Drying of salt solutions leads to the accumulation of salt at any surface where evaporation occurs. When this drying occurs within porous media, the precipitation of salts or efflorescence is generally to be avoided. A one-dimensional model for the drying processes in initially saturated porous materials was presented by Huinink et al. [Phys. Fluids 14, 1389 (2002)] and analytical results were obtained for short times when the concentration distribution evolves diffusively. Here, we present analytical results for intermediate times when convective and diffusive fluxes balance. Moreover, the approach is extended to symmetrical geometries and is generalized for porous objects with arbitrary shape, which highlights the role of the surface area to volume ratio. Estimates for the Peclet number dependence of the maximum salt concentration at the surface are obtained and the conditions that allows to avoid efflorescence are characterized.
All Science Journal Classification (ASJC) codes
- Computational Mechanics
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Fluid Flow and Transfer Processes