Flange connected steam

characteristic

JD-LUGB seriesVortex FlowmeterIt is mainly used for flow measurement of industrial pipeline media fluids, such as gases, liquids, steam, and other media. Its characteristics are small pressure loss, large range, high accuracy, and almost unaffected by parameters such as liquid density, pressure, and temperature when measuring volumetric flow rate under working conditions. No movable mechanical parts, therefore high reliability and low maintenance. The instrument parameters can remain stable for a long time. This instrument adopts a piezoelectric stress sensor with high reliability and can operate within a working temperature range of -25 ℃ to+250 ℃. It has both analog standard signals and digital pulse signal outputs, making it easy to use in conjunction with digital systems such as computers. It is a relatively advanced and ideal flow meter.

Working principle

Setting up a vortex generator (blocking fluid) in the fluid and alternately generating regular vortices from both sides of the vortex generator is called a Karman vortex street, as shown in Figure 1. The vortices are arranged asymmetrically downstream of the vortex generator. Assuming the frequency of vortex occurrence is f, the average velocity of the incoming medium is U, the width of the vortex generator face is d, and the diameter of the body is D, according to the principle of Karman vortex street, the following relationship is obtained: f=StU1/d=StU/md In the formula, U1 represents the average velocity on both sides of the vortex generator, m/s St 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

Instantaneous volumetric flow rate qvFor: In the formula, K represents the instrument coefficient of the flowmeter, pulse count/(P/)

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, within the range of Re=2 × 104 to 7 × 106, St can be regarded as a constant, which is the normal operating range of the instrument. When measuring gas flow rate, the flow calculation formula for HLUG is

In the formula, QVn and QV - respectively represent the volumetric flow rates under standard conditions (20 ℃, 101.325kPa) and operating conditions,/h; Pn, P - are the absolute pressures in kPa under standard and operating conditions, respectively; Tn, T - thermodynamic temperatures under standard and operating conditions, 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 HLUG 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 the flowmeter.

Main technical parameters

1. Main technical parameters (see Table 1)

2. Liquid and working condition gas flow range (see Table 2)

Table 2

Diameter DN (mm) 25 32 40 50 65 80 100 150 200 Liquid（/h) 1~14 1.5～23 2.2～36 5~57 6.3～96 9~145 14~230 32~510 56~900 Gas（/h) 12~88 15~145 22.6～230 35~350 60~600 90~900 140~1400 300~3000 550~5500

3. Saturated steam mass flow range (see Table 3)

Table 3 Company: (kg/h)

Structure and dimensions

This seriesVortex FlowmeterThere are two connection methods and external dimensions available

Flange mounted and flange connected typesVortex FlowmeterThe size (1.6MPa) is shown in Table 4

centralizers Nominal Diameter mm pressure rating MPa L mm G D mm d 1 mm N－d2 d mm b mm weight Kg Room temperature and high temperature 25 2.5～4.0 80 342 500 76 - - 25 - 7 32 2.5～4.0 80 342 505 76 - - 32 - 10 50 2.5～4.0 80 337 515 86 - - 50 - 12.5 65 － 80 345 530 102 - - 65 - 28 80 1.6～2.5 100 350 540 112 - - 80 - 25 100 1.6～2.5 110 330 550 132 - - 100 - 35 150 1.6 140 355 575 203 - - 150 - 40 200 1.6 150 380 600 259 - - 200 - 46 Flange connection type 100 1.6 250 310 530 215 180 8－φ18 100 26 30 150 1.6 300 335 555 280 240 8－φ23 150 28 34 200 1.6 320 370 590 335 295 12－φ23 200 30 41

