8 replies to this topic

[alex91ro]

Hello,

 

 

Is there any reliable correlation for estimating the viscosity of a blend? I read about Refutas, Kendal-Monroe, Chevron correlation and others but I have no idea which one give better results, I didn't find anything about a range of viscosities where they are efficient.

 

Thank you! 

 

(PS: I hope you can understand my bad English)

 

[Art Montemayor]

When trying to estimate a liquid's viscosity in the past I always arrived at the unfortunate conclusion that there is no reliable method to estimate the viscosity of a pure liquid.  Only very approximate empirical rules were available.  Perhaps this has improved markedly in recent times, but I doubt it.  From a good and detailed explanation on the subject as well as sample calculations and results, go to:  http://www.owlnet.ri.../proj02/beckys/

 

Additionally, you can read the material found in Wikipedia: https://en.wikipedia...ends_of_liquids

[alex91ro]

So the only solution is to make several blends and see what proportions give the desired viscosity?

[latexman]

That will work.

[gegio1960]

Alex, once acknowledged Art's valuable words I'd like to add my 2 cents of experience in the (limited) oil refining world.

Since you're asking about blending rules and their best ranges of application, you can use the following:

- refutas for residual fuel oils

- chevron correlation for ligher cuts (eg gasoils)

Good luck!

[Profe]

Hi Alex

For your question, use procedure API 11A4.5: Liquid viscosity blending of hydrocarbon mixtures.

[alex91ro]

gegio1960:

 

This equations are giving almost similar results, Chevron is always a little higher.  The problem is that Kendal-Monroe equation gives higher values of the mixture viscosity (2-3 x results of Refutas/Chevron) when there are big differences between the viscosities of the two liquids: Liquid 1 under 20 cst + Liquid 2 over 500 cst.  Which numbers are better?

 

 

@Profe

Do you have link? I can't find it.

 

 

Thank you all for your answers.

[gegio1960]

Alex, with reference to #7

- This equations are giving almost similar results   YES, THAT'S GOOD

- The problem is that Kendal-Monroe equation gives higher values    DON'T USE IT

[Profe]

Alex

 

Review a mesage that I send you about the  API procedure. Study it and review its aplication example

 

And attached I send an example of this method.

 

I Hope this will be useful.

 

Fausto.

Attached Files

•  Procedure API 11A4.5.xlsx   332.73KB   35 downloads