Emulsion Atom Research Articles

回転円板による高粘性エマルションの微粒化

The drop formation of emulsions by spinning disks in the ligament mode was experimentally studied for the determination of any difference between the at-omization of emulsions and that of homogeneous liquids. Kerosene/water, water/kerosene and water/ (kerosene+liquid paraffin) emulsions were used. Almost all of them were non-Newtonian fluids and their viscosities were characterized using a power law relationship.To compare the atomization data of emulsions with those of homogenous liquids, the drop formation of aqueous CMC solutions and aqueous glycerol solution containing surfactants were examined. Photographic observations indicated that the atomization of both the O/W and W/O emulsions is similar to that for normal liquid, although ligaments are stably formed even at low flow rates. To apply the stability analysis of a laminar jet to atomiza-tion of emulsions, the apparent viscosity at the disk edge and the dynamic surface tension were used. It was observed that ligament numbers depend on the flow rate, and there is a bend in the relation between the ligament number and the flow rate. The ligament numbers of emulsions are in good agreement with those for normal liquids in the flow rates above this bend. The diametrs of drops formed from ligaments of both the O/W and W/O emul-sions agree with the prediction based on the stability analysis. The drop sizes of emulsions are also in good agreement with the correlation based on the atomization data of normal li-quids, even if the fraction of dispersed phase is rather high. For the non-Newtonian CMC solutions, on the contrary, the drop sizes are larger than that predicted by more than 40%.