Direct-Contact Heat Transfer for Air Bubbling Through Water

Abstract

Experiments on direct-contact heat transfer of air injected through an orifice and bubbling through a constant temperature, stagnant, pool of water showed an increase in air temperature ranging from about 100 to 200 percent. The process follows a relationship which describes heat transfer in conventional, closed-type, heat exchangers where one fluid is maintained at a constant temperature. The data is correlated by a relationship for the Nusselt number which is based on an average overall heat transfer coefficient.