Gas flowrate

[coolcando]

I am inexperienced in Gas flow .



Situation: A gas stream (distilation column overhead-Mixture of ethane/ethylene/H2/C3s/Acetylene) will be used to pressurise a hydrogenation reactor to a certain pressure. There will be an automatic shut-off valve in this line.To prepare datasheet of this valve I need following data - Maxm flow/Inlet(of the shut-off valve) pressure at maximum flow/temperature at maxm flow/gas viscosity/gas vapour pressure.

Data vailable:
Column overheads - Pr / Temp / Composition.

Reactor initial and final pressure and temperature .

What are the design concepts to solve this problem?

 

[roker]

coolcando,

since it is a shut-off valve and not a control valve you do not have to size the valve it is the line size and the conditions for selecting the shut off valve are the same design conditions as the line it is installed in (pressure and temperature).

regards,
roker

 

[dcasto]

If it is a shut off valve, you should size the to make sure it is large enough to flow the required volume. This requires a simple pressure drop calculation. Gas gravity is the only other input you need.

IF, you ment you need a control that throttles, then you'll need to do several points, like minimum flows at max DP, and max flow at min DP. You'll again need gas gravity.

 

[coolcando]

How do I get Gas gravity ??

How can I model this in AspenPlus?

 

[mbeychok]

coolcando:

In your original post, you indicated that you had the gas composition, pressure and temperature. And now you ask how to get the gas gravity? Is that correct? Do really not know how to calculate the gas gravity even though you know the composition, pressure and tempersture??

Milton Beychok
(Visit me at www.air-dispersion.com)
.

 

[dcasto]

I do not know AspenPlus equipment availability.

HOWEVER, the dcasto rule says: "If you cannot do the calculation with a sliderule or calculator, do not look for a computer program to do it."