Precession vortex flowmeter

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The precession vortex flowmeter adopts the new technology of micro-power consumption, which can work…

I. product overview

Zw-lux series precessing vortex flowmeter is a new type of gas flowmeter which adopts advanced microprocessing technology, has the advantages of strong function, wide flow range, simple operation and maintenance, easy installation and use, etc.

Due to the uniqueness of precession vortex flowmeter, it must constantly adapt to the development of mechanical manufacturing level in the development process. Therefore, precession vortex flowmeter can be divided into "intelligent precession vortex flowmeter" and "steam precession vortex flowmeter" according to the different measurement objects.

The intelligent precessing vortex gas flowmeter adopts advanced microprocessing technology, which has the advantages of strong function, wide flow range, simple operation and maintenance, easy installation and use, etc. The main technical indexes have reached the advanced level of similar foreign products. Can be widely used in petroleum, chemical, electric power, metallurgy, coal and other industries of various gases measurement.

Steam precession vortex flowmeter adopts advanced technology of precession flow sensor with two probes, strong anti-interference ability, high accuracy, no mechanical rotating parts, not easy to corrosion, compact structure, high reliability, good stability, small maintenance.

Ii. Working principle

Zw-lux series precession vortex flowmeters are designed to generate vortices when the fluid is forced to rotate violently around the body axis after passing through a vortex generator composed of spiral blades. When the fluid enters the diffusion section, the eddy current is affected by the backflow and starts to make a secondary rotation, forming the gyro type eddy current precession phenomenon. The precession frequency is proportional to the flow rate and is not affected by the physical properties and density of the fluid. The flow rate is known when the detection element measures the precession frequency of the second rotation of the fluid. Moreover, good linearity can be obtained in a wide flow range. The flowmeter formula is: K=f/q

Where: K -- flow meter coefficient l/m³

F -- vortex frequency Hz

Q -- volume flow m³ / s

The instrument coefficient of the flowmeter is independent of the temperature, pressure, composition and physical properties (density and viscosity) of the fluid within a certain range of structural parameters and specified Reynolds number.

Iii. Application:

Zw-lux series precessing vortex flowmeter is an ideal instrument for gas metering in petroleum, chemical industry, electric power, metallurgy and other industries. Can be used for all kinds of gas gas, air, hydrogen gas, natural gas, nitrogen, liquefied petroleum gas, hydrogen peroxide, flue gas, methane, butane, gas, methane, carbon dioxide, nitrogen, acetylene, oxygen, compressed air, argon, toluene, benzene, xylene, hydrogen sulfide, sulfur dioxide, ammonia gas.

Iv. The precession vortex flowmeter is composed of the following seven basic components (figure 1) :

Structure diagram of precession vortex flowmeter

1. Vortex generator

Made of aluminum alloy, the spiral blade with a certain Angle, which is fixed at the front of the shell contraction section, forces the fluid to produce strong vortex flow.

2, shell

The shell is made of cast aluminum alloy or stainless steel according to different working pressure.

3. Intelligent flow meter integrating meter

It is composed of analog channel for temperature and pressure detection, digital channel for flow detection, micro-processing unit, liquid crystal driving circuit and other auxiliary circuits, and equipped with external signal interface.

4. Temperature sensor

Pt100/pt1000 platinum resistance is used as temperature sensitive element, and its resistance value corresponds to the temperature within a certain temperature range.

Pressure sensor

With piezoresistive diffused silicon bridge circuit as the sensing element, the bridge arm resistance will change as expected under the action of external pressure. Therefore, under the action of certain excitation current, the potential difference between the two output terminals is proportional to the external pressure.

6. Piezoelectric crystal sensor

The frequency signal of vortex precession can be detected by installing it near the throat of the shell expansion section.

7, the extinction

Fixed in the exit section of the shell, its function is to eliminate the vortex flow, so as to reduce the impact on the downstream instrument performance.

The flow meter is composed of a sensor and a conversion display instrument.

The sensor comprises a vortex generator, a detecting element, a rectifier and a housing.

The vortex generator is composed of a specific spiral blade, which is fixed at the front end of the shell contraction section and forces the fluid to generate strong vortex flow.

The detection element is installed near the throat of the expansion tube, and the frequency signal of vortex precession can be measured by using the detection element such as thermal sensing, piezoelectric, strain, capacitance or optical fiber.

The rectifier is fixed at the outlet of the meter body, and its function is to eliminate the vortex flow so as to reduce the influence of downstream flow pattern on the meter measurement.

The housing is designed with a certain shape of the flow passage, so that the vortex formation, fixed and protected installed in the internal parts, and connected with the pipe through the flange.

2, conversion display

After amplification, filtering and shaping, the weak voltage signal detected by the piezoelectric sensor becomes a pulse signal with frequency proportional to the flow, and then is displayed by the display counter. The display instrument is equipped with an external output interface to output various signals. The measured gas medium can be compensated for temperature and pressure, converted to volume flow under standard conditions, and displayed.

3. Structure:

The zw-lux series are compact and consist of housing, vortex generator, sensor (temperature, pressure, flow), rectifier, bracket and converter.

Vi. Main features:

1, built-in pressure, temperature, flow sensor, high safety performance, compact structure, beautiful appearance;

2. Display temperature, pressure, instantaneous flow and cumulative flow in place;

3, the use of new signal processing amplifier and unique filtering technology, effectively eliminate the pressure fluctuations and pipeline vibration produced by the interference signal, greatly improve the anti-interference ability of the flow meter, so that the small flow has excellent stability;

4, special time display and real-time data storage function, no matter what the situation, can ensure that internal data will not be lost, * save;

5, the power consumption of the machine is very low, can rely on the long-term power supply operation of the battery, is the ideal no external power supply local display instrument;

6. Reliable anti-theft function with password protection to prevent parameter changes;

7, the meter head can be rotated at 180 degrees, easy to install.