Boiling of mixture of ammonia and water

[virk]

Hello!

I have a question concerning the boiling of an 30%-ammonia/water mixture at approx. 110°C and 12 bara.
I am trying to find appropriate equations for to describe the heat transfer coefficient relating to the actual concentration of the mixture. I think (expect) there is a large decreasement in relation to the pure components, because each bubble, which evaporates, reduces the local concentration of the mixture and by this the heat transfer coefficient.
I think this to be a "normal" more-component phenomenon at boiling situations, but i did not find applicable info.
Can somebody guide me to an appropriate site, where I can get more information. Or does perhaps somebody know, how to deal with this problem.

Kind regards (from old Europe

 

[srfish]

One way to calculate this type of boiling coefficient is to use a Mostinskii correlation. This type of equation accounts for the composition by using the critical pressure of the mixture. The trick is to calculate an accurate value of the critical pressure.