Manabu Yamaguchi

Aggregation and coalescence of water droplets in a dielectric liquid phase in an electric field

When water‐in‐oil emulsions are placed in electric fields, the droplets line up into a lengthwise extended chain in the direction of the field, and then coalescence between the droplets proceeds. The process of the chain formation is studied theoretically and experimentally. Behavior for electrical coalescence of the droplets is discussed by using a model proposed by Harada.

Drop Formation from Impeller with Static Mixers.

円板にスタティックミキサーを取り付けた新規な撹拌翼からの液滴生成機構およびその挙動を実験的に調べた.液滴生成機構は翼回転数によってミキサー流路端での単一液滴あるいは液柱の分裂による滴生成からミキサー流路内生成へと変化した.生成液滴径分布は翼回転数によってunimodal形状からbimodal形状を経て小液滴のunimodal形状へと変化した.高回転数域では生成液滴の体面積平均径は翼径および回転数基準のウェーバー数の-0.59乗で相関された.

Formation of Single Charged Drops from a Laminar Liquid Jet in Electric Fields

Formation of single charged drops from a laminar liquid jet in a continuous liquid phase in various electric fields is studied theoretically and experimentally. Relations between growth rate of the interfacial wave of the jet and its wave number in the electric fields are derived from the Lagrangian equation of motion for the jet. The effects of the electric fields on the dynamic characteristics of the jet are analyzed numerically. The liquid-liquid systems used in experiments are water-cyclohexane, -hexane and -silicone oil. The jet length, jet radius and drop diameter decrease with the voltage. The experimental drop diameters agree well with those calculated by using maximum growth rate of the wave and the wave number for all the systems used.

Hydrodynamic and Mass Transfer Characteristics of a Spray Column with Vertical Parallel Plate Electrodes

ABSTRACT A spray liquid-liquid extractor with vertical plate electrodes was devised. The population behavior of dispersed drops in a d.c. electric field was studied on dispersed phase holdup, drop velocity and drop size distribution and axial mixing of continuous phase by using the system of water drops in cyclohexane. Mass transfer efficiency of iodine from the dispersed phase into the continuous phase was also measured. The axial mixing and the mass transfer were effectively improved with the applied voltage. Simulation of the present column efficiency was carried out by using a modified dispersion model.

Gas absorption by single charged drops during their formation in a uniform electric field

Abstract A new technique for measuring gas absorption rates during the formation of liquid drops was devised. By the technique, the amount of carbon dioxide absorbed during the formation of single charged drops was measured in the presence of a uniform electric field. Also the relationships between the surface area of the drop, its volume, and the time for one cycle of the growth of the drop were obtained using a TV system. The mass transfer rates are discussed by taking account of the surface area of the drop being formed in the electric field. It is clarified that the mechanism of gas absorption during drop formation is explained satisfactorily by the surface-stretch penetration model of Angelo et al., not only for uncharged drops but also for charged drops formed in the electric field.