Vortex flowmeter selection considerations

- Nov 20, 2017 -

1. Accuracy

   The accuracy of the Ott vortex flowmeter is approximately ± 0.5% R ± 2% R for liquids and ± 0.2% ± 0.5% for ± 1% R ± 2% R for gases. Vortex flowmeter due to the low coefficient of the instrument, the frequency resolution is low, the larger the caliber of the lower, so gauge diameter should not be too large. (DN300 or less). Wide range of vortex flowmeter features. But what is important is the lower limit of traffic. The average liquid flow rate of the lower limit of 0.5 m / s, the gas is 4 ~ 5 m / s. The normal flow of the vortex flowmeter is best in the normal measurement range of 1/2 to 2/3 Department.

   Vortex flowmeter meter factor is not affected by the physical properties of the time, which is a great advantage, you can use a typical plastic medium calibration applied to other media to go, to solve the problem of school driving equipment to facilitate. However, it should be noted that due to the wide range of liquid and gas flow rates, the frequency range is also very different. Vortex signal processing amplifier circuit, the filter passband is different, the circuit parameters are different, therefore, the same circuit parameters can not be used for different side of the media. Media change, the circuit parameters should also be changed.

Smart vortex flowmeter

   In addition, the density of gas and liquid vary greatly, and the signal intensity generated during vortex separation is proportional to the density. Therefore, the signal strength difference is also great, liquid, air amplifier circuit gain. Trigger sensitivity are all different piezoelectric charge difference, the charge amplifier parameters are also different. Even with the gas (or liquid, Yan steam) with the media pressure, temperature, density, the use of different flow range, the signal strength is different, the same circuit parameters to be changed. Therefore, the same vortex flowmeter without hardware or software changes, change the use of medium or instrument diameter is not feasible.


Smart vortex flowmeter

2. The main problem

    Vortex flowmeter extensive use of more than ten years, the use of results is not satisfactory. To sum up the main reasons for the following.

1) product quality problems, design principles or design programs have serious defects in product materials, poor quality of the process. Especially in recent years. Some manufacturers face the one-sided pursuit of profit, and the crude product of the product defeats the reputation of the vortex flowmeter.

2) instrument selection and use of the user inaccurate given process parameters make improper selection of the installation site have a problem. Installation does not meet the requirements

3) On-site adjustment problems, lack of adjustment on site or improper adjustment. Correct adjustment is the key to good use.


Smart vortex flowmeter

3. Applicable situation

   Vortex flowmeter is not suitable for measuring low Reynolds number fluid, low Reynolds number Strouhal number changes with the Reynolds number, the instrument linearity worse, the instrument linearity worse, high fluid viscosity will significantly affect or even hinder One of the limitations of vortex generation and selection is that it can not be used below the limiting Reynolds number.

   Ott vortex flowmeter fluid is more applicable, but for the dirty nature of the fluid to pay attention. Fluid containing solid particles scouring the vortex generating body will generate noise and wear the vortex generating body. If the contained short fibers wound on the vortex generator will change the meter factor.

   Vortex flowmeter in the application of mixed-phase fluid less experience, generally can be used for containing scattered, even the tiny bubbles, but the volume gas content should be less than 7% of a 10% gas-liquid two-phase flow, if more than 2% Instrument coefficient should be corrected. It can be used for gas-solid, liquid-solid two-phase flow with dispersed and uniform solid particles with content less than 2%. Can be used for non-dissolved liquid (such as oil and water) two-component flow.

Smart vortex flowmeter

   Pulsating and swirling flow can have a serious impact on SF. If the ripple frequency co-occurs with the vortex frequency band, the vibratile signal may be "locked-in" due to the normal operation of the resonant breakdown and the equipment, where the signal is fixed at a certain frequency. "Locked" and pulsation amplitude, vortex body shape and blockage and so on. The normal operation of the vortex flowmeter pulsation closed-value remains to be determined experiment. Since the 1980s, domestic and overseas flowmeters have carried out many experimental studies on the application of the macro-controlled vortex flowmeter in mixed-phase flow and pulsatile flow. The technical report already published by the International Organization for Standardization (ISO) has also paid attention to this aspect.


4. Economic

    Vortex flowmeter in a large number of flowmeter economy is better, is an affordable flow meter. The basic performance of the vortex flowmeter in the middle level, the purchase cost is lower than the quality, electromagnetic, volumetric, etc., while installation, operation, maintenance costs lower than throttling, volumetric, turbo and so on. If only as a control system instrumentation can be used to save school dry-cycle calibration costs.

    OTC Instrument Manufacturing Co., Ltd. Yantai Development Zone, professional selection, professional quotes, summed up years of production experience in practice, and strive to develop a variety of flow measurement products, according to different customer needs, different customer equipment requirements, professional custom All kinds of non-standard flowmeter products, in full accordance with the parameters and requirements provided by customers for customers "tailored", adhere to the "quality first, users first" principle of Zhichang to ensure long-term product quality stability and continuously improve, To provide users with high-quality products and improve their services. Ott meter factory to ensure that the flow meter to maximize the effect, to bring customers more convenience and effectiveness.

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