Turbine Flowmeter

Working principle of turbine flow meter

The turbine flow meter has a turbine, which needs to be installed in the fluid pipeline when in use, and its two ends are supported by bearings. When the fluid passes through the turbine, the fluid impacts the turbine blade and drives the turbine blade to rotate. The measuring instrument of the turbine flow meter indirectly measures the flow through the angular velocity of the turbine blade. The method is that the angular velocity of the blade is directly proportional to the fluid velocity.

The angular velocity is detected by the sensing coil installed in the casing. When the turbine blade cuts the magnetic line of force generated by the permanent magnet in the casing, the change of magnetic flux of the sensing coil will be changed. The sensing coil sends the detected periodic change signal of magnetic flux to the amplifier of the measuring instrument to amplify and reshape the signal.

The pulse signal proportional to the flow rate is generated and sent to the unit conversion and flow meter integration circuit to get and display the accumulated flow value; at the same time, the pulse signal is also sent to the frequency current conversion circuit to convert the pulse signal into analog current, and then to indicate the instantaneous flow value.

When measuring medium flow rate, instrument range and diameter, the full flow rate of turbine flow meter can be selected in the range of measuring medium flow rate 0.5-12m/s, with a wide range. The specification (diameter) of the selected instrument is not necessarily the same as that of the process pipe, and it should be determined according to whether the measured flow range is within the flow rate range.

That is, when the pipeline flow rate is too low to meet the requirements of the flow meter, or the measurement accuracy under this flow rate can not be guaranteed, the diameter of the meter needs to be reduced, so as to obtain the satisfactory measurement results.