Understanding the dynamics of precipitation and crystallization as salt solutions evaporate from porous media is of importance in the context of preservation of historical monuments, understanding soil nutrient content, and design of porous evaporators for use in distillation plants. Transient advection-diffusion equations govern the salt mass fraction profile of the solution inside the porous medium. These governing equations are solved to obtain the solute mass fraction profile within the porous medium as well as the effloresced salt crust. Further accounting for precipitation allows a study of the formation and growth of efflorescence and subflorescence. Crystallization experiments are performed by allowing a NaCl solution to evaporate from a porous medium of copper particles and the subflorescence trends predicted by the model are validated. The modeling framework offers a comprehensive tool for predicting the spatio-temporal solute mass fraction profiles and subsequent precipitation in a porous medium.
Date of this Version
R. Roy, J.A. Weibel, and S. V. Garimella, Modeling the formation of efflorescence and subflorescence caused by salt solution evaporation from porous media, International Journal of Heat and Mass Transfer 189, p. 122645, 2022.