[Neelrahs2006]

Does anyone know what does it mean, when a nitrogen buffer tank capacity is written as 6000nM3?

Trying to size the Nitrogen Buffer Tank, but i don't know what it means by that capacity.

[JoeWong]

Neelrahs2006,
In my opinion, "6000nM3" is referring to 6000 m3 of gas at NORMAL condition.

You may read this article for definition of STANDARD & NORMAL (Click HERE) *

As you can see, the definition of STANDARD & NORMAL is different from organisations, field, discipline, project, etc...You have to look for the definition in you case.

* http://en.wikipedia.org/wiki/Standard_cond...re_and_pressure

[proinwv]

Joe is correct.

[Neelrahs2006]

Thanks for the info.

[sabahboyz]

Thanks for the info.

HI, continue to above question. I just want to clarify that, if i want to design a gas buffer tank to supply 5500 Nm3/hr for 60 barg to 30 barg. Is that i find the normalize tank volume?

P1*V1/T1 = P2*V2/T2
1.0133*V1/273.15 = 61.0133*5500/303.15
V1 = 298296 m3

P1*V1/T1 = P2*V2/T2
1.0133*V1/273.15 = 31.0133*5500/303.15
V1 = 151676 m3

to determine the size of the tank,
298296 - 151676 = 146620 m3?

Will it be very large?

[gvdlans]

sabahboyz,

It would have been better if you had started a new thread.

Your calculations don't make sense. Did you do an analysis of the units on both sides of the = sign?

What is missing from your problem description is the required buffer time. Let's assume you need 6 minutes of buffer time.

Rule of thumb approach:
You have 30 bar to play with. Now this roughly means that every m3 of buffer vessel will provide you 30 Nm3 of buffer volume. You need 5500 Nm3/hr * 6 minutes / 60 minutes/hr = 550 Nm3. So you need 550 Nm3 / 30 Nm3/m3 vessel = 18.33 m3.

Now this is only a rough estimation but I am quite sure you will be fine with 19 m3 of vessel.

The detailed calculation procedure for air and nitrogen buffer vessels has been discussed before on this forum --> use the SEARCH button.