I. 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 and high precision. It is almost not affected by fluid density, pressure, temperature, viscosity and other parameters when measuring volume flow under working conditions. No moving mechanical parts, so high reliability, small maintenance. Instrument parameters can be stable for a long time. The instrument uses piezoelectric stress sensor, high reliability, can work in the working temperature range of -20℃ ~ +250℃. It has analog standard signal and digital pulse signal output. It is easy to use with computer and other digital systems. It is an ideal flowmeter.
It can be seen from the above formula that the pulse frequency signal output by VSF is not affected by the changes of fluid physical properties and components, that is, within a certain Reynolds number range, the instrument coefficient is only related to the shape and size of vortex generator and pipe. But as a flowmeter in the material balance and energy metering needs to detect the mass flow, then the output signal of the flowmeter should monitor the volume flow and fluid density at the same time, fluid physical properties and components have a direct impact on the flow metering.
LUGB series vortex flowmeter is based on karman vortex principle of closed pipeline fluid flow measurement of the new flow meter. Because of its good medium adaptability, it can directly measure the volume flow of steam, air, gas, water and liquid without temperature and pressure compensation. Equipped with temperature and pressure sensors, it can measure the volume flow and mass flow of standard conditions. It is an ideal alternative product for throttling flowmeter.
In order to improve the high temperature resistance and anti-vibration performance of vortex flowmeter, our company LUG improved vortex street flow sensor, because of its structure and material selection, the sensor can be used in the harsh working conditions of high temperature (350℃), strong vibration (≤1g).
In practical application, the large flow is often far lower than the upper limit of the instrument. With the change of load, the small flow is often lower than the lower limit of the instrument. The instrument does not work in the working section. However, in this method of reducing diameter, there must be a straight pipe section with a length of more than 15D between the reducing pipe and the instrument for rectification, so that processing and installation are not convenient. Developed by our company profile shape of circular arc LGZ variable diameter rectifier, a rectifier, improve the velocity and change the velocity distribution of multiple function, its structure size is small, just as the process pipe inner 1/3, and the vortex street flowmeter into an organic whole, not only does not need to be added a straight pipe, and can also reduce the requirement for process straight section of pipe installation is very convenient.
In order to be easy to use, battery-powered local display vortex flowmeter uses micro power consumption high-tech, using lithium battery power supply uninterrupted operation for more than a year, saving the cable and display instrument procurement and installation costs, can display instantaneous flow, cumulative flow, etc.. Temperature compensation a vortex flowmeter also has a temperature sensor that can directly measure the temperature of saturated steam and calculate the pressure, thus showing the mass flow rate of saturated steam. Temperature and pressure compensation a body with temperature and pressure sensor, used for gas flow measurement can directly measure the temperature and pressure of the gas medium, so as to display the standard condition of the gas volume flow.
Ii. Working principle:
LUGB series vortex flowmeter is composed of vortex generating body, detection probe and corresponding electronic circuit in the flow field. When the fluid flows through the vortex-generating body, two rows of vortex-generating bodies are formed on both sides of the vortex-generating body. This vortex is called Karman vortex street. On the basis of Karman vortex street theory, it is proposed that the frequency of Karman vortex street is proportional to the flow velocity of fluid, and the relationship between frequency and flow velocity is given as follows:
F = St × V/d
Frequency of F vortex street (Hz)
Average velocity on both sides of V vortex generator (m/s)
St Strohal coefficient (constant)
These alternating vortices form a series of alternating negative pressure. The pressure acts on the detection probe and produces a series of alternating electrical signals. After the conversion, shaping and amplification of the preamplifier, the output pulse frequency signal (or standard signal) is proportional to the vortex synchronization.
Iii. Selection and Application:
1, in order to convenient use, battery powered by micro power consumption high-tech, using lithium battery power supply uninterrupted operation for more than a year, saving the cable and display instrument procurement and installation costs, can display instantaneous flow, cumulative flow, etc..
2, temperature compensation a body also has a temperature sensor, can directly measure the temperature of saturated steam and calculate the pressure, so as to show the mass flow of saturated steam.
