ELECTROSPRAYING OF CONDUCTING LIQUIDS FOR MONODISPERSE AEROSOL GENERATION IN THE 4 NM TO 1.8 MU-M DIAMETER RANGE

An electrospraying system operated in the cone-jet mode is shown to produce monodisperse droplets in a wide size range and with good monodispersity. These highly charged droplets are rapidly discharged in a radioactive neutralizer. The produced droplet size can be further reduced by the evaporation process without experiencing the Rayleigh breakup. The experiment is performed using sucrose solutions and the liquid electrical conductivity is controlled by adding small amounts of nitric acid. The size distribution is quite monodisperse having a geometrical standard deviation of 1.1. The mean droplet size produced can be varied from 40 Nn to 1.8 mu m by changing the liquid feed rate and electrical conductivity. Using 0.1% sucrose concentration solution, the residue particle size is reduced by a factor of ten, in the range from 4 nm to 0.18 mu m. The parameters affecting the particle size distribution, the measured spraying current, and the operating envelope have also been obtained and quantified.