The influence of impurities in droplets of slurries, emulsions and solutions on their evaporation rates

The results of experimental studies of the integral characteristics of the evaporation of water droplets with impurities are presented. The variable parameters are as follows: gas temperature (573–873 K), type of impurities (solid - aluminum oxide, titanium dioxide, clay, silt, sand, and table salt; liquid – transformer oil, alcohol), and mass concentration of impurities (0.5–5%). Ranges of changes in the mass evaporation rate of droplets of slurries, emulsions and solutions have been established depending on the thermophysical and rheological properties of droplets with impurities, in particular, on density, heat capacity, thermal conductivity, and thermal diffusivity. An approximation expression is obtained that illustrates in the dimensionless form the dependence of the droplet evaporation rate on thermal diffusivity. An approach to predicting the evaporation rate of droplets with known thermophysical and rheological characteristics of the compound is proposed.