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Volumetric flow correction of orifice flow meter

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Taksan

Chemical
Joined
Jun 26, 2015
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US
Is it necessary to divide the normalized flow obtained from corrections of temperature, pressure, and compression factor in an orifice flow meter by the compressibility factor again?

Even if the measured flow is converted to any standard conditions such as (1 atm, 15.6C) after correction, the compression factor such as chlorine will be less than one at the standard condition. Do I need to divide the corrected flow by the compression factor?

Qc = Qa * √{ (Td/Ta)*(Pa/Pd)*(Zd/Za)} / Zd(<-???)
a: Actual flow (gas passing through orifice)
d: Orifice design conditions
 
Hi,
To answer to your question, Consider mass conservation:
Mass flow actual condition = Mass flow design condition.
As Mass flow = volumetric flow * density and ρ = Mw/V = Mw*P/(Z*R*T)
I let you develop the equations and you will get your answer.
NB: No square root !
Pierre
 
You have Qa (actual flow at P,T), and you have the equivalent flow at standard conditions.

So if your actual flow and service conditions are at the same pressure and temperature,then Qc must be equal to Qa not Qa/Zd.


 
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