5 replies to this topic

[ayan_dg]

I was calculating Nitrogen requirement for inbreathing for a nitrogen padded tank. As per API guideline I found requiremnt to be 850 Nm3/hr of air , how to convert this figure to Nm3/hr of Nitrogen ?

[Art Montemayor]

Ayan:

Why do you talk in riddles? Be Specific in your query and tell us ALL the facts. If you are seeking help from others, please communicate in a manner that we can be totally aware of what it is that is hampering you.

For example: just precisely, as per WHAT API guideline have you found the requiremnt to be 850 Nm3/hr of air? Tell us exactly what you did (or didn't do) to come up with that value. Once we know the entire story, then we can begin to add some value to our comments or answers.

Engineering is 75% about communicating and 25% about calculating.

[mbeychok]

Ayan:

I agree completely with Art Montemayor that your question needs clarification. However, if all you want to know is the volume of nitrogen equivalent to a volume of air, then 1 Nm3 of air = 1 Nm3 of hydrogen. But be aware that the mass of 1 Nm3 of air is not equal to the mass of 1 Nm3 of nitrogen.

[ayan_dg]

I am sorry Art. I was following API 2000 , "Venting Atmospheric and Low Pressure Storage Tanks" fifth edition. I am having a Demineralised Water Storage tank , storing water st 45°C having a Gross capacity of 4020 m3 , the pump taking suction from the tank has a rated capacity of 210 m3/hr . So as per API 2000 the total inbreathing rate is

647 Nm3/h of air (as per Table 2B) + 0.94 X210 Nm3/h = 844 Nm3/hr rounded to 850 Nm3/h of air.
Now the question is how I change this to Nm3/h of Nitrogen.

Also what will be the actual m3/hr of nitrogen required at 45°C.

[demank]

Hallo ayan,

of course actual m3/hr of nitrogen is the same with of air. cause it is all about the volume (although the mass is different, volume which replaced for inbreathing is the same)

[djack77494]

I have to disagree with Art.

Engineering is more like 90% communication and 10% calculation.