Direct contact heat transfer between immiscible liquid layers with simultaneous boiling and stirring

Abstract

Stratified flow-boiling in a stirred cell, in which two immiscible liquids of different density were in direct contact, has been studied. Heat transfer coefficients in a simultaneous boiling and stirred liquid were calculated from the coefficients determined independently for stirring and boiling alone. Based on a simplified hydrodynamic model, the integral boundary layer approach was used to predict the heat transfer coefficients in the two independently stirred liquids. Boiling transfer coefficients were experimentally determined. The combined coefficient for stirred pentane boiling over water is given by h 3 = h 3 stir + h 3 boil. Experimental verification and a discussion on the relative contribution of each factor in view of possible transport mechanisms are presented.