Using an orifice plate to measure gas mass flow rate?
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A combination of orifice plates and differential pressure transmitters is used to measure the mass flow rate of gas. I want to know if the orifice plate measures volumetric flow rate, which is then converted to mass flow rate in the DCS? Or is it already converted to mass flow rate in the differential pressure transmitter, so it can be displayed directly on the DCS? Are there any other methods?
Since it’s already been solved, why not share the solution? That way, others will know next time – how great is that? Helping each other, haha
Orifice plate calculations can be for volumetric flow rate or mass flow rate; the difference lies in density. Temperature and pressure compensation is required for both volumetric flow rate and mass flow rate.
What you measure is the standard volume; as long as the medium does not change, you can simply multiply the standard volume by the standard density (a constant value), and this can be done within the DCS program~~
Orifice flow meter: the differential pressure generated by the orifice represents the flow rate. Moreover, the orifice plate measures mass flow rate, which is converted into other types of flow rates as needed in practice. However, the mass flow rate measured by a orifice flow meter is obtained under the assumption that temperature, pressure, viscosity (Reynolds number), and enthalpy in thermodynamics are all constant. Changes in these parameters will affect the measurement results. Therefore, orifice plate flowmeters are all designed (calculated) directly based on the operating conditions. When the operating conditions change, and if the difference is significant, the orifice plate should be recalculated ； If the changes are minor and it is possible to derive the changes in other parameters from the changing parameter, the measurement results can be processed mathematically, such as by performing temperature and pressure compensation.
It measures mass flow rate directly, no conversion needed! There is a square root relationship between mass flow rate and differential pressure!
The orifice plate measures the actual volumetric flow rate; temperature and pressure must be taken into account to determine the mass flow rate.
Has it been resolved? ? Where is the answer? ? ? ? …… One more thing: by using the formula for measuring flow rate based on pressure difference, it’s possible to calculate the unit of measurement. Then you just need to check whether the unit is volume or mass……
Thermal and pressure compensation is required. With the 3095 transmitter, the output is directly the mass flow rate.
Thermal and pressure compensation is required. With the 3095 transmitter, the output is directly the mass flow rate.