The analysis of a three-phase direct contact heat transfer experiment

This study reports the analysis of the data obtained in a three-phase direct contact heat transfer experimental study. Regression analysis of the data indicates that the sensible heat of the heat transfer fluid and the mass flow ratio of the heat transfer fluid to the dispersed fluid combine to represent a good predictor of the amount of dispersed fluid boiling in the direct contact heat exchanger. However, very precise estimates of boiling require knowledge of dispersed phase holdup and gas void fraction in the column. The analysis appears to indicate that increases in dispersed phase holdup and gas void fraction have an adverse effect on the boiling efficiency of the direct contact heat exchanger.

Volumetric and surface area heat transfer coefficients based on all the boiling taking place in only the top one inch of the 36 inch column are reported. The volumetric heat transfer coefficients favorably agree with the coefficients obtained in a previous spray column study. The mean of the surface area heat transfer coefficients closely agrees with the heat transfer correlations derived for a theoretical model of the two-phase bubble in which the vapor resides at the interface between the two immiscible liquids. Finally, the flat temperature profile in the experimental study is discussed in a degrees of freedom analysis of the three-phase direct contact heat exchanger.