Evaporation of water liquid in very hot air (above water critical temperature)

[niels8]

I am studying the evaporation process of water liquid droplet situated in very high gas temperature, and trying to calculate the wet bulb temperature where the liquid will evaporate.
At more common condition of temperature below the critical temperature, the wet bulb temperature is calculated based on the difference in water vapor pressure on liquid surface to that in the surrounding hot air. However, if the air temperature is higher than that, the water (in the continuous phase) is no more vapour but gas (cannot be compressed into liquid), thus the concept of "vapour pressure" does not exist.
How can we measure the droplet evaporation (wet bulb) temperature in such condition?

 

[moltenmetal]

If you're above the temperature where a water phase exists, there is no condensation possible. The highest "wet bulb" temperature achievable is therefore the critical temperature of water, the point at which the "vapour pressure" becomes undefined.

But unless the PRESSURE is also above the critical pressure, the condensation temperature of a water/noncondensibles mixture is always the temperature at which the vapour pressure of water equals the PARTIAL PRESSURE of water vapour in the mixture.