Abstract
Formation of uniformly sized droplets in an electric field was investigated experimentally for Newtonian liquids in air. The field was made of a metal nozzle to which a positive DC voltage was applied and an earthed copper plate. Formation of the droplets was carried out in the range of the flow rate of dispersed phase prior to formation of a liquid jet. It was found that the size of fine charged droplets from the nozzle depended significantly on applied voltage and electrical relaxation time of the liquids. The mechanism of droplet formation and the specific charge of the droplets were discussed.
An empirical correlation for the size of the monodispersed droplets is proposed and is useful for Newtonian liquids with a wide range of physical properties; electrical conductivity, permittivity and viscosity. Also, the minimum voltage required for the formation of monodispersed droplets is proposed.
