity of said duct inlet, emitting electrode means disposed in said duct downstream of said particle pre-charging means for establishing an emitting electric field extending over a short axial length of said duct, said emitting electrode means defining a particle saturation charging region in said duct, central electrode means having a substantial particle collection surface area positioned in said duct downstream of said emitting electrode means, said central electrode being connected to a source of potential to establish a passive, non-emitting particle collection field extending over a substantial axial length of said duct, said particle collection field being directed from said central electrode to the adjacent conductive wall surfaces of said duct, and a plurality of emitting electrode means disposed throughout the length of said central electrode for providing ion showers over the aerodynamic boundary surface of said central electrode.

Claim 11

Apparatus according to claim 11 wherein said central electrode is connected to a source of potential of polarity opposite to that of the nearest of said emitting electrodes in said particle saturation charging region.

Claim 12

Apparatus according to claim 11 wherein the combination further comprises a second plurality of emitting electrode means disposed in said duct adjacent to said conductive wall surfaces thereof over an axial length thereof substantially equal to the axial length in said duct of said central electrode, said second plurality of emitting electrodes being connected to a source of potential for establishing ion showers over the aerodynamic boundary layer portion of the adjacent conductive wall surfaces of said duct.

Claim 13

Apparatus according to claim 13 further comprising channeling means inserted in said duct in the areas thereof defined by said particle pre-charging electrode and said particle saturation charging region for dividing said gas stream into a plurality of subducts, each of said subducts including a particle pre-charging electrode and at least one particle saturation charging electrode, wherein at least one of said subducts includes a particle pre-charging electrode connected to a source of potential of opposite polarity to that to which the particle pre-charging electrode of another of said subducts is connected.

Claim 14

Apparatus according to claim 14 wherein the particle pre-charging and particle saturation charging electrodes within the same subduct are connected to respective sources of potential having the same polarity.

Claim 15

Apparatus according to claim 13 wherein said first plurality of emitting electrodes is biased to provide ion showers of opposite polarity to that provided by said second plurality of ion showers.