A liquid turbine flow meter uses a turbine for measurement. It first converts the flow rate into the rotational speed of the turbine, and then converts the rotational speed into an electrical signal proportional to the flow rate.
This flow meter is used to detect instantaneous flow and total integrated flow. Its output signal is frequency, which is easy to digitize. In the figure, the induction coil and permanent magnet are fixed on the housing together. When the ferromagnetic turbine blade passes through the magnet, the magnetic resistance of the magnetic circuit changes, thereby generating an induction signal. The signal is amplified and shaped by the amplifier and sent to the counter or frequency meter to display the total integrated flow. At the same time, the pulse frequency is converted from frequency to voltage to indicate the instantaneous flow. The speed of the impeller is proportional to the flow, and the number of revolutions of the impeller is proportional to the total amount flowing.
The output of the turbine flowmeter is a frequency modulated signal, which not only improves the anti-interference ability of the detection circuit, but also simplifies the flow detection system. Its range ratio can reach 10:1, and the accuracy is within ±0.2%. The time constant of the turbine flowmeter with small inertia and small size can reach 0.01 seconds. The output signal of the turbine flowmeter is a pulse, which is easy to digitize. The turbine flowmeter has a small pressure loss, the blades are corrosion-resistant, and can measure viscous and corrosive media. A pulse signal inversely proportional to the flow rate is generated. When the fluid passes through the pipeline, the rotation angular velocity of the turbine flowmeter is inversely proportional to the fluid flow rate.
A turbine is placed in the center of the pipeline, which will cause the magnetic flux in the sensor coil to change. The sensor coil sends the detected magnetic flux period change signal to the preamplifier, and also sends the pulse signal to the frequency current conversion circuit to amplify and shape the signal, so that the turbine flowmeter suppresses the friction torque and fluid resistance torque to generate changes. The turbine flowmeter generates a driving torque, and the blades of the liquid turbine flowmeter, when the turbine flowmeter blades cut the magnetic lines of force generated by the permanent magnet in the shell, the fluid flow rate can be lost through the change angular velocity of the turbine flowmeter, and the pulse signal is converted into an analog current. For a certain fluid medium viscosity, the speed of the turbine flowmeter is detected by the sensor coil installed outside the casing. Both ends are supported by bearings. Thus, the fluid flow rate through the pipeline can be roughly compared. In a certain flow range, the instantaneous flow value is further indicated. It is sent to the unit conversion and flow integration circuit to obtain and display the accumulated flow value.
The above is the "Working Principle of Liquid Turbine Flowmeter" shared by turbine flowmeter manufacturers. Thank you for watching. If you have any questions, you can consult online or leave us a message. We will answer you wholeheartedly.
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