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『Vortex flowmeter transmitter』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
Why is there only 24V for vortex power supply? Vortex flowmeter is a type of transmitter, which mainly includes temperature, pressure, flow rate, liquid level and other categories; In addition to the interference reasons mentioned by Lead Xian upstairs, there are several other reasons:
1. Transmitter instruments need to enter the DCS or PLC system to obtain information. The most convenient connection method for these systems is a two-wire instrument (24V without power supply, the circuit is directly connected in series with a 250 ohm high excitation impedance to measure the signal).
2. The vortex flowmeter itself does not require too high power, a two-wire system is sufficient, and it can also be equipped with HART protocol, which means that two wires can have 24V+4~20mA+HART.
. (Recommend a product) http://www.bjzrzc.com/products/h880.htm For reference)3. In fact, vortex flowmeters are also powered by a 3.6V ER14505 battery, which is different from 24V applications.
4、 The transmitter is powered by 220V, and there are two main possibilities:
1. Special on-site requirements or user customization;
2、 For instruments with high power consumption such as electromagnetic flowmeters, it is not meaningful to use 24V (a 24V power supply can only carry a few instruments and the circuit pressure drop is too large). 5. For two-wire vortex flowmeters, 24V power supply actually refers to 10V~30V or 12~32V, depending on the manufacturer. 2. Working principle of vortex flowmeters. 1. Placing a triangular vortex generator in the fluid will cause regular vortices to alternate on both sides of the vortex generator, which is called Karman vortex. These vortices are arranged in an asymmetric man
2、 The vortex flowmeter measures the volumetric flow rate, standard state volumetric flow rate, or mass flow rate of gases, vapors, or liquids based on the K á rm á n Vortex Street principle, and can be integrated as a flow transmitter into automated positive osmosis control systems.
3、 Vortex flowmeter uses the principle of fluid oscillation to measure flow rate. When a fluid passes through a vortex flow transmitter, two alternating columns of vortices are generated behind the vortex generator, whose frequency is proportional to the average velocity of the fluid flowing through the vortex generator and the characteristic width of the vortex generator. The release frequency of a vortex can be expressed as: f=(v/d) * St, where f is the frequency (in Hz), v is the average velocity of the fluid (in m/s), d is the characteristic width of the vortex generator (in m), and St is the Strouhal number, which is usually a dimensionless value between 0.14 and 0.27.
4、 The Strouhal number St is a function of the Reynolds number Re, and within a specific range of Reynolds numbers, the value of St is approximately 0.2. In practical measurements, it should be ensured that the Reynolds number of the fluid is within this range, and the vortex frequency is proportional to the fluid velocity.
5、 By measuring the vortex frequency, the average velocity v of the fluid flowing through the vortex generator can be calculated, and the flow rate q can be obtained using the corresponding formula, where A is the cross-sectional area of the fluid flowing through the vortex generator.
3. What is a vortex flowmeter? What are the characteristics?
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