急冷却時の膜状沸騰*(第2報)
伝熱面の条件による影響
1952 年 16 巻 4 号 p. 104-100
詳細
1952 年 16 巻 4 号 p. 104-100
The authors intend to report in the present paper as to the early stage of rapid cooling, the film state boiling, due to quenching of high temperature body. the series of experiments were carried out keeping the conditions of coolants constant inspite of the various conditions of test body. Variety of the conditions was made by changing the initial temperature, surface smoothness and diameter of the test cylinder.
Arranging the data of the experiments, the authors came to the next conclusion.
(1) When the initial temperature was lowered, the coefficient α took the higher value because of the lowering of the durability and the thickness of vapor film.
(2) α can be improved by roughing the surface of test bar, but α may decrease if the grooves on the surface are so deep that the vapor film will not be quickly scraped away.
(3) A decisive result was not obtained for the effects of diameter of test bars on heat-transfer coefficients.
