Calculating time required to pressurize compressed air tank

[chris.styles]

Hello,

I searched as best I could but could not find a direct answer to my question; I've seen similar questions but without the required data to be able to make the calculation. I thought this would be a simple calculation to find but apparently not.

Compressed air source is 4.46cfm @ 93psi - assume this stays constant
Tank volume is 636 cubic feet
Initial tank pressure is 0psig
Final tank pressure is 15psig

I need to calculate the time required to pressurize this 636cf tank from 0psig to 15psig when the supply of compressed air is 4.46cfm @ 93psi.

If anyone could provide me with the equation to make this calculation, I would be grateful.
Cheers

 

[Doug Huffman]

LOL PV=nRT The Ideal Gas Law https://en.wikipedia.org/wiki/Ideal_gas_law
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