Meets the requirements of GB/T9119-2000. Selection and Calculation 1. The diameter of the flowmeter should be selected based on the maximum operating flow rate Qv. In order to obtain the widest possible operating flow range, the maximum operating flow rate should not be less than half of the rated maximum flow rate Qmax of the flowmeter. The linear flow range of the flowmeter corresponds to a Reynolds range of 2 × 104 to 7 × 106. The liquid meter can be selected by directly referring to Table 2 according to Figure 6, while the gas meter should be selected by calculating the flow range of the operating conditions and referring to Table 2 according to Figure 7. For measuring saturated steam, refer to Table 3. 4. The density of commonly used gas media under standard conditions (0.101235MPa, 20 ℃) is shown in Table 5 Table 5 gas Density (kg)/) gas Density (kg)/) gas Density (kg)/) acetylene 1.083 Butane 2.4163 ethane 1.2500 ammonia 0.7080 ethylene 1.1660 methane 0.6669 propane 1.8332 neon 0.83914 natural gas 0.776 air 1.2041 argon 1.6605 carbon dioxide 1.829 carbon monoxide 1.165 hydrogen 0.0838 oxygen 1.3302 Propylene 1.7459 nitrogen 1.1646 5. Pressure loss i. Pressure loss when measuring liquids Figure 8 shows the measurement of water (20 ℃, 1013mbar, ρ=998kg/）The relationship between pressure loss and flow rate during flow The measured density is ρSWhen dealing with other liquids, the pressure loss can be calculated using the following formula △ P '- pressure loss of the measured liquid (mbar) △ P - Pressure loss of water detected from Figure 8 (mbar) Ii. Pressure loss when measuring gas (superheated steam) Figure 9 shows air (20 ℃, 1013mbar, ρ=1.2kg/）The pressure loss. The pressure loss of other gases with different densities ρ S and air can be calculated according to the following formula △ P '- pressure loss of the measured medium △ P - The pressure loss of air detected from Figure 9 Figure 9 Air pressure loss (20 ℃, 1013mbar, ρ＝1.2kg/) 6. Calculation Example a. Examples of Liquid Calculation Examples of Liquid Calculation Liquid density 850kg/The kinematic viscosity is 2cst (=2 × 10 ^ 3)）The maximum flow rate is 50/h. Try to determine the diameter of the flowmeter. 1)QV=50/h. Directly refer to Table 2 and select caliber DN50 (Qmax=55)/h) . 2) According to Figure 6, the minimum linear flow rate corresponding to viscosity 2cst is Qmin=6/H. 3) Press QV=50/Refer to Figure 8 for △ P=460mbar 　 b. Examples of Gas Calculation CO2 gas with a temperature of 85 ℃ and a working pressure of 0.5MPa. Flow rate of 3500N m3/h, try to determine the diameter of the flow meter. ρn=1.829kg/ 2) Calculate operating flow rate: QV＝Qn×(ρn/ρ)＝3500×1.829/8.886=720/h. Refer to Table 2 and select caliber DN80 (Qmaz=900)/h) 3) Minimum flow rate: When ρ=8.886kg/m3, according to Figure 7, QVmin=50/h. Convert standard flow rate: QNmin=50×(ρ/ρn)=242.9/h 4) Pressure loss: QV=720/h. According to Figure 9, Δ P=19mbar, Find Δ P '=(8.886/1.2) × 19=140.7mbar c. Overheated steam measurement The maximum and minimum flow rates for measuring superheated steam can be obtained by multiplying the saturated steam parameters by the correction factors shown in Figure 10. Example: Diameter of 50mm, pressure of 10kgf/cAt a temperature of 250 ℃, the flow range of superheated steam is as follows: a=0.890b=0.840 from Figure 10. Refer to Table 3 for the measurement range of saturated steam (corresponding to DN50, 1.0MPa), and calculate the minimum flow rate Qmin=0.890 × 112=99.68kg/h and the maximum flow rate Qmax=0.840 × 1120=940.8kg/h. Minimum flow correction coefficient a Figure 10 Correction diagram of superheated steam coefficient model selection Vortex Flowmetertype JD-LUGB JD-LUW pulse output On site display with 4-20mA output Diameter (mm) Flow range（/h) DN25 DN32 DN40 DN50 DN80 DN100 DN150 Dn200 1-10 (liquid) 25-60 (gas) 1.5-18 (liquid) 15-150 (gas) 2.2-27 (liquid) 22.6-150 (gas) 4-55 (liquid) 35-350 (gas) 9-135 (liquid) 90-900 (gas) 14-200 (liquid) 140-1400 (gas) 32-480 (liquid) 300-3000 (gas) 56-800 (liquid) 550-5500 (gas) Note: 1. Please refer to Table 3 for the steam flow range. 2. DN250~DN600 can be ordered according to customer requirements. 3. Recommended for DN300 and above caliberInsertion vortex flowmeterCan be customized. pressure rating P1 P2 P3 1.6MPa 2.5MPa 4.0MPa Flange Material B1 B2 stainless steel carbon steel medium temperature T1 T2 T3 normal temperature high temperature steam Connection method L1 L2 Flange card installation type Flange connection type power supply D1 D2 Internal 3.6V power supply DC24V power supply accuracy class E1 E2 Level 1.0 Level 1.5 JD-LUGB- DN25- P1 B1 T1 L1 D2 E1 Example of Model

If there are two 90 points upstream of the sensor installation point on different planes. Bend, then: upstream straight pipe section ≥ 40D, downstream straight pipe section ≥ 5D

4. Pipeline adopts vibration reduction measures
Sensors should be avoided as much as possible from being installed on pipelines with strong vibrations, especially lateral vibrations. If installation is necessary, vibration reduction measures must be taken by installing pipeline fastening devices and adding anti vibration pads at the upstream and downstream 2D positions of the sensor.

7. Sensors installed on the side of horizontal pipelines
Regardless of the type of fluid being measured, the sensor can be installed on the upper side of the horizontal pipeline, especially for measuring superheated steam, saturated steam, and low-temperature liquids. If conditions permit, it is best to use side installation, so that the temperature of the fluid has less impact on the amplifier.

Correct wiring of vortex flowmeter

General principle: Use shielded cables in places that are susceptible to electrical noise interference. The shielding layer should be reliably connected to the grounding screw of the amplifier or to the working grounding in the control room. When working in high or low temperature environments or when the on-site air contains oil, solvents, or other corrosive gases, shielded cables suitable for such special situations should be used.
Wiring for frequency signal output
The flowmeter that outputs frequency signals is transmitted to other devices using a three wire system, with a power supply of 24VDC ± 10% (or 12VDC). The minimum load resistance of the output circuit is 10K Ω, and the maximum capacitance is 0.2UF.

Ordering instructions:

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