No abstract

Measurements have been made of local heat transfer coefficients to liquid-vapor mixtures flowing upwardinside vertical tubes at atmospheric pressure. Four tube sizes and six liquids were tested with a 10 to 1 range in feed rates. The heat transfer coefficient has been found to depend mainly on the vapor velocity when liquid-film (generally known as "climbing film") conditions have been established, For any one liquid the heat transfer in the liquid-film region is dependent solely on the vapor velocity and independent of the liquid feed rate. An equation has been derived which correlates our data and those of other authors for liquid-film conditions, irrespective of whether the film b e moving upward or downward in vertical tubes, or on the inside of a horizontal tube.N RECENT years, considerable attention has been paid to the