Dielectric liquid-in-liquid dispersion by applying pulsed voltage
ABSTRACT Liquid-in-liquid dispersion, such as organic liquid in water or water in organic liquid, has been performed using dc or ac voltage applied between nozzle and ground electrode. In the present study, pulsed high voltage was applied to produce droplets with controlled diameter in wide range. The high voltage pulse source was capacitor discharge type with 20 - 50 Hz and ranged from 0 to several kV. Water glass was atomized in alcohol solution into diameters ranging from several mum to sub-mm, depending on applied voltage. The atomized water glass droplets were solidified by removing water molecules from the water glass. Synchronized droplet formation with pulse frequency was possible by controlling pulse voltage, width and frequency, which produced uniform sized droplets successively. When the pulse voltage was raised, the droplet formation mode changed from the synchronized formation to dispersion mode through transient mode. In the dispersion mode, droplets of several mum diameter having high uniformity were produced. Utilization of high voltage and high-speed pulse to liquid-liquid dispersion could make it possible to atomize in a conductive liquid without electrolysis.
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ABSTRACT: 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.IEEE Transactions on Industry Applications 01/2011; DOI:10.1109/TIA.2010.2074171 · 2.05 Impact Factor