Thermal Interaction of Water Droplet with Molten Tin

Abstract

Thermal interaction which is caused by explosive boiling of water droplet in contact with hot molten tin was investigated, paying attention on the influences of the tin temperature T tin and the water temperature T water together with the impact Weber number We. The results were summarized as follows. (1) T tin of lower boundary of thermal interaction zone (TIZ) is almost constant at about 290°C for a larger We than about 70, independent of T water. (2) The corresponding contact interface temperature is around 275°C and almost agrees with (27/32) T crit, or the spontaneous nucleation temperature, where T crit = 647K (= 374°C). (3) T tin of upper TIZ boundary increases from around T crit to above 500°C as T water decreases. (4) T tin of upper TIZ boundary is about 80°C. (5) For the woodsmetalwater system, in spite of a very low melting point of 78°C, the woodsmetal temperature of lower TIZ boundary rises up to about 350°C because of a low thermal conductivity of woodsmetal. (6) The Leidenfrost temperature is about 195°C for water droplet on solid tin, which has a melting point of 232°C, and appreciably lower than T tin of lower TIZ boundary. In conclusion, the present results support the spontaneous nucleation temperature concept by Fauske & Henry, as far as extremely energetic thermal interaction is concerned.