Direct contact condensation characteristics in cool water of steam jet with non-condensable gas in it were investigated experimentally in this paper. The jet plume length of the mixture gas was obtained by measuring temperature field

which was used later to get condensation heat transfer coefficient. Using a circular nozzle with a diameter of 1.6 mm

this experiment covered the range of mixture gas mass flux from 100 to 330 kg·m-2·s-1

non-condensable gas content from 0 to 15% and cool water temperature from 300 to 340 K. The results showed that the existence of non-condensable gas led the decrease of temperature more slowly near the nozzle exit and the increase of jet plume length with increasing content of non-condensable gas. The effect of the addition of non-condensable gas on mixture mass flux and water subcooling was the same as pure steam jet. The condensation heat transfer coefficient was found to be in the range of 0.7 and 2 MW·m-2·K-1

and it decreased with increasing subcooling and non-condensable gas content

while the mixture mass flux has a little effect on it. Finally

correlations predicting the jet plume length and the condensation heat transfer coefficient were obtained by fitting the experimental dates.