Method and apparatus for electrostatically charging and separating particles that are difficult to separate

1. A method for separating dust-particles from industrial waste gases, in which dust-particles are difficult to separate are removed from a gas fluid, wherein the dust-particles being successively ionized and separated within a high-voltage zone which comprises one or several individual ducts with the help of electrostatic charging and separation by means of only one high-voltage supply source for this high-voltage zone, and wherein the dust-particles being ionized and separated both in ionization zones as well as in separation zones of the individual ducts by connected negative electrodes which are connected to the only one high-voltage supply source, characterized in that the high-voltage zone comprises one or several individual ducts of even duct width, in which the dust-particles are successively ionized and separated, wherein the connected negative electrodes are connected with only one output of the one high-voltage supply source and wherein by suitable choice of the negative electrode geometry for the ionization zones and separation zones a substantially higher current flow is generated in the ionization zones than in the separation zones, so that in the ionizing zones a sufficient charging of the dust-particles is achieved which are then separated optimally in the following separation zones.

2. A method according to claim 1 , characterized in that the dust-particles are ionized and separated twice or several times successively within the individual ducts of the high-voltage zone in the manner of a series connection.

3. A method according to claim 1 , characterized in that the grounded electrodes of the ionization zone are cooled.

4. An electrically working filter for separating dust-particles from industrial waste gases for performing the method according to one of the claims 1 , 2 or 3 , comprising a high-voltage zone with individual ducts each of comprising ionization zone with downstream separation zones, for successively ionizing and separating the dust-particles within the high-voltage zone with the help of electrostatic charging and separation by means of connected negative electrodes which are connected to only one high-voltage supply source, characterized in that the filter comprises one or several high-voltage zones ( 11 ), with both the ionization zones ( 4 ) as well as the separation zones ( 5 ) each being provided with different negative electrodes ( 6 , 7 ) which are connected in a joined manner to only one output of the one high-voltage supply source ( 1 ) wherein by a suitable choice of the negative electrode geometry for the ionization zones ( 4 ) and separation zones ( 5 ) a substantially higher current flow is generated in the ionization zones ( 4 ) than in the separation zones ( 5 ), so that in the ionizing zones ( 4 ) a sufficient charging of the dust-particles is achieved which are then separated optimally in the following separation zones ( 5 ).

5. An apparatus according to claim 4 , characterized in that the geometries of the negative electrodes ( 6 , 7 ) for the ionization zones ( 4 ) and the separation zones ( 5 ) are provided with different configurations, with negative electrodes ( 6 ) in high-current-intensive corona discharge electrode forms being used for the ionization zones ( 4 ) and negative electrode ( 7 ) substantially low-current or voltage-intensive electrode forms ( 7 ) being used for the separation zones ( 5 ).

6. An apparatus according to claim 4 , characterized in that several ionization zones ( 4 , 4 a ) and separation zones ( 5 , 5 a ) are arranged in the direction of flow of the gas fluids behind one another in the individual ducts of the high-voltage zone ( 11 ).

7. An apparatus according to claim 4 , characterized in that the collecting electrodes ( 9 ) of the ionization zones ( 4 ) are provided with cooling chambers ( 10 ).