Hysys Tutorial of Packed bed Absorption Column

Hysys tutorial from Bijol Luis

Complete tutorial for designing the packed bed absorption column in Aspen Hysys. Flash calculation for designing of column is also given, the pressure and temperature standered are also described in detail. Fluid package selection, setting up the simulation environment, adsorption column input experts, solvent properties, running the simulation environment etc are described in expansion.

Success Mindset

Success mindset from Bijol Luis

Achieving your Dreams

Achieve your Dreams in 2013, Remember your
A to Z 

A: Avoid Negative sources, people, places, things and Habits

B: Believe in yourself

C: Consider Things from every angle

D: Don't Give up and don't give in

E: Enjoy Life today yesterday is gone, tomorrow may never come

F: Family and Friends are Hidden treasures, seek
them and enjoy the riches

G: Give more than you planned to

H: Hang on to your dreams

I: Ignore those who try to discourage you. 

J: Just DO IT!!!!!

K: Keep trying no matter how hard it seems - it will
get easier

L: Love yourself first and MOST

M: Make it Happen

N: Never Lie, Cheat or Steal; always strike a fair deal 

O: Open your eyes and see things as they really
are.

P: Practice makes PERFECT

Q: Quitters never win, and Winners never quit

R: Read Study and Learn About everything
important in your life 

S: Stop Procrastinating

T: Take control of your own DESTINY

U: Understand yourself to better understand others

V: Visualize it!

W: Want it more than anything

X: Xcellerate your efforts

Y: You are unique of all God's creations,nothing can replace you.

Z: Zero in on your target and go for it! 

"Give the world the BEST you have"
Live Life Light
Enjoy your Life Today because Yesterday has GONE and Tomorrow may never Come

Friction Factor

This topic has often caused a lot of confusion in many people while calculating pressure drop of fluids in pipe. Many people are even unaware of the presence of 2 types of friction factor, wherein one is 4 times the other.

Moody's friction factor (also known as the Darcy friction factor) and Fanning friction factor are the two types of friction factor used in this world for pressure drop calculations.

Relationship between the two: 

fd = Darcy friction factor
ff  = Fanning friction factor.

In text books you'll come across various pressure drop equations, the only difference lies in the type of friction factor used. Darcy / Moody friction factor is most widely used for pressure drop calculations, as they can be easily interpreted from moody's chart. Fanning friction factor charts are difficult to find.

To keep it simple and straight forward, note the following points and equations very carefully to avoid any confusion on this topic henceforth. 

Equations:


   1.  Darcy Friction Factor --- Laminar condition

    Pressure drop equation: 

2.  Fanning Friction Factor --- Laminar condition

 

    



    Pressure drop equation:

Moody's Chart:

The graph above is a Moody's chart for calculating friction factor using Reynolds Number (Re) and relative roughness. The " f '" on Y-axis is Darcy friction factor and not Fanning friction factor.

TRICK:
Follow the red line marked on the graph, it indicates that for Re = 1000, f = 0.064 which satisfies the Darcy's equation for laminar case. Thus this moody's chart gives us the Darcy friction factor and now I can, without any hesitation, use this " f D " value to calculate the pressure drop by using the corresponding pressure drop equation.

BEWARE !! Many a times the graph that you might be referring to will give a value of f = 0.016 for Re = 1000 i.e. using f = 16 / Re, so this is fanning friction factor. The following Moody's chart shows the aforementioned case.

I have highlighted here, only the equations for the laminar condition, just to make my point clear of explaining you the trick to help you to check whether the curve that you are referring to gives you Darcy or Fanning friction value.

I Hope, the point of this article is clear and friction factors won't be any confusion in any minds from now on. I follow the same practice while determining the value of friction factor and this check has never failed me.

Fix your steps of calculating pressure drop, but I insist on using Darcy equation i.e. Darcy friction factor. This should not lead to a conclusion that fanning friction factor should not be used. Remember either of it can be used, and both will lead to correct pressure drop, provided you use the right set of equations and keep the relationship in mind

Just in case you get confused again, you can re-visit this article and if you have any doubts in mind you can leave a comment here.