Electrostatic atomisation of liquids

The electrostatic spraying of liquids is based on electrostatic forces that result from an electrical field and are capable to overcome the capillary forces. In contrast to gravitational and centrifugal fields the value as well as the direction of electrostatic fields depend not only on the setup geometry but additionally on the shape of the liquid surface, This results in a complex interaction between geometries, material properties, and mass and charge currents with respect to the formation of droplets, A capillary tip facing a wide flat counterelectrode has to be considered as the basic geometry. The electrical field needed for droplet production is maintained by a high voltage supply. One has to distinguish between droplet production solely by charge induction and droplet formation influenced by a corona discharge together with an electric wind. Characteristic time constants serve to differentiate between the different spraying modes.