2003 年 44 巻 5 号 p. 877-884
The melting process of a Zn ingot in the continuous hot dip plating bath was investigated using an ice prism simulated with Nu number and a transparent cold model vessel with a reduced scale of one-tenth. The ice prism was used as a model for the Zn ingot. The Nusselt number similitude was selected to determine the size of the ice prism. The melting process of the ice prism fixed in the entry region was observed with a high-speed video camera. The local heat transfer coefficient around the ice prism was calculated from the local melting rate of the prism. The mean flow velocity and the root-mean-square (r.m.s.) value of the turbulence component of water flow approaching the ice prism were measured with a hot-wire anemometer. The mean heat transfer coefficient calculated by averaging the local heat transfer coefficients over the entire surface of the ice prism was hardly dependent on the turbulence intensity under the Reynolds number range considered. The turbulence intensity was defined as the ratio of the r.m.s. value of the turbulence component to the mean flow velocity.
