1、 Product Overview:

ZW-LUGB seriesvortex flow meterMainly used for flow measurement of industrial pipeline media fluids, such as gases, liquids, vapors, and other media. Its characteristics are small pressure loss, large range, high accuracy, and almost unaffected by parameters such as fluid density, pressure, temperature, viscosity, etc. when measuring volumetric flow rate under working conditions. No movable mechanical parts, therefore high reliability and low maintenance. The instrument parameters can remain stable for a long time. This instrument uses piezoelectric stress sensors with high reliability and can operate within a temperature range of -20 ℃ to+250 ℃. It has both analog standard signals and digital pulse signal outputs, making it easy to use in conjunction with digital systems such as computers. It is a relatively advanced and ideal flowmeter.

As can be seen from the above equation, the pulse frequency signal output by VSF is not affected by fluid properties and composition changes, that is, the instrument coefficient is only related to the shape and size of the vortex generator and pipeline within a certain Reynolds number range. However, as a flowmeter in material balance and energy measurement, it is necessary to detect mass flow rate. At this time, the output signal of the flowmeter should simultaneously monitor volume flow rate and fluid density. Fluid properties and components still have a direct impact on flow measurement.

ZW-LUGB seriesvortex flow meterIt is a new type of flowmeter for measuring fluid flow in closed pipelines based on the Karman vortex principle. Due to its excellent medium adaptability, it can directly measure the volumetric flow rate of steam, air, gas, water, and liquid without temperature and pressure compensation. Equipped with temperature and pressure sensors, it can measure standard volumetric flow rate and mass flow rate, making it an ideal alternative to throttling flow meters.

To improve the high temperature resistance and vibration resistance of the vortex flowmeter, our company's HLUG improved vortex flowmeter sensor can be used in harsh working conditions such as high temperature (350 ℃) and strong vibration (≤ 1g) due to its * structure and material selection.

In practical applications, large flow rates are often much lower than the upper limit value of the instrument, and with changes in load, small flow rates often fall below the lower limit value of the instrument. The instrument does not work in the working section. To solve this problem, it is usually necessary to reduce the diameter at the measuring point to increase the flow rate at the measuring point, and select instruments that are more ********* to facilitate the measurement of the instrument. However, this variable diameter method requires a straight pipe section of at least 15D in length between the variable diameter pipe and the instrument for rectification, which makes processing and installation inconvenient. Our company has developed an LGZ variable diameter rectifier with a curved longitudinal section, which has multiple functions such as rectification, increasing flow velocity, and changing flow velocity distribution. Its structural size is small, only one-third of the inner diameter of the process pipe, and it is integrated with the vortex flowmeter. It not only does not require an additional straight pipe section, but also reduces the requirements for the straight pipe section of the process pipe, making installation very convenient.

For the convenience of use, the battery powered local display vortex flowmeter adopts micro power consumption technology. It can operate continuously for more than a year with lithium battery power supply, saving the procurement and installation costs of cables and display instruments. It can display instantaneous flow, cumulative flow, etc. on site. The temperature compensated integrated vortex flowmeter also comes with a temperature sensor, which can directly measure the temperature of saturated steam and calculate the pressure, thereby displaying the mass flow rate of saturated steam. The temperature pressure compensation integrated type is equipped with temperature and pressure sensors, which can directly measure the temperature and pressure of the gas medium for gas flow measurement, thereby displaying the standard volume flow rate of the gas.

