Influence of the interfacial tension on the droplet formation by bubble rupture in Sn(Te) and salt system

Using a molten chloride and Sn system, in-situ observation of the bubble rupture and metal droplet formation can be carried out because the molten chloride phase is transparent. The size distribution of droplets with diameters in the range of 0.1 to 1.0 mm is measured using a high resolution camera, and the influence of the interfacial tension is discussed. The following results were obtained: (1) The addition of Te to the Sn decreased the interfacial tension and increased the number of small droplets, while the total surface area and total volume of droplets in the chloride bath decreased; (2) As the gas flow rate increased, the number of droplets in the Sn system formed by Mode B, where the metal emulsion was generated by the disintegration of the metal column, increased and large droplets were observed. In the Sn-Te system, even at the highest gas flow rate, droplets formed by Mode A, where the metal droplets formed by the rupture of the metal film, were observed in addition to those formed by Mode B; (3) In the Sn system, the size of the bubbles produced in Mode B was larger than that for Mode A. In the Sn-Te system the bubble size was generally smaller than that in the Sn system; (4) The total volume of the droplets formed by a bubble increased with increasing bubble size. In particular, the bubble rupture in Mode B generated a greater volume of droplets than in Mode A, even though the bubble size was the same.