高温固体浸漬冷却中の急速冷却開始条件

急速冷却開始に及ぼす被膜の影響

抄録

When a high temperature sphere covered with a poor conductive material is cooled by liquid, the temperature as the quench temperature which causes quenching rapid cooling of the material significantly shifts to a higher temperature by an effect of the poor material. We recently proposed a new idea[1] whether a stable phase change immediately after the contact of liquid and solid can be maintained continuously on a contact surface between liquid and solid or not. According to this idea, its condition strong depends on a corresponding critical heat flux which can be transferred from the solid to the liquid and a critical time when its phase change takes place after the solid-liquid contact. In the present study, the governing equation for among the sphere and the poor materials and cooling firstly is proposed and then its exact solutions is derived for each one. The effect of the poor material how it controls the heat flow to the liquid can be clearly explained and also the reason that the temperature at the occurrence of rapid cooling shifts to higher temperature is understood. It reveals that the critical time for the sphere covered with the Teflon becomes longer than that for bare one.