2、 Working principle:
ZW-LUGB seriesvortex flow meterIt is composed of vortex generators designed in the flow field, detection probes, and corresponding electronic circuits. When the fluid flows through a vortex generator, two alternating rows of vortices are formed on both sides, which are called Karman vortex streets. On the basis of the Karman vortex street theory, it was proposed that the frequency of the Karman vortex street is proportional to the flow velocity of the fluid, and the relationship between frequency and flow velocity was given
f = St × V/d 式中:
Frequency of vortex street occurrence (Hz)
Average velocity on both sides of the vortex generator (m/s)
St Strohal coefficient (constant)
These alternating vortices form a series of alternating negative pressures, which act on the detection probe to generate a series of alternating electrical signals. After conversion, shaping, and amplification by a preamplifier, the output is a pulse frequency signal (or standard signal) proportional to the synchronization with the vortices.
3、 Usage selection and application:
1. For the convenience of use, the battery powered type adopts low-power technology, which can run continuously for more than a year using lithium batteries, saving the procurement and installation costs of cables and display instruments. It can display instantaneous flow, cumulative flow, etc. on site.
2. The temperature compensation integrated model also comes with a temperature sensor, which can directly measure the temperature of saturated steam and calculate the pressure, thereby displaying the mass flow rate of saturated steam.
3. The temperature pressure compensation integrated type is equipped with temperature and pressure sensors, which can directly measure the temperature and pressure of the gas medium for gas flow measurement, thereby displaying the standard volume flow rate of the gas.
4. Widely used in the process measurement and energy-saving management of various low viscosity single-phase fluids such as liquids, gases, steam, etc. in industries such as petroleum, chemical, metallurgy, machinery, papermaking, as well as urban pipeline heating, water supply, gas, etc.
4、 Main features:
1. Can accurately measure the flow rates of gases, liquids, and vapors over a wide range of flow rates without being affected by fluid physical properties;
2. Not affected by temperature and pressure, and not easily clogged, stuck, or scaled, resistant to high temperatures and pressures;
3. Safe and explosion-proof, suitable for harsh environments;
4. No movable parts, no holes or gaps design, the product is wear-resistant, dirt resistant, does not require mechanical maintenance, and has a long service life;
5. Adopting low-power technology and battery powered on-site display flowmeter, it can operate continuously for more than two years without power supply;
6. Integrated design of temperature and pressure compensation;
7. The current output is all electrically isolated, with good common mode interference suppression capability;
8. Simultaneously display the flow value and cumulative flow value, without the need to switch between them;
9. Adopting anti vibration probes to effectively eliminate the influence of external vibrations;
10. Adopting a split type signal converter with a cable length of 100 meters;
11. The range ratio is up to 20:1;
12. The overall structure design of the instrument is reasonable, with a wide dynamic measurement range and low pressure loss;
13. The body is made of stainless steel material, which is suitable for measuring corrosive media;
14. On site LCD display, pulse, 4-20mA output or 485 communication, can be connected to industrial automation systems.
5、 Technical parameters:
1. Measurement medium: gas, liquid, vapor;
2. Connection methods: flange card type, flange type, plug-in type;
3. The caliber specification for flange card mounted calibers is 25, 32, 50, 80, and 100;
4. The selection of flange connection caliber is 100, 150, 200;
5. Flow range (see flow range table)
6. The normal measurement flow rate range is Reynolds number 1.5 × 104 to 4 × 106; Gas velocity of 5-50m/s; Liquid 0.5-7m/s;
7. Measurement accuracy of 1.0 level and 1.5 level;
8. Temperature of the tested medium: normal temperature -25 ℃~100 ℃, high temperature -25 ℃~150 ℃ -25 ℃~250 ℃;
9. Output signal pulse voltage output signal high level 8-10V low level 0.7-1.3V;
10. Pulse duty cycle of about 50%, transmission distance of 100m;
11. Pulse current remote transmission signal 4-20 mA, transmission distance of 1000m;
12. Instrument operating environment temperature: -25 ℃~+55 ℃ humidity: 5-90% RH50 ℃;
13. Material: stainless steel, aluminum alloy;
14. Power supply DC24V or lithium battery 3.6V;
15. Explosion proof level: intrinsic safety type iaIIbT3-T6, protection level: IP65.
6、 Installation requirements:
1. Vortex street can only measure in one direction. When installing, pay attention to ensuring that the direction of medium flow is consistent with the direction indicated by the flow meter arrow.
2. The installation method is vertical installation, and the medium passes through the flowmeter from bottom to top. Install the flowmeter on a vertical pipeline with a flow direction from bottom to top.
3. When installing horizontally, the flowmeter must be installed in the high-pressure area of the entire system and ensure the corresponding outlet pressure; Do not install it at the highest point of the pipeline, as gas often accumulates at this point. If the pipeline is not full, the outlet cannot be directly vented.
4. When measuring high-temperature fluids, try to use a vertical installation method as much as possible; If horizontal installation is necessary, please install the transmitter part of the flowmeter vertically downwards or horizontally on the side to avoid excessive temperature; Pay attention to good air flow or ventilation at the installation location.
5. Requirement for straight pipe section: Ensure at least 15 times the diameter of the pipe in front of the flowmeter and 5 times the diameter behind the flowmeter. If there are interference sources such as bends, indentations, and expansions in front of the flowmeter, it is necessary to ensure a diameter of 30-40 times the diameter in front of the flowmeter and 6 times the diameter behind the flowmeter. The flowmeter should be installed upstream of the regulating valve, pressure or temperature sensor.
6. During installation, it should be noted that the diameter of the pipeline should be slightly larger than or equal to the inner diameter of the instrument.
7. When using a sealing ring, it should be noted that the inner diameter of the sealing ring should be slightly larger than or equal to the inner diameter of the instrument, and the center of the sealing ring should be located at the center of the pipeline.
8. When sealing the electrical connection of cable entry instruments, attention must be paid to the sealing of the inlet holes. Select the corresponding sealing interface (M20 X 1.5; 1/2'NPT; G1/2 ') according to the instrument cable entry model, and install it correctly and tightly. Without sealed joints or careless installation, the sealing effect cannot be achieved.

