A regime map for direct contact condensation

Direct-contact condensation is studied by injecting steam downward through a pipe and out of the submerged end into a pool of subcooled water. The motion of the steam/water interface is recorded by high-speed movies and systematically classified, based on the injection rate and the pool subcooling. The resulting regime map shows the existence of three main condensation modes as the injection rate is reduced: At a high rate of steam injection $\text{(>125}\text{kg/m}{}^2\text{s}\text{)}$ an oscillatory jet is observed. At a low rate of injection $\text{(<50}\text{kg/m}{}^2\text{s}\text{)}$ a phenomenon called “steam chugging,” in which the pool water periodically enters the injection pipe, is observed. At intermediate injection rates an oscillatory bubble exists continuously at the pipe exit.