Measurement of the temperature of water solutions, emulsions, and slurries droplets using planar-laser-induced fluorescence

The paper presents the results of experimental research into the heating and evaporation of droplets of water and water-based solutions, emulsions, and slurries. The main focus is on the potential opportunities of gaining new insight into the temperature fields of evaporating droplets of solutions, emulsions, and slurries, using a promising optical technique, planar-laser-induced fluorescence (PLIF). An important aspect was to define the limitations of this technique when varying droplet dimensions, the concentration and properties of additives, as well as heating conditions. Such experiments were necessary to identify opportunities to develop a large group of applications (such as thermal and flame cleaning of liquids from unspecified impurities, the production of hydrogen and syngas by heating oil-water or coal-water slurries, firefighting, etc) in order to increase the efficiency by means of high values of heating rates, phase transformations, and chemical reactions. Such values can be achieved by implementing the processes under extreme conditions, which can only be studied using non-contact techniques, in particular, PLIF. (paper)