Calculation of compressed air flow rate
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The rotameter was originally calibrated for 0.35 MPa, while the current design specifies a operating pressure of 0.2 MPa. I want to know what the actual flow rate is for 100 cubic meters per hour as measured by the flow meter There are no other flowmeter references!
When measuring gases with a rotameter, air is typically used as a standard for calibration, and the displayed value is a standard volume rather than the actual volume at that pressure. For conversion, it is necessary to know the average molecular weight of the medium; flow rate in standard cubic units = displayed value * (29/M)^0.5
If the flow meter indicates a flow rate that is in standard volume terms (that is, a flow rate corrected for temperature, pressure, compressibility factor, etc.), then the standard flow rate can be roughly divided by (the working pressure in BAR units + 1) to obtain the actual amount of fluid that has passed through. Data can be recorded over multiple time periods, and then the quantities for each period can be calculated separately to determine the extent of the error. No more than 5% is sufficient (because the flow meter itself has errors).
100/(2+1)=33.3m3
Approximately: SQRT(3/4.5) = 82% = 82 NM3
This post was last edited by SihaiYouXianTian on 2022-2-28 09:05. Also check whether there is a difference between the operating temperature and the temperature used during calibration. I assume they are all calibrated and operated at a temperature of 300K. The calculation shows around 75 cubic meters per hour. It depends on whether the calibration pressure you provided is absolute or gauge pressure; if it’s absolute pressure, then it’s 75 m3/h, while if it’s gauge pressure, it’s 81 m3/h
It depends on whether the calibration pressure you provided is absolute or gauge pressure; if it’s absolute pressure, then it’s 75 m3/h, while if it’s gauge pressure, it’s 81 m3/h