1 reply to this topic

[garych]

Hi, I was asked to find the latent heat for a mixture of components (assuming to be at the bottom of the column) based on graph (Figure A.1) in Annex A, API 521.

 

From the graph, we can see the temperature axis, vapour pressure axis and also the molecular weight axis.

Do we have to know all the three properties above to get the latent heat value?

 

i am somehow confused that,

- What does that equilibrium temperature indicates? And how to calculate it?

- Vapour pressure of the main component? or multicomponents?

- Molecular weight as of the mixture components. right?

 

Kindly enlighten me on this. Thank you.

[serra]

in my copy (API 521 Jan 2007) it is limited to pure fluids (parafins),

to use the graph you need to know vapor pressure (at given temperature),

for example for isobutane at 690 Kpa.a 50.31 C

the graph returns about 140 Btu/Lb ,

to compare, the value calculated with software (Prode) is 124 Btu/Lb

 

perhaps you have a different edition...

Edited by serra, 09 September 2014 - 02:37 AM.