1. Product overview:

LUGB series vortex flowmeter is mainly used for flow measurement of industrial pipeline medium fluid, such as gas, liquid, steam and other media. It is characterized by small pressure loss, large measuring range, high precision, and is almost not affected by parameters such as fluid density, pressure, temperature, viscosity, etc. when measuring the volume flow of the working condition. No moving mechanical parts, so high reliability and low maintenance. Instrument parameters can be stable for a long time. This instrument adopts piezoelectric stress sensor, which has high reliability and can work in the working temperature range of -20℃～+250℃. There are analog standard signals and digital pulse signal output, which is easy to be used with digital systems such as computers, and is an ideal flowmeter.

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

LUGB series vortex flowmeter is a new type of flowmeter for fluid flow measurement in closed pipelines based on the Karman vortex principle. Because of its good medium adaptability, it can directly measure the volume flow of steam, air, gas, water and liquid under working conditions without temperature and pressure compensation. Equipped with temperature and pressure sensors, it can measure the volume flow and mass flow under standard conditions. An ideal alternative to the type flowmeter.

In order to improve the high temperature resistance and anti-vibration performance of the vortex flowmeter, our company LUG improved vortex flow sensor, because of its structure and material selection, the sensor can be used in harsh working conditions of high temperature (350℃) and strong vibration (≤1g). use below.

In practical applications, the large flow is often much lower than the upper limit of the instrument, and with the change of the load, the small flow is often lower than the lower limit of the instrument, and the instrument does not work in the working section. In order to solve this problem, usually The diameter reduction at the measurement place is used to increase the flow rate at the measurement place, and the instrument is selected to facilitate the measurement of the instrument, but this type of diameter reduction method must have a straight pipe section with a length of 15D or more between the reducer pipe and the instrument for rectification, so as to facilitate processing and installation. Not convenient. The LGZ variable diameter rectifier developed by our company with a circular arc in the longitudinal section has multiple functions of rectifying, increasing the flow velocity and changing the flow velocity distribution. , not only does not need to add another straight pipe section, but also can reduce the requirements for the straight pipe section of the process pipe, and the installation is very convenient.

In order to be convenient to use, the battery-powered local display vortex flowmeter adopts high-tech micro-power consumption, and can run continuously for more than one year with lithium battery power supply, which saves the purchase and installation costs of cables and display instruments, and can display instantaneous flow, cumulative flow, etc. The temperature compensation integrated vortex flowmeter also has a temperature sensor, which can directly measure the temperature of the saturated steam and calculate the pressure, so as to display the mass flow of the saturated steam. The integrated temperature and pressure compensation type is equipped with temperature and pressure sensors for gas flow measurement. It can directly measure the temperature and pressure of the gas medium, so as to display the standard volume flow of the gas.

2. Working principle:

LUGB series vortex flowmeter is composed of a vortex generator designed in the flow field, a detection probe and corresponding electronic circuits. When the fluid flows through the vortex generator, two alternating rows of vortices are formed on both sides of the vortex. This vortex is called the Karman vortex street. On the basis of the Karman vortex street theory, it is proposed that the frequency of the Karman vortex street is proportional to the flow velocity of the fluid, and the relationship between the frequency and the flow velocity is given:

f = St × V/d where:

f Vortex occurrence frequency (Hz)

V Average flow 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 the preamplifier, the output is synchronized with the vortex. Proportional pulse frequency signal (or standard signal).

3. Use selection and application:

1. In order to be convenient to use, the battery-powered type adopts high-tech micro-power consumption, and it can run continuously for more than one year with lithium battery power supply, which saves the purchase and installation costs of cables and display instruments, and can display instantaneous flow, cumulative flow, etc. on the spot.

2. The integrated temperature compensation type also has a temperature sensor, which can directly measure the temperature of the saturated steam and calculate the pressure, so as to display the mass flow of the saturated steam.

3. The integrated temperature and pressure compensation type is equipped with temperature and pressure sensors for gas flow measurement, which can directly measure the temperature and pressure of the gas medium, thereby displaying the standard volume flow of the gas.