3, temperature and pressure compensation a body with temperature and pressure sensor, used for gas flow measurement can directly measure the temperature and pressure of the gas medium, so as to display the volume flow of the gas standard condition.
4, widely used in petroleum, chemical, metallurgy, machinery, papermaking, as well as urban pipeline heating, water supply, gas and other industries of low viscosity liquid, gas, steam and other single-phase fluid process measurement and energy saving management.
Iv. Main Features:
1, can accurately measure the flow of gas, liquid and steam in a wide flow range without being affected by the physical properties of the fluid;
2, not affected by temperature and pressure, and not easy to block, not easy to stick, not easy to scale, high temperature, high pressure;
3. Safe and explosion-proof, suitable for harsh environment;
4, no moving parts, no holes and gaps design, no wear products, dirt resistance, no mechanical maintenance, long service life;
5, the use of micro power consumption high-tech, battery-powered field display flowmeter, without power operation for more than two years;
6. Integrated design of temperature and pressure compensation;
7, the current output is electrical isolation type, with good common mode interference suppression ability;
8, display the flow value and the accumulated flow value at the same time, do not have to take turns to switch;
9, using anti-vibration probe, effectively eliminate the impact of external vibration;
10, split type signal converter, cable length of 100 meters;
11, range ratio of 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 body is made of stainless steel, suitable for the measurement of corrosive media;
14, the field LCD display, pulse, 4 ~ 20mA output or 485 communication, can be connected with the industrial automation system.
Five, technical parameters:
1, measurement medium: gas, liquid, steam;
2, connection mode: flange card type, flange type, insert type;
3, caliber specifications flange card mounted caliber selection of 25,32,50,80,100;
4, flange connection caliber of 100,150,200;
5. Flow range (see flow range table)
6. Reynolds number of normal measured flow velocity range 1.5×104 ~ 4×106; Gas 5 ~ 50M /s; Liquid 0.5 ~ 7m/s;
7. Measurement accuracy 1.0 and 1.5;
8, the measured medium temperature: 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 is about 50%, transmission distance is 100m;
11, pulse current far-transmission signal 4 ~ 20 mA, transmission distance is 1000m;
12, the 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 grade intrinsical safety type IAIIBT3-T6, protection grade IP65.
Six, installation requirements:
1. Vortex street can only be measured in one direction. When installing, ensure that the flow direction of media is consistent with the direction indicated by the flowmeter arrow.
2, the installation mode is vertical installation, medium from bottom to top through the flow meter. The flow meter is installed in a vertical pipe with flow direction from bottom to top.
3. When installed horizontally, the flowmeter must be installed in the high pressure area of the whole system, and ensure the corresponding outlet pressure; Do not install in the highest point of the pipeline, because the highest point is often gas accumulation, the pipeline is not full, the outlet can not be directly empty.
4, when measuring high temperature fluid, try to use vertical installation mode; If it has to be installed horizontally, please put the transmitter part of the flowmeter vertically downward or horizontally side mounted to avoid high temperature; Note that the installation position has good air flow or ventilation.
5. Requirements for straight pipe section: ensure at least 15 times pipe diameter in front of flowmeter and 5 times pipe diameter in back of flowmeter. If there is elbow, indent, expansion and other interference sources in front of the flowmeter, it is necessary to ensure that the pipe diameter of the front of the flowmeter is 30-40 times, and the pipe diameter of the back of the flowmeter is 6 times. The flowmeter shall be installed upstream of the regulator, pressure or temperature sensor.
6, pay attention to the pipe diameter should be slightly greater than or equal to the instrument diameter.
7. When using the sealing ring, note that the inner diameter of the sealing ring should be slightly greater 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, cable inlet sealing Instrument electrical connection, pay attention to the wire inlet hole sealing. Must *** select corresponding sealing interface according to meter cable inlet type (M20 χ 1.5; 1/2'NPT; G1/2') and install correctly and tightly. No sealing joint, or careless installation, can not reach the sealing effect.
