DN80 Vortex Flow Meter

Product Name:DN80 Vortex Flow Meter

Manufacturer: Jiangsu Runyi Instrument Co., Ltd

Product Overview:

DN80 Vortex Flow Meter--Jiangsu Runyi specializes in producing products with temperature and pressure compensation, specifically designed for measuring steam flow meters. The companyWith years of R&D and production experience, all products have passed the inspection. Every product produced by the company is included in the inspection package,strengthManufacturer, trustworthy! The boiler steam vortex flowmeter produced by the company utilizes the "Karman vortex street" measurement principle and adopts digital signal processing technology in the signal processing circuit. It is designed with a 14 level digital bandpass filter and uses fast Fourier software algorithm to improve the signal detection sensitivity of the vortex street, enhance the anti vibration performance of the vortex street flowmeter, and break through the limitations of traditional simulation methods for processing vortex street signals. By using anti-interference circuit and anti vibration sensing head, the instrument has certain anti environmental vibration performance to measure the working condition volume flow rate of the medium in the closed pipeline. It has many advantages that cannot be achieved by other flow meters. Since the 1970s, it has developed rapidly. Compared with the turbine flowmeter, it has no movable mechanical parts, so the maintenance volume is small, the instrument constant is stable, and it is easy to maintain. Ensure accuracy in the work environment. Compared with orifice plates, it has a larger measurement range, smaller pressure loss, and higher accuracy. Vortex flowmeter belongs to fluid vibration flowmeter, which can be used to measure saturated steam, superheated steam, various gases (such as coal gas, natural gas, compressed air, oxygen, nitrogen, argon, hydrogen, carbon dioxide, etc.), water and low viscosity, low-temperature liquids (such as salt water, liquid nitrogen). Gas liquid universal, no need for real liquid calibration; Can accurately measure the flow rate of steam, gas, and liquid in closed pipelines. There are various types available for selection, including anti vibration, anti-corrosion, high temperature, explosion-proof, etc. DN200 and above are insertable; Suitable for industrial processes such as metallurgy, chemical industry, petroleum, gas, urban water supply and drainage, food, textile, mining, energy management, and environmental engineering.

Product working principle:

The boiler steam vortex flowmeter is equipped with a triangular column type vortex generator in the steam fluid, which alternately generates regular vortices from both sides of the vortex generator. This type of vortex is called a Karman vortex, as shown in the right figure. The vortex columns are asymmetrically arranged downstream of the vortex generator.
Assuming the frequency of vortex occurrence is f, the average flow velocity of the measured medium is, the width of the upstream surface of the vortex generator is d, and the diameter of the body is D, the following relationship can be obtained:
f=SrU1/d=SrU/md （1）
In the formula, U1 represents the average velocity on both sides of the vortex generator, m/s；
Sr Strouhal number;
M - The ratio of the bow shaped area on both sides of the vortex generator to the cross-sectional area of the pipeline
The volumetric flow rate qv inside the pipeline is
qv=πD2U/4=πD2mdf/4Sr (2)
K=f/qv=[πD2md/4Sr]-1 (3)
In the formula, K represents the instrument coefficient of the flowmeter, with pulse count in m3 (P/m3).
K is not only related to the geometric dimensions of the vortex generator and pipeline, but also to the Strouhal number. The Strouhal number is a dimensionless parameter that is related to the shape of the vortex generator and the Reynolds number. Figure 2 shows the relationship between the Strouhal number of a cylindrical vortex generator and the Reynolds number of a pipeline. As shown in the figure, Sr can be regarded as a constant within the range of ReD=2 × 104 to 7 × 106, which is the normal operating range of the instrument. When measuring gas flow rate, the flow calculation formula for VSF is
(4)
Figure 2: The relationship curve between Strouhal number and Reynolds number
In the equation, qVn and qV - represent the volumetric flow rates under standard conditions (0oC or 20oC, 101.325kPa) and operating conditions, respectively, m3/h；
Pn and P - are the pressures under standard and operating conditions, respectively, Pa；
Tn and T - are the thermodynamic temperatures under standard and operating conditions, respectively, K；
Zn and Z - are the gas compression coefficients under standard and working conditions, respectively.
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.
The steam vortex flowmeter is a new type of flowmeter that measures 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 steam vortex flow meters, our company has recently developed the SKLUG improved vortex flow sensor. Due to its structure and material selection, the sensor can be used in harsh working conditions such as high temperature (350 ℃) and strong vibration (≤ 1g).
In practical applications, large flow rates are often much lower than the upper limit of the instrument, and with changes in load, small flow rates often fall below the lower limit of the instrument. The instrument does not work in its working section. To solve this problem, it is usually used to reduce the diameter at the measuring point to increase the flow velocity at the measuring point, and smaller diameter instruments are selected to facilitate the measurement of the instrument. However, this variable diameter method requires a straight pipe section with a length of 15D or more between the variable diameter tube 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 on-site display steam vortex flowmeter adopts low-power high-tech. It can operate continuously for more than a year using 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 and 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

Product advantages:
1. The boiler steam vortex flowmeter has a wide temperature range for the measured medium and can measure high temperature media ranging from -25 ° C to 400 ° C;
2. Continuous flow under normal temperature fluid conditions can be repaired online.
3. Adopting a new structural design that is resistant to mechanical vibration, impact, and dirt.
4. Adopting advanced integrated circuits, it has high signal processing accuracy, high anti-interference ability, and high reliability.
5. Wide range models can be selected to achieve * low flow performance and expanded flow range.
6. Blunt cross-sectional shape: This is the condition for generating vortices;
7. The upper and lower cross-sectional shapes are the same, and the left and right are also symmetrical: the flow is close to the condition of two-dimensional flow;
8. The boundary layer separation point is fixed under the condition that the Strouhal number St remains constant. The installation position of the vortex generator in the pipeline must be strictly symmetrical. The upstream of the vortex generator must have a straight pipe with a diameter of more than 10 times D, and the downstream must have a straight pipe with a diameter of 5 times D.

Product Technical Parameters:

1. Measurement medium: gas, liquid, vapor
2. Caliber specification: Flange card mounted caliber selection: 25, 32, 50, 80, 100
3. Flange connection type caliber selection: 100, 150, 200
4. The normal measurement range for flow rate is Reynolds number 1.5 × 104 to 4 × 106; Gas velocity of 5-50m/s; Liquid 0.5-7m/s
The normal measurement range for liquid and gas flow is shown in Table 2; The steam flow range is shown in Table 3
5. Measurement accuracy level 1.0 and 1.5
6. Temperature of the tested medium: normal temperature -25 ℃ -100 ℃
7. High temperature -25 ℃~150 ℃ -25 ℃~250 ℃
8. Output signal pulse voltage output signal high level 8-10V low level 0.7-1.3V
9. Pulse duty cycle of about 50%, transmission distance of 100m
10. Pulse current remote transmission signal 4-20 mA, transmission distance of 1000m
11. Instrument operating environment temperature: -25 ℃~+55 ℃ humidity: 5-90% RH50 ℃
12. Material: stainless steel, aluminum alloy
13. Power supply DC24V or lithium battery 3.6V
14. Explosion proof grade intrinsic safety type iaIIbT3-T6
15. Protection level IP65

Product selection: