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3

# Packed Column Diameter

packed

4 replies to this topic
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### #1 TI-83

TI-83

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Posted 21 March 2021 - 12:53 PM

hello all,

I am trying to size a packed column and I an using the Eckert generalized pressure drop correlation (GPDC) along with packed column pressure drop correlation chart. I have the pressure drop and I am solving for (Mass flow _Liq./Mass fow_gas)*(density_vapor/density_Liquid) so that I get the y-axis G_p. My question is that if the purpose of the packed column is to remove Methyl-Acetylene and Propadine from a mixture of other liquid components with the use of hydrogen gas, would I take into account only the liquid flow rates of  Methyl-Acetylene and Propadine as well as their density or i would also need to take into account all the other liquid flowrates and for the mass flow of gas I am only taking into account the mass flow of hydrogen gas going in.

thank you

Edited by TI-83, 21 March 2021 - 12:54 PM.

### #2 Pilesar

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Posted 21 March 2021 - 02:31 PM

If I understand your question correctly, you should use the bulk liquid flow and the bulk vapor flow. Column hydraulics and pressure drop calculations are for the bulk fluids.

### #3 TI-83

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Posted 21 March 2021 - 03:14 PM

Hello Pilesar,

1.) Thank you for your response , yes that is what I was wondering about. I asked that question because  when I use the bulk fluid and bulk vapor it gives me

(M_L/M_G)*(density_V/density_L)^1/2 value of 155.2  which is not on the x-axis for the packed column correlation chart. as a reference im following the GPSA engineering data book.

2.) another question is for the viscosity (mu) i am assuming we use the viscosity of the bulk fluid as well and not that of  Methyl-Acetylene.

once again thank you for your response

### #4 Bobby Strain

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Posted 21 March 2021 - 04:35 PM

It sounds like you are designing a bubble flow reactor. It won't translate well to the usual packed column design. The reactors normally used for this are packed beds with co-current down-flow. For this you need different correlations.

Bobby

Edited by Bobby Strain, 21 March 2021 - 06:27 PM.

### #5 breizh

breizh

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Posted 22 March 2021 - 08:31 AM

Hi,

For packed tower design a few tools .

For hydrodynamic calculations you need to consider bulk liquid and bulk gas .

https://checalc.com/calc/packcol.html

Good luck

Breizh