Gas vortex flowmeter

gas vortex flowmeter series is mainly used for medium industrial pipe fluid flow measurement of steam, steam vortex flowmeter features low pressure loss, measuring range, high precision in the measurement conditions are not nearly the volume density of the fluid flow , Pressure, temperature, viscosity and other parameters. No moving mechanical parts, so high reliability and little maintenance. Long-term stability of the instrument parameters. Gas flowmeter using piezoelectric stress sensors, high reliability, can be **0 ℃ ~ ***0 ℃ operating temperature range. With analog standard signal, but also digital pulse signal output, easily supporting the use of computers and other digital systems is a more advanced and ideal flow meter。

1、Works
    Triangle set in the steam flow cylindrical bluff body, alternately from both sides of the bluff body to generate a regular vortex, this vortex is called Carmen vortex, as shown, the vortex downstream of the bluff body listed in the non-symmetrically Order。
The occurrence frequency of the vortex set f, the average flow rate of the measured medium, the bluff body surface facing the flow width d, the body of the path to D, you can get the following relation：

　f=SrU1/d=SrU/md 　　　　　　　　　　　　　　　　　　　　（1）
Where U1 - the average velocity on both sides of the bluff body，m/s；
Sr*-Strouhal numberï¼›
m*-Segment Area on both sides of the bluff body and the pipe cross-sectional area ratio

　Pipe volume flowqv为
qv=πD2U/4=πD2mdf/4Sr 　　　　　　　　　　　　　　　　(2)
K=f/qv=[πD2md/4Sr]*1 　　　　　　　　　　　　　　　　 (3)
Where K - the instrument flow coefficient, the number of pulses / m3（P/m3）。
K addition to the bluff body, the relevant geometry of the pipeline, but also with the Strouhal number related. Strouhal number of dimensionless parameters, it is with the bluff body shape and Reynolds number on Figure 2 shows the cylindrical bluff body of the Strouhal number and the pipe Reynolds number diagram. The figure shows that in ReD = 2 × **4 ~ 7 × **6 range, Sr can be considered as a constant, which is the normal operating range instrument. When the measurement of gas flow, VSF formula for the flow meter

 

(4)

Figure 2 Relationship between Strouhal number and Reynolds number curve

Where qVn, qV - were under standard conditions (0oC or *0oC, **1.**5kPa) and the volume of traffic conditions，m3/h； 
Pn，P*-Respectively, under standard conditions and conditions for the absolute pressure，Pa；
Tn，T*-Respectively, under standard conditions and conditions of the thermodynamic temperature，K；
Zn，Z*-Respectively, under standard conditions and conditions for the gas compressibility。 
Can be seen from the above equation, VSF output pulse frequency signal from fluid properties and composition changes, that instrument coefficient in a certain Reynolds number range, and only with the bluff body shape and size of the pipe and so on. But as the material balance and energy flow in the measurement of mass flow to be detected, then the flow meter should also monitor the volume of the output signal flow and fluid density, fluid properties and composition of the flow measurement or have a direct impact。

　　Gas flowmeter is based on the vortex principle Carmen Measurement of fluid flow in closed conduits new flow meter. Media because of its good ability to adapt, without direct measurement of temperature and pressure compensation can be steam, air, gas, water, liquid volume flow conditions, with temperature and pressure sensor measures the standard volume flow and mass flow conditions, is to cut expenditure Flowmeter ideal alternative。
To improve the high temperature gas flowmeter and anti-vibration performance, the company recently developed a JGLUG improved vortex flow sensors, because of its unique structure and selection of materials so that the sensor at high temperature (**0 ℃), high vibration (≤ 1g) use of harsh conditions。
In practice, the maximum flow rate is often much lower than the upper limit of the instrument, as the load changes, the minimum flow rate and often lower than the lower limit of the instrument, meters are not working in its optimum operating segment, in order to solve this problem , commonly used in the measurement at the reduced diameter to improve the measurement at the flow rate, and smaller-diameter instrument to facilitate selection of the measurement instrument, but this must be adjustable means between adjustable tube and instrument over a length of straight pipe section *5D to Rectifier, the processing, installation is not easy. Our company has developed a vertical section of the shape of arc rectifier LGZ adjustable, with a rectifier to improve the flow and velocity distribution change multiple roles, its structure, small size, process tube diameter of only 1 / 3, one made with the vortex flowmeter Not only do not need to add another section of straight pipe, you can also reduce the process tube straight pipe requirements, installation is easy。

    For ease of use, battery-powered local display type gas flowmeter with high-tech micro-power consumption, the use of lithium uninterrupted power supply can run more than one year, saving the cable and display instruments for the procurement and installation costs, may in Display instantaneous flow, cumulative flow. Temperature compensation is also a body vortex flowmeter with a temperature sensor, can measure the temperature of saturated steam and calculate the pressure, which shows the mass flow of saturated steam. Temperature and pressure compensation for a body with a temperature and pressure sensors, gas flow measurement can be directly used to measure the temperature and pressure of gas medium, which shows the standard conditions of gas volume flow。
â—†Measurement medium: gas, liquid, vapor
â—†Caliber caliber cartridge specifications Fa Lanka choice*5,*2,*0,*0,**0
â—†Flange type caliber choice **0,**0,**0
◆Flow velocity measurement range of normal measurement range of Reynolds number 1.5 × **4 ~ 4 × **6; gas 5 ~ *0m / s; liquid 0.5 ~ 7m / s
The normal range of liquid flow measurement, gas flow measurement range shown in Table 2; steam flow range in Table 3
â—†Accuracy 1.0 1.5
◆Measured medium temperature: temperature **5 ℃ ~ **0 ℃
◆High temperature –*5℃～**0℃ **5℃～**0℃
â—†Output signal pulse high voltage output signal low 8 ~ *0V 0.7 ~ 1.3V
â—†Pulse duty cycle of about *0%, transmission distance is **0m
â—†Remote signal pulse current 4 ~ *0 mA, transmission distance is ***0m
◆Instrument ambient temperature: **5 ℃ ~ **5 ℃ Humidity: 5 ~ *0% RH*0 ℃
â—†Material stainless steel, aluminum
â—†Power Supply DC*4V or lithium battery 3.6V
â—†Intrinsically safe explosion-proof leveliaIIbT*-T6
Protection IP*5

Intelligent Vortex Flowmeter Selection of gas