Vortex Flow Meter
The vortex flowmeter is used for measuring the flow velocity of gases and liquids in pipelines flowing full. The measuring principle is based on the development of a Karman vortex shedding street in the wake of a body built into the pipeline.
The periodic shedding of eddies occurs first from one side and then from the other side of a bluff body (vortex-shedding body) installed perpendicular to the pipe axis. Vortex shedding generates a so-called “Karman vortex street” with alternating pressure conditions whose frequency is proportional to the flow velocity.
The discharge rate of Karman Vortex Street is related to the width of triangular prism and the flowrate of the fluid, but have nothing to do with parameters like fluid temperature and pressure. It can be expressed by the formula as below:
f=StV/d Thereinto:
f—-the frequency of Karman Vortex Shedding
St—-Strouhal Number V—-velocity
d—-width of the triangular prism
| DN | B0 | C0 | D0 | H0 | matched with seamless steel tube |
|---|---|---|---|---|---|
| 15 | 65 | 101 | 125 | 422 | φ18×1.5 |
| 20 | 65 | 101 | 125 | 422 | φ26×3 |
| 25 | 65 | 101 | 125 | 422 | φ32×3.5 |
| 32 | 70 | 110 | 145 | 427 | φ38×4 |
| 40 | 75 | 115 | 145 | 427 | φ45×2.5 |
| 50 | 75 | 117 | 160 | 435 | φ57×35 |
| 65 | 75 | 123 | 180 | 445 | φ73×4 |
| 80 | 84 | 132 | 296 | 450 | φ89×4.5 |
| 100 | 90 | 138 | 230 | 474 | φ108×4 |
| 125 | 100 | 152 | 245 | 482 | φ133×4.5 |
| 150 | 120 | 174 | 280 | 499 | φ159×4.5 |
| 200 | 150 | 206 | 336 | 526 | φ219×9 |
| 250 | 160 | 216 | 406 | 563 | φ273×10 |
| 300 | 170 | 228 | 460 | 590 | φ325×12 |
Strouhal number(St) is a important parameter of vortex flowmeter, it is only related to Reynolds number(Re). Only if Re is between 2 × 104 and 7 × 106, keeps being a constant(0.17~0.18). In this case, the flowrate can be measured through measuring vortex frequency signal and the flow can be worked out through the flowrate of the fluid.
- Based on Von Kármán Effect
- Highly Accurate
- Used to measure Flow Velocities of Liquid & Gases
- Useful in Flow measurements in Petroleum, Chemical, Power Industry etc
- No moving Parts makes it more useful in longer working hours
- Available in Line sizes from DN15 to DN500
- Having larger Temperature withstanding to suit to measure hot media
- Suitable for Gases
- air, oxygen, nitrogen, coal gas, natural gas, chemical gas, etc
- Suitable for Liquids
- water, high temperature water, oil, beverage, chemical liquid, etc.
- Suitable for Steam (Saturated, Super heated)
- Available in various Operating Voltages 24 V DC, 230 V AC
- Optional outputs of 4-20 mA, Pulse, RS485, Hart
- Suitable for Hazardous Location Installations
Remark: Reference fluid:
Liquid: normal temperature water (t=20℃,ρ=1000kg/m3)
Gas: normal temperature and pressure air (t=20℃, p=0.1MPa, ρ=1.025kg/m3)
| Nominal Diameter(mm) | Liquid Measuring range | Gas Measuring range | Nominal Diameter(mm) | Liquid Measuring range | Gas Measuring range |
|---|---|---|---|---|---|
| 15 | 0.25~5.00 | 4.0~50.0 | 125 | 10.0~400 | 133~4000 |
| 20 | 0.33~10.0 | 5.0~60.0 | 150 | 15.0~600 | 200~6000 |
| 25 | 0.40~16.0 | 6.0~160 | 200 | 25.0~1000 | 333~10000 |
| 32 | 0.63~25.0 | 10.0~250 | 250 | 40.0~1600 | 533~16000 |
| 40 | 1.00~40.0 | 16.0~400 | 300 | 580.0~2000 | 666~20000 |
| 50 | 1.50~60.0 | 25.0~600 | 350 | 75.0~3000 | 1000~30000 |
| 65 | 2.50~100 | 40.0~1000 | 400 | 1400~4000 | 1330~40000 |
| 80 | 4.00~160 | 60.0~1600 | 450 | 125~5000 | 1660~50000 |
| 100 | 6.00~250 | 80.0~2500 | 500 | 150~6000 | 2000~60000 |