When the liquid is introduced into a vertical tube and heated to its boiling point

convective boiling occurs. If an inert gas is introduced at the bottom of the tube

it can be observed that the boiling vapor nuclei are not formed on the heating pipe wall and the evaporation of liquid takes place at the gas-liquid interphase instead. Such an operation is called Gas Carrying Evaporation(GCE). In this paper studied by visual observation and with an electric conductivity probe

the flow pattern transition was measured as a function of carrying gas flow rate

liquid rate and operating pressure and an empirical flow regime diagram was obtained. Moreover

the effects of various operating parameters on heat transfer in GCE were studied and the mechanism of the enhancement of heat transfer in GCE was analyzed. The following conclusions can be drawn from this study. In GCE

the heat transfer coefficient is higher than that obtained either in convective boiling or in gas-liquid two phase flow. It can be considered that there is a quick diffusion of liquid vapor at the initial instant with the result of lowering the gas-liquid interfacial temperature and enhancement of the heat transfer. The heat transfer in GCE may be considered as an overall effect of boiling

convective transfer and the enhancement by quick mass diffusion and can be correlated with dimensionless groups. The heating wall temperature will be lowered in GCE

so it can be applied to evaporation of heat-sensitive materials and to the evaporation of solutions which will form scales on the heating surface.