Turbine flowmeter configuration

The operating principle of a turbine flowmeter is that when fluid flows along the pipe axis and strikes the turbine blades, a force proportional to the product of the flow rate qv, the flow velocity V, and the fluid density ρ acts on the blades, driving the turbine to rotate. As the turbine rotates, the blades periodically cut the magnetic lines of force generated by the electromagnet, changing the magnetic flux in the coil. Based on the principle of electromagnetic induction, a pulsating potential signal is induced in the coil. The frequency of this pulsating signal is proportional to the flow rate of the measured fluid. The pulse signal output by the turbine transmitter is amplified by a preamplifier and then fed into a display instrument, enabling flow measurement.

Selecting a High-Precision Turbine Flowmeter:

1. Bearing life is inversely proportional to the square of the flow rate, so a flow rate of 1/3 of the maximum flow rate is ideal. Tungsten carbide, polytetrafluoroethylene, and carbon graphite are commonly available. Tungsten carbide offers the highest precision and is used as a standard component in industrial control systems. Polytetrafluoroethylene and carbon graphite are corrosion-resistant and are generally preferred in chemical plants. 2. The induction probe detects the motion of the rotating body and converts it into a pulsed digital electrical signal. The voltage output of its electromagnetic coil approximates a sinusoidal curve, and the frequency range of the pulse signal varies linearly with the measured flow rate. Typical ranges are 10:1, 25:1, and 100:1.
3. The flowmeter body is preferably made of 316 stainless steel for corrosion resistance. If located in an explosion-proof area, it must also be explosion-proof.
The measurement principle of a turbine flowmeter: The measured fluid impacts the turbine blades, causing the turbine to rotate. The turbine speed varies with the flow rate; that is, the higher the flow rate, the higher the turbine speed. A magnetoelectric converter then converts the turbine speed into electrical pulses of the corresponding frequency. After amplification by a preamplifier, the pulses are counted and displayed on a display instrument. The instantaneous and cumulative flow rates can be calculated based on the number of pulses per unit time and the cumulative number of pulses. How should the turbine flowmeter system parameters be adjusted? The turbine flowmeter features an explosion-proof design and uses a long-lasting lithium battery. The single-function integrated battery has a service life of over five years and can display total flow, instantaneous flow, and percentage of flow. The multi-function display has a battery life of over 12 months. Therefore, how should turbine flowmeter system parameters be adjusted?
1. Maintenance intervals are generally six months. During inspection and cleaning, be careful not to damage the components within the measuring chamber, especially the impeller. During assembly, pay careful attention to the position of the guide and impeller.
2. The filter should be cleaned regularly. When not in use, the internal fluid should be removed. Like the sensor, a dust cover should be installed and stored in a dry place. When not in use, the internal fluid should be removed and protective covers should be installed on both ends of the sensor to prevent dust and dirt from entering. The sensor should then be stored in a dry place.
3. The sensor transmission cable can be installed overhead or underground (use an iron pipe if underground). Before installation, connect the cable to the display instrument or oscilloscope, apply power, blow on the impeller or manually rotate it rapidly, and observe whether a display appears. Install the sensor only when a display appears. If there is no display, check the relevant components and correct the problem.
4. During use, the measured liquid should be kept clean and free of impurities such as fibers and particles. When initially using the sensor, slowly fill the sensor with liquid before opening the outlet valve. Avoid subjecting the sensor to high-speed fluid impact when it is empty of liquid.