Abstract: A method for the neutralization of aerosol particles uses a bipolar ion atmosphere generated by a dielectric barrier discharge to achieve a symmetric charge distribution on the particles. The aerosol-laden sample air passes, with a defined velocity, through the central flow channel of a first electrode, an adjoining discharge chamber and a downstream equilibration chamber. The wall electrode and the discharge chamber are surrounded by a plasma-resistant dielectric. The dielectric is at least in the region of the discharge chamber surrounded by a ring-shaped excitation electrode. A pulsating high voltage applied to the excitation electrode causes a dielectric barrier discharge between wall electrode and dielectric in the largely field-free discharge chamber, which generates positive and negative ions. A rod-shaped control electrode generates a weak electric field.

Abstract: A method produces a bipolar ionic atmosphere using a dielectric barrier discharge, and to a device suitable for carrying out the method. The solution for achieving this aim is to trigger an electrical surface discharge at more or less regular intervals on the wall of a channel through which a gaseous medium flows. The flow channel is formed by a dielectric and a wall electrode such that the channel wall consists in the direction of flow alternately of a conductive electrode material and a dielectric. In principle it will suffice if the channel is formed of only one dielectric and one conductive section which adjoin each other. The electrical surface discharge is triggered by a second electrode which is separated by the dielectric from the wall electrode and the flow channel, and to which a temporally varying high voltage is applied by an impulse generator.