Nozzleless EHD Spraying for Fine Droplet Production in Liquid-in-Liquid System

Electrostatic atomization technology is useful for producing fine droplets with narrow size distribution. However, the droplet production rate has been very low, compared with other methods such as solid injection, pneumatic, and rotating. In a liquid-in-liquid system, nozzleless droplet formation was proposed using membrane filter and applying electrostatics. The atomization pattern was categorized into three modes, i.e., dripping, transient, and spray modes. Water glass aqueous solution was atomized in kerosene from 300 μm to 200 nm by applying 0-2 kV positive dc voltages. Comparing between a single nozzle and the proposed nozzleless system, based on the similar average diameters and size distributions, the production rate of the droplets was 53 times (in the dripping mode) and 6.4 times (in the spray mode) higher in the case of a nozzleless system than that of a single nozzle.