1987 Volume 13 Issue 5 Pages 678-684
The governing equations for the growth of a vapor bubble of solvent in a uniformly superheated solution containing a non-volatile solute has been formulated by taking into account the combined effects of heat and mass diffusions in the region of solution.
Numerical solutions of the governing equations obtained by means of a finite difference procedure are illustrated for specific examples of bubble growth rates in the superheated aqueous solutions of NaCl, covering the ranges of bulk temperatures of solution from 40 to 80°C, superheats from 5 to 20°C and mass fractions of solute from 0 to 0.20.
It is found that the superheat defined by the temperature difference between the bulk temperature of solution and the equilibrium temperature of solution corresponding to the ambient pressure dominates the rate of bubble growth at a given bulk temperature of solution.
Quantitative comparisons are also made to determine the effects of both the concentration of solute at the bubble wall due to the evaporation of solvent and the superheat of generated vapor due to the boiling point elevation by non-volatile solute on the numerical solutions.