4. It is widely used in the process measurement and energy-saving management of various low-viscosity liquid, gas, steam and other single-phase fluids in petroleum, chemical, metallurgy, machinery, papermaking, and urban pipeline heating, water supply, gas and other industries.

Fourth, the main features:

1. The flow rate of gas, liquid and steam can be accurately measured in a wide flow range without being affected by the physical properties of the fluid;

2. Not affected by temperature and pressure, at the same time not easy to block, not easy to stick, not easy to scale, high temperature and high pressure;

3. Safe and explosion-proof, suitable for harsh environments;

4. No moving parts, no holes and gaps, the product has no wear, is resistant to dirt, does not require mechanical maintenance, and has a long service life;

5. The use of micro-power high-tech, battery-powered on-site display flowmeter, can run for more than two years without power;

6. Integrated design of temperature and pressure compensation;

7. The current output is of electrical isolation type, with good common mode interference suppression capability;

8. The flow value and the accumulated flow value are displayed at the same time, and there is no need to switch in turn;

9. Anti-vibration probe is adopted to effectively eliminate the influence of external vibration;

10. The split signal converter is adopted, and the cable length is 100 meters;

11. The range ratio is as wide as 20:1;

12. The overall structure design of the instrument is reasonable, the dynamic measurement range is wide, and the pressure loss is small;

13. The meter body is made of stainless steel, which is suitable for the measurement of corrosive media;

14. On-site liquid crystal display, pulse, 4~20mA output or 485 communication, can be connected with industrial automation system.

Five, technical parameters:

1. Measuring medium: gas, liquid, vapor;

2. Connection method: flange-mounted type, flange type, plug-in type;

3. Diameter specifications: flange-mounted caliber options are 25, 32, 50, 80, 100;

4. The diameter of flange connection type is 100, 150, 200;

5. Flow range (see flow range table)

6. The normal measurement flow velocity range: Reynolds number 1.5×104～4×106; gas 5～50m/s; liquid 0.5～7m/s;

7. Measurement accuracy 1.0 class 1.5 class;

8. The temperature of the measured 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. The pulse duty cycle is about 50%, and the transmission distance is 100m;

11. The pulse current remote transmission signal is 4～20 mA, and the transmission distance is 1000m;

12. The operating environment of the instrument 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 grade Intrinsically safe iaIIbT3-T6, protection grade IP65.

6. Installation requirements:

1. The vortex street can only be measured in one direction. When installing, pay attention to ensure that the flow direction of the medium is consistent with the direction indicated by the arrow of the flowmeter.

2. The installation method is vertical installation, and the medium passes through the flow meter from bottom to top. That is, the flowmeter is installed on the vertical pipe, and the flow direction is 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, because the highest point often accumulates gas, the pipeline is not full, and the outlet cannot be directly Let go.

4. When measuring high temperature fluid, try to install it vertically; if it has to be installed horizontally, please install the transmitter part of the flowmeter vertically downward, or install it horizontally to avoid excessive temperature; pay attention to the air flow at the installation location or well ventilated.

5. Requirements for straight pipe sections: at least 15 times the pipe diameter before the flowmeter and 5 times the pipe diameter after the flowmeter. If there are interference sources such as elbows, indents, and expansions in front of the flowmeter, it is necessary to ensure that the pipe diameter is 30-40 times the pipe diameter before the flowmeter, and 6 times the pipe diameter after the flowmeter. The flow meter should be installed upstream of the regulating valve, pressure or temperature sensor.

6. When installing, note that the diameter of the pipe should be slightly larger than or equal to the inner diameter of the instrument.

7. When using the sealing ring, pay attention 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 is located in the center of the pipeline.

8. When the cable inlet is sealed for the electrical connection of the instrument, the sealing of the inlet hole must be paid attention to. It is necessary to select the corresponding sealing interface (M20×1.5; 1/2'NPT; G1/2') according to the model of the instrument cable entry, and install it correctly and tightly. There is no sealing joint, or the installation is sloppy, and the sealing effect cannot be achieved.