Heat and mass transfer characteristics of air bubbles and hot water by direct contact

This paper has dealt with direct contact heat and mass transfer characteristics of air bubbles in a hot water layer. The experiments were carried out by bubbling air in the hot water layer under some experimental conditions of air flow rate, inlet air temperature and humidity as a dispersion fluid, and hot water temperature and hot water layer depth as a continuous fluid. Heat transfer and evaporation of water vapor from hot water to air bubbles occurred during air bubbles ascending into the hot water. Air bubble flow patterns were classified into three regions of independent air bubble flow, transition and air bubble combination growth. Non-dimensional correlation equations of direct contact heat and mass transfer between air bubbles and hot water were derived by some non-dimensional parameters for three regions of bubble flow pattern.