Weibiba flowmeter and its applications

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Weiba Flow Meters and Their Applications Differential pressure flow meters are widely used, accounting for over 70% of the total number of flow meters. However, the drawbacks of orifice plates in traditional applications, such as high pressure loss, high operating costs, a small range ratio, edge wear and deformation affecting long-term accuracy, as well as extensive installation and maintenance requirements, limit their use. The Aoniuba sensing elements have fatal weaknesses from design to practical application, which severely hinder the widespread use of this product in industrial settings. 　　The Weiliba sensing element and its technology represent the innovation and development of AnuoBa measurement technology. It has reached a new level in terms of accuracy, reliability, repeatability, clog resistance, and long-term high precision. 1 Principle of Operation The measurement principle of the Wilo sensor element is the same as that of other differential pressure flowmeters, following Bernoulli’s equation and the principle of fluid continuity. Its flow rate formula is: where qv is the volumetric flow rate under operating conditions ； p 0 is the average pressure in front of the probe ； p is the average pressure behind the probe ； K is the flow coefficient of Weibaa ； ρ is the fluid density ； S is the cross-sectional area through which the fluid flows in the Weiba. 2 Shape, Structure, and Technical Features Weiliba features a **cross-sectional shape of the head, along with an integrated metal chamber structure ； Ainiuba cross-sectional shape: one is circular, and the other is diamond-shaped. Their structure is all three-piece. Weiliba’s negative pressure holes are located on the sides and rear of the probe, before the point where the fluid separates from the probe; the front surface of the probe has a rough texture as well as anti-sedimentation grooves. The negative pressure hole of Aoniuba is located right behind the probe, on its central axis; the surface of the probe that faces the fluid is smooth. The differences in shape and structure between these two probes determine that their interaction characteristics when in contact with the fluid being measured also differ. 　　Figure 2 is a schematic diagram showing the interaction characteristics between Weiliba and the fluid. In terms of shape, the probe experiences the least pulling force, and the vortex shedding force generated is also small; the separation point between the fluid and the probe remains fixed. The front part of the probe is given a rough surface treatment, which functions as a turbulence generator; this ensures that the linearity of the flow coefficient K hardly changes with the Reynolds number, thereby maintaining measurement accuracy at low flow speeds. The Weiliba probe features a complete metal chamber structure, which prevents leakage between the high-pressure and low-pressure chambers, ensures long-term accuracy, and allows it to withstand higher pressures and temperatures. The location of the low-pressure port is placed before the point where the probe separates from the fluid, which prevents the low-pressure port from being affected by eddies and thus essentially resolves the problems of clogging and unstable signals. The probe passes through the entire velocity profile of the fluid in the pipeline after being inserted. The position of the pressure sampling holes is determined through area integration, and the pressure sampling method employs uniform sampling across multiple holes; this unique design ensures that the measured signal reflects the true average velocity of the fluid in the cross-section. Figure 1 shows a comparison diagram of the structures of Anubaa and Weiliba. Figure 2 illustrates the interaction characteristics between Weiliba and fluids. Additionally, a mathematical model for the flow coefficient K was creatively derived theoretically, and this K coefficient does not change with the Reynolds number; this K coefficient model has been verified by independent fluid laboratories in the United States. 　　Therefore, the Weiliba sensing element is an advanced differential pressure flow sensing element with a wide measurement range, high long-term accuracy, good stability and repeatability, suitable for gases, liquids, and vapors. 3 Applications 3.1 Application Trials In May 1998, application trials were commenced in industrial settings. First, a V200-10-H-R2-B5C and a V500-10-H-R2-F615C sensing element were selected to conduct application tests for measuring the flow rate of water-based media and blast furnace gas media. 　　Before installation, the Veritas probe used for measuring the water medium was tested for accuracy on a volumetric flow rate calibration device with an accuracy of 0.5 grade. After 3 repeated data tests, its accuracy was verified to be ≤1%. When the differential pressure is less than 25.4 Pa, the accuracy lies between 3% and 4%, and stable measurement is possible, which meets the technical performance specifications provided by VERIS Company. 　　The testing of the Wilo meter used to measure blast furnace gas involves primarily assessing the clogging resistance of its sensing elements. This component is installed on the main pipeline for blast furnace gas in a three-rolling mill. The operating conditions are as follows: the dust content in the blast furnace gas is around 10 mg/m3, the relative humidity is 100%, the typical flow rate is 10,000–13,000 m3/h, the pipe specifications are Φ820×6, the working pressure of the medium is 6–8 kPa, and the operating temperature range is 20°C–30°C. After 140 days of continuous operation, inspection revealed no significant scaling or fouling on the surface of the component, and the pressure tapping holes were not blocked; the instruments remained stable and functional throughout the operation period. Prior to this, with the same medium, an Anuba unit that we installed at the inlet of the TRT blast furnace gas suffered from clogging after less than two months in operation. 　　The installation of this component is also extremely simple, saving effort, time, and cost. The V200 model is an online installation type that allows continuous operation. With the assistance of the technical staff from Shenzhen Tiandi Jiu Company, it was installed in less than 0.5 hours using specialized tools. The installation of the V500 model also took only about half an hour when it was discontinued. 3.2 Promotion and Application Based on the success of the application tests, a total of 36 units were subsequently used for measurement in hot water media, superheated steam media, cold air media, converter gas media, and blast furnace gas media. The maximum measured pipeline for application is Φ2526mm×10mm (blast furnace gas), and the minimum measured pipeline is Φ159mm×8mm (superheated steam). Relatively satisfactory results have been achieved with a maximum medium flow rate of over 100 m/s (superheated steam) and a minimum medium flow rate of around 5 m/s (blast furnace gas). When the differential pressure calculation is accurate and the installation meets the technical requirements, the measurement results remain precise and reliable over a wide measurement range of 10∶1. During the little over a year of operation, no breakage of the measuring elements occurred. 　　Its operation with low pressure loss is another very important advantage of Wiliba. For the measurement in the thermoelectric blast furnaces at our company, round-notch orifice plates were previously used; when the gas flow rate was 1×104 m3/h, the differential pressure was 976 Pa, and the pressure loss δp was 637 Pa. After adopting Weiliba, the gas flow rate remains at 1×104 m3/h, the differential pressure is 280 Pa, and its pressure loss δp is 8.4 Pa. 　　The pressure loss of Weiliba is only about 1.6% of that of the orifice plate; by comparing the power losses associated with these two methods, an annual savings of around 30,000 yuan in operating costs can be achieved. 4 Conclusion Weiba is a new, advanced differential pressure flow sensing element – a product that achieves exceptional levels of precision, efficiency, and reliability. In practical applications, as long as its operating conditions are met and a complete and reliable measurement system is established, this type of flow meter is likely to gradually replace other differential pressure flow meters and become the mainstream in flow meter usage.