7、 External dimensions:

8、 Requirements for pipelines:
1. Requirements for straight pipe sections:
In order to ensure the normal and accurate operation of the instrument, there must be a certain amount of straight pipes upstream and downstream of the sensor installation point to adjust the flow field, as shown in the figure.

Figure 1: Concentric contraction tube;
Figure 2: Concentric expansion tube;
Figure 3: A 90 degree elbow;
Figure 4: Two 90 degree elbows on the same plane;
Figure 5: Two 90 degree elbows in different planes;
Figure 6: The regulating valve should be installed 5D downstream of the sensor. If it needs to be installed upstream of the sensor, there should be an equal diameter straight pipe section of not less than 50D upstream and an equal diameter straight pipe section of not less than 5D downstream.
2. Requirements for pipelines:
a、 The inner diameter D of the upstream and downstream piping is the same as the inner diameter DN of the sensor, and the difference satisfies the following condition: 0.95DN ≤ D ≤ 1.1DN.
b、 The piping should be concentric with the sensor, and the coaxiality should be less than 0.05DN.
c、 The sealing gasket cannot protrude into the pipeline, and its inner diameter may be slightly larger than that of the sensor.
d、 If it is necessary to cut off the flow for inspection and cleaning of sensors, a bypass pipeline should be installed,As shown in the following figure.

3. Requirements for pipeline vibration:
Sensors should be avoided from being installed on pipelines with strong vibrations as much as possible. If installation is necessary, shock absorption measures must be taken, and pipeline fastening devices should be installed at 2D upstream and downstream of the sensor, along with anti vibration pads.
Special attention: The vibration at the outlet of the air compressor is strong, and sensors cannot be installed. They should be installed after the air storage tank.
4. Requirements for airflow conditions:
a、 The tested gas should be a single-phase, continuous circular flow through the pipeline.
b、 Before the gas flows through the flowmeter, its velocity must be parallel to the pipeline axis and there must be no vortex flow.
c、 The airflow should be subsonic and non pulsating, and its flow rate changes slowly over time.
5. Installation requirements for flow meters:
Flowmeters do not have many special requirements for process installation and usage environment, but any type of flow measuring instrument has a commonality, which is to avoid vibration and high-temperature environment interference components (such as compressors, separators, pressure regulating valves, reducers and manifolds, elbows, etc.) as much as possible, maintain smooth and straight inner walls of the straight pipe sections before and after the instrument, and ensure that the measured medium is a clean single-phase fluid.
9、 Issues to be noted during debugging and use:
1. The installation and maintenance of flow meters on site must comply with the warning message 'Do not open the cover when there is explosion-proof gas', and turn off the external power before opening the cover.
2. When used outdoors, it is recommended to add a protective cover.
3. Do not loosen the fixed part of the flowmeter at will. Protection of pressure sensors. When using a flowmeter, users should note that the pressure overload value of the flowmeter is 1.5 times the rated working pressure of the pressure sensor (i.e. 1.5 times the highest pressure of the medium). The selection should be within the specified flow range to prevent overspeed operation, in order to achieve ideal accuracy and ensure normal service life. (Due to overspeed caused by pressure testing, pipeline purging, or exhaust, as well as turbine operation in reverse flow, the flow meter may be damaged)
4. When put into operation, the valve should be slowly opened to prevent damage to the turbine caused by instantaneous airflow impact. Lubricating oil should be added according to the signs, and the frequency of refueling depends on the cleanliness of the gas, usually 2-3 times a year.
5. It is not allowed to open the back cover or change internal parameters during operation, otherwise it will affect the normal operation of the flowmeter.

