3 replies to this topic

[kalovon]

Hi.
I'm looking for a general equation to calculate the vaporization rate.
I found this on the internet:

Vr = (σ * ps * Na) / ( 2 π * M * R * T)^0,5 =

σ …..condensationcoeffiecient
ps ….Saturation vapor pressure(Pa)
M....molecular weight
Na....Avogadros number
R....ideal gas constant
T...temperature

Does anybody know if this works? Or where I can find information about this topic?
(Hope I translated the variables right).
Thanks.

[Art Montemayor]

You should never pick up any thing you don't know any thing about or who formulated it and for what reason. You simply don't know nothing about it and it is worth exactly that - nothing.

How can you expect to get a RATE out of an equation that doesn't even mention TIME? Your expectation is like expecting to calculate the velocity of a car with an equation that involves the name of the driver, the make of the car, the kind of gasoline, and the license number. None of these parameters yield distance, time, and direction.

Additionally, you don't even tell us the URL, the webpage, or the originator of the equation, or the units of the rate. Are they tons/milisecond, kg/yr, lbs/week, etc.?

[kalovon]

yeah, youre right. thanks.

[chenblue]

What is ur system? pure solvent? binary? For the pure liquid, u can use Fick's law to calculate the mass transfer rate in air, and that is also 'vaporization rate'. But for binary system, that would be a bit difficult. But if u are interested in it, I can give u some documents.