Dear All,
We are commissioning a new Dilute Phosphoric Plant and facing a problem in Magnetic Type Flowmeter. The designed service fluid is Phosphate Rock Slurry(70% solid) however we are currently conducting Water Run Tests, so the fluid is water.
The flow signal is coming quite erratic, the normal flow is 110 m3/h but it is indicating flow as 10000 m3/h . My Instrument team informed that signal is quite erratic because pipe line is not full. If the pipeline is full then the signal will be correct.
I personally do not agree that the erratic value is because of pipeline not full. As I understand that magnetic flowmeter detects the flow based on the magnetic field generated proportional to the flow rate. Magnetic field in turn depends upon the conductivity. Conductivity of the Water and Phosphate Slurry(70% Solid) is quite different. That conductivity difference is causing the erratic signals.
Kindly let me know the is it a requirement for the magnetic flowmeters that the pipeline should be full? Also let me know your opinion what could be the probable cause of different flowrate.
JKM