10、 Precautions during installation and use:
No mechanical movable parts, small size, corrosion resistance, stable performance, can directly display the working pressure, temperature, flow rate, and gas volume under standard conditions of the medium, with a wide range of measurement and small measurement errors. It has been widely used in production measurement of oil and gas wells and sales measurement of natural gas. In years of on-site application, we believe that this flowmeter is suitable for relatively clean dry gas metering and has gradually become a small and medium-sized gas metering instrument. To ensure accurate measurement of the flowmeter and reduce measurement errors, please note:
1. Reasonable selection
Do not make the actual minimum flow rate QVmin lower than the lower limit of the flow range of the selected flow meter.
2. Install correctly
There should be a measuring straight pipe section of at least 10D length upstream of the vortex flowmeter. The inner wall of the straight pipe section should be smooth, and there should be no steps. The welds connecting the flanges should be ground flat, and the flange gasket should not protrude into the pipeline. The installation direction of the flowmeter cannot be reversed. Experimental evidence shows that any unreasonable installation will result in a low measurement value of the flow meter.
3. Stay away from vibration sources or install supports upstream and downstream of the flow meter to avoid the impact of pipeline vibration. Avoid interference from strong magnetic fields on the flowmeter chip.
4. Relatively clean temperament
Especially, liquid gas two-phase flow should not occur. When the gas quality is dirty, the flowmeter should be cleaned immediately.
5. Reduce the impact of airflow pulsation
A buffer tank can be installed in front of the flowmeter, or the length of the measuring straight pipe upstream of the flowmeter can be extended.
6. Timely calibrate the flowmeter to ensure accurate and reliable measurement values.

11、 Attention:
1. When welding flanges and straight pipe sections, sensors cannot be used for welding.
2. During installation, the flow direction indicator of the sensor should be consistent with the fluid flow direction inside the pipeline.
3. Before installing the sensor, the sealing ring must be properly placed in the flange groove. The positions of pressure and temperature measurement points are as follows: the pressure measurement point is located 3-5 DN downstream of the sensor, and the temperature measurement point is located 5-8 DN downstream.
4. When measuring high-temperature media, do not wrap the sensor connecting rod around it with insulation materials.

5. The shielded cable connecting the transmitter should be routed as far away as possible from strong electromagnetic field interference. ******It is not allowed to be laid together with high-voltage cables. Shielded cables should be shortened as much as possible and should not be coiled to reduce distributed inductance. The maximum length should not exceed 200 meters.
6. Before installing the sensor, the pipeline must be cleaned. Remove impurities from the tube to avoid clogging the sensor after flow. The pipeline for measuring liquids must be filled with the measured liquid to prevent interference from bubbles.
7. The pipeline for measuring gases is designed to prevent interference from stored fluids. The installation location is shown in Figure 5. When replacing the probe body under high temperature and high pressure, it is necessary to ensure safe operation and take good high-temperature protection measures. After cooling and reducing pressure, the probe can be replaced under safe conditions.
12、 Standardized management of installation:
The standardized installation of flow meters provides strong technical support for the user department in subsequent management. The following specific requirements are proposed to the construction unit, which have been verified to be effective for many years.
1. Equipped with 4-20mA output and pulse output.
2. GPRS remote transmission equipment requires pulse input, 4-20mA input.
3. Equipped with power lightning protection and signal lightning protection (4-20mA).
4. The requirements for the instrument cabinet are: UPS power supply, air switch and socket inside the cabinet, centralized installation of GPRS communication device, intelligent vortex flowmeter converter, etc. with lock.
5. The stability of the instrument cabinet requires a cement pier base, suitable outdoor protection level, insulation layer on the top of the cabinet to prevent direct sunlight, and anti splash function.
6. There should be sufficient straight pipe section on one side of the meter well to facilitate the detection, comparison, and subsequent management of the intelligent vortex flowmeter.
7. During design, a straight pipe section with a diameter of at least 10 times the nominal diameter (10DN) must be left at the front end, and a straight pipe section with a diameter greater than 5DN must be left at the rear end to ensure accurate measurement.
8. It should be installed strictly according to the instructions, and after installation, the grounding should be measured. The grounding resistance value should be below 10 Ω. The equipotential bonding wire uses multi strand copper bundle wires, and the cable must be greater than or equal to 16mm2; The instrument grounding wire uses multi strand copper bundle wires, and the cable requirement is greater than or equal to 6mm2. The grounding standard is detailed in GB50343-2009 "Technical Specification for Lightning Protection of Building Electronic Information Systems".
13、 Key selection points:
Proper selection is necessary to ensure better use of vortex flowmeters. What type of vortex flowmeter should be selected based on the physical and chemical properties of the measured fluid medium? What are the diameter, flow range, lining material, electrode material, and output current of the vortex flowmeter? Can adapt to the properties of the measured fluid and the requirements of flow measurement.
1. Precision functional inspection
The accuracy level and function of the instrument are selected based on measurement requirements and usage scenarios to achieve cost-effectiveness. For example, in situations such as trade settlement, product handover, and energy measurement, higher accuracy levels such as 1.0, 0.5, or higher should be selected; For process control applications, choose different accuracy levels according to control requirements; In some cases where only the process flow rate needs to be detected without accurate control and measurement, a slightly lower accuracy level, such as 1.5, 2.5, or even 4.0, can be selected. In this case, a low-cost plug-in vortex flowmeter can be used.
2. Measurable medium
When measuring medium flow rate, instrument range, and caliber for general medium measurement, the full flow rate of the vortex flowmeter can be selected within the range of 0.5-12m/s for measuring medium flow rate, which is relatively wide. The selection of instrument specifications (caliber) may not necessarily be the same as the process pipeline, and should be determined based on 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 instrument or the measurement accuracy cannot be guaranteed at this flow rate, the instrument port diameter needs to be reduced to increase the flow rate inside the pipeline and obtain satisfactory measurement results.
3. Selection of Vortex Flow Transmitter
In saturated steam measurement, VA type piezoelectric vortex flowmeter is used. Due to the wide range of the vortex flowmeter, in practical applications, it is generally considered that the flow rate of saturated steam should not be lower than the lower limit of the vortex flowmeter, which means that the fluid flow velocity must not be lower than 5m/s. Choose vortex flow transmitters with different diameters based on the amount of steam used, rather than selecting the transmitter diameter based on the existing process pipeline diameter.
4. Selection of pressure compensation pressure transmitter
Due to the long saturated steam pipeline and significant pressure fluctuations, it is necessary to use pressure compensation. Considering the correspondence between pressure, temperature, and density, only pressure compensation is required for measurement. As the saturated steam pressure in the pipeline is in the range of 0.3-0.7MPa, the range of the pressure transmitter can be selected as 1MPa.
5. Display instrument selection
Intelligent flow display instrument with voltage stabilization compensation, instantaneous flow display, and cumulative flow calculation functions.

14、 Summary Table of Standard Flow Range: Unit (m3/h)

15、 Selection code: