Evaporation of a highly superheated liquid

• Approximation of a vapor flux density was made by analogy with compaction jump theory.
• A continual model of evaporation gives a result that coincides with kinetic theory.
• A criterion of choice of the main reason limiting the evaporation rate was obtained.
• A continual model is suitable for calculating intensive evaporation.

Methods of calculating processes of intensive evaporation in conditions where the vapor flux density j is limited by the evaporation kinetics and the heat supply have been considered. A convenient approximation of the superheat dependence of j based on the continual theory of a pressure jump stopped by a counter flow at the interface has been obtained. It has been found that a pressure jump may be assumed to be isoentropic with a sufficient accuracy, which simplifies the calculations considerably. It is shown that calculations of the process of intensive evaporation by a continual model, without invoking molecular kinetics, practically coincide with calculations by the kinetic evaporation theory. A simple criterion of transition from the regime limited by the evaporation kinetics to that limited by the heat supply has been suggested from conjugation at the interface of heat and mass flows.