flow rate of N2 past regulator

[Engineerworx]

I am interested in finding the flow rate (lb/hr) of nitrogen after a regulator. the outlet pressure of regulator is around 45 psig. the N2 is going to a unit which has a volume of X lbs. the unit is to be filled with N2 just below the set psv pressure of 50 psig.

I am trying to find out the time it would require to fill the unit.

can someone give a suggestion on how to solve the problem? thanks

 

[dcasto]

If the N2 supply pressure is constant, then is just the flow rate based on supply pressure, regulator outlet (45 psig) and Cv of the regulator. You may heve to convert mass to volume(N2 .07381 Lb/ CF @ 14.696 and 60F).

Use Fisher's, Kimrays, or Crane 410 Chapter 4.2.

 

[tkdhwjd]

Since the unit volume is known, calculate number of moles of N2 required to keep the unit at various pressures from the starting pressure to 45 psig. Then, you can perform hydraulic calculations to see "how fast" you can deliver that specific number of moles from one pressure to the next. Add times to obtain the total time. Finer the pressure intervals, more accurate your results.

 

[Engineerworx]

tkdhwjd:

I have the number of moles N2 required from 25 psig to 45 psig, can you recommend the hydraulic calculation procedure? thanks

 

[dcasto]

PV=znRT

 

[tkdhwjd]

Hydraulic calculations = pressure drop calculations based on your piping/regulator system.