US Patent 7160391 Electrostatic nozzle apparatus

A nozzle spray head is provided for use in a dynamic electrostatic air filter, in which the nozzle spray head assembly exhibits multiple nozzle orifices as outlet ports, which extend from the bottom of the nozzle body such that the distances between the outlet ports and a target member are not constant. The charged multiple outlet ports exhibit a more uniform electric field at their tips, thereby enabling a better and more uniform spray pattern to be emitted by each of the individual outlet ports. In one embodiment, the outlet ports are grouped in concentric circles, in which the innermost circle comprises outlet ports of the greatest lengths, and the outermost circle comprises outlet ports of the smallest lengths.