Superheated air

[envcook]

I have a process where humid air goes through a blower. The temperature rise across the blower makes the humid air superheated at the outlet. Does anyone have a method for calculating the density of the superheated air at the discharge of the blower? Humidity ratio at the blower inlet is known as well as temperature and pressure at the inlet and outlet.

 

[katmar]

The air we breathe is superheated because it is not in equilibrium with liquid air. Air, including moist air, at low pressure and high temperature can be regarded as an ideal gas for the calculation of the density.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[envcook]

This is superheated in the sense that the temperature is above the dew point and there is no new liquid water to evaporate. This is really a mixture of two gases at this point. Knowing the humidity ratio, I can calculate an average molecular weight for the mixture. The humidity ratio doesn't change through the blower. So I agree that the ideal gas law would give me a density using this average molecular weight. However, there are numerous correction factors listed for air water mixtures, none of which apply in this regime.