Application: LU series vortex flowmeter is mainly used for flow measurement of industrial pipeline media, such as gas, liquid, steam and other media. It is characterized by small pressure loss, large measuring range and high accuracy, and is almost unaffected by fluid density, pressure, temperature, viscosity and other parameters when measuring volume flow in working conditions. No moving mechanical parts, so high reliability, small maintenance, instrument parameters can be long-term stability. The vortex flowmeter adopts piezoelectric stress sensor with high reliability and can operate in the operating temperature range of -20℃ ~ +250℃. There are analog standard signal, but also digital pulse signal output, easy to use with computer and other digital systems, is a more advanced, ideal flow meter. Principle of vortex flowmeter: the vortex flowmeter sets triangular column vortex generator in the fluid, and then regular vortexes are generated alternately from both sides of the vortex generator. Such vortexes are called karman vortexes. As shown in the figure on the right, the vortex columns are arranged asymmetrically in the downstream of the vortex generator. Assuming that the occurrence frequency of the vortex is f, the average velocity of the measured medium is, the width of the inlet surface of the vortex generator is, and the surface diameter of the vortex generator is D, the following relationship can be obtained: f=SrU1/=SrU/m, U1-- the average velocity on both sides of the vortex generator, m/s; Sr-- strouhal number; The volume flow in the pipeline qv is: qv= 2U/4= 2mf/4Sr, K=f/qv=[2m/4Sr]-1 K-- meter coefficient of the flow meter, pulse number /m3 (P/m3). K is related not only to the vortex generator and the pipe geometry size, but also to the strouhal number. Strouhal number is a dimensionless parameter, which is related to the shape and Reynolds number of the vortex generator. Figure 2 shows the relationship between the strouhal number of the cylindrical vortex generator and the Reynolds number of the pipeline. As can be seen from the figure, in the range of Re=2×104 ~ 7×106, Sr can be regarded as a constant, which is the normal working range of the instrument. When measuring the gas flow, the flowmeter formula of V is

In the relation curve between strauhal number and Reynolds number, qVn and qV are respectively the volume flow under standard state (0oC or 20oC, 101.325kPa) and working condition, m3/h. Pn, P-- are the pressure under standard state and working condition, respectively, Pa; Tn, T-- are the thermodynamic temperature under standard state and working condition, K; Zn and Z-- are gas compressibility in standard state and working state respectively. As can be seen from the above equation, the pulse frequency signal output by V is not affected by the physical properties and component changes of the fluid, that is, the meter 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, mass flow rate should be detected in material balance and energy measurement. In this case, the output signal of the flowmeter should be simultaneously monitored for volume flow rate and fluid density. The physical properties and components of the fluid have a direct impact on the flow measurement. The vortex flowmeter is a new type of flowmeter which can measure the fluid flow in closed pipeline according to the principle of karman vortex. 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, making it an ideal substitute for throttling flowmeter. In order to improve the high temperature resistance and anti-vibration performance of the vortex flowmeter, our company has recently developed the LU improved vortex flow sensor. Due to its special structure and material selection, the sensor can be used under the harsh conditions of high temperature (350℃) and strong vibration (≤1g). In practical application, often traffic far below the threshold value, as the change of load, flow rate and tend to be lower than the lower limit value, the instrument is not in its work, in order to solve this problem, usually used in the measurement of reducing, improve the measurement of flow velocity and select the instrumentation for measuring instrument, but this way of variable diameter in variable diameter pipe length between the instrument and have for more than 15 straight pipe rectifier, processing, installation is inconvenient. 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 use conveniently, the local display vortex flowmeter powered by battery adopts the new technology of micro-power consumption, which is powered by lithium battery and can run continuously for more than one year, which saves the cost of cable and display instrument procurement and installation, and can display instantaneous flow, accumulated flow, etc. The temperature compensation 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 of saturated steam. The temperature-pressure compensation system is equipped with temperature and pressure sensors for gas flow measurement, which can directly measure the temperature and pressure of the gas medium, thus showing the standard volume flow of the gas. ◆ measuring medium: gas, liquid and steam; ◆ diameter: flange card-mounted caliber: choose 25,32,50,80,100; flange connection caliber: choose 100,150,200; flow measurement range: normal measurement flow rate range: Reynolds number: 1.5×104 ~ 4×106; Gas 5 ~ 50m/s; The measurement range of liquid and gas flow is shown in table 2. Steam flow range are shown in table 3 pieces measuring accuracy 1.0 magnitude 1.5 on the Richter scale temperature measured medium: normal temperature - pieces of 25 ℃ ~ 100 ℃ high temperature - 25 ℃ ~ 150 ℃ to 25 ℃ ~ 250 ℃ mixer output signal pulse voltage output signal high level 8 ~ 10 V low-level pieces from 0.7 V to 1.3 V pulse duty ratio of about 50, transmission distance is 100 m pieces pulse current 4 ~ 20 mA remote transmission signal, transmission distance is 1000 m instrument using the environment temperature: 25 ℃ ~ + 55 ℃, humidity: 5 ~ 90 RH50 ℃ in pieces of stainless steel material, Aluminum alloy ◆ C24V power supply or lithium battery 3.6v ◆ explosion-proof class iaiibt3-t6 protection class IP65 vortex flowmeter product selection