air pressure flow time calculator

[microlab]

dear friends

is there any formula which can be used to calculate the air pressure transfer time from a high pressured vessel to a low pressure vessel.
ie:the high pressured vessel contains say 500 PSI pressure, and the low pressured vessel contains 50 PSI which is connected with a tube of 1 inch diameter. how can we define the time to transfer 25 PSI (so the total pressure will be 50 + 25 = 75 PSI) pressure from the vessel 1 to vessel 2? is there any mathematical formula for that? both the vessels are in same atmospheric condition.

regards

ml

 

[FvM]

is there any mathematical formula for that?

The pressure difference between both vessels results in a flow, limited by the connecting tube. Depending on the geometry, you'll either face a laminar flow, resulting in a pressure drop proportional to volume flow or turbulent flow, resulting in a quadratic pressure drop, or something in between. I guess, it's mostly quadratic. The flow konstant (formular sign Kv) has to be determined empirically or estimated from the tube diameter. The flow speed and pressure follows a differential equation.

both the vessels are in same atmospheric condition.

The point is meaningless for the problem.

P.S.: For a rough estimation, you can assume an average constant pressure drop, resulting in a constant mass flow.

 

[mister_rf]

:-D
Not so simple to do all the calculations, you may start using Bernoulli Equation, but in practice there are so many unknown parameters we need to consider in order to obtain the exact results.

**broken link removed**
Pressure

 

[microlab]

hi

thank you for the answer
what are the other expected parameters?
is it possible to calculate roughly?
may be using some algorithms?

regards

ml

 

[mister_rf]

Need to try this:
Natural gas pipe diameter, flow rate and pressure drop calculator